STS-123/ISS-1J/A MISSION ARCHIVE (FINAL)
Updated: 03/26/08

By William Harwood
CBS News/Kennedy Space Center

The following copy originally was posted on the Current Mission space page at http://cbsnews.com/network/news/space/current.html.

Comments, suggestions and corrections welcome!

TABLE OF CONTENTS

  • 03/26/08: Shuttle Endeavour glides to smooth night landing
  • 03/26/08: Shuttle braking rockets fired
  • 03/26/08: Shuttle landing delayed one orbit
  • 03/26/08: Endeavour astronauts ready shuttle for landing
  • 03/26/08: Good weather expected for shuttle landing
  • 03/25/08: Astronauts prepare for Wednesday landing
  • 03/25/08: Contamination samples point to possible bearing problem in solar array joint; but troubleshooting not definitive
  • 03/24/08: Shuttle Endeavour undocks after solar panel glitch resolved
  • 03/24/08: Shuttle astronauts bid station crew farewell
  • 03/23/08: Astronauts prepare for farewell, undocking
  • 03/23/08: Astronauts take a break, prepare for undocking Monday
  • 03/22/08: Spacewalk No. 5 ends
  • 03/22/08: Experiment package installed; solar array joint inspected
  • 03/22/08: Heat shield inspection boom mounted on space station
  • 03/22/08: Spacewalk No. 5 begins
  • 03/22/08: Astronauts suit up for fifth spacewalk
  • 03/21/08: Heat shield inspection
  • 03/21/08: Shuttle external tank production issues slow delivery; launch delays possible
  • 03/21/08: Spacewalk ends
  • 03/20/08: Heat shield repair tests go smoothly
  • 03/20/08: Circuit breaker replaced; stuck electrical connector prevents cable change
  • 03/20/08: Spacewalk No. 4 begins
  • 03/20/08: Astronauts set for heat shield repair test
  • 03/19/08: Astronauts take a break (CBS News interview)
  • 03/18/08: Astronauts work through busy day of robotics
  • 03/18/08: Spacewalk ends; experiments not mounted because of fitting problems
  • 03/17/08: Astronauts complete Dextre assembly
  • 03/17/08: Spacewalk No. 3 begins
  • 03/17/08: Astronauts gear up for third spacewalk
  • 03/16/08: Dextre checked out
  • 03/16/08: Dextre tests on tap
  • 03/16/08: Spacewalk No. 2 ends
  • 03/16/08: First arm mounted on Dextre
  • 03/15/08: Tight bolts slow spacewalkers
  • 03/15/08: Spacewalk No. 2 begins
  • 03/15/08: Astronauts gear up for second spacewalk
  • 03/14/08: Robot arm routes power to Dextre
  • 03/14/08: Doi, crewmates enter Japanese module
  • 03/14/08: Engineers fine-tune out Dextre power-up plan; shuttle heat shield cleared for entry
  • 03/14/08: Canadian engineers focus on suspect cable as culprit in robot power problem
  • 03/14/08: Spacewalk ends
  • 03/14/08: Japanese module pulled from cargo bay; Dextre robot hands attached
  • 03/14/08: Japanese module prepped for move to station; spacewalkers begin Dextre assembly work
  • 03/13/08: Spacewalk No. 1 begins
  • 03/13/08: Suffredini optimistic Canadian software patch will resolve Dextre glitch
  • 03/13/08: Canadians work on software patch to power Dextre components
  • 03/13/08: Reisman joins station crew; engineers troubleshoot pallet power-up glitch
  • 03/12/08: Shuttle Endeavour docks with international space station
  • 03/12/08: Shuttle crew gears up for station docking
  • 03/12/08: Astronauts inspect heat shield; no obvious damage seen; possible bird impact assessed
  • 03/11/08: Astronauts awakened for heat shield checkout; docking preps
  • 03/11/08: Shuttle Endeavour launched
  • 03/10/08: Shuttle fueled for flight
  • 03/10/08: Shuttle fueling begins
  • 03/10/08: Comm cable swapped out; countdown on track for Tuesday launch
  • 03/09/08: Mission preview
  • 03/09/08: Fuel cells loaded; weather still 90 percent 'go'
  • 03/08/08: Shuttle countdown on track
  • 03/08/08: Astronauts arrive for launch; countdown begins
  • 03/07/08: Weather 90 percent 'go' for Tuesday launch; UHF radio issue not a constraint
  • 02/29/08: Endeavour cleared for March 11 launch
  • 02/25/08: Astronauts strap in for practice countdown
  • 02/20/08: Space shuttle Atlantis returns to Earth

    8:55 PM, 3/26/08, Update: Shuttle Endeavour glides to smooth night landing (UPDATED at 12:05 a.m. with post-landing news conference)

    Running one orbit late because of troublesome low clouds, the shuttle Endeavour plunged back to Earth today, dropping out of the night for a picture-perfect landing at the Kennedy Space Center to close out a marathon 16-day space station assembly mission. Joining the shuttle astronauts for the trip back to Earth was European Space Agency astronaut Leopold Eyharts, launched to the station in February and returning after 48 days in space.

    "I can't imagine the mission could have gone any better," said NASA Administrator Mike Griffin. "They made it look easy."

    Reflecting on the addition of the first of two Japanese modules and the assembly of a Canadian maintenance robot during Endeavour's five-spacewalk mission, Griffin said "if you look around, there really isn't, any more, a U.S. human spaceflight program or a Russian human spaceflight program. There is a world human spaceflight program, centered around the building and then later utilization of the international space station. And we hope when we get that under our belt, this partnership will return to the moon and later go on to Mars."

    Flying upside down and backward over the Indian Ocean, commander Dominic Gorie and pilot Gregory Johnson fired Endeavour's twin braking rockets for two minutes and 48 seconds starting at 7:33:14 p.m., slowing the ship by about 206 mph and dropping the far side of the shuttle's orbit deep into the atmosphere.

    After a half-hour free fall, Endeavour plunged back into the discernible atmosphere at 8:07 p.m. at an altitude of 76 miles above the south Pacific Ocean. Minutes later, the shuttle's heat shield was subjected to 3,000-degree temperatures as the spaceplane decelerated from its orbital velocity of 5 miles per second.

    Crossing high above Central America's Yucatan Peninsula, Endeavour's flight computers guided the shuttle across the Gulf of Mexico and then over the west coast of Florida just south of Tampa, dropping through 84,000 feet at 1,700 mph seven minutes before touchdown.

    Three minutes later, at an altitude of about 50,700 feet, Endeavour's speed dropped below Mach 1 and a double sonic boom rumbled across the space center. Gorie took over manual control a few seconds later and after letting Gregory get a few moments of "stick time, guided the shuttle through a sweeping 255-degree left overhead turn to line up on runway 15.

    As Gorie pulled the shuttle's nose up just before touchdown, Johnson lowered Endeavour's landing gear and the orbiter settled to a tire-smoking touchdown at 8:39:08 p.m. as jets of flame from the exhaust ports of the ship's three hydraulic power units flared in the night.

    "Houston, Endeavour. Wheels stopped," Gorie radioed as the shuttle rolled to a stop.

    "Welcome home, Endeavour," astronaut James Dutton called from mission control. "Congrats to the entire crew, to JAXA and CSA (the Japanese and Canadian space agencies), on a very successful mission."

    "Thanks, Jim," Gorie replied. "It was a super rewarding mission, exciting from the start to the ending and we just thank you for all your help. Looking forward to seeing you guys soon."

    It was the 16th night landing at KSC and the 22nd in shuttle history. Mission duration was 15 days 18 hours 10 minutes and 54 seconds, covering 6.6 million miles and 249 complete orbits since blastoff March 11 from nearby launch complex 39A.

    Observers were startled by the hydraulic power units' exhaust jetting from vents on either side of Endeavour's vertical tail fin. The exhaust is produced by the orbiter's three auxiliary power units, which provide the muscle needed to move the ship's wing flaps, speed brake, landing gear brakes and nose wheel steering. The exhaust appeared normal in infrared views, but was more pronounced than usual in NASA's visible-light camera. NASA spokesman Kyle Herring in mission control said the APUs were operating normally.

    Gorie, Johnson and their shuttle crewmates - flight engineer Michael Foreman, Richard Linnehan, Robert Behnken and Japanese astronaut Takao Doi - doffed their pressure suits and joined technicians and NASA managers on the runway about an hour after landing for a traditional walk-around inspection.

    Eyharts made the flight back to Earth resting on his back in a special recumbent seat on Endeavour's lower deck. As with all returning long-duration space station astronauts, a team of flight surgeons was standing by to monitor Eyharts as he began the long process of readjusting to Earth's gravity. The French air force general was replaced aboard the station by NASA astronaut Garrett Reisman, who hitched a ride the lab complex aboard Endeavour.

    Eyharts and his shuttle crewmates are expected to fly back to the Johnson Space Center in Houston on Thursday.

    Endeavour's 16-day mission was the longest yet for a space station assembly flight and the five spacewalks carried out by Linnehan, Behnken, Foreman and Reisman set another one-flight station assembly record of 33 hours and 28 minutes.

    Endeavour took off March 11 and docked with the space station two days later. The day after that, Doi, operating the shuttle's robot arm, moved a Japanese storage module into position for attachment to the station while Linnehan and Reisman staged the mission's initial spacewalk.

    During the next spacewalk, Linnehan and Behnken then began assembly of the Canadian Space Agency's special purpose dexterous manipulator, a maintenance robot known as Dextre. Attached to the end of the station's robot arm, Dextre can be used to replace components on the station that might otherwise require a spacewalk.

    Along with mounting the Japanese module and building Dextre, the astronauts also transferred critical spare parts to the station and mounted Endeavour's heat shield inspection boom on the lab for use by the next shuttle crew. That shuttle, Discovery, is carrying Japan's huge Kibo lab module and does not have enough room for the inspection boom as well.

    Liftoff had been scheduled for May 25 - minutes before NASA's Phoenix lander is scheduled to touch down on Mars - but Griffin confirmed Wednesday that launch will slip a few days because of late delivery of the shuttle's external fuel tank.

    "You can go watch the Phoenix landing (at the Jet Propulsion Laboratory in Pasadena, Calif.)," Griffin told a reporter. "We're working on the exact date for STS-124." He said launch would take place within a few days of May 25, "but we know you'll be deconflicted enough that you can manage with a round-trip ticket. Because I'll tell you this, the landing day on Mars is fixed! It ain't moving."

    NASA is still assessing its schedule for subsequent shuttle flights. Eleven more flights are planned before the shuttle fleet is retired in 2010, with four flights on tap this year, four in 2009 and three in 2010.

    Along with Discovery's upcoming station flight, the shuttle Atlantis is scheduled for launch Aug. 28 on a final mission to service the Hubble Space Telescope. Endeavour returns to orbit in October for a space station resupply mission and Discovery closes out the year in December with a flight to deliver a final set of solar arrays to the international lab.

    But external tank production problems at Lockheed Martin's Michoud Assembly Facility in New Orleans threaten delays for downstream flights. The tank needed by Discovery for the next mission reached the Kennedy Space Center behind schedule Wednesday and while that flight remains roughly on track, the Hubble mission could slip into October when all is said and done, triggering domino-like slips for subsequent flights.

    NASA managers have not yet made any official changes. But Bill Gerstenmaier, chief of space operations for NASA, said Wednesday production of new tanks based on post-Columbia design modifications involves numerous changes and based on actual experience, it appears delays are likely.

    "The tanks we're getting now, you can think of them as clean-build tanks, whereas before, the tanks we had were built before the Katrina hurricane and we were repairing and making modifications to those tanks," Gerstenmaier said. "So we're gaining some experience and seeing how long it takes to put those tanks together, how to fabricate them.

    "And then HST is a little unique because we need to have two tanks down here ready to go support that mission, the tank for the flight itself and the tank for the contingency (rescue) flight. So we're off evaluating now what that production schedule looks like. We really don't have a good handle on that schedule yet. Once we understand a little bit better where that fits, we'll then announce where those flights are going, if they're going to move.

    "But right now, it's a little early to look at that," Gerstenmaier said. "But we understand the work is a little bit different than we had before and we're going to have to have a different production schedule. So things will slip, probably, a little bit for those tanks."


    07:36 PM, 3/26/08, Update: Shuttle braking rockets fired

    Encouraged by improving weather, commander Dominic Gorie and pilot Gregory Johnson fired the shuttle Endeavour's twin braking rockets for two minutes and 45 seconds today starting at 7:33:14 p.m., slowing the ship by about 206 mph to drop out of orbit. Landing at the Kennedy Space Center in Florida is targeted for around 8:39:06 p.m. This status report will be updated after Endeavour lands or as conditions warrant.


    05:30 PM, 3/26/08, Update: Shuttle landing delayed one orbit

    Florida's hard-to-predict weather surprised NASA forecasters today, forcing flight director Richard Jones to delay the shuttle Endeavour's re-entry by one orbit because of low clouds over the Kennedy Space Center. Shuttle commander Dominic Gorie and pilot Gregory Johnson are now setting up for a deorbit rocket firing at 7:33 p.m., which would result in a landing at 8:39 p.m.

    "Dom, unfortunately the weather trend did not improve as we had hoped," astronaut James Dutton radioed from Houston. "So we are going to be waving off one orbit."

    "Jim, we copy the waveoff for one rev," Gorie replied.

    "The forecast for the second opportunity is scattered (clouds) at 5,000," Dutton said. "So we're looking for some improvement."

    There are no technical problems of any significance and the weather remains the only concern. If Gorie and his crewmates cannot get down on their second opportunity, the mission will be extended 24 hours and they will try again Thursday.


    02:30 PM, 3/26/08, Update: Endeavour astronauts ready shuttle for landing

    The Endeavour astronauts are working through their deorbit timeline today, rigging the shuttle for re-entry and touchdown on runway 15 at the Kennedy Space Center at 7:05 p.m. There are no technical problems of any significance and forecasters continue to predict good weather for landing.

    "All right, Dom, we just took the weather brief and it's looking really nice at KSC for the first opportunity," astronaut James Dutton radioed commander Dominic Gorie from mission control. "The forecast remains 'go,' scattered (clouds) at 5,000 (feet), seven miles vis, winds zero-nine-zero, 8 (knots) peak 12. That's a cross(wind) of 11, headwind of 5. So the clouds have lifted a bit. We'll be keeping track of those, but we think it's looking really nice to get you home on the first opportunity."

    "Thanks, Jim, that sounds great. It sounds like the weather forecasters were really accurate on this one," Gorie replied. "They're doing a great job. Thanks!"

    The astronauts were awakened at 10:58 a.m. by a recording of Train's "Drops of Jupiter" radioed up from mission control.

    "Good morning Endeavour. And good morning to you, Box," astronaut Al Drew called from Houston, using pilot Gregory Johnson's fighter pilot call sign.

    "Good morning, Al. Wow, that's a great song to listen to on landing day," Johnson replied. "I'd like to thank my wife, Cari, and my kids Matthew, Susan and Rachel. That's one of the songs that we play in Max Q, our all-astronaut band. We do keep our day jobs, though. But this has been a two-week adventure, it's been a pleasure and an honor to be on it and although we had wonderful events and some great successes, we're ready to get home. ... We'll see you guys on the ground."

    "I'm sure your families will be happy to see you back on the ground there in Florida and we'll look forward to seeing you back here in Houston when you get here," Drew said.

    "Thanks, Al. I've also got my 1984 (Air Force) academy shirt on."

    "'84, hard core..." said Drew, a fellow academy graduate.

    "Wings that soar," Johnson finished.

    Gorie, Johnson, flight engineer Michael Foreman, Richard Linnehan, Robert Behnken, Japanese astronaut Takao Doi and returning space station flight engineer Leopold Eyharts, a European Space Agency astronaut returning to Earth after 48 days in space, have two landing opportunities today, one at 7:05:08 p.m. and the other at 8:39:06 p.m.

    The first opportunity occurs in daylight and the second in darkness. The crosswind limit for daylight landings is 15 knots, decreasing to 12 knots at night. But the winds are expected to decrease as the evening wears on and crosswinds are expected to peak around 9 knots for the second opportunity.

    With a good forecast, NASA is not staffing its backup landing site at Edwards Air Force Base, Calif., and if the weather or some other problem prevents a touchdown today, the astronauts will remain in orbit an additional 24 hours and try again Thursday.

    Working through a carefully scripted timeilne, the astronauts planned to close the shuttle's cargo bay doors around 3:18 p.m. and to fire the shuttle's twin braking rockets for two minutes and 51 seconds starting at 5:58:14 p.m. That will slow the shuttle by 209 mph, just enough to cause the ship to drop out of orbit.

    About a half-hour later, at 6:33 p.m., Endeavour will fall into the discernible atmosphere at an altitude of about 76 miles. Within a few minutes, atmospheric friction will produce temperatures of more than 3,000 degrees Fahrenheit on the reinforced carbon carbon nose cap and wing leading edge panels as the shuttle rapidly slows down from its orbital velocity of 5 miles per second.

    Endeavour's ground track will carry the shuttle across Central America west of the Panama Canal, high above central Cuba and then up the east coast of Florida. Dropping through 83,000 feet, Endeavour will have slowed to a velocity of 1,700 mph by around 6:58 p.m. and to Mach 1 three minutes later, producing twin sonic booms as Endeavour drops below the speed of sound at an altitude of 51,100 feet.

    At that point, Gorie will take over manual control, guiding the spaceplane through a sweeping 195-degree left overhead turn to line up on runway 15.

    Here is a timeline of re-entry events (in EDT throughout):

    EDT...........EVENT
    
    ..............Rev. 248 descent to KSC runway 15
    
    01:58:00 PM...Begin deorbit timeline
    02:13:00 PM...Radiator stow
    02:23:00 PM...Mission specialists seat installation
    02:29:00 PM...Computers set for deorbit prep
    02:33:00 PM...Hydraulic system configuration
    02:58:00 PM...Flash evaporator cooling system checkout
    03:04:00 PM...Final payload deactivation
    03:18:00 PM...Payload bay doors closed
    03:28:00 PM...Mission control 'go' for OPS-3 entry software load
    03:38:00 PM...OPS-3 software loaded
    04:03:00 PM...Entry switch list verification
    04:13:00 PM...Deorbit maneuver update
    04:18:00 PM...Crew entry review
    04:33:00 PM...Commander/pilot don entry suits
    04:50:00 PM...Inertial Measurement Unit alignment
    04:58:00 PM...CDR/PLT strap in; mission specialists don suits
    05:15:00 PM...Shuttle steering check
    05:18:00 PM...Hydraulic power system prestart
    05:25:00 PM...Toilet deactivation
    05:33:00 PM...Vent doors closed for entry
    05:38:00 PM...Mission control 'go' for deorbit burn
    05:44:00 PM...MS seat ingress
    05:53:00 PM...Single APU start
    
    05:58:14 PM...Deorbit ignition (Alt: 215.2 sm; Vel: 17,251 mph; dV: 209 mph; dT: 2:51)
    06:01:05 PM...Deorbit burn complete
    
    06:33:06 PM...Entry interface (alt: 75.7 sm; Vel: 16,979 mph; range: 4,959 sm)
    06:38:03 PM...1st roll command to left
    06:52:00 PM...C-band radar acquisition
    06:54:34 PM...1st left to right roll reversal
    06:58:36 PM...Velocity less than mach 2.5 (alt: 83,000 ft; vel: 1,709 mph)
    07:00:47 PM...Velocity less than mach 1 (alt: 51,100 ft; vel: 613 mph)
    07:02:05 PM...Shuttle on the heading alignment cylinder
    07:05:08 PM...Landing
    
    
    ..............Rev. 249 descent to KSC runway 15
    
    07:13:14 PM...Mission control 'go' for deorbit burn
    07:19:14 PM...MS seat ingress
    07:28:14 PM...Single APU start
    
    07:33:14 PM...Deorbit ignition (alt: 216 sm; vel: 17,251 mph; dV: 206 mph; dT: 2:48)
    07:36:02 PM...Deorbit burn complete
    
    08:07:23 PM...Entry interface (alt: 75.6 sm; vel: 16,979 mph; range: 5,055 sm)
    08:12:18 PM...1st roll command to right
    08:21:14 PM...1st right-to-left roll reversal
    08:26:00 PM...C-band radar acquisition
    08:32:34 PM...Velocity less than mach 2.5 (alt: 83,900 feet; vel: 1,704 mph)
    08:34:46 PM...Velocity less than mach 1 (alt: 50,700 feet; vel: 613 mph)
    08:35:32 PM...Shuttle on the heading alignment cylinder
    08:39:06 PM...Landing
    


    12:00 AM, 3/26/08, Update: Good weather expected for shuttle landing

    The Endeavour astronauts tested the shuttle's re-entry systems Tuesday and packed for landing Wednesday at the Kennedy Space Center to close out a 16-day space station assembly mission. Entry Flight Director Richard Jones said the shuttle is in good shape and the weather is "go" for a late afternoon descent.

    "The flight control system behaved beautifully, there are no issues to really talk about," Jones said of today's entry preparations.

    Flying upside down and backward, Gorie and pilot Gregory Johnson plan to fire Endeavour's twin braking rockets for two minutes and 51 seconds starting at 5:58:14 p.m., slowing the ship by about 209 mph and dropping it out of orbit.

    Flying northward over Central America just west of the Panama Canal, the shuttle's flight path will carry it high above central Cuba and then up the east coast of Florida before a left overhead turn to line up on runway 15. Touchdown is expected at 7:05:08 p.m.

    Jones said one of the shuttle's three hydraulic power units appears to be suffering a slight decrease in fuel pressure, but telemetry indicates the problem is a slow nitrogen leak, which poses no problem for the auxiliary power unit in question.

    "We started APU 1 during FCS (flight control system) checkout," Jones said. "As you know, we have been monitoring a small, slight fuel tank pressure decrease for many days now. ... They determined that this leak behaved and looked like a gaseous nitrogen leak. We started that APU today to go through FCS checkout so that we could essentially get a warm fuzzy that it is behaving exactly like we had intended. And sure enough, APU 1 did just great and there's nothing that would tell me or the flight control team that that APU is not ready for entry. Because it is." The astronauts also tested Endeavour's re-entry software, known as "OPS-3."

    "We got into that mode for a specific reason, so that we could look at the GPS system," Jones said. "This vehicle, the Endeavour, is a three-string GPS vehicle. It's the only one in our fleet and we are going to use that system to come home tomorrow. GPS is one of our primary navigation aids. That system also did very well."

    Endeavour's primary steering thrusters also were test fired and again, no problems were uncovered.

    But engineers were notified of an orbital debris impact on one of the shuttle's cockpit windows. The ding is about the size of a BB, but Jones said an engineering analysis shows the multi-pane window has plenty of margin for entry.

    "We've seen these dings before that have happened throughout the course of our shuttle history," he said. "This ding was looked at today by our engineering community. It's about one eighth to about three sixteenths of an inch in diameter, so it's very small. But our engineers did look at it, it's cleared for entry and we have plenty of margin in that window."

    Gorie and Johnson took turns practicing landing procedures using a computer flight simulator. While Endeavour is healthy and checked out for entry, Gorie told a reporter he still gets butterflies thinking about his responsibilities.

    "The orbiter's really been performing really marvelously this whole flight, we don't have any concerns at all about it," he said. "We were just talking a little bit ago when Box (Johnson) and I were working the little trainer for the landing. You always have a little butterflies when you approach an event like that. We're certainly not scared about it, but yeah, you're a little bit nervous about wanting to do it just right and just like you've been training for. But Endeavour's in great shape and we're looking forward to getting back into Florida right before sunset tomorrow."

    Because of the favorable weather forecast, NASA is not staffing its backup landing site at Edwards Air Force Base, Calif. Endeavour's crew will have two opportunities, on successive orbits, to land in Florida at 7:05 p.m. and 8:39 p.m. respectively. If the weather or some other problem blocks both opportunities, the astronauts will remain in orbit an extra day and try again Thursday. The shuttle has enough on-board supplies to stay in orbit until Friday. Here is a timeline of re-entry events (in EDT throughout):

    EDT...........EVENT
    
    ..............Rev. 248 descent to KSC runway 15
    
    01:58:00 PM...Begin deorbit timeline
    02:13:00 PM...Radiator stow
    02:23:00 PM...Mission specialists seat installation
    02:29:00 PM...Computers set for deorbit prep
    02:33:00 PM...Hydraulic system configuration
    02:58:00 PM...Flash evaporator cooling system checkout
    03:04:00 PM...Final payload deactivation
    03:18:00 PM...Payload bay doors closed
    03:28:00 PM...Mission control 'go' for OPS-3 entry software load
    03:38:00 PM...OPS-3 software loaded
    04:03:00 PM...Entry switchlist verification
    04:13:00 PM...Deorbit maneuver update
    04:18:00 PM...Crew entry review
    04:33:00 PM...Commander/pilot don entry suits
    04:50:00 PM...Inertial Measurement Unit alignment
    04:58:00 PM...CDR/PLT strap in; mission specialists don suits
    05:15:00 PM...Shuttle steering check
    05:18:00 PM...Hydraulic power system prestart
    05:25:00 PM...Toilet deactivation
    05:33:00 PM...Vent doors closed for entry
    05:38:00 PM...Mission control 'go' for deorbit burn
    05:44:00 PM...MS seat ingress
    05:53:00 PM...Single APU start
    
    05:58:14 PM...Deorbit ignition (Alt: 215.2 sm; Vel: 17,251 mph; dV: 209 mph; dT: 2:51)
    06:01:05 PM...Deorbit burn complete
    
    06:33:06 PM...Entry interface (alt: 75.7 sm; Vel: 16,979 mph; range: 4,959 sm)
    06:38:03 PM...1st roll command to left
    06:52:00 PM...C-band radar acquisition
    06:54:34 PM...1st left to right roll reversal
    06:58:36 PM...Velocity less than mach 2.5 (alt: 83,000 ft; vel: 1,709 mph)
    07:00:47 PM...Velocity less than mach 1 (alt: 51,100 ft; vel: 613 mph)
    07:02:05 PM...Shuttle on the heading alignment cylinder
    07:05:08 PM...Landing
    
    
    ..............Rev. 249 descent to KSC runway 15
    
    07:13:14 PM...Mission control 'go' for deorbit burn
    07:19:14 PM...MS seat ingress
    07:28:14 PM...Single APU start
    
    07:33:14 PM...Deorbit ignition (alt: 216 sm; vel: 17,251 mph; dV: 206 mph; dT: 2:48)
    07:36:02 PM...Deorbit burn complete
    
    08:07:23 PM...Entry interface (alt: 75.6 sm; vel: 16,979 mph; range: 5,055 sm)
    08:12:18 PM...1st roll command to right
    08:21:14 PM...1st right-to-left roll reversal
    08:26:00 PM...C-band radar acquisition
    08:32:34 PM...Velocity less than mach 2.5 (alt: 83,900 feet; vel: 1,704 mph)
    08:34:46 PM...Velocity less than mach 1 (alt: 50,700 feet; vel: 613 mph)
    08:35:32 PM...Shuttle on the heading alignment cylinder
    08:39:06 PM...Landing
    


    11:30 AM, 3/25/08, Update: Astronauts prepare for Wednesday landing

    The Endeavour astronauts faced a busy day in space today, testing the shuttle's re-entry systems and packing up for landing Wednesday at the Kennedy Space Center to close out a 16-day space station assembly mission. There are no technical problems of any significance and forecasters are predicting good weather for Endeavour's 7:05 p.m. Wednesday touchdown.

    Commander Dominic Gorie, pilot Gregory Johnson and flight engineer Mike Foreman planned to fire up one of the shuttle's hydraulic power units this afternoon for a detailed flight control system checkout before test firing maneuvering jets to make sure the orbiter's entry systems are ready for the descent from orbit.

    The astronauts also will set up a reclining seat on the shuttle's lower deck for European Space Agency astronaut Leopold Eyharts, returning to the uncomfortable tug of Earth's gravity after 48 days in weightlessness. Eyharts was launched to the international space station Feb. 7 to help commission ESA's Columbus research module. His replacement, Garrett Reisman, was ferried to the outpost aboard Endeavour.

    Two final astronaut interview sessions are on tap today, one with Eyharts at 6:33 p.m. and the other, at 8:13 p.m., with U.S. reporters. A mission status briefing with entry flight director Richard Jones to review the weather and landing preparations is scheduled for 10 p.m.

    Here is an updated timeline of today's activity (in EDT and mission elapsed time; includes revision M of the NASA television schedule):

    EDT........DD...HH...MM...EVENT
    
    03/25/08
    10:58 AM...14...08...30...Crew wakeup
    01:53 PM...14...11...25...Orbit adjust rocket firing
    01:58 PM...14...11...30...Cabin stow begins
    02:28 PM...14...12...00...Flight control system checkout
    03:53 PM...14...13...25...Reaction control system hotfire
    04:08 PM...14...13...40...PILOT landing simulator practice
    06:08 PM...14...15...40...Crew meals begin
    06:33 PM...14...16...05...ESA PAO event
    08:13 PM...14...17...45...U.S. media interviews
    08:33 PM...14...18...05...Cabin stow resumes
    08:33 PM...14...18...05...Entry video setup
    09:28 PM...14...19...00...Launch/entry suit checkout
    10:00 PM...14...19...32...Mission status briefing on NASA TV
    10:28 PM...14...20...00...Recumbent seat setup
    10:38 PM...14...20...10...Wing leading edge sensors deactivated
    10:58 PM...14...20...30...Laptop computer teardown (part 1)
    11:18 PM...14...20...50...KU-band antenna stow
    11:28 PM...14...21...00...Deorbit review
    
    03/26/08
    02:58 AM...15...00...30...Crew sleep begins
    03:00 AM...15...00...32...Daily video highlights
    10:58 AM...15...08...30...Crew wakeup
    12:58 PM...15...10...30...Group B computer powerup
    01:13 PM...15...10...45...Inertial measurement unit alignment
    01:58 PM...15...11...30...Deorbit timeline begins
    05:58 PM...15...15...30...Deorbit ignition (rev. 248)
    07:05 PM...15...16...37...Landing
    


    02:30 AM, 3/25/08, Update: Contamination samples point to possible bearing problem in solar array joint; but troubleshooting not definitive

    Analysis of metallic contamination from a critical solar array rotary joint on the international space station indicates a "high-friction event" of some sort, possibly a misaligned bearing roller or some other like defect, has chewed up and damaged one of the surfaces of a 10-foot-wide gear and bearing race, the station's program manager said Monday.

    A definitive answer to what caused extensive damage to the race ring is not yet complete and as a result, NASA managers have not yet decided what sort of repairs might be needed to restore the joint to normal operation. But Program Manager Mike Suffredini said an analysis shows the station's solar arrays can generate enough power for near-normal station operations through the rest of this year and early next with the right side solar alpha rotary joint, or SARJ, locked in place or only occasionally moved to improve power generation.

    "We may have to manage how we do research, but we should be able to do the research that we planned," he said.

    But this is a critical issue for the long-term health of the space station and Suffredini provided the most detailed update yet on where the ongoing troubleshooting stands.

    The space station is equipped with two SARJ joints, one on each side of its main power truss. Each SARJ features two 10-foot-wide drive gears, one of which is a backup. The main gear/race ring is gripped by 12 so-called trundle bearing assemblies spaced evenly around the circumference. The trundle bearings each feature three rollers that grip different faces of the drive gear/race ring. The gear is driven by a motor called a drive lock assembly, or DLA. Each joint features two DLAs, but only one is used at a time.

    The SARJ system is critical to the station's long-term viability. To provide the power necessary to run all the station's planned science operations, along with life support systems, computers, communications gear, cooling systems, etc., the solar arrays must track the sun as the station circles the planet.

    The station's left-side SARJ is operating normally. But last fall, engineers noticed higher-than-expected vibration levels in the right-side SARJ and drive motor power spikes indicative of mechanical resistance of some sort.

    During a subsequent spacewalk inspection, extensive internal metallic contamination was discovered in the form of apparent shavings found clumped and scattered across one face of the race ring. The surface of the ring itself appeared mottled and damaged. To minimize additional damage, flight controllers decided to suspend "auto-track" drive operations, although the starboard SARJ is occasionally repositioned to improve power generation.

    During previous spacewalks, astronauts removed 17 of 22 thermal covers around the circumference of the joint to look for signs of micrometeoroid impact damage or any other issues that might explain the problem. In addition, one of the 12 trundle bearing assemblies positioned around the race ring - TBA No. 5 - was removed and returned to Earth for analysis, along with samples of the metallic debris.

    During the Endeavour crew's fifth and final spacewalk Saturday, astronaut Mike Foreman removed the final five thermal covers and looked inside the joint. There were no signs of any impact damage. He also examined a small spot on the undamaged "datum A" race ring that was seen in earlier photographs. Engineers were not sure whether the blemish was a pit or a bump-like defect caused by a buildup of contaminants. Foreman said it felt rough to him, indicating it might be a depression, but with thick gloves on, the astronaut could not be definitive.

    NASA managers initially held out hope spacewalking astronauts could somehow clean up the contamination and restore the joint to normal, or near-normal, operation. That no longer appears possible and NASA is expected to order a switch to the redundant drive gear at some point. But that's a last-resot sort of option. Engineers want to make sure they understand the cause of the problem first, to make sure the same thing won't happen on the backup gear.

    "SARJ is going to take us a while to figure out," Suffredini said. "But we did bring home quite a bit of information on the last flight and we did learn a few things that we're still working on. The data does suggest, from the way that the material has come off of the race, that it was caused by a high-friction event. We have been postulating for a while that perhaps contamination had gotten on the race and when we rolled over it, we created a weak spot in this brittle surface that we talked about, perhaps it was damaged that way, kind of like the pothole in the road theory, and chewed it up. The problem with that theory was we chewed it up awfully quick if it started off as one small spot.

    "So based on the way the material has come off and where the fracture lines are - and it is incredible to watch these guys do this work to try to do detailed analysis of these very small particles we brought home - but they've been able to conclude that ... some of these larger flakes that we brought home were the result of high-friction events. And what that tells you is that perhaps we had either a roller that was cocked or one that wasn't quite rolling as freely as we thought. There are a number of scenarios that lead you down that path. So that is a piece of information we gleaned from that.

    "One of the interesting things from the last EVA, we sent the crew to go look at what we had assumed was contamination, maybe I should say we wished was contamination. The crew seems to have indicated that the spot that they saw was rough. Now that may be contamination that got pressed on to the race as we rolled over it. That is a more likely candidate, but we couldn't tell. Was it rough because it's high? Was it rough because it's low? So we'll have to think about that.

    "Damage to datum A would be an interesting piece of information," Suffredini said. "To date, we've seen the damage only on the upper inclined surface. And so if you postulated that we had a roller or something that was canted wrong for whatever reason, not aligned quite right, then that would explain why only that surface was damaged. If over a much longer period of time we were starting to see the same thing on datum A, of course, that makes our theory a little more difficult. But there are still 111 branches on our fault tree and 300-plus actions left to be closed. And so our job is to give the team as much time as possible to try to sort this out."

    A major question mark throughout the troubleshooting is how long station assembly and operation can go without having full auto-track solar power available. Suffredini said the latest analysis shows NASA can go ahead and attach Japan's huge Kibo research module in May as planned and even bolt on the S6 solar array segment to complete the right side of the station's power truss. That flight, known as assembly mission 15A, currently is scheduled for launch in December, although external tank delivery issues could force a delay.

    In any case, the station should have enough power without any SARJ repairs until the next flight in the sequence, launch of a third Japanese component next spring.

    "We have, for all intents and purposes, cleared ourselves through the 15A stage, which means we can install the S6 truss on the 15A flight and make our way all the way to the end of that stage," Suffredini said. "As you may know, the flight after that is the exposed facility for JAXA, which requires not an insignificant amount of power. So that's probably the next bump we have to get through on the road.

    "In order to get through that hump and keep runway in front of us before we actually have to do something like swap races, one option is we're looking at whether we can do the analysis that lets us temporarily rotate that joint during low-power periods," he said. "Today, we try to hold it locked. And so, if we can get about 60 days worth of rotations out of that joint, then perhaps we can buy ourselves a little more time to finish our failure analysis and decide what changes we might need to make. If it's just a matter of swapping over (to the outboard, redundant race ring), I can do that almost any time. But we might decide there are some hardware changes we want to implement, which would take us a little more time.

    "Today I don't know the answer to what causes this problem, we have a number of legs left to work down the fault tree where every day we get a new piece of data. We pulled all the rest of the covers off (during Forman's spacewalk Saturday) and we didn't find an MMOD (micrometeoroid debris) strike that started this whole thing. So that was important information for us. And so if we can give the team enough time, I'm convinced we can figure out how to prevent this once we go to outboard ops. So our job is to work the failure analysis as hard as we can and give the team as much time to do that before we have to swap to outboard ops. That's kind of where we're at."

    Asked if the station could operate normally in the near term without an operational right-side SARJ, Suffredini said: "We may have to manage how we do research, but we should be able to do the research that we planned.

    "We won't be able to line everybody up and run them at the same time, but typically crew time doesn't allow us to do that anyway," he said. "So I would not see any major implications to research during that particular stage. Somewhere in there, we'll also finish our analysis on whether we can rotate the SARJ for a certain period of time and so we'll have that in our hip pocket as well."

    NASA has one spare set of trundle bearings. Suffredini was asked if NASA might consider simply installing the new bearings on the damaged race ring, preserving the option of switching to the outboard ring later if necessary.

    "The race is damaged to a significant level such that my personal opinion is it would be difficult to get the structural life that we would need out of the outboard truss if we kept running along that damaged race," he said. "That is something we've looked at and thought a lot about. Of course, when we go to outboard ops we'll replace all of those bearings. So if we can figure out that that's the cause, then we have a dozen of those bearings sitting on the ground and we can certainly check them for whatever we believe the root cause is."

    One option, perhaps, would be to "go ahead and do the reconfiguration to outboard ops but not rotate, get the rest of those trundle bearings home and see if we can find a smoking gun."

    "But that's just one of many things that we've talked about doing," Suffredini said. "But I don't think I have an option, if I have to continually rotate the SARJ, I really don't think structural life is going to allow me to rotate on that bad race. Other than structural life, though, I think the system can drive through and our speculation is it will get easier over time as we knock the high points off that rough surface. I think the system can drive through it even with the existing bearings we have, but it'll just chew up the structural life of those quickly."

    Asked if NASA had ruled out moving the bearings to the outboard race this year, Suffredini said "I learned a long time ago not to make those kind of predictions. You guys trained me that way."


    08:30 PM, 3/24/08, Update: Shuttle Endeavour undocks after solar panel glitch resolved

    With shuttle pilot Gregory Johnson at the controls, the Endeavour gently undocked from the international space station this evening, a half hour behind schedule because of problems getting one of the lab's solar arrays locked in place. After a second command successfully got the left-side outboard arrays to latch as required, Endeavour disconnected from the station's shuttle docking port at 8:25 p.m.

    "Houston, Endeavour, we have physical separation," an astronaut radioed as the shuttle slowly pulled away, 215 miles above the Indian Ocean west of Australia.

    Newly arrived station flight engineer Garrett Reisman, following a naval tradition established by NASA's first station commander eight years ago, rang the ship's bell mounted in the Destiny laboratory module and formally announced, "Endeavour. Departing."

    "Copy, fair winds and following seas to you guys," shuttle commander Dominic Gorie radioed.

    "Well, we're the happy recipients of the (Japanese) Kibo module and Dextre, we really appreciate everything you've done for us over the last couple of weeks," station commander Peggy Whitson replied. "Thanks a bunch, and especially thanks for being such great guys."

    "Thanks, Peggy," Gorie said. "My friends, we'll see you on the ground here in about a month."

    Endeavour, oriented with its tail toward Earth and its open payload bay facing the space station, pulled straight away from the outpost in its direction of travel as the two spacecraft streaked through low-Earth orbit at five miles per second. Johnson planned to guide the ship through a slow 360-degree loop to photograph the lab complex from a variety of angles before leaving the immediate area. Landing back at the Kennedy Space Center is scheduled for 7:05 p.m. Wednesday.


    06:00 PM, 3/24/08, Update: Shuttle astronauts bid station crew farewell

    With hugs and handshakes, the Endeavour astronauts said farewell to their space station colleagues today, gathering one last time to mark the end of a marathon five-spacewalk assembly mission before floating back into the shuttle, closing hatches and preparing to undock.

    European Space Agency astronaut Leopold Eyharts, launched to the station aboard the shuttle Atlantis in February to help activate ESA's new Columbus research module, departed with Endeavour's crew, leaving his replacement, Garrett Reisman, behind with Expedition 16 commander Peggy Whitson and flight engineer Yuri Malenchenko.

    "Expedition 16 has had a number of flight engineers, I've already called Garrett "Clay" (Anderson) once," Whitson laughed. "I'm sure I'll be messing up some more, but we really had the privilege of having some great flight engineers. ... I want to especially thank Leo for being here at a special time when we inaugurated the Columbus module and especially thank him for all the work he did inside the Columbus module.

    "I think the ground team is just as proud of him as I am, and I'm really glad he was here during this stage," Whitson said. "I'm really looking forward to all the laughs I'm going to have with Garrett, because he is just a lot of fun and I think it's going to be a great time, the next few weeks we have together before Yuri and I bail on him."

    Whitson and Malenchenko are scheduled to return to Earth in April after being replaced by Expedition 17 commander Sergey Volkov and Oleg Kononenko. Reisman will remain aboard as part of Volkov's crew until he is replaced by astronaut Gregory Chamitoff, scheduled for launch May 25 aboard the shuttle Discovery.

    "It's hard for me to believe that it's already finished," Eyharts said of his seven-week stay in space. "It has been a great flight, it was a great team and a great crew. I'd like to thank all who have made the flight possible. I mean, bringing the station up to what it is now, bringing the Columbus here and activating it and making it a scientific laboratory. This was a great time. ... Of course, I'd like to wish all the best to Garrett. I know he has a lot of things coming on his plate. He will do well. I would like to thank Peggy and Yuri and the 122 and 123 crews for their tremendous help and for their friendship, too."

    Reisman than took the microphone, saying "I have to tell you, it's a little intimidating taking over, replacing Leo, because Leo is a general in the French air force and I never even made it through (Cub Scout) Weblos, let along getting on to Boy Scouts. So I feel a little mismatched!

    "But I will do my best, and I want to thank Leo for leaving us in such great shape, especially all the hard work and long hours you put into Columbus," said Reisman. "You did a fantastic job getting Columbus activated and checked out and we're all going to benefit from that. Finally, I just want to say I already feel nostalgia coming on about the STS-123 crew. It was really fantastic being a part of this crew. It's a crew that excels not only on a professional level, but also a human level. I mean that with all sincerity. It's just been a wonderful chapter in my life to be a part of all that."

    Looking at his former shuttle crewmates, Reisman joked: "I'm really going to miss all of you. Except you, Rick (Linnehan)." Then, to pilot Gregory Johnson, "Have a great landing - don't forget (to lower the) gear - and I look forward to seeing you all back home in a couple of months."

    Shuttle commander Dominic Gorie thanked Whitson for the station crew's help staging a record five space station assembly spacewalks, adding "we had a great time here, looking forward to a wonderful return home."

    "It's sort of a strange feeling to want to see your families but not wanting to leave a wonderful place," Gorie said. "You made it that way, so thank you very much."

    As the shuttle crew floated through the hatch toward Endeavour, Reisman jokingly moved to join them, prompted Whitson to grasp him firmly about the waist.

    The hatches were closed at 5:49 p.m., setting the stage for undocking at 7:56 p.m.


    12:30 PM, 3/23/08, Update: Astronauts prepare for farewell, undocking

    The Endeavour astronauts are gearing up to undock from the international space station this evening to close out a marathon five-spacewalk assembly mission. A brief farewell ceremony is planned for 5:13 p.m., followed by hatch closure around 5:30 p.m. With shuttle pilot Gregory Johnson at the controls, Endeavour is scheduled to disconnect from the space station's forward docking port, pressurized mating adapter No. 2, at 7:56 p.m. After looping around the lab complex for a photo survey, Johnson will fire the shuttle's maneuvering jets to leave the area around 9:40 p.m.

    "There are a number of key steps both vehicles have to go through to make sure the undocking goes smoothly," said space station Flight Director Bob Dempsey. "First of all, we have to maneuver the combined space station-orbiter vehicle to the undocking attitude, as it's called. Normally, when the orbiter's docked there, the PMA-2, or the pressurized mating adapter 2 (docking port) is flying in the direction the vehicle is going. When the orbiter is docked, we actually flip the vehicle 180 degrees around ... so the delicate thermal protection system on the orbiter, the tiles, are not into the wind, as we say, and vulnerable to debris strikes. So we fly with the shuttle sort of in the back with the belly sort of facing downwind.

    "But we can't undock in that position. So we will flip the station around 180 degrees to get them in the right orientation. Then another thing we will do to get ready for the undock is we will park the KU antenna on the space station. We do that so we don't radiate the orbiter. ... And then we will begin a series of minor power downs. The reason we're doing that is, the next thing we have to do is configure the solar arrays on the space station, both the giant U.S. arrays and the Russian arrays, so that as the orbiter's undocking and it's firing its thrusters, that impinges material that can dirty up and push, do some structural damage, to the solar arrays. So we park those so they're kind of edge on to the thrusters so when the orbiter's backing away, we minimize the amount of impact to the solar arrays.

    "So once we do all those things, we're in the undocking configuration," Dempsey said. "The shuttle will give the commands and back off from the space station. It'll move away slowly, we don't want to impart a big moment to the space station and push it very hard, cause it to tumble or anything like that. So it'll back off slowly and once the crew gets far enough away, they'll start some minor thruster firings, do it as gently as possible ... then they'll actually do a fly around."

    Johnson will guide Endeavour through a full 360-degree loop, flying directly above, behind and below the station for a detailed photo survey.

    "That's going to be a great thing for a pilot," Johnson told CBS News before launch. "Undocking is about the opposite of docking, you're leaving the space station at a pretty controlled rate. And then at the end of the undocking timeline, when we get about 300 to 400 feet away, then we start what's called a fly-around and that's where you take the orbiter and go 360 degrees all the way around the station, about 45 minutes of flying. You get to see angles of space station that aren't normally observed and just a great, exciting period for the whole crew."

    When the shuttle is a safe distance away, station commander Peggy Whitson, flight engineer Yuri Malenchenko and newly arrived flight engineer Garrett Reisman will begin work to put the station back into its normal operating mode, putting the solar arrays back in sun-track and powering up systems that were shut down earlier. Because of ongoing problems with one of the station's solar array rotary joints, the S4 solar panels on the right side of the complex will remain locked in place.

    Here is an updated timeline of today's activity (in EDT and mission elapsed time; includes revision L of the NASA television schedule):

    EDT........DD...HH...MM...EVENT
    
    03/24/08
    11:43 AM...13...09...15...Crew wakeup
    02:58 PM...13...12...30...Spacesuits transferred to shuttle
    04:13 PM...13...13...45...Oxygen system teardown
    05:13 PM...13...14...45...Farewell ceremony
    05:28 PM...13...15...00...Hatch closure
    05:33 PM...13...15...05...Group B computer powerup
    05:58 PM...13...15...30...Leak checks
    06:39 PM...13...16...11...ISS maneuvers to undocking attitude
    06:42 PM...13...16...14...Sunrise
    06:43 PM...13...16...15...Centerline camera setup
    07:09 PM...13...16...41...ISS in undocking attitude
    07:13 PM...13...16...45...Noon
    07:13 PM...13...16...45...Undocking timeline begins
    07:21 PM...13...16...53...US solar arrays in undocking configuration
    07:23 PM...13...16...55...PMA-2 departure config
    07:44 PM...13...17...16...Sunset
    
    07:56 PM...13...17...28...UNDOCKING
    
    07:58 PM...13...17...30...ISS holds attitude
    08:01 PM...13...17...33...Range: 50 feet; reselect -X jets
    08:03 PM...13...17...35...Range 75 feet; low Z
    08:13 PM...13...17...45...Sunrise
    08:25 PM...13...17...57...Range: 400 feet; start fly around
    08:34 PM...13...18...06...Range: 600 feet
    08:36 PM...13...18...08...Shuttle directly above ISS
    08:40 PM...13...18...12...ISS in TEA attitude
    08:44 PM...13...18...16...Noon
    08:48 PM...13...18...20...Shuttle directly behind ISS
    08:59 PM...13...18...31...Shuttle directly below ISS
    09:11 PM...13...18...43...Separation burn No. 1
    09:15 PM...13...18...47...Sunset
    09:39 PM...13...19...11...Separation burn No. 2
    09:43 PM...13...19...15...Post undocking computer reconfig
    09:45 PM...13...19...17...Sunrise
    10:28 PM...13...20...00...Group B computer powerdown
    10:28 PM...13...20...00...PMA-2 leak checks
    10:30 PM...13...20...02...Mission status briefing on NASA TV
    10:58 PM...13...20...30...ISS crew sleep begins
    11:03 PM...13...20...35...EVA unpack and stow
    11:03 PM...13...20...35...Undocking videoi replay
    11:28 PM...13...21...00...Shuttle arm (SRMS) powerdown
    
    03/25/08
    02:58 AM...14...00...30...Crew sleep begins
    03:00 AM...14...00...32...Daily video highlights reel on NASA TV
    
    The fly around, Dempsey said, is "a good chance for us to really view the space station all the way around."

    "The orbiter crew will be taking all kinds of high resolution photos of the space station and we can use that to check the configuration, make sure everything looks healthy. We will get some baseline photos of the JLP, the Japanese pressurized module that we just installed during this mission and then over time, we'll be able to compare those to other photos ... and just monitor over time. So it gives us a good opportunity to check out the space station."

    Departing station crews normally carry out a detailed heat shield inspection just after undocking to make sure the orbiter's nose cap and wing leading edge panels were in good shape for re-entry. Endeavour's crew did that inspection Friday and stowed the shuttle's inspection boom on the station during a spacewalk Saturday so it will be available to the next station assembly crew. Because of interference issues with the Japanese Kibo research module scheduled for launch in May, there was not enough room to carry an inspection boom on that mission.

    If all goes well, Johnson, commander Dominic Gorie, flight engineer Michael Foreman, Richard Linnehan, Robert Behnken, Japanese astronaut Takao Doi and returning European Space Agency astronaut Leopold Eyharts will pack up Tuesday and prepare the ship for landing Wednesday evening at the Kennedy Space Center.

    Landing is targeted for 7:05:08 p.m. Wednesday and forecasters are calling for good weather, with scattered clouds at 3,500 feet and winds out of the north at eight knots, gusting to 12. A second landing opportunity is available one orbit later, at 8:39:06 p.m.

    "I know we're still three days out from landing but the weather is looking pretty reasonable," astronaut Terry Virts radioed the shuttle Sunday evening. "For now it looks good. We'll keep our fingers crossed."


    12:45 PM, 3/23/08, Update: Astronauts take a break, prepare for undocking Monday

    The Endeavour astronauts are enjoying a final few hours of off-duty time today before making preparations for undocking Monday evening. The joint shuttle-station crews will share an Easter meal later today before participating in a news conference to discuss the progress of the mission.

    "Fortunately, the mission has been going extremely well so there's not a whole lot left for the crew to do," said space station Flight Director Bob Dempsey. "In fact, they're getting a half-day off to give them a chance to rest after the five EVAs and all the busy work they've been doing. And of course, preparing for the undocking and re-entry in a few days."

    The astronauts were awakened at 12:28 p.m. by a recording of "I am Free" beamed up from mission control. The song was recorded by members of astronaut Mike Foreman's church near the Johnson Space Center.

    "Good morning Endeavour," astronaut Al Drew called from mission control. "And a happy Easter to you, Mike."

    "Thanks, Alvin," Foreman replied. "That's one of my favorite songs in church, so I especially want to thank all my friends at Friendswood United Methodist Church for their thoughts and prayers. ... That was awesome, how appropriate for this special day. It sounded as good up here as it does down there. Happy Easter." Dempsey said the main items on today's agenda are a few final equipment and experiment sample transfers from the station to the shuttle for return to Earth.

    "The main things that are left open is some transfer items, for example, the crew has some laptops they've been using for the last few days during the mission that need to be transferred back to the shuttle for return to Earth," he said. "There's also a number of biological specimens that need to be returned and because they're frozen, we keep them in the freezer on the space station up until the last possible moment. That'll happen later today. ... And then the spacesuits need some final configuration and transfer over to the shuttle.

    "There are two suits we need to transfer back to the shuttle," Dempsey said. "This is is how we accomplish things like rotating suits on the space station. Two new suits come up on the space shuttle, are used and then are left behind and we take two of the older suits (and bring them down). In addition, we need to configure those suits so that if the shuttle crew has to do a contingency spacewalk before re-entering they would have two good suits. So that'll be the main activities today by several of the crew members.

    "And then the final thing that's kind of on the open to-do list is the very important crew photo. That's where both the station and shuttle crew will get together and take sort of a goodbye photo, a team photo, of everyone together."

    Undocking is targeted for 7:56 p.m. Monday, which will set the stage for landing at 7:04 p.m. Wednesday. The preliminary weather forecast calls for favorable conditions.

    Here is an updated timeline of today's activity (in EDT and mission elapsed time; includes revision K of the NASA television schedule):

    EDT........DD...HH...MM...EVENT
    
    12:28 PM...12...10...00...Crew wakeup
    03:28 PM...12...13...00...Crews off duty
    06:30 PM...12...16...02...Mission status briefing on NASA TV
    08:18 PM...12...17...50...Joint crew meal
    09:18 PM...12...18...50...EVA prep for transfer to shuttle
    09:18 PM...12...18...50...Rendezvous tools checkout
    11:18 PM...12...20...50...Joint crew news conference
    11:58 PM...12...21...30...Joint crew photo
    
    03/24/08
    01:43 AM...12...23...15...RIGEX activation
    03:13 AM...13...00...45...ISS crew sleep begins
    03:43 AM...13...01...15...STS crew sleep begins
    04:00 AM...13...01...32...Daily video highlights reel on NASA TV
    09:30 AM...13...07...02...Flight director update on NASA TV
    11:43 AM...13...09...15...Crew wakeup
    
    For readers interested in looking ahead, the undocking timeline is posted on the CBS News STS-123 Quick-Look page, along with the latest NASA television schedule and an updated list of deorbit opportunities.


    10:50 PM, 3/22/08, Update: Spacewalk No. 5 ends (UPDATED at 2:30 AM with mission status briefing; SARJ update)

    Astronauts Robert Behnken and Michael Foreman staged a successful six-hour two-minute spacewalk Saturday, mounting the shuttle Endeavour's heat-shield inspection boom on the station, deploying an experiment package and carrying out a critical inspection of a stalled solar array positioning mechanism. It's still not clear what is causing internal contamination, but an impact from orbital debris does not appear to be the root cause.

    "You were just fabulous out there today," spacewalk coordinator Richard Linnehan radioed as the spacewalk ended. "I can't say enough. Thanks for making everyone look good."

    Thank you, Rick," Foreman said.

    "It was an absolutely fantastic EVA today, fellas, I'm just happy to have had a chance to play along," added space station flight engineer Garrett Reisman, who helped Linnehan direct the operation. "Thanks for letting me join in."

    It was the 109th spacewalk devoted to station assembly and maintenance since construction began in 1998 and the fifth and final excursion for Endeavour's crew. Total station EVA assembly time now stands at 687 hours and 11 minutes. Total spacewalk time for Endeavour's crew stands at 33 hours and 28 minutes.

    During today's outing, Behnken and Foreman bolted Endeavour's heat shield inspection boom to the station's solar power truss for use by the next shuttle assembly crew. The shuttle Discovery is scheduled for launch May 25 to deliver Japan's huge Kibo research module to the station, a payload so large there's no room in the shuttle's cargo bay for an inspection boom.

    The astronauts also deployed a materials science experiment that could not be attached earlier and installed thermal covers over fittings on a newly installed Japanese logistics module.

    "We now have the OBSS transferred and installed over on station," said lead station Flight Director Dana Weigel. "It has power to both of its heater strings, so it'll be nice and toasty when flight 1J goes up to retrieve it at the end of May. We also went back to install the MISSE-6 payloads we had problems with before. We were able to get them installed. Bob had the same problems with the pit pins he had before, but a hammer helped persuade them in place and now they're secure on station."

    The astronauts plan to take time off Sunday before making final preparations for undocking Monday evening and landing back at the Kennedy Space Center on Wednesday. Weigel said engineers assessing data from laser scans of the shuttle's nose cap and wing leading edge panels Friday, a "late inspection" to look for signs of micrometeoroid impact damage, found no problems of any significance.

    "Over on the orbiter side, the ground teams have completed the analysis for all of the late inspection imagery that we took yesterday and the TPS (thermal protection system) has been cleared for entry," she said. "Tomorrow is flight day 14, and it's a certainly well-deserved off-duty day for the crew."

    Trouble with the starboard Solar Alpha Rotary Joint, or SARJ, has proven especially troubling for station engineers. The lab complex is equipped with two massive SARJs, one on each side of the station's main solar power truss, that use 10-foot-wide motor-driven gears to turn outboard solar arrays like giant paddle wheels to track the sun. Last fall, engineers discovered extensive internal metallic contamination in the right-side SARJ indicative of a major problem of some sort. To minimize additional damage, flight controllers no longer run that starboard SARJ in "auto-track" mode, although it is occasionally repositioned to improve power generation.

    During previous spacewalks, astronauts removed 17 of 22 thermal covers around the circumference of the joint to look for signs of micrometeoroid impact damage or any other issues that might explain the problem. In addition, one of the 12 trundle bearing assemblies positioned around the race ring was removed and returned to Earth for analysis, along with samples of the metallic contamination.

    During the Endeavour crew's fifth and final spacewalk Saturday, Forman removed the final five thermal covers and looked inside. So far, nothing obvious has emerged. But Weigel said today's inspection should let engineers close at least one branch of the fault tree.

    "One of the key things that we learned during the EVA today was that we don't have any obvious MMOD (micrometeoroid debris) hit through the covers," Weigel said. "They're aluminum plates with beta cloth over them. We're looking to see if we have an MMOD hit through them and if that's a source of the debris. That's a big help for us, that kind of narrows down one of the chains of the fault tree."

    Engineers are assessing a variety of potential repair options, ranging from cleaning up the debris and resuming normal operation to moving the 12 trundle bearing assemblies to a redundant, outboard gear/race ring. But the latter is a last-resort option, requiring several spacewalks, and mission managers do not want to take that step without understanding the cause of the current problem.

    The right-side SARJ can still be used to periodically move its solar panels to improve power generation and an analysis of the station's electrical demand, even with the addition of Japan's Kibo research module in May, shows near-normal operation is possible without putting the SARJ in auto track.

    "In terms of when decisions need to be made from a power standpoint, we're actually doing pretty well," Weigel said. "We can get by for quite a few more flights. The program, though, was interested in kind of coming up with more of a game plan by the end of March, just so we can figure out when we want to start attacking the different pieces of this puzzle. And there are a lot of different options we have.

    "One is to try to clean it up and live with using the current race ring as is. And that's something they're going to go and talk about now that we've finished the rest of the inspection and we understand we do have uniform debris around the ring. We also have experience now with cleaning. I think with those pieces, we'll be able to figure out if we want to go clean and use it as is. I'm not exactly sure when we'll talk about if we want to go to the outboard ops. If we have a good solution that lets us stay on the inboard or the current race ring, then we're not as anxious to get to the outboard because we don't have as much redundancy when we run in that configuration. So I think the first decision point is going to be the end of March.

    "Our current power predictions show that we're good for the next couple of flights without auto tracking, so we can continue to do what we've been doing, which is positioning the solar arrays strategically. For certain power contingencies, we could get into cases where we'd want to auto track for a while so it's desirable to get into a configuration where we could do it if we wanted to. Technically, we can auto track right now, it's just that we're putting the hardware at higher risk by doing that. So we really want to make sure we understand what's going on and clean it up as much as we can before we commit to using it in auto-track mode."

    One of the items Foreman inspected was a small blemish on the race ring that appeared to be either a small divot or perhaps an accumulation of debris. Flight controllers could not tell whether the blemish represented a bump or a depression. Foreman's inspection was not totally conclusive, but Weigel said it appears to be a small divot. It's not yet clear whether there's any relationship between the blemish and the overall SARJ problem.


    9:15 PM, 3/22/08, Update: Experiment package installed; solar array joint inspected

    Astronaut Robert Behnken successfully mounted an experiment package on the Columbus research module after initial attempts during a spacewalk last week were called off due to problems with an attachment fitting.

    Known as MISSE-6, for "materials international space station experiment," the briefcase-size folding package is designed to expose a variety of materials and coatings to the space environment.

    "So Houston, that complete the MISSE-adventure," Behnken radioed after he secured it in place.

    "And from Houston, Bob and the team, great job," astronaut Steve Robinson called from mission control. "I guess your new call sign will be Thor."

    "All right, Thor, Bam Bam, whatever it takes," spacewalk Michael Foreman radioed, using Behnken's nickname. "We're here to serve."

    "We're really glad we making humor up here because it alleviates some of the stress," said station flight engineer Garrett Reisman. "Bob's done a great job and we're really happy for the MISSE investigators in that we were able to get these payloads installed for them because we know there's a lot of good science to be had. I know they've been walking on eggshells watching all this, so everything's good." "Houston definitely concurs," astronaut Steve Robinson radioed from Houston.

    Astronaut Michael Foreman, meanwhile, was busy inspecting the space station's right-side solar alpha rotary joint, or SARJ. The SARJ uses a 10-foot-wide drive gear to turn outboard solar arrays to track the sun. But a problem of some sort has marred the right side bearing race ring and generated large amounts of metallic contamination.

    During spacewalks late last year and earlier this year, astronauts removed 17 of 22 thermal covers around the joint to inspect the bearing race ring and look for signs of damage. The flight plan called for Foreman to remove the final five covers today to complete the inspection.

    Looking inside the mechanism, Foreman observed "it's pretty ugly."

    "You're talking about the race ring, right?" Reisman asked.

    "Yeah, the race ring. It looks all corroded or something, it's real rough in most spots."

    "Garrett, for Mike, we'd like a little bit more description as to what he sees," Robinson radioed. "Is it different than the similar location or the similar site that he saw under a previous cover? Or is it different radially, or circumferentially?"

    "It looks exactly the same," Foreman said. "It looks like where the bearing rides on the surface, it's about a one-inch-wide track all the way across. It's like very rough in some spots, just sort of bubbled in other spots. So it looks the same." Looking under a different cover, Foreman reported: "It looks exactly the same, the same mottled surface. There's a cover missing next to this one so I can see a good three feet of circumference here and it looks all the same. ... Nothing significant. It's not the best lighting conditions, but I don't see ... anything that looks like a divot. I don't see anything like that on this one."

    The thermal covers themselves showed no signs of any impacts from orbital debris.

    Running well ahead of schedule, Behnken was asked to perform a get-ahead task, installing thermal covers on the massive keel fittings used to hold a newly installed Japanese logistics module in the shuttle Endeavour's cargo bay during launch.


    7:00 PM, 3/22/08, Update: Heat shield inspection boom mounted on space station

    Astronaut Garrett Reisman, operating the space station's robot arm, handed the shuttle Endeavour's 50-foot-long heat shield inspection boom to spacewalkers Robert Behnken and Michael Foreman, who plugged in keep-alive power and mounted it on the front of the station's solar power truss.

    Behnken's end snapped into an attachment fitting with no problem, but Foreman had to wrestle his into place due to minor alignment problems. After several adjustments, he coaxed his end into its mounting bracket.

    "Wait, I've got it soft docked, Rick," Foreman called to spacewalk coordinator Richard Linnehan as his end snapped into place.

    "Good work, Mike," Behnken called.

    "OK, copy soft dock, Mike," said Reisman. "It looks like you're right on the edge of good alignment." "Yeah, with a little elbow grease," Foreman replied. "I've got good alignment with the plates on the outside where they belong."

    "Excellent, good job, Mike."

    THe spacewalkers then attached a thermal cover to the boom's instrument package to keep its laser scanner and camera system from getting too cold over the next few weeks.

    Endeavour's orbiter boom sensor system, or OBSS, was stowed on the space station because the crew of the next shuttle assembly mission, scheduled for launch May 25, is ferrying the huge Japanese Kibo lab module to the station. That module is so large, the shuttle Discovery will not have enough room to carry an OBSS of its own.

    The Discovery astronauts will retrieve Endeavour's boom and use it to inspect their shuttle's heat shield after they have docked with the station and attached Kibo.

    WIth the OBSS safely mounted on the station, Behnken and Foreman are moving on to separate tasks. Behnken will attempt to install a materials science space exposure experiment package to the Columbus module while Foreman begins an inspection of the station's right side solar array rotary joint.


    05:00 PM, 3/22/08, Update: Spacewalk No. 5 begins

    Running well ahead of schedule, astronauts Robert Behnken and Michael Foreman switched their spacesuits to battery power at 4:34 p.m. to officially kick off the Endeavour crew's fifth and final spacewalk. The primary goals of the excursion are to mount the shuttle's heat shield inspection boom on the space station; to deploy a materials science experiment package; and to inspect the station's right side solar array rotary joint.

    The 50-foot-long orbiter boom sensor system, or OBSS, is in the process of being handed from the shuttle's robot arm to the station's arm, operated by pilot Gregory Johnson. Behnken will attach an extension cord to the boom to provide keep-alive heater power before the spacewalkers mount it on the front side of the station's solar power truss.


    01:00 PM, 3/22/08, Update: Astronauts suit up for fifth spacewalk

    Astronauts Robert Behnken and Michael Foreman are preparing for a fifth and final spacewalk, a six-and-a-half hour excursion this evening to mount the shuttle Endeavour's 50-foot-long heat shield inspection boom on the space station for use by the next station assembly crew. The astronauts also plan to install an experiment package they were unable to attach earlier and inspect the station's right-side solar array rotary joint in an ongoing effort to determine what might be causing internal interference and contamination.

    This will be the 109th spacewalk devoted to station assembly and maintenance since construction began in 1998, the 10th so far this year and the third each for Behnken and Foreman. The spacewalk is scheduled to begin around 5:23 p.m. when the astronauts switch their spacesuits to battery power. For identification, Behnken, call sign EV-1, will be wearing a suit with no markings. Forman, EV-2, will be wearing a suit with broken red stripes around the legs.

    The primary goal of the spacewalk is to install the shuttle's 50-foot-long orbiter boom sensor system, or OBSS, on the station for use by the next shuttle crew in late May. The goal of that flight is to deliver Japan's huge Kibo lab module to the space station.

    "That mission is very full, Discovery's payload bay is carrying up the very large Japanese pressurized module and there just simply wasn't enough room to carry up the boom as well," said station Flight Director Ginger Kerrick. "So a long time ago, the program decided to go ahead and leave it on board. We're going to be keeping it powered and keeping a very close watch on it and we promise it will be ready to support that mission when they arrive in May."

    The boom will be attached to brackets on the front face of the station's solar power truss.

    While the spacewalkers are setting up their tools and running a 30-foot-long power cord down the truss, the shuttle's robot arm will hand the sensor boom to the station arm. As soon as possible, Behnken will plug the power cable into the boom to activate internal heaters to keep the boom's laser scanner and camera warm. The arm then will release the boom so Behnken and Foreman can bolt it in place.

    With the OBSS mounted on the station, Behnken and Foreman will split up. Behnken will float to Endeavour's cargo bay, retrieve the briefcase-size MISSE-6 experiment package, and make his way to the Columbus lab module. The astronauts made an initial attempt to attach the materials exposure package to a mounting plate on the outboard side of Columbus during the crew's third spacewalk last Monday. But they were unable to insert locking pins in the mounting bracket. This time around, Behnken has smaller pins and cable ties.

    While Behnken focuses on MISSE-6, Foreman will make his way to the right side of the station's main power truss to inspect the starboard solar alpha rotary joint, one of two massive motor-driven joints that turn outboard solar panels to track the sun.

    Last fall, engineers became concerned about high vibration levels and power usage and ordered an inspection. To their dismay, spacewalking astronauts reported metal shavings covering the interior of the bearing race ring and damage to the ring itself. One of 12 bearing assemblies later was removed and returned to Earth for analysis, along with samples of the contamination. Engineers are still not sure what is causing the damage and the joint is no longer allowed to "auto track" the sun.

    Engineers are considering a plan to remove all 12 bearing assemblies and move them to an identical race ring that is available as a backup. But the work would require multiple spacewalks and flight planners don't want to take that last-resort step until they have a better idea of what might be wrong.

    Behnken and Foreman originally planned to replace the bearing assembly that was removed earlier. But that task was deferred to give Behnken time to install the higher-priority MISSE package. Instead, Foreman will focus on inspection only, removing five thermal covers to examine areas of the race ring that have not yet been assessed.

    Kerrick said the absence of one bearing assembly is not expected to affect flight controllers' ability to reposition the joint as required.

    "The joint has an inner ring and an outer ring and evenly spaced along those rings are 12 trundle bearing assemblies," Kerrick said. "Their primary function is to hold the two rings together and provide a rolling surface for the rings that will allow the joint to rotate. Will it be a problem that we're not installing it? The short answer is no. Right before we removed the trundle bearing back in December, we had our engineering teams go off and assess whether or not we would be good operating the SARJ with 11 of 12 of those trundle bearings installed and they declared that we would be. So while we would prefer to be in our nominal config with a total of 12, it doesn't impede our operations any."

    The SARJ is protected by 22 thermal blankets. Astronauts have examined the mechanism under 17 of those blankets and Foreman will inspect under the final five during this evening's spacewalk.

    "The signature we were seeing was indicative of a resistance in the rotation of the joint," Kerrick said. "So the things we want to look for, we want to inspect all the mechanical components to make sure they're not wearing unevenly or somehow breaking up and causing this resistance. We would also want to investigate the potential for having a debris impact.

    "So what we have been doing in a series of EVAs leading up to this (is) opening covers, because all those mechanical components are underneath thermal covers. So you open up the cover and inspect the mechanical components and then you also inspect the cover for potential debris strikes. So we've done pieces of that and for this EVA, there are five covers left - there's 22 covers total in the SARJ - so five left to go. And then we're going to go off and re-inspect one particular area."

    Pictures taken during a January spacewalk showed a small area on the race ring that might be a pit or depression.

    "We couldn't tell if it was damage or if it was buildup of material," Kerrick said. "So we want the crew to take a second look there because the answer to that question will help us narrow down the scope of potential problems that could be causing this."

    Assuming an on-time start, the spacewalk will end around 11:53 p.m. Here is an updated timeline of today's activity (in EDT and mission elapsed time; includes revision J of the NASA television schedule):

    EDT........DD...HH...MM...EVENT
    
    12:28 PM...11...10...00...Crew wakeup
    01:08 PM...11...10...40...EVA-5: 14.7 psi repress/hygiene break
    01:58 PM...11...11...30...EVA-5: Airlock depress to 10.2 psi
    02:28 PM...11...12...00...EVA-5: Campout EVA preps
    02:28 PM...11...12...00...Station arm (SSRMS) EVA-5 setup
    03:48 PM...11...13...20...EVA-5: Spacesuit purge
    04:03 PM...11...13...35...EVA-5: Spacesuit prebreathe
    04:53 PM...11...14...25...EVA-5: Crew lock depressurization
    05:23 PM...11...14...55...EVA-5: Spacesuits to battery power
    05:28 PM...11...15...00...EVA-5: Airlock egress
    05:33 PM...11...15...05...SSRMS grapples inspection boom (OBSS)
    05:48 PM...11...15...20...EVA-5: Setup
    06:03 PM...11...15...35...Shuttle arm (SRMS) releases OBSS
    06:08 PM...11...15...40...EVA-5: OBSS KAU install
    06:18 PM...11...15...50...OBSS handoff to spacewalkers
    07:33 PM...11...17...05...Crew meals begin
    07:43 PM...11...17...15...EVA-5: OBSS stow
    08:58 PM...11...18...30...EVA-5 (EV1): MISSE experiment package install
    08:58 PM...11...18...30...EVA-5 (EV2): Starboard SARJ inspection
    11:08 PM...11...20...40...EVA-5: Cleanup
    11:33 PM...11...21...05...EVA-5 Airlock ingress
    11:53 PM...11...21...25...EVA-5: Airlock repressurization
    
    03/23/08
    12:08 AM...11...21...40...Post EVA spacesuit servicing
    12:28 AM...11...22...00...SRMS powerdown
    01:30 AM...11...23...02...Mission status briefing on NASA TV
    03:58 AM...12...01...30...ISS crew sleep begins
    04:28 AM...12...02...00...STS crew sleep begins
    05:00 AM...12...02...32...Daily video highlights reel on NASA TV
    09:30 AM...12...07...02...Flight director update on NASA TV
    12:28 PM...12...10...00...Crew wakeup
    


    02:40 PM, 3/21/08, Update: Heat shield inspection on tap (UPDATED at 12:30 AM with completion of heat shield inspection)

    The Endeavour astronauts carried out a final heat shield inspection Friday and prepared for a final spacewalk Saturday night to mount the shuttle's inspection boom on the space station's solar power truss for use by the next station assembly crew.

    Shuttle crews normally carry out so-called "late inspections" after undocking from the station. But the next assembly mission, scheduled for launch in late May, will deliver Japan's huge Kibo laboratory module to the station and there's not enough room in the shuttle Discovery's cargo bay for the module and an inspection boom. So Endeavour' boom will be mounted on the station during a fifth and final spacewalk Saturday and left behind for Discovery's crew to use and bring home.

    "We had an absolutely fantastic day today," said lead shuttle Flight Director Mike Moses. "This is something we've been working on for a very long time, a lot of people on the ground spent a lot of time getting this docked late inspection ready to go. The crew executed perfectly. They actually went faster than we thought.

    "The starboard wing (inspection) was a brand new procedure and we literally started by scanning up on top of it and then pulling the arm the whole way out, underneath the orbiter, sticking it under the belly and scanning the bottom half. So that was a very complicated set of maneuvers and to sequence all that together went fantastic."

    The data collected during the inspection will be analyzed on the ground to make sure Endeavour's critical nose cap and wing leading edge panels have not been struck by orbital debris since a similar inspection the day after launch. Assuming no problems are found, 50-foot-long inspection boom will be mounted on the station's solar power truss.

    "That sensor boom is going to be left on station because the following mission is going to deliver the next portion of the Japanese laboratory," said spacewalker Robert Behnken in a NASA interview. "That module is a very large module and there’s actually not room in the shuttle payload bay to launch both that module and this sensor boom on the same shuttle flight.

    "So to provide the inspection capability to allow that next shuttle mission to be able to inspect their thermal protection system before they come back for re-entry, they’re going to need to have a sensor boom. They can’t bring their own and so our flight is going to do an inspection late in the mission and then we’ll stow the boom during our EVA 5 on the ISS and hook up the power to it and it’ll be all ready for those guys when they actually arrive and install the Japanese module."

    Behnken and his crewmates were awakened today by a recording of Metallica's "Enter Sandman" radioed up from mission control.

    "Good morning Endeavour. And good morning to you, Dr. Bob," astronaut Al Drew called from Houston.

    "Good morning, Alvin. I hope everything's going great down there," Behnken replied. "Thanks for that great wakeup music and I'd like to thank my fiance for choosing that for me. I just want to tell her I miss her and I can't wait to get back and see her here in a couple of days."

    "Thanks for the good words, Bob. The music has got us awake down here, I'm sure that shook you out of bed as well."

    "It did, Al. Thanks!"

    Along with carrying out the late heat shield inspection, the astronauts also plan to move an experiment rack from the U.S. Destiny laboratory to the European Space Agency's new Columbus research lab. The work will take about four hours to complete.

    "Four hours seems like a long time to move a rack from one location to another," said station Flight Director Ginger Kerrick. "This is a special rack, it has an active rack (vibration) isolation system and there are a lot of individual pieces of hardware that the crew is going to have to remove in order to (move) that rack. A standard rack relocation, you would power down the rack, you would remove all the electrical connectors, you'd remove all the thermal connectors, the vacuum system connectors. But this rack has all those additional pieces of hardware that are designed to isolate the experiments inside from the effects of any (vibration) that may be going on in the space station, for example, running on the treadmill or using the exercise bike."

    Another rack will be moved later in the mission.

    In one other bit of news, Kerrick said engineers are still looking into a glitch involving the Canadian Space Agency's Dextre maintenance robot. During testing after the robot's assembly, one of its joints did not operate as expected.

    "We positioned arm 2 of the SPDM (special purpose dexterous manipulator) in a good location that would provide the EVA crew access to remove the thermal cover on (the hand of) arm number two," Kerrick said. "After we repositioned the arm, we sent the crew to bed and the ground team proceeded with performing some checkouts that were not performed when we originally relocated SPDM to the lab. And that check out was to test out an alternate power path through the PDGF (lab power and data grapple fixture). We have a primary path and an alternate. We had powered up on the primary and just wanted to make sure the alternate power path worked.

    "Well, the alternate power path did work. But when we repowered up the SPDM, the shoulder roll joint on its arm number two did not know what position it was in. And this was the exact same joint we had just repositioned for the EVA. We power cycled again and were not able to talk to it. The software gave us the message 'unknown position.' We have some diagnostic tests we can run to help us figure out where inside that roll joint the problem is occurring. But we can't run the diagnostics test until we clear that message. So our CSA counterparts are off investigating whether or not we can uplink a software patch that will clear that message for us so we can run the appropriate diagnostics test.

    "But for right now, we had no other planned use of the arm. It was in a good config for the EVA. ... So still more work to be done on that, but no impact to the mission."

    Here is an updated timeline of today's activity (in EDT and mission elapsed time; includes revision I of the NASA television schedule):

    EDT........DD...HH...MM...EVENT
    
    03/21/08
    01:28 PM...10...11...00...Crew wakeup
    04:03 PM...10...13...35...Heat shield sensor boom (OBSS) starboard wing survey
    04:43 PM...10...14...15...Logistics transfers resume
    05:23 PM...10...14...55...Experiment rack 3 transfer
    06:33 PM...10...16...05...OBSS laser scan downlink
    07:43 PM...10...17...15...OBSS nose cap survey
    07:43 PM...10...17...15...OBSS mounting bracket assembly
    09:08 PM...10...18...40...Crew meals begin
    09:13 PM...10...18...45...OBSS port wing survey
    10:23 PM...10...19...55...EVA-5: Tool config
    11:00 PM...10...20...32...Mission status briefing on NASA TV
    11:18 PM...10...20...50...Airlock prep
    
    03/22/08
    12:18 AM...10...21...50...OBSS laser scan downlink
    12:58 AM...10...22...30...EVA-5: Procedures review
    02:43 AM...11...00...15...EVA-5: Mask pre-breathe/tool config
    03:33 AM...11...01...05...EVA-5: Airlock depress to 10.2 psi
    03:58 AM...11...01...30...ISS crew sleep begins
    04:28 AM...11...02...00...STS crew sleep begins
    05:00 AM...11...02...32...Daily video highlights reel on NASA TV
    09:30 AM...11...07...02...Flight director update on NASA TV
    12:28 PM...11...10...00...Crew wakeup
    


    05:00 AM, 3/21/08, Update: Shuttle external tank production issues slow delivery; launch delays possible

    With the shuttle Endeavour's mission entering the home stretch, shuttle Discovery remains on track for blastoff May 25 to ferry a huge Japanese laboratory module to the international space station. But subsequent near-term flights, including a high-profile mission to service the Hubble Space Telescope, face possible delays, sources say, because of ongoing external tank production issues.

    The tank used by Endeavour for its current mission was the last in the inventory of tanks built before the 2003 Columbia disaster and subsequently modified to reduce potentially dangerous losses of foam insulation. The tank slated for use with Discovery in late May, ET-128, is the first so-called "in-line" external tank built from the ground up with post-Columbia upgrades, including a new ice-frost ramp design and titanium oxygen line support brackets. Both improvements address areas of possible foam shedding.

    ET-128 departed Lockheed Martin's Michoud Assembly Facility in New Orleans Thursday for the 900-mile barge trip to the Kennedy Space Center in Florida.

    But a backlog of work at Michoud is hampering downstream tank deliveries. The tank that would be needed for a rescue mission should some mishap strand Discovery's crew in orbit is not expected to reach the Kennedy Space Center until late summer. NASA managers say the space station has enough supplies on board to support a combined crew for more than three months if necessary and as of this writing, Discovery's launch remains on track.

    But the picture is cloudier for NASA's next shuttle flight, a mission by the shuttle Atlantis to service the Hubble Space Telescope. Launch currently is targeted for Aug. 28. ET-127, the tank designated as the emergency backup for Discovery's May mission, is the prime tank for the Hubble flight.

    Safe haven aboard the space station is not an option for Atlantis' crew if major heat shield damage occurs. The observatory and the station are in different orbits and the shuttle does not have the ability to move from one to the other. As a result, NASA Administrator Mike Griffin early on approved plans to have a second shuttle, Endeavour, ready for launch on a rescue mission just in case.

    That means NASA needs two ready-to-fly external tanks for the Hubble mission, ET-127 and ET-129 respectively. Manpower and production issues, triggered in part by unplanned work to upgrade low-level hydrogen fuel sensors and other post-Columbia design upgrades, have slowed external tank manufacturing and sources say the Hubble mission faces a possible delay to October.

    Senior program managers visited Michoud for a first-hand look earlier this week and a more realistic assessment of the tank production schedule is expected in the next week or so. For now, the Hubble mission remains officially targeted for launch Aug. 28.

    Shuttle Program Manager John Shannon told CBS News Thursday that NASA has "added many new features to further ensure the safety of this tank and since these were the first in-line tanks, we took extra time to make sure we got it right."

    "We have margin in the schedule to absorb small delays and we have learned a lot in the process of putting these tanks together so that the '09 and '10 tanks will flow much faster," he said.

    Shannon did not address specific launch dates.

    NASA plans to complete the space station and retire the shuttle by the end of fiscal 2010. The current manifest calls for four more flights this year - in May, August, October and December - four in 2009 and up to three in 2010.


    12:40 AM, 3/21/08, Update: Spacewalk ends (UPDATED at 04:10 a.m. with mission status briefing)

    Astronaut Bob "Bam Bam" Behnken and Michael "Dr. Goo" Foreman wrapped up a six-hour 24-minutes spacewalk early today, successfully replacing a faulty circuit breaker and testing a promising heat-shield repair technique, one of the final steps in NASA's recovery from the Columbia disaster. The tile repair demonstration went smoothly and while a complete assessment will require detailed post-landing analysis, the astronauts and NASA managers were pleased with the results.

    "This was a huge success for a lot of people on the ground, a lot of people on the space station," said Zeb Scoville, lead spacewalk officer at the Johnson Space Center in Houston. "We're just thrilled with the way it turned out."

    Efforts to develop viable heat shield repair options in the wake of the 2003 Columbia disaster were "a monumental effort that has been going on for years by hundreds of people, literally, to develop the tools and the techniques to be able to pull off this tile repair test," Scoville said.

    "I remember in 2003, shortly after the Columbia accident, they hadn't really figured out what the root cause was of the accident. And there was an EVA officer at the time who leaned over to me and said, 'Zeb, regardless of what happens, we're going to have to figure out a way to repair tiles.' And now this person is the ISS lead flight director sitting right next to me."

    He was referring to Dana Weigel, lead space station flight director for Endeavour's mission.

    "For many years she worked as one of the lead operations officers trying to develop this technique and the tools and the repair capability, along with just hundreds of people in engineering and the contractor world, developing the materials and making sure the material's properties were correct," Scoville said. "So I really salute everyone involved. I feel it's a little unfair for me to sit up and talk about what a great success it was without really giving them as much credit as I possibly can. I congratulate them all on a huge success."

    Behnken and Foreman tested a pressure-drive gun-like applicator and a heat-resistant two-compound material known as STA-54, squirting the pink goo into deliberately damaged or scooped-out heat shield tiles mounted on a sample board. On Earth, bubbles that form when the compounds mix and flow out of the applicator rise to the surface. Engineers worried that in the space environment, the bubbles would be more evenly distributed, causing the STA-54 to swell like a rising loaf of bread.

    That could cause problems if the repair material bulged out beyond the surface of surrounding tiles because it could disrupt airflow during re-entry and cause extreme downstream heating.

    But the material proved relatively easy for the spacewalkers to manage and swelling, while present, was not extreme.

    "I'm thrilled with what we saw today," Weigel said. "In fact, I actually thought the material would swell quite a bit more than it did. It behaved very similar to what we've seen on the ground. That gives me a lot of comfort. We've done a lot of testing in the vacuum chamber, so we do have a lot of experience with the off gassing and what that looks like, both while we're manipulating the material and also post repair.

    "My expectation is when we get this material to the ground and cross section it, we'll find that everything with the material's performance is very much in family with all the testing that we've done. We learned a lot in terms of validating what we've done on the ground. But we really didn't have any big surprises. So I'm confident that it performed very well and as we expected it to."

    Behnken and Foreman also completed two get-ahead tasks, freeing launch locks on two Harmony module ports and removing a thermal cover from the Canadian Space Agency's Dextre maintenance robot. Foreman also inspected one of the robot's joints that did not operate properly after power was turned off and back on. Engineers don't yet know what the problem is, but Weigel said they are working to resolve the issue.

    The spacewalkers were unable to unplug a stuck electrical connector from a patch panel in the station's Z1 truss that would have re-routed power to one of four control moment gyroscopes. CMG-2 and CMG-3 were wired into the same circuit in the wake of an earlier failure and the cable change today was needed to hook CMG-2 back up to its own power supply, restoring lost redundancy. As it now stands, a single failure could take out both CMGs, a situation NASA wanted to correct.

    The astronauts made two attempts to free the connector. Working in the so-called "rat's nest" where dozens of cables are routed to various station systems, Foreman made an initial attempt early in the spacewalk and Behnken had another go at it toward the end of the excursion. But the connector refused to budge.

    Weigel said the CMGs were left in the same state they've been in for several years and that there was no pressing urgency to rectify the situation.

    This was the 108th spacewalk devoted to station assembly and maintenance since construction began in 1998 and the fourth of five planned for Endeavour's mission. The crew's cumulative EVA time now stands at 27 hours and 26 minutes. Total station EVA time through all 108 spacewalks is 681 hours and nine minutes.

    Behnken and Foreman plan a fifth and final spacewalk - the third for each astronaut - Saturday evening.


    10:00 PM, 3/20/08, Update: Heat shield repair tests go smoothly

    Astronaut Michael Foreman earned some of the more unusual kudos in spacewalking history this evening during tests of a new heat shield repair technique. Filling deliberately damaged tiles with a thick pink toothpaste-like material, "Mr. Goo" was praised his skill as a "tile and grout specialist," a "brain surgeon" and a "Rembrandt" for his deft work.

    After testing a pressure-driven caulk gun-like applicator, Foreman, assisted by Robert Behnken, began filling various cavities in a tile sample board mounted on the bottom of the Destiny laboratory module.

    "Looking for a success here," Foreman said as the work began.

    "You are Capt. T-RAD, Mr. Goo," Richard Linnehan replied from inside the shuttle Endeavour. "You're in control today."

    The repair material, known as STA-54, looks like pink silly putty. It is made up of two compounds that are mixed together in a pressure-driven applicator gun just before they exit the nozzle. The gun, called a tile repair ablator dispenser, or T-RAD, was operated by Foreman, wearing an STA-54 reservoir attached to the bottom of his spacesuit's emergency jetpack.

    One of the compounds making up STA-54 causes bubbles to form. On Earth, those bubbles typically rise to the top. During this evening's test in the absence of air or gravity, the bubbles tended to spread throughout the material causing it to bulge slightly in a phenomenon known as "bread loafing."

    Too much bulging could cause the material to swell up over the surface layer of surrounding tiles, disrupting air flow during re-entry and causing excessive downstream heating. Based on this evening's tests, though, the STS-54 appeared to behave more benignly. While bubbles formed, the astronauts were able to use pads to tamp the material down and as the STA-54 "set up," the swelling seemed to diminish.

    "You're going to be our tile and grout specialist," Linnehan said at one point as Foreman worked the material in a cavity.

    "I hope we don't need one," Foreman said.

    Later, he said "I can see the bubbles under the surface, those little nodule-type bubbles, they're still forming in the material but it's not building as much as it was. ... It's still bread loafing, but it seems like when I hit it with the tamping it doesn't bounce back quite as quickly or as much."

    "And for Houston, we're pretty happy with how things are going," Linnehan called to flight controllers in Houston. "These guys are doing a great job and the material is reacting in a very, I guess, tame way."

    "Endeavour, Houston, EVA," Steve Robinson replied from mission control. "We are absolutely captivated by what you guys are doing here. It's like brain surgeons up there."

    "You hear that Mike? You're a brain surgeon," Linnehan said.

    "I've never been called that before."

    "Probably never will be again," Linnehan agreed.

    Wrapping up the work, Behnken added: "Mike, you're a regular Rembrandt. I think he was a brain surgeon."

    "I'm sure not every work was a masterpiece," Foreman said.

    "This is."

    Foreman and Behnken finished the tile repair demonstration well ahead of schedule.

    After cleanup, the astronauts were expected to make another attempt to free a stuck electrical cable on a patch panel on the space station's Z1 truss. Foreman attempted to move the cable to a different connector after a circuit breaker was replaced earlier in the spacewalk. The goal was to reconnect one of the station's four gyroscopes, CMG-2, to its own power supply. Without the cable swap, CMGs 2 and 3 remained connected to the same circuit. A failure in that circuit could take out both CMGs, a condition NASA wants to rectify with the cable swap.


    07:05 PM, 3/20/08, Update: Circuit breaker replaced; stuck electrical connector prevents cable change

    Astronaut Robert Behnken replaced a faulty space station circuit breaker today but fellow spacewalker Michael Foreman was unable to disconnect an electrical cable as part of a patch panel reconfiguration. As a result, flight controllers were not immediately able to switch one of the station's four stabilizing gyroscopes back to its own power supply as planned.

    Before beginning the patch panel work, Foreman reported an apparent strike from a micrometeoroid on a tool box door.

    "And Rick, I don't know if you can see this from up here, but on the port door, lower hinge, there's a nice crater right there by my right index finger," Foreman radioed.

    "We do see that Mike, and it's good you're doing this inspection," Richard Linnehan called from inside the shuttle. "I didn't pick that up in the dark."

    "Yeah, that looks like a direct hit from something else," Foreman observed.

    A few minutes later, both spacewalkers ran into problems. Behnken wasn't initially able to get the failed circuit breaker, known as a remote power control module, or RPCM, out of its slot in a rack in the S0 truss; and Foreman was unable to disconnect a cable from an electrical patch panel as required.

    "The (connector-locking) bale is past the over center, all the way back," Foreman radioed.

    "Houston, do you think it's worth a cycle on the bale, back and forth, would that help, maybe, loosen it?" Linnehan asked.

    "I think where it clicks in there, it's just not coming out," Foreman said. "Can I tap it with a waist tether or something?"

    "And Rick, I've also got eight turns in there," Behnken joined in. "The RPCM did move to the unlock position, but it still seems to be engaged."

    A few minutes later, however, he managed to pull the RPCM out of its slot.

    "Bob, good work, I see you got that RPCM out now," Linnehan radioed.

    "Yeah, I just kept wiggling it," Behnken said. "It was a little ornerier than I thought it would be."

    Foreman, meanwhile, was still having problems with the stuck cable connector.

    "Send Bam Bam up here!" he said, referring to Behnken. Behnken was on his way back to the airlock to retrieve the equipment needed for a heat shield tile repair demonstration.

    Foreman made several more attempts to free the cable before Flight Director Dana Weigel, a former spacewalk planner, decided to call of the effort and to leave the connector in place.

    "Endeavour, Houston, for EVA. We can see MIke trying his absolute best," astronaut Steve Robinson radioed from Houston. "We think at this point, if you guys concur, that it's time to re-throw the bale, put the cap back on and move on to greener pastures."

    "Sounds good, Steve. Sorry about that, guys," Foreman replied.

    "Good work, Mike, thanks for sticking with it that long," Linnehan said.

    Lead Flight Director Mike Moses said one of the goals of the RPCM swap-out and cable reconfiguration was to restore lost redundancy to control moment gyro No. 2, one of four used to stabilize the space station and change its orientation as required. Because of the earlier RPCM failure, CMG-2 was tied into the power circuit supplying CMG-3.

    "Both are being fed by one unit so if that one failed, it would take down two CMGs," Moses said earlier today. "We prefer them to each be on their own to provide redundancy.


    6:10 PM, 3/20/08, Update: Spacewalk No. 4 begins

    Running 24 minutes ahead of schedule, astronauts Robert Behnken and Michael Foreman, floating in the Quest airlock module, switched their spacesuits to battery power at 6:04 p.m. to officially kick off a six-and-a-half-hour spacewalk. The goals of the excursion are to replace a faulty space station circuit breaker and to test a shuttle heat shield repair technique.

    After a half-hour setting up tools and tethers, the astronauts will split up for the circuit breaker swapout. Behnken will release the faulty electronic unit in the station's S0 solar power truss segment while Foreman reconfigures an electrical patch panel to restore redundant power to one of the station's stabilizing gyroscopes.

    That work should take about an hour to complete. The rest of the spacewalk will be devoted to testing a caulk gun-like tool designed to help astronauts repair damaged heat shield tiles. See the 2:20 p.m. CBS News STS-123 Status Report for complete details.


    2:20 PM, 3/20/08, Update: Astronauts set for heat shield repair test

    Astronauts Robert Behnken and Michael Foreman are gearing up for a six-and-a-half-hour spacewalk today to replace a faulty space station circuit breaker and to test a new heat shield repair technique that represents one of NASA's final post-Columbia safety upgrades.

    "I consider it to be kind of the last thing we're going to do on the return to flight tile and (wing leading edge) repair tasks that we took on," said shuttle Program Manager John Shannon. "We have high confidence in it, but this will just be the final activity that we'll do to verify that's indeed a good repair capability."

    NASA plans to launch the shuttle Atlantis in late August on a final Hubble Space Telescope servicing mission, a flight that cannot take advantage of safe haven aboard the space station if major heat shield damage occurs. While a second shuttle will be standing by if a rescue mission is required, a successful test today would give NASA added confidence about dealing with any heat shield damage that might occur on the Hubble mission or any other shuttle flight.

    This will be the 108th spacewalk devoted to station assembly and maintenance since construction began in 1998, the ninth so far this year and the fourth of five planned for Endeavour's crew. For identification, Behnken, call sign EV-1, will wear a white suit with no markings. Foreman, EV-2, will wear a suit with broken red stripes around the legs.

    The spacewalk is scheduled to begin at 6:28 p.m. The first item on the agenda is to replace the faulty circuit breaker, known as a remote power control module, or RPCM. As it now stands, two of the station's four control moment gyroscopes, or CMGs, are tied to a single RPCM. By replacing the faulty unit, the astronauts will restore lost redundancy.

    But to do that, flight controllers first must power down numerous station systems, including one of the lab's two external ammonia cooling loops.

    "Right now, CMG-2 and I think it's CMG-3 are both hooked up to a single RPCM," said lead flight director Mike Moses. "Both are being fed by one unit so if that one failed, it would take down two CMGs. We prefer them to each be on their own to provide redundancy.

    "The power downs that are required, a good analogy is if you're about to go do electrical work in your house and change out an outlet, you want to turn the circuit breaker off upstream. This IS the circuit breaker, so we have to go one step further and take down the power distribution units upstream, which feed power to a whole lot more than just this bank of circuit breakers. We require two inhibits, so we have to take two things upstream down to verify that the EVA crew will be safe while they're working with this hardware."

    Behnken will change out the circuit breaker in the central S0 solar array truss segment while Foreman moves to the Z1 truss atop the central Unity module to reconfigure an electrical patch panel.

    With the RPCM installed, flight controllers will reactivate the powered down systems while Behnken and Foreman make their way back to the Quest airlock module to retrieve the equipment needed for the heat shield repair test. The work will be conducted on the bottom of the Destiny laboratory module.

    "We'll actually take a couple of bags of equipment with us, all the things that you might have in your garage if you were going to do some spackling and some dry-wall repair," Behnken said in a NASA interview. "We'll have that stuff in the bag. We'll have scrapers and brushes and all that sort of equipment. We'll also have some engineering equipment. If you wanted to really understand how well of a repair job you're doing, we're taking some thermometers and a camera and things like that so that we can actually assess the progress of the repair material and our repair technique and see how we're doing with it."

    The repair material, known as STA-54, looks like thick, pink silly putty. It is made up of two compounds that are mixed together in a pressure-driven applicator gun just before they exit the nozzle. The gun, called a tile repair ablator dispenser, or T-RAD, will be operated by Foreman, wearing an STA-54 reservoir attached to the bottom of his spacesuit's emergency jetpack.

    "Mike Foreman will get in a foot restraint to give him good reach and access and restraint while he's working," said Moses. "He'll be the one actually dispensing the goo into the samples. Bob Behnken will be there to assist with cleanup and handing tools back and forth as he needs them."

    Foreman will fill in a variety of cavities in a tile sample board. The astronauts will use pads and brushes to smooth the material out before it cures and hardens.

    Some of the cavities were machined while others represent actual foam impact or ice damage. Engineers will dissect the repaired tiles after they are returned to determine the mechanical properties of the material, it's ability to adhere to the underlying tile and how much it swells due to bubbles that form when the materials are mixed in the gun just before application.

    "There are a number of different sizes and shapes of samples and really, this correlates to the different objectives we're trying to get out of this test," said Zeb Scoville, the lead spacewalk planner. "Some of of our tests are going to be involving a study of the material itself, how it adheres to tile substrates, how it expands, if it bubbles, what sort of density it's going to have. Other objectives of this test are really to focus on how well the crew can operate and perform. It's one thing to be able to repair a very evenly machined sample. It's another thing to have a divot or pock mark that's been cut by an ice impact or foam damage. So we've modeled a couple of tile damage samples to represent things we've seen on previous missions or on ground testing.

    "There's really one main reason why we're trying to perform this test," Scoville said. "On the ground, we were able to develop techniques in a vacuum chamber to see how the material would react and then we performed tests on NASA's zero gravity airplane to understand how the repair process works in a zero gravity environment, albeit for a short period of time. But being able to combine both the vacuum and the zero gravity aspects of these together is what we're trying to figure out here."

    When the two compounds making up STA-54 are mixed, a chemical reaction causes bubbles to form. On Earth, those bubbles typically rise to the top. In space, they may be more evenly distributed throughout the material. This is a critical question because it could affect the material's ability to protect damaged tiles from the heat of re-entry.

    "One of the big questions we have, in zero gravity are those bubbles going to rise to the surface or are they going to act more like a bread loaf as it bakes with the gas expanding in the material and being evenly distributed bubbles that then cause the surface to rise up over the top?" Scoville explained.

    If the "bread loaf effect" causes the material to swell up above the surface of the surrounding tiles, it could disrupt the airflow across the belly of the shuttle during re-entry, causing more severe downstream heating.

    "The surface smoothness is a big key in understanding how this will react during a re-entry scenario," Scoville said. "If you have a lot of bubbles and expanded ridges and what not, this can disrupt the airflow ... and cause a turbulent flow transition, which can cause downstream heating and damage the orbiter on re-entry. So being able to understand how this material's going to react and expand and what we can do to control that is really one of our primary objectives of this test."

    Here is an updated timeline of today's activity (in EDT and mission elapsed time; includes revision G of the NASA television schedule):

    EDT........DD...HH...MM...EVENT
    
    01:28 PM...09...11...00...Crew wakeup
    02:13 PM...09...11...45...EVA-4: 14.7 psi repress/hygiene break
    03:03 PM...09...12...35...EVA-4: Airlock depress to 10.2 psi
    03:23 PM...09...12...55...EVA-4: Campout EVA preps
    04:53 PM...09...14...25...EVA-4: Spacesuit purge
    05:08 PM...09...14...40...EVA-4: Spacesuit prebreathe
    05:58 PM...09...15...30...EVA-4: Crew lock depressurization
    06:28 PM...09...16...00...EVA-4: Spacesuits to battery power
    06:33 PM...09...16...05...EVA-4: Airlock egress
    06:38 PM...09...16...10...EVA-4: Setup
    06:58 PM...09...16...30...EVA-4 (Behnken): RPCM R&R
    06:58 PM...09...16...30...EVA-4 (Foreman): Patch panel
    07:28 PM...09...17...00...EVA-4: T-RAD worksite setup
    08:48 PM...09...18...20...EVA-4: T-RAD demonstration
    10:33 PM...09...20...05...EVA-4: Tool cleanup
    11:13 PM...09...20...45...EVA-4: Payload bay ops
    11:58 PM...09...21...30...EVA-4: Node 2 ACBM launch locks removal
    
    03/21/08
    12:18 AM...09...21...50...EVA-4: Cleanup
    12:38 AM...09...22...10...EVA-4: Airlock ingress
    12:58 AM...09...22...30...EVA-4: Airlock repressurization
    01:13 AM...09...22...45...Spacesuit servicing
    03:00 AM...10...00...32...Mission status briefing on NASA TV
    04:58 AM...10...02...30...ISS crew sleep begins
    05:28 AM...10...03...00...STS crew sleep begins
    06:00 AM...10...03...32...Daily video highlights reel
    10:30 AM...10...08...02...Flight director update on NASA TV
    01:28 PM...10...11...00...Crew wakeup
    


    10:00 PM, 3/19/08, Update: Astronauts take a break (UPDATED at 10:00 p.m. with CBS News interview)

    Midway through a grueling 16-day mission, the Endeavour astronauts and their space station counterparts enjoyed a second half-day off today, taking a call this evening from Japan's prime minister and fielding questions from reporters before gearing up for a fourth spacewalk Thursday.

    In an interview with CBS News, station commander Peggy Whitson said the time off was a welcome break.

    "We're having a great time, taking a break, just relaxing a little bit," she said. "I think we really needed it. For the station guys and for the shuttle guys, we had to do a pretty big sleep shift to get to this time, to (get in synch) with the launch and the landing and everything. So it was nice to be able to get eight hours of sleep."

    The Endeavour crew gave flight engineer Garrett Reisman a lift to the space station. He will remain behind when the shuttle undocks next Monday night and European Space Agency astronaut Leopold Eyharts will return to Earth in his place after a month and a half in orbit.

    Asked to describe the fast-growing space station, Reisman said the crew was struck by the view during final approach and similarities with the famous space station scene in the movie "2001: A Space Odyssey" by Stanley Kurbrick and Arthur C. Clarke. Clarke died Tuesday at the age of 90.

    "It's interesting you should bring that up," Reisman said. "As we were rendezvousing, a bunch of us commented about that movie and how much the view out the window of the space station approaching, all we needed was 'The Blue Danube' playing in the background and it would have been just like the movie.

    "Coming in from the shuttle, which is relatively small volume, it was pretty overwhelming. It's amazing how big station is, it's about the same size from stem to stern as a Boeing 767 and it's been astonishing to me how long it takes just to get from one end to the other. It's so big, you actually have to plan how you carry your stuff around because if you have to go back and get something, it takes time. And that's really marvelous."

    For his part, Eyharts said he's looking forward to seeing his family again. And returning to a bit more relaxed life style.

    "Of course, I'm looking forward to seeing my family after seven weeks on board the station," he said. "It has been a relatively short flight for a (station crew member), but very busy, with two shuttle flights and a lot of work with Columbus. So I'm looking forward also to having a little bit of rest and kind of a normal life back on Earth."

    Linnehan, veteran of three spacewalks during Endeavour's mission and three during a 2002 Hubble Space Telescope servicing flight, provided an interesting insight into what it's like to walk in space.

    "We were talking about this yesterday. I feel really lucky to have had the opportunity to have gone to Hubble and now the station," he said. "You know, we talk about 'spacewalks' but it's a bit of a misnomer. It's more like space floating. You're really not out there walking. I guess the best analogy I can tell everybody is, if you can imagine yourself scuba diving in a suit of armor, that's about what spacewalking is like."

    The astronauts were awakened for their 10th "day" in space around 1:40 p.m. by a recording of Elvis Presley's "Burning Love" radioed up from Houston.

    "Good morning, Endeavour, these were words from the 'King' for another sort of king, I guess, captain, U.S. Navy, MIke Foreman," radioed Canadian astronaut Julie Payette. "Good morning to you all."

    "Good morning, Houston, and thank you Elvis," Foreman replied. "And I especially want to thank my wife, Lorrie, whom I've been with for a long time and I still have a burning love for her. I couldn't do it without you."

    The Canadian Space Agency's Dextre maintenance robot, now fully assembled and mounted on the Destiny lab module, is in good shape and ready for use when needed. Station Flight Director Ginger Kerrick said one minor glitch during testing Tuesday, when the robot's waist joint turned the opposite direction from what controllers expected, can easily be fixed with a software patch.

    "It is on its new temporary home on the lab," Kerrick said. "I say temporary, but it'll stay there until we have a planned use for it. Right now, we don't have a planned use for it until the 2 J/A mission sometime next spring. It's in great shape. You may have heard about some software funnies as we attached it to the lab yesterday. We have taken a look at that, we understand what happened and it's just going to take a quick fix, nothing to worry about and no concerns for future operations."

    Work with the mission's other major payload, a Japanese equipment storage room now attached to the station's Harmony module, also is complete, as are a variety of get-ahead tasks. The storage module ultimately will be attached to Japan's huge Kibo pressurized laboratory module, scheduled for attachment to the station in late May.

    "There's not a whole lot of exciting things to tell you about that right now," Kerrick said of the logistics module. "They are done. They were pretty much done with the setup yesterday, not only on the activities that were scheduled for this docked mission, but also for the activities that were scheduled after the shuttle left, before the arrival of the next shuttle. So you'll see a couple of five- to 10-minute activities on the timeline but it's really just to take pictures and to document the configuration that it's in."

    Japanese astronaut Takao Doi, Whitson and shuttle commander Dom Gorie chatted with Japanese Prime Minister Yasuo Fukuda this evening, showing off the newly attached logistics module and answering questions from school kids.

    "Doi-san, thank you for the hard work. Congratulations on the completion of the first stage of (the attachment of) Kibo," Fukuda said in Japanese. "Congratulations. Doi-san, for a very long time have been engaged in this project. How do you feel now, the fact that you've completed the first step, what is your impression? What are your thoughts?"

    "Hello, prime minister, from space station," Doi replied. "Kibo module is filled with the dreams of the Japanese people. I'm very happy to be able to complete the first step, the attachment. People on the ground have been working hard supporting us up in space and we thank all of you very much indeed."

    Said Whitson: "It's been a very special honor to me to welcome JAXA (the Japanese space agency) officially aboard the space station with the addition of this module. We are very happy to have Kibo up here with us."

    Here is an updated timeline of today's activity (in EDT and mission elapsed time; includes revision G of the NASA television schedule):

    EDT........DD...HH...MM...EVENT
    
    03/19/08
    02:58 PM...08...12...30...ISS crew off duty
    04:28 PM...08...14...00...STS crew off duty
    07:08 PM...08...16...40...Japanese VIP event
    08:58 PM...08...18...30...CBS News, NBC News, WMUR-TV interviews
    09:28 PM...08...19...00...Joint crew meal
    11:00 PM...08...20...32...Mission status briefing on NASA TV
    11:13 PM...08...20...45...T-RAD tile repair preps
    11:58 PM...08...21...30...EVA-4: Tools configured
    
    03/20/08
    01:28 AM...08...23...00...EVA-4: Procedures review
    03:43 AM...09...01...15...EVA-4: Mask pre-breathe/tool config
    04:38 AM...09...02...10...EVA-1: Airlock depress to 10.2 psi
    04:58 AM...09...02...30...ISS crew sleep begins
    05:28 AM...09...03...00...STS crew sleep begins
    06:00 AM...09...03...32...Daily video highlights reel on NASA TV
    10:30 AM...09...08...32...Flight director update on NASA TV
    01:28 PM...09...11...00...Crew wakeup
    


    4:00 PM, 3/18/08, Update: Astronauts work through busy day of robotics (UPDATED at 11:55 p.m. with Dextre, pallet moves; mission status briefing)

    The Endeavour astronauts carefully moved the Canadian Space Agency's 3,400-pound Dextre robot from its assembly pallet to a long-term mounting point on the space station's Destiny laboratory module today. The robot's construction pallet was then moved back to the shuttle's payload bay for return to Earth.

    "They have successfully reconfigured and stowed the robotic arms of Dextre and Dextre is now grappled to the lab, which is where it will remain for the next several weeks," said station Flight Director Kwatsi Alibaruho. "The significant robotics activities today, the stowing of Dextre and the relocation of the Spacelab pallet, are the major activities on the crew's timeline.

    The astronauts will enjoy a few hours of off-duty time early Wednesday and another break Wednesday afternoon before beginning preparations for a fourth spacewalk Thursday.

    "One of the things that we've had to really manage with these crews, this shuttle crew and this station crew particularly, is that they're so efficient and so motivated. ... We've been working them at a pretty good pac e and they've gotten very far ahead on the activities that were prescribed for this mission. ... They've gotten far enough ahead that we certainly won't have to twist their arms too much to get them to rest tomorrow."

    Getting the special purpose dexterous manipulator built and tested has taken up most of the crew's time through the first half of the 16-day mission. Prior to installation on the Destiny module today, the astronauts and flight controllers completed a series of tests to make sure the robot's multi-joint arms, grapple fixtures and television system were working as expected.

    The only issue today cropped up when commands were sent to rotate the robot's waist joint. The joint moved in the opposite direction from what flight controllers expected. Alibaruho said engineers suspect an incorrect sign in a configuration file may be to blame and they are optimistic a simple software patch will resolve the matter. Otherwise, the robot operated as expected.

    Dextre's components were carried into orbit mounted on a Spacelab pallet. The SLP was moved to an attachment point on the front of the station's solar power truss for the robot's assembly. After mounting Dextre on the Destiny module, the station arm, operated by shuttle pilot Gregory Johnson, locked onto the SLP and moved it back to the shuttle's cargo bay for return to Earth. The astronauts were assisted by camera views from the shuttle's robot arm.

    After the Spacelab pallet was locked in the shuttle's payload bay, the flight plan called for the station arm to move back to the front of the solar power truss and lock onto its mobile transporter for a short trip to a different worksite.

    During a spacewalk overnight Monday by Richard Linnehan and Robert Behnken, two space exposure experiment packages could not be attached to a mounting plate on the Columbus module because of interference issues with the pins needed to lock the first package in place. Mission managers today tentatively decided a second attempt will be made during the crew's fifth spacewalk Saturday.

    To make time for the unscheduled work, the astronauts likely will forego mounting a bearing assembly on the station's right side solar alpha rotary joint, or SARJ. The starboard SARJ has been experiencing problems and is not being used to turn outboard arrays to track the sun. One of the bearings in the right-side SARJ was removed during an earlier mission and returned to Earth for analysis. But installation of a replacement, originally planned for the fifth spacewalk, is not a pressing issue and can be done later with no major impact to station operations.

    "We took a look at that list of priorities and we determined there were a couple of tasks we could defer, one of which being the trundle bearing assembly installation," said station Flight Director Ginger Kerrick. "It's not required for the mission, it's not required for the time frame between this mission and the next and it provided an opportunity to re-arrange some activities on that day to allow a couple of hours for the installation of MISSE (the experiment packages)."

    Here is an updated timeline of today's activity (in EDT and mission elapsed time; includes revision G of the NASA television schedule):

    EDT........DD...HH...MM...EVENT
    
    02:28 PM...07...12...00...Crew wakeup
    04:28 PM...07...14...00...ISS daily planning conference
    04:43 PM...07...14...15...Dextre arm 1 stow
    05:13 PM...07...14...45...Cabin water line inspection
    05:43 PM...07...15...15...Dextre arm 2 stow
    06:13 PM...07...15...45...Module outfitting
    06:43 PM...07...16...15...Dextre roll
    06:43 PM...07...16...15...Retrieve jive boom
    06:53 PM...07...16...25...Dextre stow on lab module
    07:53 PM...07...17...25...Crew meals begin
    08:30 PM...07...18...02...Mission status briefing on NASA TV
    08:53 PM...07...18...25...Station arm (SSRMS) releases Dextre
    09:08 PM...07...18...40...SSRMS grapple Spacelab pallet (SLP)
    09:18 PM...07...18...50...Spacesuit swap and reconfig
    09:53 PM...07...19...25...SLP release from station attachment fitting
    10:08 PM...07...19...40...SLP berthing in shuttle payload bay
    11:38 PM...07...21...10...SLP ungrapple
    11:53 PM...07...21...25...SSRMS walkoff node 2 to mobile base system
    
    03/19/08
    12:28 AM...07...22...00...Crew off duty
    01:28 AM...07...23...00...SSRMS releases node 2
    01:48 AM...07...23...20...SSRMS translation to T-RAD support 2position
    04:58 AM...08...02...30...ISS crew sleep begins
    05:28 AM...08...03...00...STS crew sleep begins
    06:00 AM...08...03...32...Daily video highlights reel on NASA TV
    11:30 AM...08...09...02...Flight director update on NASA TV
    01:28 PM...08...11...00...Crew wakeup
    


    01:55 AM, 3/18/08, Update: Spacewalk ends; experiments not mounted because of fitting problems (UPDATED at 4:15 a.m. with mission status briefing)

    Astronauts Richard Linnehan and Robert Behnken wrapped up a six-hour 53 minute spacewalk early today, completing assembly of a 3,400-pound Canadian maintenance robot and moving critical spare parts from the shuttle Endeavour to the space station.

    "This really was the kind of spacewalk that, when it's all done, you just want to throw your hands up in the air and howl at the moon," said Zeb Scoville, lead spacewalk officer for Endeavour's mission. "It really was a great day for us. There were a few challenges we had along the way, but I consider this a real huge success for the EVA team, for the assembly of (the robot), getting all the (spares) transferred, is just a monumental feat by the robotics team and the EVA team together."

    The only problem of any significance cropped up late in the spacewalk when two suitcase-size experiment packages designed to expose a variety of materials and coatings to the space environment could not be installed on the station's hull as planned because of problems getting the first package firmly locked in place.

    "Endeavour, Houston, for EVA," astronaut Steve Robinson radioed from mission control. "OK, for MISSE (Materials International Space Station Experiment), we're going to plan right now to reverse course, do your U-turn and Bob, if you would take that right back where you found it."

    "OK," Behnken replied. A few moments later, inspecting the troublesome attachment fitting, he added, "I'm not sure what else I can do. You can see metal shavings..."

    "Yeah, I could see the metal shavings as I went by, floating," Linnehan said. "So, you know, better look at the quality control, I guess."

    "We tried those probes at KSC," Behnken remarked.

    "Yeah, I remember. In the shops, and they fit then. ... Anyway, nice work for staying out so long."

    This was the 107th spacewalk devoted to station assembly and maintenance since construction began in 1998 and the third of five planned for Endeavour's mission. The spacewalk ended on the 43rd anniversary of history's first spacewalk, a 12-minute excursion in 1965 by cosmonaut Alexei Leonov.

    Behnken and Michael Foreman plan two more spacewalks Thursday and Saturday to replace a circuit breaker in the station's solar power truss, to test a heat shield repair tool and to mount Endeavour's heat shield inspection boom on the station for use by the next shuttle crew. If time is available, they also will inspect a massive solar array rotary joint as part of an ongoing investigation to find out what is preventing it from freely turning.

    Linnehan and Behnken completed assembly of the Canadian Space Agency's special purpose dexterous manipulator, or Dextre, robot, a $209 million attachment for the space station's Canadian-built robot arm that will, in effect, give it a pair of hands and permit replacement of faulty components that might otherwise require a spacewalk.

    The spacealkers attached a camera system and a post to hold components being installed or removed. Dextre was assembled on the same Spacelab pallet that was used to carry its components into space inside Endeavour's cargo bay. Early today, the robot was pulled off the assembly pallet and maneuvered to an overnight park position. This evening, the robot will be moved to a mounting fixture on the hull of the Destiny laboratory module.

    "SPDM is in its final assembled configuration," lead station Flight Director Dana Weigel told reporters early today. "We ended up leaving two of the (thermal) blankets on it. We don't think that'll be problem (but) we will have to remove those on some future EVA."

    Along with completing Dextre's assembly, Linnehan also moved to direct current switching units, or DCSUs, to an external storage depot on the station, along with a spare robot arm yaw joint. While he was moving the spares, Behnken was attempting to install the first materials exposure package on a platform installed on the outboard end of the Columbus lab module. It's not yet clear whether Behnken and Foreman might make another attempt to install the experiment packages later in the mission.

    Other than that one snag, the spacewalk went smoothly. The astronauts fell a bit behind schedule early on with Dextre, but they were able to make up most of the lost time. Toward the end of the excursion, Behnken reported a tear in the outer covering of an overglove. The overgloves are now routinely used to protect spacesuit gloves from damage.

    "OK, MIke, glove inspection," Behnken called. "I do have, on my left hand, on the overglove, I do have a large piece of RTV that's starting to peel off. I don't see any damage underneath it to the Vectran. But there is a tear in the RTV, there's just a big flap, it's over an inch long. It was delaminated before when we came out, but now it's split all the way through. There's no visible damage on the fingers. And on my right hand, also RTV is coming off of the overglove, but the fingers look pretty good.

    Glove damage is a recurring problem for station assembly spacewalkers.


    10:23 PM, 3/17/08, Update: Astronauts complete Dextre assembly

    Spacewalkers Richard Linnehan and Robert Behnken have completed assembly of the Canadian Space Agency's Dextre maintenance robot. They fell behind schedule installing an equipment mounting platform on the robot, but they were able to make up lost time later by deferring work to remove a few thermal blanks.

    "I think I just maybe saw the Southern Cross... and definitely a satellite fly over," Linnehan said at one point. "Three satellites. Wow!" While Behnken was wrapping up work to attach a camera light pan and tilt assembly on Dextre, Linnehan, riding the space station's robot arm, was moved to the shuttle Endeavour's cargo bay to retrieve an experiment mounting platform that will be attached on the outboard end of the European Space Agency's Columbus research module. An experiment designed to expose a variety of materials and coatings to the space environment will be mounted on the bracket later in the spacewalk.

    Linnehan also plans to move a spare robot arm joint and two power switching units from Endeavour to an external storage platform near the space station's Quest airlock.


    6:55 PM, 3/17/08, Update: Spacewalk No. 3 begins

    Running about a half-hour ahead of schedule, astronauts Richard Linnehan and Robert Behnken switched their spacesuits to battery power at 6:51 p.m. to officially kick off a planned six-and-a-half-hour spacewalk, the third of five planned for the shuttle Endeavour's space station assembly mission.

    "Happy St. Patrick's Day, guys, and have a good EVA," astronaut Michael Foreman radioed from inside the shuttle. "How do you read?"

    "Mike, I read you loud and clear," Linnehan replied. "I forgot it was St. Paddy's day. Should have worn the green EMUs (spacesuits)."

    The goals of this evening's excursion are to finish assembly of a Canadian maintenance robot and to move spare parts and an experiment package from the shuttle to the station. If all goes well, the special purpose dexterous manipulator robot, also known as Dextre, will be removed from its asssembly pallet Tuesday and moved to a mounting point on the Destiny laboratory module.

    For identification, Linnehan, call sign EV-1, is wearing a suit with red stripes around the legs. Behnken, call sign EV-2, is wearing an unmarked suit.


    3:15 PM, 3/17/08, Update: Astronauts gear up for third spacewalk

    Astronauts Richard Linnehan and Robert Behnken are gearing up for a planned six-and-a-half-hour spacewalk this evening to complete assembly of a Canadian maintenance robot and to move spare parts and an experiment package from the shuttle Endeavour to the international space station.

    The spacewalk is scheduled to begin at 7:23 p.m. when the astronauts, floating in the station's Quest airlock module, switch their spacesuits to battery power. This will be the 107th EVA devoted to station assembly and maintenance since construction began in 1998, the eighth so far this year and the third of five planned for Endeavour's crew.

    The astronauts were awakened at 2:30 p.m. today to begin their seventh day in space by a recording of a tune by shuttle pilot Gregory Johnson's brother that was beamed up from mission control.

    "Good morning, Endeavour," astronaut Al Drew called from Houston. "And top of the morning to you, Box."

    "Good morning, that was my brother singing his original music, 'Sharing the World.' What a way to wake up. We're looking for a really exciting day, spacewalk number three."

    Linnehan and Behnken spent the night in the Quest airlock module at a reduced air pressure to help purge nitrogen from their bloodstreams in preparation for today's excursion. This will be Linnehan's third and final spacewalk for this mission while Behnken, making his first, will participate in two more EVAs Thursday and Saturday.

    With Linnehan once again on the end of the station's robot arm, the astronauts will wrap up assembly of the Canadian Space Agency's special purpose dexterous manipulator (SPDM) robot, known as Dextre, by removing thermal covers and installing the robot's tool carrier. Behnken also will install a camera pan and tilt unit and prepare the Spacelab pallet that carried Dextre's components into orbit for its eventual reberthing in the shuttle for the return to Earth.

    Dextre was launched disassembled. During the crew's first spacewalk last week, gripper-like hands were attached to each of the robot's 11-foot-long arms. The assembled arms then were attached to Dextre's torso during a spacewalk overnight Saturday.

    Each arm features seven joints and all 14 were checked out Sunday. One joint did not meet initial expectations, but station Flight Director Ginger Kerrick said today that all 14 joints had been given a clean bill of health.

    "I wouldn't categorize what we saw as a problem," she said. "We performed two separate subtests on the brakes. In the signatures we got back, a few of the joints did not meet the criteria that were specified in the procedure. We had the SPDM engineers on line, following along, they took a detailed look at the signatures we were seeing and they also went back and looked at how they came up with the criteria that was defined in the procedures. They determined that their criteria were a little bit overly conservative and after looking at the data again, they determined that all joints did pass. So there's no impact."

    With Dextre's assembly complete, Linnehan will move back to the shuttle's cargo bay, collect an experiment mounting platform and attach it to the outboard end of the European Columbus research module. He then will move a spare robot arm yaw joint and two spare electronic boxes, called direct current switching units, or DCSUs, from the shuttle to an external storage platform on the station.

    At that point, Linnehan will be done. As he is winding up his work, Behnken will retrieve a materials exposure experiment, known as MISSE-6, and attach it to the mounting fixture Linnehan earlier bolted to the Columbus module. After the astronauts return to the Quest airlock module, the station's robot arm will lock onto Dextre and remove it from the Spacelab pallet. If all goes well, the robot will be mounted on the Destiny laboratory module Tuesday.

    "At the end of today's spacewaklk, the crew members will ... move the SPDM to its overnight position," Kerrick said. "While it's in its overnight position, our robotics officers on the ground will be performing some additional checkouts to make sure the now free end of the SPDM is ready to support the relocation and grapple of the lab grapple fixture."

    Here is an updated timeline of today's activity (in EDT and mission elapsed time; includes revision F of the NASA television schedule):

    EDT........DD...HH...MM...EVENT
    
    03/17/08
    02:28 PM...06...12...00...Crew wakeup
    03:08 PM...06...12...40...EVA-3: 14.7 psi repress/hygiene break
    03:53 PM...06...13...25...EVA-3: Airlock depress to 10.2 psi
    04:18 PM...06...13...50...EVA-3: Campout EVA preps
    05:48 PM...06...15...20...EVA-3: Spacesuit purge
    05:58 PM...06...15...30...SSRMS setup
    06:03 PM...06...15...35...EVA-3: Spacesuit prebreathe
    06:53 PM...06...16...25...EVA-3: Crew lock depressurization
    07:23 PM...06...16...55...EVA-3: Spacesuits to battery power
    07:28 PM...06...17...00...EVA-3: Airlock egress
    07:48 PM...06...17...20...EVA-3: Setup
    07:58 PM...06...17...30...EVA-3 (Behnken): OTP/THA remove/install
    08:08 PM...06...17...40...EVA-3 (Linnehan): OTP/THA remove/install
    09:23 PM...06...18...55...EVA-3 (Behnken): Spacelab pallet cleanup
    09:23 PM...06...18...55...EVA-3 (Linnehan): Dextre arm 2 EP blanket removal
    09:53 PM...06...19...25...EVA-3 (Linnehan): MISSE-6 mounting transfer
    10:23 PM...06...19...55...Japanese module outfitting
    10:38 PM...06...20...10...EVA-3 (Behnken): CLPA install (2)
    10:53 PM...06...20...25...EVA-3 (Linnehan): Yaw joint transfer to ESP-2
    11:18 PM...06...20...50...EVA-3 (Behnken): MISSE experiment relocate/deploy
    11:38 PM...06...21...10...EVA-3 (Linnehan): DCSU 1 transfer to ESP-2
    
    03/18/08
    12:23 AM...06...21...55...EVA-3 (Linnehan): DCSU 2 transfer to ESP-2
    01:08 AM...06...22...40...EVA-3: Cleanup
    01:28 AM...06...23...00...Station arm (SSRMS) Dextre grapple maneuver
    01:28 AM...06...23...00...EVA-3: Airlock ingress
    01:53 AM...06...23...25...EVA-3: Airlock repressurization
    02:08 AM...06...23...40...SSRMS grapples Dextre
    02:28 AM...07...00...00...Spacesuit servicing
    03:23 AM...07...00...55...Dextre release from Spacelab pallet
    03:30 AM...07...01...02...Mission status briefing on NASA TV
    03:43 AM...07...01...15...Dextre overnight park
    05:58 AM...07...03...30...ISS crew sleep begins
    06:28 AM...07...04...00...STS crew sleep begins
    07:00 AM...07...04...32...Daily video highlights reel on NASA TV
    11:30 AM...07...09...02...Flight director update on NASA TV
    02:28 PM...07...12...00...Crew wakeup
    


    9:26 PM, 3/16/08, Update: Dextre checked out

    The Canadian Space Agency's $209 million space station robot, Dextre, was subjected to joint-by-joint brake tests today to make sure the gangly mechanical handyman's 11-foot-long arms are working properly. All but one of the joints passed the first round of tests and managers said the one that didn't was only slightly out of limits and not a major concern.

    "All the diagnostics ... were successfully accomplished," said Pierre Jean, acting space station program manager for the Canadian Space Agency. "In the last couple of hours, we went into the next phase of testing, or really more calibration if you will, which were the brake run-in checks. The brake run-in checks, basically, is a special test, or checkout, to ensure the brakes are operating nominally. You could think of it essentially as if you start your car and put your foot on the brake and you accelerate a little bit. You don't want the car to move. That's exactly what we tried to do.

    "In this case, we know what force to apply and we did exactly that with Dextre, going through each of the arms, arm 1 followed by arm 2, each joint, joint by joint, basically stepping up the voltage to about 20 volts until we got a .5-amp current and then seeing what motion, or displacement, we got on the joints.

    "Arm 1 passed, the highest slippage we had in any of the joints was 4.1 degrees," Jean said. "Arm 2, unfortunately with one of the joints, the wrist-pitch joint, we're right on the margin. The generic number we were trying to target was 10.3 degrees ... of slippage. However, we were getting 10.4."

    Repeating the test, engineers saw some improvement and Jean said he was confident the issue would be resolved.

    "Basically, both arms performed extremely well during the brake run-in tests with the exception of one joint," he said. "We're not too concerned about it, but we just want to make sure we meet the requirements we have to meet."


    3:55 PM, 3/16/08, Update: Dextre tests on tap

    The Endeavour astronauts, well ahead of schedule in their space station assembly mission, face a busy day of work stowing equipment needed for the next shuttle mission and testing a Canadian maintenance robot nearing completion after two spacewalks.

    The astronauts were awakened at 3:43 p.m. by a recording of Caedmon Call's "God of Wonders" radioed from mission control for shuttle commander Dominic Gorie.

    "Good morning Endeavour," astronaut Al Drew called from Houston. "Good morning to you, Dom. You guys worked so hard yesterday we gave you an extra 17 minutes of sleeping in. How 'bout that?"

    "Good morning, Al. That timing was perfect," Gorie replied. "Right before the music came on, the sun hit the space station, it was just beautiful. So very, very appropriate song, thank you for waking us up with that. The glory is apparent this morning."

    Astronauts Richard Linnehan and Michael Foreman attached two 775-pound, 11-foot-long arms to the special purpose dexterous manipulator robot, known informally as Dextre, during a spacewalk overnight Saturday and flight controllers spent the morning making sure the robot's circuitry was healthy.

    "The ground checkouts of Dextre went great," said Flight Director Ginger Kerrick. "During the EVA, we made the physical and electrical connections for the arms and so (this morning), we sent some diagnostic commands just to test out, make sure all the connectors were configured in the fashion we expected them to be. And all those tests were great, so we are ready and set up for the crew's part of the checkout today."

    Working from a robotics work station in the Destiny laboratory module, Robert Behnken and Garrett Reisman will send commands to move Dextre's joints slightly to make sure internal brakes are working properly.

    "The crew will be sending some commands to test out each of the individual joints, specifically the brakes on the joints," Kerrick said. "We don't want to command any significant motions with any of the joints until we make sure that those brakes work first. Everything is looking great so far."

    Kerrick said the crew is well ahead of the mission timeline and that the shuttle astronauts will work today to help the station crew stow some of the equipment that was ferried up inside a new Japanese logistics module. That equipment will be needed for the next shuttle mission in late May when Japan's huge Kibo laboratory module is attached to the fast-growing station.

    "They finished all their rack reconfigurations yesterday," Kerrick said. "So we moved a whole bunch of activities up into today's timeline. There are things like configuring hatches to the on-orbit configuration, and we also were able to move up some additional stowage-related activities. We brought up a significant amount of hardware in the JLP (Japanese logistics module) and all that hardware is needed for execution of the 1J, or STS-124, mission (in May).

    "So what we're having the crew do is gather all the hardware into specific kits that are tied to specific activities and that way, that'll help the activities go a little bit more efficiently, the crew can grab this kit and go off and run that activity on the next shuttle mission. Normally during a shuttle mission, we transfer a lot of cargo and we don't have time to put it away. But because the crew is getting so far ahead, we have scheduled some time for them to stow all the hardware. ... We are getting significantly ahead and the crew is doing a great job."

    The astronauts also will participate in news media interviews this evening, starting at 10:18 p.m., and review procedures for a third spacewalk that will begin Monday evening. Linnehan and Behnken will spend the night in the station's Quest airlock module to help purge nitrogen from their bloodstreams in preparation for the spacewalk.

    Here is an updated timeline of today's activity (in EDT and mission elapsed time; includes revision F of the NASA television schedule):

    EDT........DD...HH...MM...EVENT
    
    03:28 PM...05...13...00...Crew wakeup
    05:18 PM...05...14...50...ISS daily planning conference
    05:43 PM...05...15...15...Brake run in arm 1
    06:43 PM...05...16...15...Brake run in arm 2
    07:33 PM...05...17...05...Japanese module (JLP) outfitting
    08:00 PM...05...17...32...Mission status briefing on NASA TV
    08:48 PM...05...18...20...Spacesuit swap
    09:18 PM...05...18...50...Joint crew meal
    10:18 PM...05...19...50...Crew interviews
    10:38 PM...05...20...10...JLP stow prep
    10:58 PM...05...20...30...EVA-3: Tool config
    11:48 PM...05...21...20...EVA-3: Dextre arm stow
    
    03/17/08
    12:33 AM...05...22...05...Airlock preps
    02:58 AM...06...00...30...EVA-3: Procedures review
    04:43 AM...06...02...15...EVA-3: Mask pre-breathe/tool config
    05:38 AM...06...03...10...EVA-3: Airlock depress to 10.2 psi
    05:58 AM...06...03...30...ISS crew sleep begins
    06:28 AM...06...04...00...STS crew sleep begins
    07:00 AM...06...04...32...Daily video highlights reel on NASA TV
    11:35 AM...06...09...07...French ambassador visits mission control (on NASA TV)
    12:00 PM...06...09...32...Flight director update on NASA TV
    02:28 PM...06...12...00...Crew wakeup
    


    03:00 AM, 3/16/08, Update: Spacewalk No. 2 ends

    Astronauts Richard Linnehan and Michael Foreman began repressurizing the Quest airlock module at 2:57 a.m., ending at seven-hour eight-minute spacewalk to attach a pair of 775-pound, 11-foot-long arms to a Canadian maintenance robot known as Dextre.

    Because of problems releasing a few tight bolts, the astronauts fell behind schedule early in the excursion and did not have time to remove thermal blankets protecting Dextre's joints. That work will be carried out during a spacewalk next week.

    This was the 106th spacewalk devoted to station assembly and maintenance since construction began in 1998, the seventh so far this year and the second of five planned by the shuttle Endeavour's crew. Fifty-four NASA astronauts, 15 Russians, three Canadians, two Germans, a Japanese astronaut, a Frenchman and a Swedish astronaut have now logged 667 hours 52 minutes of station spacewalk assembly time.

    Linnehan, veteran of a Hubble Space Telescope servicing mission in 2002, has now logged five spacewalks - two on this mission - totaling 35 hours and 30 minutes, putting him 22nd on the list of most experienced spacewalkers. This was the first of three spacewalks for Foreman.


    12:50 AM, 3/16/08, Update: First arm mounted on Dextre

    After falling behind schedule, astronauts Richard Linnehan and Michael Foreman have successfully attached the first of two 11-foot-long, seven-joint arms to the Dextre maintenance robot being assembled at the internaional space station.

    Linnehan, anchored to the end of the space station's 50-foot-long robot arm, praised operator Gregory Johnson for his precision maneuvers.

    "That was pretty impressive," Linnehan said.

    "Thanks, Rick. You're awesome."

    "You're Mr. Roboto," Linnehan replied. "It's really eerie out here. It's pitch black and there's just this big, white kind of humanoid-looking thing below me. Arms and legs, and..."

    "Are you talking about Mike (Foreman)?" Johnson joked.

    "Yeah. Exactly. Him too. Except he's not as handsome."

    A few moments later, after Foreman checked the fasteners holding the first arm in place, Johnson quipped: "Good work, guys, we've got a one-armed monster now."


    10:55 PM, 3/15/08, Update: Tight bolts slow spacewalkers

    Forced to resort to brute force and a pry bar, spacewalkers Richard Linnehan and Michael Foreman fell nearly an hour behind schedule tonight forcing two tight expansion bolts out of their receptacles. With grunts and heavy breathing, Linnehan finally forced the bolts out, releasing the first of two 775-pound mechanical arms that will be attached to a Canadian maintenance robot later in the spacewalk.

    "We're really having to get medieval on Mr. Dextre," Foreman said at one point, using the informal name for the special purpose dexterous manipulator, or SPDM.

    "I didn't expect we were going to get this workout today, did you Mike?" Linnehan asked after getting the second bolt out.

    "I thought it would be a workout, but not this kind," Foreman agreed.

    "We really ARE longshoremen," LInnehan observed, an analogy he used before launch to describe the physical nature of the spacewalks.

    "Great work, guys. Hopefully, that didn't wear anybody out too much," astronaut Robert Behnken radioed.

    "Oh, not at all."

    Tonight's excursion was expected to last seven full hours and given the delay coaxing the bolts out, flight planners are considering changes to help the spacewalkers make up lost time.

    Because of clearance issues, both of Dextre's arms must be removed from their mounting brackets on the robot's assembly pallet and temporarily stowed on different fittings while the robot's torso is pivoted out 60 degrees. Linnehan, anchored to the space station's robot arm, rotated the first Dextre arm like a baton, turning it a full 180 degrees, and then held it steady while the station's main arm carried him to the temporary stow location."

    "Whoa, this piece is massive," Linnehan said, but he quickly reassured flight controllers that he had control over the appendage. "It's not going anywhere..."

    "Yeah," Foreman said.

    "It's just..."

    "Got a lot of mass," Foreman finished.

    "It's got a lot of mass. As a matter of fact, when you've got your hand on it, you're probably going to use more force than you think initially. But don't put a high rate in, just go real slow with it..."

    "I will."

    "...because it's not going to stop for you once you get it going."

    After the first arm was safely "temp stowed," the astronauts were running about 45 minutes behind schedule.


    7:55 PM, 3/15/08, Update: Spacewalk No. 2 begins

    Running 34 minutes ahead of schedule, astronauts Richard Linnehan and Michael Foreman switched their spacesuits to battery power at 7:49 p.m., kicking off a planned seven-hour spacewalk to attach two 11-foot-long arms to a Canadian maintenance robot being assembled at the international space station.

    This is the 106th spacewalk devoted to station assembly and maintenance since construction began in 1998, the seventh so far this year and the second of five planned by the shuttle Endeavour's crew,. Linnehan, veteran of a 2002 Hubble Space Telescope repair mission, is making his fifth spacewalk while Foreman is making his first.

    In the daily "execute package" of instructions uplinked to the shuttle-station complex, flight controllers jokingly paraphrased science fiction writer Isaac Asimov's three laws of robotics to fit the special purpose dexterous manipulator robot, known as Dextre for short.

    "Optimus Prime, Gigantor and Robbie the Robot are here in MCC (mission control center) today, representing the Robot Actors Guild, to celebrate the launch of Dextre," the note said. "There was an embarrassing gaffe last month, during (shuttle flight) STS-122 when they came out to honor the wrong "Dex." (shuttle pilot Alan Poindexter) "We've incorporated a few new flight rules, now that we are about to have robotic EV's:

    1. Dextre may not injure a human being or, through inaction, allow a human being to come to harm.
    2. Dextre must obey orders given to it by human beings, except where such orders would conflict with the First Law.
    3. Dextre must protect its own existence as long as such protection does not conflict with the First or Second Law.
    "The guild members bristled about these rules and, 'being held down by the man,' but figure that they can't be held back for long. 'First Dextre, next Data, then THE MATRIX!' declared Optimus at arrival at JSC."

    It will take the astronauts a half hour or so to set up tethers and tools and to make their way to the forward face of the station's solar power truss where they will spend the next several hours attaching Dextre's arms.


    04:20 PM, 3/15/08, Update: Astronauts gear up for second spacewalk

    Richard Linnehan and Michael Foreman are suiting up for a planned seven-hour spacewalk this evening to attach two 11-foot-long arms with gripper-like hands to the torso of a 12-foot-tall Canadian maintenance robot being assembled on the international space station.

    "The assembly of these arms and the configuration of those arms for nominal operations takes a highly choreographed series of events," said space station Flight Director Ginger Kerrick. "So it will actually take the full seven hours duration just to assemble the arms."

    The astronauts were awakened at 3:30 p.m. today by a recording of "We're Going to be Friends" by The White Stripes beamed up from mission control.

    "Good morning, Endeavour, and a particular good morning to you, Dr. Bob," astronaut Al Drew radioed from Houston.

    "Thanks for that, Al," Robert Behnken replied. "Good morning to you as well, and thanks for that great wakeup music, that's one of my favorite songs. It always reminds me of all the great friends that I've met going to different schools, or through different training, just like the shuttle crew I'm with right now. Thanks again, Al, and a great good morning to you."

    "You bet. Have a find day out there."

    After exiting the Quest airlock, Linnehan and Foreman will make their way back to the front side of the station's solar power truss where Dextre's components are mounted on a U-shaped Spacelab pallet. Each 11-foot-long arm features seven joints and thermal covers protecting those joints must be removed, along with the clamps holding the arms and joints in place. Each arm will be temporarily stowed on a pallet fitting during work to ready them for attachment to the torso.

    At this point, Linnehan will get back on the station arm while Foreman assists as a free floater.

    "On the second EVA, Mike and I will take the constructed arms that Garrett (Reisman) and I built from the previous EVA, which are still positioned on the sides of the SLP, but constructed so that the wrists and the hands, so to speak, are on the arms," Linnehan said. "At that point, Mike and I will take each of those arms off the sides of the pallet and we'll have to rotate the main body of the (robot) up and then plug those arms in on these giant outriggers.

    "That's when it takes on its big mantis kind of robot look. Once those arms are on, we have several other things that we have to do, such as install cameras, go down and put these special tool platforms and adaptors that allow it to hold equipment from the space station on the lower part of it and actually plug in and interface its own tools, take them out and work on things. All that takes a little bit more time at the end of the EVA and some of it involves me on the end of the arm, the robot arm, flying around doing it and at other times both of us will be free floating, moving around all over the pallet and building stuff that way.

    "And we hope to finish all of that in two EVAs and, as I said, if for some reason we're slow or something doesn't go the way we like, then on the third EVA Bob Behnken and I would be able to finish most of that."

    The torso of the robot will be pivoted up about 60 degrees for the attachment of the arms and hands. Once the appendages are in place, engineers on the ground will begin tests and checkout operations. If all goes well, the assembled robot will be parked on a power and data grapple fixture on the hull of the Destiny laboratory module Tuesday.

    "I personally am going to be sighing a big sigh of relief at the end of EVA-2 when we get ... both the arms installed," said Zeb Scoville, lead spacewalk officer. "There's a lot of really complex EVA activities going on there and coordination with some very fine robotics maneuvers required to get those installed. There have definitely been some challenges in ground training."

    Here is an updated timeline of today's activity (in EDT and mission elapsed time; includes revision D of the NASA television schedule):

    EDT........DD...HH...MM...EVENT
    
    03:28 PM...04...13...00...Crew wakeup
    04:08 PM...04...13...40...EVA-2: 14.7 psi repress/hygiene break
    04:53 PM...04...14...25...EVA-2: Airlock depress to 10.2 psi
    05:18 PM...04...14...50...EVA-2: Campout EVA preps
    06:23 PM...04...15...55...Japanese module (JLP) outfitting
    06:48 PM...04...16...20...EVA-2: Spacesuit purge
    07:03 PM...04...16...35...EVA-2: Spacesuit prebreathe
    07:08 PM...04...16...40...Station arm (SSRMS) ungrapples Dextre (SPDM)
    07:53 PM...04...17...25...EVA-2: Crew lock depressurization
    08:23 PM...04...17...55...EVA-2: Spacesuits to battery power
    08:28 PM...04...18...00...EVA-2: Airlock egress
    08:48 PM...04...18...20...EVA-2: Setup
    09:08 PM...04...18...40...EVA-2: SPDM arm 2 stow
    10:38 PM...04...20...10...EVA-2: SPDM arm 1 stow
    11:38 PM...04...21...10...EVA-2: SPDM arm install
    
    03/16/08
    01:28 AM...04...23...00...EVA-2 (EV2): Cover removal; SLP cleanup
    01:28 AM...04...23...00...EVA-2 (EV1): SPDM cover removal
    02:38 AM...05...00...10...EVA-2: Cleanup
    02:58 AM...05...00...30...SSRMS grapples SPDM
    03:08 AM...05...00...40...EVA-2: Airlock ingress
    03:28 AM...05...01...00...EVA-2: Airlock repressurization
    03:43 AM...05...01...15...Spacesuit servicing
    05:30 AM...05...03...02...Mission status briefing on NASA TV
    06:58 AM...05...04...30...ISS crew sleep begins
    07:28 AM...05...05...00...STS crew sleep begins
    08:00 AM...05...05...32...Daily video highlights reel on NASA TV
    08:43 AM...05...06...15...SPDM power up and testing
    12:30 PM...05...10...02...Flight director update on NASA TV
    03:28 PM...05...13...00...Crew wakeup
    


    10:30 PM, 3/14/08, Update: Robot arm routes power to Dextre (UPDATED at 1 a.m.. with mission status briefing)

    Performing electronic bypass surgery, the Endeavour astronauts late Friday successfully routed power to a Canadian maintenance robot being assembled at the international space station. Using the station's mechanical arm to feed electricity directly to a power-and-data plug on one end of the unfinished robot's torso, the crew was able to bypass suspect circuitry in the pallet used to carry the robot's components into orbit. The power-up operation was confirmed by telemetry at 10:10 p.m. A few minutes later, engineers confirmed critical heaters were working as required.

    "Well, I guess I have to say it: It's alive!" joked Pierre Jean, acting space station program manager for the Canadian Space Agency. "I'm happy to report Dextre's in keep-alive mode. There was no issue with commanding it through Canadarm2 as was anticipated. The system's functioning well. ... As a result, we have both good power and data connections between Dextre and Canadarm2. The situation looks really good."

    Phil Engelauf, a senior mission operations manager at the Johnson Space Center in Houston, said the successful operation relieved "some real concern over the last day or two over getting that powered up."

    "It was quite a relief and a real sense of success for the joint team to see power applied," he said. "Now we'll be able to complete the rest of the planned mission with only some minimal changes."

    The special purpose dexterous manipulator, or Dextre, was launched to the space station unassembled, its arms, hands and torso bolted to a Spacelab pallet. During a spacewalk overnight Thursday, two astronauts attached gripper-like hands to the robot's arms. The primary goal of a second spacewalk overnight Saturday is to attach the 11-foot-long arms to the torso and prepare the robot for tests and checkout.

    Designed as an attachment for the station's Canadian-built robot arm, Dextre is capable of replacing space station components when repairs are required that might otherwise require a spacewalk.

    But engineers ran into trouble earlier in the week when they were unable to route keep-alive power to critical heaters. They initially believed the problem was a software timing issue and programmers quickly wrote a patch to change the parameters.

    Studying the issue in more detail Thursday, engineers concluded the problem actually was with the 1553 data bus built into Dextre's Spacelab construction pallet. The problem is similar to what happens when a personal computer hard drive is not properly "terminated." The drive might be fully functional, but data will not flow properly. In this case, the 1553 bus should have included circuit termination but for reasons not yet understood, it does not. By connecting the station arm directly to a different grapple fixture on the robot's torso, the astronauts were able to bypass the bus and supply power directly.

    The station arm does not have to stay attached around the clock. Periodic power ups will suffice to keep Dextre's joints warm until the robot is fully assembled and mounted directly to a power and data grapple fixture on the Destiny lab module.


    9:50 PM, 3/14/08, Update: Doi, crewmates enter Japanese module

    Japanese astronaut Takao Doi and space station commander Peggy Whitson officially opened Japan's new logistics module this evening, dedicating the latest addition to the international lab complex and setting the stage for launch of Japan's huge Kibo experiment module in late May.

    "This is a small step for one Japanese astronaut," Doi said, floating in front of the logistics module's open hatch. "But a giant entrance for Japan to a greater and newer space program."

    Said Whitson: "We aboard the ISS would like to officially welcome the Japanese elements on board the international space station. We love our new room already, it looks great and we're very happy to have our new partners working with us, much more actively now with a new module on board. We look forward to all our future work together."

    "From Houston, it looks great," astronaut Steve Robinson radioed. "Congratulations."

    "And from Tsukuba (Space Center near Tokyo), thanks Takao and Peggy," a Japanese flight controller radioed. "You are about 'Kibo,' hope. Thank you very much."

    The crew initially planned to open the new module early Saturday, but they completed preparations ahead of schedule and moved the long-awaited event up several hours.

    While Doi and Whitson were opening up the logistics module, Robert Behnken and European Space Agency astronaut Leopold Eyharts, using a robotics work station in the U.S. Destiny lab module, were moving the station's robot arm into position to lock onto a maintenance robot under construction on a pallet mounted on the station's solar power truss.

    Engineers have been unable to route keep-alive power to the robot's components, presumably because of a wiring problem in its support pallet. By locking the station's arm onto a power-and-data-grapple fixture on the robot's torso, engineers hope to route power directly to the system and bypass the suspect circuitry.

    The logistics module is the first of two Japanese additions to the space station that will complement U.S. and European laboratory modules. In late May, the shuttle Discovery will ferry the Greyhound bus-size Kibo lab module to the station, attaching it to the Harmony module's left port.

    The logistics module, loaded with equipment racks that later will be moved into the larger lab module, was temporarily mounted on Harmony's upper port early Thursday. After the lab module arrives in late May, the logistics segment will be moved to an outboard port on the larger Japanese module.


    06:15 PM, 3/14/08, Update: Engineers fine-tune out Dextre power-up plan; shuttle heat shield cleared for entry

    Taking a break between spacewalks, the shuttle/station astronauts plan to open up the newly installed Japanese logistics module early Saturday for activation and checkout. They also plan to use the station's robot arm this evening to lock onto a $209 million Canadian maintenance robot under construction on the station to provide keep-alive power, bypassing suspect circuitry on its assembly pallet that was not set up properly before launch.

    NASA's Mission Management Team, meanwhile, wrapped up its post-launch assessment of Endeavour's heat shield, or thermal protection system, and formally cleared the ship for a normal end-of-mission re-entry.

    "Essentially, they were able to clear all the areas of interest on the TPS," said MMT Chairman LeRoy Cain. "So today in the mission management team, we went ahead and cleared the TPS for deorbit and entry. So the vehicle is safe to come home whenever we get ready to do so. ... Overall, the orbiter's performing very, very well. We don't have any new problems we're working."

    Engineers are, however, keeping close tabs on a slow pressure decay in the fuel system of auxillary power unit No. 1, one of three machines that provide hydraulic power for the shuttle during launch and re-entry. The pressure loss noted in APU 1 could be the result of a harmless nitrogen pressurization system leak or a more troublesome hydrazine fuel leak. Either way, the problem is not expected to have any impact on Endeavour's mission.

    The astronauts were awakened to begin their fifth flight day at 4:35 p.m. by a recording of "Turn, Turn, Turn" radioed up from mission control.

    "And good morning, particularly to you, Rick," called astronaut Al Drew from the Johnson Space Center called for Endeavour spacewalker Richard Linnehan.

    "Houston, Endeavour, this is Dom," commander Dominic Gorie replied. "Good morning. Rick heard that, he's getting to sleep over in the Columbus (module) this morning, enjoying that after a spacewalk. Looking forward to a great day, the pace is going to drop back a little bit for us this morning after that first EVA. We're looking forward to getting in the JLP with (Japanese astronaut) Takao (Doi)."

    The Japanese module, the first of two making up the station's largest research section, was moved from Endeavour's cargo bay to an upward-facing port on the forward Harmony module early today. After the much larger Kibo experiment module is launched and attached to Harmony's left side port in late May, the logistics module will be moved to a port on the outboard end of the Japanese lab module.

    "The reason why we are going to do this is that (larger lab module) is too heavy to carry all the system racks inside," Doi said in a NASA interview. "So first, we carry half of the system racks inside this logistics module. When the (larger module) arrives, we transfer this half of the system racks so that we can activate the systems in the (experiment) module safely."

    But for the next two months or so, the logistics module will be mounted atop Harmony, also known as Node 2, and the astronauts plan to float inside early Saturday to begin initial activation and checkout.

    "As soon as the crew wakes up, they're going to start configuring the vestibule area (between the logistics module and Harmony)," said flight director Ginger Kerrick. "Some of the things they need to do are to remove all the hardware that is just there to help establish the connection for mating the JLP to Node 2. So they'll take all of that hardware out of the way. And then they'll also make some connections to establish airflow between JLP and Node 2 as well as provide some temporary data and power connections. The JLP is not intended to stay on the node 2 overhead port, it's just a temporary setup."

    This evening, astronaut Robert Behnken, operating the space station's robot arm from a work station inside the Destiny laboratory module, plans to pull the shuttle's heat shield inspection boom from its perch on the right side of the ship's payload bay and hand it off to the shuttle's arm, operated by commander Dom Gorie and pilot Gregory Johnson. The boom will be used later in the mission to carry out a final inspection before being stowed on the front of the lab's solar power truss during a fifth and final spacewalk. The boom is being left on the station for the next shuttle crew, which cannot carry their own boom because of clearance issues with the large Kibo module.

    After handing off the orbiter boom sensor system to the shuttle arm tonight, Behnken plans to lock the station arm onto the Canadian Space Agency's special purpose dexterous manipulator, or SPDM, a $209 million maintenance robot known as Dextre, around 9:53 p.m. The goal is to bypass the assembly pallet's suspect 1553 data bus and provide keep-alive power to critical heaters.

    Engineers ran into trouble earlier in the week when they were unable to route keep-alive power to the robot's components. They initially believed the problem was a software timing issue and programmers quickly wrote a patch to change the parameters.

    Studying the issue in more detail Thursday, engineers concluded the problem actually was with the 1553 bus built into Dextre's Spacelab construction pallet. The problem is similar to what happens when a personal computer hard drive is not properly "terminated." The drive might be fully functional, but data will not flow properly. In this case, the 1553 bus should have included circuit termination but for reasons not yet understood, it does not. By connecting the station arm directly to a different grapple fixture on the robot's torso, engineers can bypass the bus and supply power directly.

    "The software patch did not work but to be perfectly honest, we were not surprised by that," Kerrick said earlier today. "Teams continued to look at the data and their latest theory is that it's not a problem with the SPDM at all, it's a problem with the pallet on which it sits, specifically a cabling issue that doesn't allow data to flow appropriately. We fully expect if we apply power from the (station arm) that we will be able to power up SPDM and have connectivity with it. That is what we are planning to do later this evening.

    "First, the station arm has to hand off the OBSS to the shuttle arm and as soon as that is complete and the station arm is free, the crew will maneuver the station arm over to the SPDM and grapple it. When grapple is complete, the ground team will retry a power up of the SPDM and we fully expect that to work."

    The station arm does not have to stay attached around the clock. Periodic power ups will suffice until Dextre is fully assembled and mounted directly to a power and data grapple fixture on the Destiny lab module.

    "So we will test it out, we will leave it there in an overnight config and then on (Saturday), we will release it and free up the arm to support (spacewalk) activities," Kerrick said. "At the end of EVA-2, we'll re-grapple it for thermal reasons so we can keep some of the components within their temperature limits overnight. EVA-3, we may have some deltas to, but the teams are just starting to look at that."

    Here is an updated timeline of today's activity (in EDT and mission elapsed time; includes revision C of the NASA television schedule):

    EDT........DD...HH...MM...EVENT
    
    03/14/08
    05:00 PM...03...14...32...Post-MMT briefing on NASA TV
    06:08 PM...03...15...40...ISS daily planning conference
    06:53 PM...03...16...25...Japanese logistics module (JLP) vestibule outfitting
    07:03 PM...03...16...35...Station arm (SSRMS) grapples OBSS (Behnken)
    07:33 PM...03...17...05...SSMRS unberths OBSS
    07:48 PM...03...17...20...SSMRS hands OBSS off to shuttle arm (SRMS)
    08:33 PM...03...18...05...SRMS grapples OBSS (Gorie/Johnson)
    08:48 PM...03...18...20...JLP vestibule outfitting (part 2)
    08:53 PM...03...18...25...SSRMS releases OBSS
    09:38 PM...03...19...10...Logistics transfers
    09:53 PM...03...19...25...SSRMS grapples Dextre robot; provides power/data
    10:00 PM...03...19...32...Mission status briefing on NASA TV
    10:53 PM...03...20...25...Crew meals begin
    11:53 PM...03...21...25...EVA-2: Tool config
    
    03/15/08
    12:18 AM...03...21...50...JLP ingress
    12:38 AM...03...22...10...Spacesuit swap
    01:08 AM...03...22...40...JLP inspection
    01:23 AM...03...22...55...Negative pressure relief valve checkout
    01:28 AM...03...23...00...PAO event
    01:53 AM...03...23...25...Airlock preps
    03:58 AM...04...01...30...EVA-2: Procedures review
    05:43 AM...04...03...15...EVA-2: Mask pre-breathe and tool config
    06:38 AM...04...04...10...EVA-2: Airlock depress to 10.2 psi
    06:58 AM...04...04...30...ISS crew sleep begins
    07:28 AM...04...05...00...STS crew sleep begins
    08:00 AM...04...05...32...Daily video highlights reel on NASA TV
    01:00 PM...04...10...32...Flight director update on NASA TV
    03:28 PM...04...13...00...Crew wakeup
    


    07:45 AM, 3/14/08, Update: Canadian engineers focus on suspect cable as culprit in robot power problem

    After extensive troubleshooting, Canadian robotics experts now believe a suspect data cable - not a software timing issue - is preventing computer commands from powering up a $209 million maintenance robot under construction aboard the international space station. Covering the bases, they uplinked a software patch early today to adjust the timing of the computer commands as originally planned, but, as most expected, the patch didn't work.

    The special purpose dexterous manipulator, or SPDM - also known as Dextre - was launched disassembled, its arms, hands and torso mounted on a Spacelab pallet in the shuttle Endeavour's cargo bay. After the shuttle's docking with the space station Wednesday night, the pallet was pulled from Endeavour's cargo bay and mounted on the mobile base normally used to move the station's robot arm from one work site to another.

    All of that went well. But fight controllers were unable to route electricity to the robot's components to power so-called keep-alive heaters. Engineers initially thought a software timing issue was to blame, believing power-up commands were timing out before the robot's electronics could fully respond. Similar problems have occurred in the past with the station's robot arm and transporter, which feature similar electronic components.

    "We've had some experience in the past with timing issues and we thought, well, we can fix that with software," said Pierre Jean, acting space station program manager for the Canadian Space Agency. "We kicked that off right away, that was something we're very comfortable with.

    "As we looked through it and we really delved into the design, it became apparent to our engineers across the team that the actual design of the cable was wrong. It passes the power, but the way it handles the data, it doesn't guarantee that data will be passed properly and returned. So it basically boils down to a design issue in the cable that was not discovered prior to this moment.

    "I guess it's somewhat related to the fact that the hardware that Dextre is trying to mate to is the MBS (mobile base system), which was launched in 2002, so we don't have existing hardware on the ground. Some of the testing that was done was done in the simulation environment. There was lots of testing done, but it wasn't until the last day, really, that we looked at the design and we realized there was an issue there. That's why we're fairly confident, we have strong confidence, this is going to be resolved and shown to be the way it is, to be the smoking gun, if you will."

    The cable in question runs between Dextre's latching end effector and the power and data attachment fitting holding the Spacelab pallet in place on the mobile base system. Engineers now plan to lock the station's arm onto Dextre late today, bypassing the pallet cable and supplying power and data directly to the robot's electrical systems.

    "At this point in time, we're pretty confident that by 10 o'clock (Central Time) tonight we should have the answer to this particular question," Jean said.

    During an overnight spacewalk, the first of five planned for Endeavour's mission, astronauts Richard Linnehan and Garrett Reisman attached gripper-like hands to Dextre's 11-foot-long arms. The arms, in turn, will be attached to the robot's torso during a second spacewalk overnight Saturday.

    Jean said Dextre can survive the extreme temperatures of space without keep-alive power for 100 to 125 hours, much longer than engineers believe they will need to resolve the problem.


    4:35 AM, 3/14/08, Update: Spacewalk ends

    Astronauts Richard Linnehan and Garrett Reisman completed a seven-hour one-minute spacewalk early today, successfully preparing a Japanese module for attachment to the space station and beginning assembly of a Canadian maintenance robot. The spacewalk began at 9:18 p.m. Thursday and ended at 4:19 a.m. today.

    "Boy, I can't wait to take a shower," one of the spacewalkers said from inside the Quest airlock.

    "You're going to be waiting a long time," his companion laughed.

    This was the 105th spacewalk devoted to station assembly and maintenance since construction began in 1998 and the first of five planned by Endeavour's crew.


    2:36 AM, 3/14/08, Update: Japanese module pulled from cargo bay; Dextre robot hands attached

    Operating the shuttle Endeavour's 50-foot-long robot arm, Japanese astronaut Takao Doi and shuttle commander Dominic Gorie pulled a Japanse supply module out of the shuttle's cargo bay early today for attachment to the international space station.

    Astronauts Richard Linnehan and Garrett Reisman, meanwhile, wrapped up a spacewalk to attach gripper-like hands to the arms of maintenance robot being built as an attachment for the station's Canadian-built mechanical arm. Engineers ran into problems routing power to the robot Thursday, but troubleshooters are confident they can resolve the problem before a second spacewalk overnight Saturday to complete the assembly of the special purpose dexterous manipulator, or Dextre for short.

    Late Thursday, Reisman and LInnehan prepared the Japanese module for extraction from the shuttle's cargo bay, clearing the way for Doi and Gorie to begin a complex series of arm motions to move the drum-shaped storage facility to a temporary home atop the forward Harmony connecting module. Spectacular television views showed the module suspended agaionst the blue-and-white backdrop of Earth as the shuttle's arm slowly moved it toward Harmony.

    "Look at the JLP, it's coming out!" one of the spacewalkers exclaimed.

    "Wow!"

    A few minutes earlier, both men marveled at the view of America at night as the shuttle-station complex sailed 215 miles above the nation's heartland.

    "Wow, wow, wow! What are we going over now? A pretty amzing view at nighttime of a huge city."

    "Maybe Chicago?"

    "It looks coastal, but it could be Chicago. It could be the lake. Oh, that's beautiful!"

    "Wow."

    Moving through space at five miles per second, it only took a few moments to move over New England.

    "Don't look now, but over your left shoulder is New York," one of the spacewalkers said. "You can make out Long Island Sound, you can see the whole thing at night. Amazing!"


    12:26 AM, 3/14/08, Update: Japanese module prepped for move to station; spacewalkers begin Dextre assembly work

    Spacewalkers Richard Linnehan and Garrett Reisman have completed preparations for moving a Japanese logistics module from the shuttle Endeavour's cargo bay to the international space station's Harmony connecting module. Japanese astronaut Takao Doi, operating Endeavour's 50-foot-long robot arm, plans to pull the new module out of the cargo bay around 2 a.m.

    The module will be temporarily mounted atop Harmony while the station crew awaits delivery of Japan's Kibo research lab in late May. The much larger experiment module will be mounted to Harmony's left port and the logistics module launched aboard Endeavour will be moved from Harmony's upper port to a hatch on the far end of the Japanese lab.

    Reisman and Garrett prepared the logistics module for its trip to Harmony by removing thermal covers and unplugging power cables to internal heaters. The remainder of the spacewalk, the first of five planned for Endeavour's mission, will be devoted to initial assembly of the Canadian Space Agency's special purpose dexterous manipulator, or SPDM, robot.

    Engineers have not yet been able to route power to the disassembled robot's components, but they are optimistic about resolving the glitch. A software patch has been written to eliminate a potential timing problem between a power distribution unit and a work station computer in the Destiny laboratory module.

    Linnehan and Reisman plan to attach hand-like grippers to each of Dextre's two arms during today's spacewalk. The arms will be attached to the robot's torso during a second spacewalk overnight Saturday. Engineers hope to have the power problem fixed by then.


    9:25 PM, 3/13/08, Update: Spacewalk No. 1 begins

    Floating in the Quest airlock module, astronauts Richard Linnehan and Garrett Reisman switched their spacesuits to battery power at 9:18 p.m. to officially begin a planned six-and-a-half-hour spacewalk. The goals of the excursion are to prepare a Japanese storage module for attachment to the space station and to begin the assembly of a Canadian maintenance robot known as Dextre.

    This is the 105th spacewalk devoted to station assembly and maintenance since construction began in 1998, the sixth so far this year and the first of five planned by the shuttle Endeavour's crew. For identification purposes, Linnehan, call sign EV-1, is wearing a suit with solid red stripes around the legs. Reisman, call sign EV-2, is wearing a suit with diagonal stripes.

    Reisman is a rookie making his first spacewalk. Linnehan, a veterinarian before becoming an astronaut, completed three spacewalks as part of the most recent crew to service the Hubble Space Telescope in 2002.

    After exiting the airlock, Linnehan and Reisman will make their way to Endeavour's cargo bay where they first will remove eight thermal blankets protecting the Japanese logistics module's common berthing mechanism. Moving to the front of the module, Reisman will unplug an electrical cable that supplied shuttle power to internal heaters.

    "Our job is to prepare the JLP for installation on the space station," Reisman said in a NASA interview. "There are covers, kind of blankets that keep it warm in the coldness of space, that need to be removed before it gets installed. So we have to take off those covers and blankets. Then we also have to unplug (an) electrical cable that is used to keep it warm while it's inside the payload bay and that cable needs to be unplugged before it's lifted out, installed on the space station."

    Once that is completed, Japanese astronaut Takao Doi, operating Endeavour's robot arm, will pull the module out of the cargo bay and begin the slow process of moving it to the upward-facing port of the Harmony connecting module on the front of the station. Linnehan and Reisman, meanwhile, will move up to the front of the station's power truss, make their way to the mobile base system to begin assembling Dextre.

    "The business end of Dextre if you like, Dextre's hands, also called the ORU tool changeout mechanisms (OTCMs), are equipped with force moment sensors," said Daniel Rey, Dextre integration manager for the Canadian Space Agency. "What makes Dextre able to perform these human scale tasks is the sense of touch it has and the automatic control that allows it to compensate for sets of forces, or moments, so that despite the crews commands, since they have no direct view and no direct force feedback except what's on their graphical display, Dextre will be able to prevent something from jamming."

    Replacing a failed space station component, he said, is similar to pulling out and re-inserting a drawer.

    "An insertion or an extraction is quite a delicate task, it's like trying to remove an old drawer from a chest that maybe is a bit damp and it requires that sense of touch that Dextre has built into it," Rey said. "Other features of the hand are the grippers ... and in the middle of the grippers, you notice there's a socket that can be extended identical to what you'd find on the EVA crew member's pistol grip tool. So it's a seven-sixteenths socket and that extends to unbolt an ORU."

    When fully assembled and attached to the station's robot arm, Dextre can be positioned next to a failed component. Using one of its hands to lock onto the station to provide rigidity, the other hand's grippers can lock onto the component, the socket wrench can unbolt it, the unit can be withdrawn and a replacement inserted.

    "There's a choreography that goes on with Canadarm2 to place Dextre in front of the work site," Rey said. "One arm will then be used to advance and stabilize the system. Since it's at the very end of a large, flexible arm 17 meters long, it's required to stabilize to avoid too many oscillations for the delicate maintenance tasks. So once the stabilization arm has acquired the stabilization fixture, the other arm is advanced.

    "We're looking forward to being used on orbit," Rey said. "We have every reason to believe that Dextre will meet and exceed its specifications the same as Canadarm2 did.

    But first, it has to be assembled. Dextre's two arms are mounted on either side of the Spacelab pallet with the robot's central torso in the center. After setting up their tools, Reisman will mount a foot restraint on the pallet while Linnehan clips his boots into a foot restraint on the end of the station's robot arm. He then will release two clamps to free the first OTCM, which will be attached to its arm with four mechanical fasteners and two electrical cables.

    To provide plenty of clearance for Doi, who will still be maneuvering the Japanese module into place using the shuttle's robot arm, Linnehan will get off the station arm and the second OTCM will be install while he and Reisman are free floating.

    If all goes well, the two assembled arms will be attached to the torso during a second spacewalk Saturday.


    7:00 PM, 3/13/08, Update: Suffredini optimistic Canadian software patch will resolve Dextre glitch; Cain says shuttle heat shield in good shape

    Space station Program Manager Mike Suffredini said today he's optimistic a software patch will resolve a timing problem that engineers believe has prevented them from successfully powering up the Canadian Space Agency's Dextre robot. Similar problems involving an electronic component common to the station's Canadian-built robot arm and its mobile transporter were resolved by similar patches that adjusted when power-up commands sent from the lab's robotic work station timed out.

    Suffredini said the patch will be ready for installation Friday morning, after an overnight spacewalk by Richard Linnehan and Garrett Reisman to prepare a Japanese logistics module for attachment to the space station and to begin assembly of the special purpose dexterous manipulator, or SPDM, known affectionately as Dextre.

    Dextre was launched disassembled, its arms, hands and central torso bolted to a Spacelab pallet. That pallet was moved from Endeavour's cargo bay and mounted on the station's robot arm transporter earlier today. Tonight's assembly work involves attaching hand-like grippers to each of the robot's 11-foot-long arms.

    Without power, engineers will be unable to activate heaters to keep the robot's joints warm. But Suffredini said it would take at least five days without power to cause any problems and that he was confident the problem would be resolved long before then.

    "From a time standpoint, we're just not real critical right now," he said.

    Engineers believe the power-up problem involves the time needed for commands sent from the station's robotic work station to make their way through three amplifiers, multiple connectors and associated wiring before reaching a device known as a power distribution unit, or PDU, in the robot's torso.

    "This PDU is a common component in the SSRMS (station robot arm) system and the mobile servicing system," Suffredini said. "And in fact, in both of those cases we had a timing issue and we went and made a patch to the RWS, the robotic work station, to fix the problem. The problem is, it sends out a command and says 'turn on' and then waits five seconds and starts commanding. If the thing hasn't warmed up and been ready to accept it so it can react, then (the RWS) goes 'oh, you didn't do what I asked you to do so I'm going to stop talking to you.'

    "The problem is, all these things are wired differently, they go through a number of connectors, they go through a number of amplifiers. The clock starts ticking when the RWS sends out a command. In this case, it goes through three amplifiers, a bunch of wires, it gets to the PDU, the PDU starts thinking about it and meanwhile, the clock's ticking. At that point if it doesn't react right, the RWS says 'you're sick.'"

    Suffredini said telemetry from the Spacelab pallet Dextre's components are mounted on shows the PDU is on and drawing power as expected. The problem, engineers believe, is in the software controlling the robotic work station. If the patch works, the issue will be resolved and the astronauts will press ahead with Dextre asssembly during a second spacewalk overnight Saturday.

    In other developments, LeRoy Cain, chairman of NASA's Mission Management Team, told reporters this afternoon that analysis of launch imagery, an inspection of Endeavour's nose cap and wing leading edge panels and a preliminary assessment of the shuttle's heat shield tiles based on photographs shot by the station crew before docking Wednesday night indicate the ship's heat shield is in good shape.

    No major problems have been identified and commander Dominic Gorie was told today there is no need for any additional, "focused" inspections. Cain said he expects the MMT to clear the heat shield for re-entry, after a few remaining, relatively minor questions are resolved.

    One such open item is a very small depression, or ding, in the carbon composite material around the fitting that helps attach the shuttle's nose to the external fuel tank. Cain said the pit might represent a debris impact, but it is very small and not expected to require any additional attention.

    "The team worked through the night, poring over the data from the scans that we get from the orbiter boom system as well as the data from the rendezvous pitch maneuver that we did. All of that data looks really good. The team has determined that we don't need any focused inspection, that is to say, we don't have any areas that we have any concern about that would require us to do a focused inspection."

    He said NASA's Debris Assessment Team would continue to examine the data "and we anticipate being able to clear the vehicle for entry within a day or two."


    03:30 PM, 3/13/08, Update: Canadians work on software patch to power Dextre components; spacewalk to proceed as planned (UPDATED at 04:30 p.m. with crew wakeup)

    Astronauts Richard Linnehan and Garrett Reisman will press ahead with a near full-duration spacewalk this evening to prepare a Japanese logistics module for attachment to the space station and to begin assembly of a Canadian robot known as Dextre. Canadian robotics experts, meanwhile, are working on a software patch that might resolve a problem preventing engineers from routing power to the robot's components. Power is not required for this evening's spacewalk, but the problem must be resolved at some point.

    Linnehan and Reisman spent the night in the station's Quest airlock module at a reduced 10.2 psi air pressure. The so-called "camp out" procedure is designed to help purge nitrogen from their bloodstreams before spending the day in a low-pressure spacesuit that might otherwise cause the bends.

    The astronauts were awakened at 4:28 p.m. by a recording of "Saturday Night" by the Bay City Rollers uplinked from mission control.

    "Good morning Endeavour," astronaut Al Drew radioed from the control center. "A special good morning to you, Garrett, where by presidential decree for the remainder of the flight day you'll be known as 'Mr. Saturday Night.'"

    "That song was an outstanding selection, thank you very much," Reisman replied. "It gets us all pumped up and we're ready to go out the hatch and do it all, have a ball, S-a-t-u-r Saturday night!"

    If all goes well, the six-and-a-half-hour spacewalk will begin around 9:23 p.m.

    Endeavour docked with the space station late Wednesday and earlier today, the astronauts used the lab's robot arm to move a Spacelab pallet carrying the components of the $209 million special purpose dexterous manipulator, or SPDM, robot - Dextre - to a worksite on the lab's solar power truss.

    Once assembled, Dextre will, in effect, serve as high-precision arms and hands that can be wielded by the station's robotic arm to make repairs that might otherwise require a spacewalk. The goal of today's assembly work is to attach hand-like components called orbital replacement unit/tool changeout mechanisms, or OTCMs, to each of Dextre's arms. The 11-foot-long arms themselves will be attached to the robot's central torso during a second spacewalk overnight Saturday.

    Dextre cannot support its own weight in Earth's gravity and it has never been fully assembled. Power and data are provided to the Spacelab pallet through the attachment fitting holding it in place on the mobile base that normally moves the station arm along the solar power truss.

    But so far, engineers have been unable to power up the robot's components.

    "Shortly after the robotics crew installed the Spacelab pallet with Dextre onto the motion base system, our robotics officer in mission control attempted to power up Dextre," said station flight director Ginger Kerrick. "And that was unsuccessful. So we've been spending the majority of the (day) troubleshooting that and assessing the impacts to (the) timeline.

    "Luckily, the primary objective of the spacewalk today is to install the JLP, or the Japanese logistics module, onto the zenith port of node 2 (Harmony) and it does not require Dextre to be powered. We have some assembly tasks associated with Dextre as well that also do not require it to be powered. So the plan is to execute today's spacewalk per the nominal timeline."

    Without power, however, engineers cannot turn on internal heaters and the spacewalkers will not remove thermal covers around the robot's joints as originally planned.

    "Since we're unable to provide keep-alive to Dextre at this time, we'll probably defer those tasks," Kerrick said. "But those only represented about 25 minutes out of the EVA."

    She said engineers have attempted a variety of workarounds to get power to the robot's systems, all of them unsuccessful.

    "The power that's provided to Dextre can actually go through two separate strings and each of those strings have two separate channels," she said. "So we attempted to provide power with every combination of channel and string that we could think of, and that was unsuccessful. The second thing we tried from the ground was, when you attach the SLP to the port on the mobile base system, there is a connector that is supposed to mate to provide power and data access through there. So from the ground, we remotely commanded that to disconnect and then reconnect just in case the connection did not mate properly. Then we tried to repower Dextre after that, again, unsuccessful.

    "With respect to the mechanical things we can try to restore power, there's one more thing we can do, but it requires the help of the EVA crew. And that is to go off and inspect all the connectors and cables that we were anticipating were already connected to determine whether or not that might be a source of the problem. So that is about everything we can do mechanically.

    "Now we have talked to our Canadian Space Agency counterparts and there is a possibility that this could be the result of a timing issue with the software," Kerrick said. "When we command power to Dextre, the lab robotics workstation we're working from attempts to communicate with it shortly after that power command is set up. The theory is that the box we're powering on, which is called the power switching unit, the PSU, that we are trying to communicate with it while it is still powering up. So our Canadian Space Agency counterparts are looking into a software patch that would extend the amount of time between the power up and when the workstation tries to communicate with it.

    "This is just a theory, but it's one of the things folks are working on. They're hoping to deliver that patch within 24 hours. As soon as that patch is delivered, we'll uplink it and attempt to repower. Now if that isn't successful, we have another leg that we have talked about on the overnight shift, which would be to attempt to grapple the Dextre with the station arm and attempt to power it that way."

    LeRoy Cain, chairman of NASA's Mission Management Team, will brief reporters today at 5 p.m. to provide an update on image analysis, the overall health of Endeavour and any other issues of interest. The briefing will be carried on NASA television.

    In the meantime, here is an updated timeline of today's activity (in EDT and mission elapsed time; includes revision C of the NASA television schedule):

    EDT........DD...HH...MM...EVENT
    
    03/13/08
    04:28 PM...02...14...00...Crew wakeup
    05:00 PM...02...14...32...Post-MMT briefing
    05:08 PM...02...14...40...EVA-1: 14.7 psi repress/hygiene break
    05:53 PM...02...15...25...EVA-1: Airlock depress to 10.2 psi
    06:18 PM...02...15...50...EVA-1: Campout EVA preps
    07:48 PM...02...17...20...EVA-1: Spacesuit purge
    08:03 PM...02...17...35...EVA-1: Spacesuit oxygen prebreathe
    08:53 PM...02...18...25...EVA-1: Airlock depressurization
    09:23 PM...02...18...55...EVA-1: Spacesuits to battery power (official start time)
    09:28 PM...02...19...00...EVA-1: Airlock egress
    09:48 PM...02...19...20...EVA-1: Payload bay setup
    10:08 PM...02...19...40...EVA-1: Japanese module prepped for unberthing
    11:23 PM...02...20...55...EVA-1: OTCM 2 install on Dextre
    
    03/14/08
    01:23 AM...02...22...55...EVA-1: OTCM 1 install
    01:58 AM...02...23...30...Logistics module unberthing
    02:38 AM...03...00...10...SODF deploy
    02:43 AM...03...00...15...SPDM assembly preps
    03:08 AM...03...00...40...EVA-1: Cleanup
    03:23 AM...03...00...55...Logistics module installation
    03:33 AM...03...01...05...EVA-1: Airlock ingress
    03:53 AM...03...01...25...Common berthing mechanism first stage bolts driven
    03:53 AM...03...01...25...EVA-1: Airlock repressurization
    04:08 AM...03...01...40...Spacesuit servicing
    04:13 AM...03...01...45...CBM second stage bolts driven
    05:58 AM...03...03...30...Logistics module leak checks
    06:00 AM...03...03...32...Mission status briefing on NASA TV
    06:03 AM...03...03...35...Shuttle arm ungrapples logistics module
    07:58 AM...03...05...30...ISS crew sleep begins
    08:28 AM...03...06...00...STS crew sleep begins
    09:00 AM...03...06...32...Daily video highlights reel (repeated hourly)
    01:30 PM...03...11...02...Flight director update on NASA TV
    04:28 PM...03...14...00...Crew wakeup
    


    6:00 AM, 3/13/08, Update: Reisman joins station crew; engineers troubleshoot pallet power-up glitch

    A high-tech Canadian robot, launched disassembled on large pallet, was moved from the shuttle Endeavour to a work site on the international space station's solar power truss early today. An initial attempt to route power to the pallet was not successful, but power is not required for the robot's initial assembly and the astronauts were told to press ahead with preparations for a spacewalk Thursday night, the first of five planned for Endeavour's mission.

    Garrett Reisman, meanwhile, officially joined the crew of the international space station early today, replacing outgoing flight engineer Leopold Eyharts. Launched to the station in February aboard the shuttle Atlantis, Eyharts, representing the European Space Agency, will return to Earth in Reisman's place aboard Endeavour on March 26. The crew swap was reported at 3:50 a.m. when Garrett's custom Soyuz seat liner was transferred from Endeavour to the station's Russian lifeboat.

    Reisman and Richard Linnehan are spending the night in the station's Quest airlock module at a reduced air pressure to help purge nitrogen from their bloodstreams in preparation for this evening's spacewalk, or EVA. The goals of the excursion are to prepare a Japanese logistics module for attachment to the Harmony module and to begin assembly of the Canadian special purpose dexterous manipulator, or Dextre.

    The $209 million Dextre will provide a set of hands for the station's Canadian-built robot arm, making it capable of repairs that might otherwise require a spacewalk. The robot was launched disassembled on a Spacelab pallet that was mounted on the station a few hours after Endeavour's docking earlier today. Engineers ran into a snag when an attempt to route power to the pallet failed. Power is not required for the robot's assembly, but engineers want to figure out what might be causing the problem.

    "Peggy, we tried powering up the SPDM but were unable to power it up as planned," Mark Vande Hei radioed from mission control. "We're troubleshooting it still. Bottom line is, EVA-1 is as planned, but we may have some deltas (changes) in the morning."

    "OK, we're all excited about that," station commander Peggy Whitson replied.

    "As are we," Vande Hei laughed.

    The disassembled Dextre, designed to operate in weightlessness, has been tested but never fully assembled on Earth. It cannot be assembled in the shuttle's cargo bay because of its sheer size. If an emergency developed requiring a quick separation from the station, Endeavour's cargo bay doors could not be closed due to interference with Dextre.

    As a result, NASA flight planners decided to have the crew anchor the Spacelab pallet to the mobile base system and to build the robot on the station's power truss. After assembly is complete, Dextre will be mounted on the hull of the Destiny module and the pallet will be reberthed in Endeavour's cargo bay for return to Earth.


    11:55 PM, 3/12/08, Update: Shuttle Endeavour docks with international space station (UPDATED at 3 a.m. with hatch opening; mission status briefing

    The shuttle Endeavour glided to a gentle docking with the international space station late Wednesday as the two spacecraft sailed 212 miles above Malaysia at five miles per second. With commander Dominic Gorie at the controls, the shuttle's docking system engaged its counterpart on the front of the lab complex at 11:49 p.m. to wrap up a two-day orbital chase that began with Endeavour's sky-lighting blastoff early Tuesday.

    "Houston, Endeavour, capture confirmed," a shuttle astronaut radioed as the two vehicles came together.

    "Houston copies," astronaut Terry Virts replied from mission control.

    "Houston, Endeavour, we see flashing lights. Free drift."

    "And Alpha can verify station is in free drift," Expedition 16 commander Peggy Whitson confirmed. In keeping with naval tradition, she then rang the ship's bell in the Destiny laboratory module, saying "Endeavour, arriving."

    "Peggy, that's the sweetest sound I've ever heard," Gorie said. "Thank you very much."

    Whitson, flight engineer Yuri Malenchenko and outgoing European Space Agency astronaut Leopold Eyharts welcomed Gorie and his crewmates - pilot Gregory Johnson, flight engineer Michael Foreman, Richard Linnehan, Robert Behnken, Japanese astronaut Takao Doi and space station flight engineer Garrett Reisman - aboard at 1:36 a.m., a little more than one orbit after docking.

    "Today was a textbook rendezvous and docking," said lead flight director Mike Moses. "I couldn't have asked for anything better, picture perfect. ... It was a great rendezvous."

    After a mandatory safety briefing to familiarize the shuttle astronauts with emergency procedures, the two crews got busy transferring spacesuits and other equipment to the station's Quest airlock to prepare for the mission's first spacewalk overnight Thursday. They also planned to transfer astronaut Garrett Reisman's Soyuz seat liner to the station's Russian ferry craft, allowing him to replace Eyharts as a member of the Expedition 16 crew. Eyharts, launched to the outpost in February to help activate the European Space Agency's new Columbus research module, will return to Earth aboard Endeavour after six weeks in space.

    "Our EVA crews ... are transferring all the EVA gear in prep for (Thursday night's) EVA," Moses said. "Garrett Reisman, our crew member that we're taking up for Expedition 16 and going to leave behind, and Yuri are busy installing his seat liner in the Soyuz. They're going to do a leak check on his Sokol suit, his Russian entry suit, to make sure he's good to go, at which point he'll become an official ISS crew member."

    Reisman and Linnehan will sleep in the station's Quest airlock module at a reduced pressure of 10.2 pounds per square inch. The so-called "camp-out" procedure is designed to help purge nitrogen from the astronauts' bloodstreams and prevent the bends after working in NASA's five-psi spacesuits.

    The goal of Thursday's spacewalk, the first of five EVAs planned for the mission, is to prepare a Japanese logistics module for attachment to the station and to begin assembly of a Canadian Space Agency robot known as the special purpose dexterous manipulator, or Dextre for short. Dextre is an attachment that will, in effect, give the station's Canadian-built robot arm two hands and the ability to remotely change out components that might otherwise require a spacewalk.

    The disassembled Dextre robot, designed to operate in weightlessness, has been tested but never fully assembled on Earth. It made the climb to space in pieces bolted to a Spacelab pallet in the shuttle's cargo bay. Behnken and Johnson, operating the station's robot arm from inside the Destiny lab module, pulled the pallet out of the cargo bay three hours after docking. The pallet will be attached to a grapple fixture on the side of the mobile base system normally used to move the station arm along the front face of the main solar power truss.

    Moses said Wednesday's rendezvous went off without a hitch, starting round 8:42 p.m. with a critical rocket firing as Endeavour trailed the station by about 9.2 miles. After reaching a point about 600 feet directly below the lab complex, Gorie fired small maneuvering jets to put the shuttle through a slow 360-degree back flip, exposing the ship's heat shield to cameras on the space station.

    Whitson, using a camera with a 400-mm lens, and Malenchenko, wielding an 800-mm telephoto, shot dozens of digital pictures of the shuttle's belly as the spacecraft streaked over Australia to help engineers assess the health of the ship's heat shield. No obvious problems could be seen in television views from the station, but it will take image analysts another day or so to examine the 300 or so pictures downlinked by Whitson and Malenchenko.

    Initial analysis of imagery and laser scan data collected overnight Tuesday show Endeavour's reinforced carbon carbon nose cap and wing leading edge panels, which experience the most extreme heating during re-entry, came through launch in good shape. "There weren't very many regions of interest at all and they don't suspect we're going to have any focused inspection requirements," Moses said. "We'll let them officially chew over that and decide that later tonight. But quick look was that that all looked great yesterday."

    "We also got word that the debris we saw at about 10 seconds that appeared to pass over the nose and possibly strike (the shuttle), the image analysis has confirmed that it did not strike the orbiter. It didn't come near the vehicle."

    Moses said engineers initially thought the object, possibly a bird, hit the nose of the shuttle because at the moment the trajectory seemed to indicate a hit, a protective cover over a rocket nozzle pulled away in the wind as designed. Closer analysis, however, showed the two were unrelated events and that the mystery object passed out of view behind a shuttle booster and did not strike the orbiter.

    "You can see in the video there's clearly something coming from above the orbiter," Moses said. "And it passes behind the SRB (solid rocket booster), it doesn't go near the nose of the shuttle. About the same time, about two frames later, a Tyvek cover releases off the nose and so you see the streak start again and you could have drawn a conclusion that it was the same piece of debris. The analyst folks have looked at that and it's definitely not, it's two separate events. And so whatever it was that was coming from above passed behind us. I don't have any idea what that is."


    04:15 PM, 3/12/08, Update: Shuttle crew gears up for station docking

    The Endeavour astronauts are closing in on the international space station today, on track for a docking around 11:25 p.m. to kick off a five-spacewalk assembly mission. The shuttle crew was awakened at 4 p.m. by a recording of Blue Oyster Cult's "Godzilla" beamed up from Houston for Japanese astronaut Takao Doi.

    "We are very happy to hear 'Godzilla,'" Doi radioed. "We are ready to go and we'll have a great time today docking with the space station. Arigato."

    "Arigato," astronaut Al Drew replied from the Johnson Space Center. "Take on the day like a monster."

    The terminal phase of the rendezvous will begin around 8:42 p.m. with a critical rocket firing as Endeavour trails the station by about 9.2 miles. After reaching a point about 600 feet directly below the lab complex, commander Dominic Gorie will fire maneuvering jets to put the shuttle through a slow 360-degree back flip, exposing the ship's heat shield to cameras on the space station.

    "The rendezvous pitch maneuver is a 360-degree pitch almost like a loop where we expose the bottom of the orbiter to the space station where they have some very powerful cameras," Gorie said in a NASA interview. "And with those cameras, they are able to detect whether there's any white tile showing on the surface of the orbiter and that would mean that the black coating on the belly tiles has been damaged.

    "During the RPM, the commander is in charge of the orbiter and flying the vehicle, so I'll be at the aft station of the space shuttle flight deck and we'll be looking out through the overhead windows as we start this maneuver and make sure that we are in the right position with the right rates. We'll start that off with an auto pilot maneuver that takes us through this hands-off pitch at that point. It's sort of different than anything we've done before as, as astronauts, to be hands-off of the orbiter as we cannot see the space station any more. But the last couple flights that have done this have had great luck and it's worked very well for us."

    The pictures snapped during the RPM will be downlinked to imagery analysts who are assessing the health of the shuttle's heat shield in a now-standard process intended to identify any possible damage sites before re-entry. The only debris events noted during Endeavour's launching occurred at 10 seconds and 83 seconds after liftoff. The 10-second event may have been a bird that strayed too close to the climbing space shuttle, but lead flight director Mike Moses said earlier today it was not clear whether anything actually hit the shuttle. No signs of damage were seen during an overnight inspection of the shuttle's nose cap and wing leading edge panels.

    With the RPM complete, Gorie will guide Endeavour to a point about 400 feet directly in front of the space station with the shuttle's tail pointed toward Earth and its open payload bay facing pressurized mating adapter No. 2 on the front end of the station's Harmony module.

    "We slowly back into the space station with the commander at the controls and flying it manually," Gorie said. "That is one of the most exciting parts of the mission for me. You get to fly formation with the space ship being framed by creation underneath you, that's just spectacular. So it's very easy to get distracted by the beauty of what's going on underneath and the beauty of the space station. Flying formation at that time is a really, really exciting thing that demands everybody on the flight deck to be participating. Everybody has a role in that process so it really relies a lot on teamwork and training."

    The actual docking, Gorie said, "is really exciting. ... The docking system is a very elaborate, beautifully designed piece of equipment that can connect the two vehicles together after a very slow collision. There are hooks that grab onto the space station, once all of the motions are damped out, with springs like shock absorbers on this extended ring. We slowly draw the two vehicles together with the screw drives that pull it together and after an hour of pressure checks and docking system checks we are able then to open the hatch. But knowing that there's this space station crew on the other side waiting for our arrival, eager to have a replacement for one of their folks and, and some of the re-supply items that we're bringing, it makes it a really an exciting time as well."

    Space station commander Peggy Whitson, flight engineer Yuri Malenchenko and European Space Agency astronaut Leopold Eyharts will welcome the shuttle crew aboard. After a mandatory safety briefing to familiarize the visiting astronauts with emergency procedures, the crews will get busy transferring spacesuits and other equipment to the station's Quest airlock to prepare for the first spacewalk the following day.

    The goal of that excursion is to prepare a Japanese logistics module for attachment to the station and to begin assembly of a Canadian Space Agency robot known as the special purpose dexterous manipulator, or Dextre for short. Dextre is an attachment that will, in effect, give the station's Canadian-built robot arm two hands and the ability to remotely change out components that might otherwise require a spacewalk.

    The disassembled Dextre robot, designed to operate in weightlessness, has been tested but never fully assembled on Earth. It made the climb to space in pieces bolted to a Spacelab pallet in the shuttle's cargo bay. After docking, Robert Behnken and shuttle pilot Gregory Johnson, operating the station's robot arm from inside the Destiny lab module, plan to pull the pallet out of the cargo bay. It will be attached to a grapple fixture on the side of the mobile base system normally used to move the station arm along the front face of the main solar power truss.

    "Right after we rendezvous we're going to take that SLP and install it in a temporary location on the ISS," Johnson said. "Then through the next three or four days, actually five or six days, we're going to assemble Mr. Dextre on the various spacewalks and that's a pretty involved process."

    Here is an updated timeline of today's activity (in EDT and mission elapsed time; includes revision B of the NASA television schedule):

    EDT........DD...HH...MM...EVENT
    
    03/12/08
    03:58 PM...01...13...30...STS crew wakeup
    04:28 PM...01...14...00...ISS crew wakeup
    05:00 PM...01...14...32...Post-MMT briefing on NASA TV
    05:08 PM...01...14...40...Group B computer powerup
    05:18 PM...01...14...50...ISS daily planning conference
    05:28 PM...01...15...00...Rendezvous timeline begins
    06:11 PM...01...15...43...NH rendezvous rocket firing
    07:10 PM...01...16...42...NC-4 rendezvous rocket firing
    07:58 PM...01...17...30...Spacesuits removed from airlock
    08:42 PM...01...18...14...TI burn
    09:18 PM...01...18...50...Service module lights on
    09:18 PM...01...18...50...Sunset
    09:23 PM...01...18...55...ISS crew meal
    09:28 PM...01...19...00...Hand-held laser ops
    09:41 PM...01...19...13...Range: 10,000 feet
    09:49 PM...01...19...21...Range: 5,000 feet
    09:53 PM...01...19...25...Approach timeline begins
    09:54 PM...01...19...26...Sunrise
    09:55 PM...01...19...27...Range: 3,000 feet
    09:59 PM...01...19...31...MC-4 rendezvous burn
    10:03 PM...01...19...35...Range: 1,500 feet
    10:05 PM...01...19...37...U.S. solar arrays feathered
    10:08 PM...01...19...40...Range: 1,000 feet
    10:11 PM...01...19...43...KU antenna to low power
    10:12 PM...01...19...44...+R bar arrival directly below ISS
    10:17 PM...01...19...49...Range: 600 feet
    10:22 PM...01...19...54...Noon
    10:24 PM...01...19...56...RPM start window open
    10:24 PM...01...19...56...Start pitch maneuver
    10:30 PM...01...20...02...RPM full photo window close
    10:32 PM...01...20...04...End pitch maneuver
    10:34 PM...01...20...06...Initiate pitch up maneuver (575 ft)
    10:38 PM...01...20...10...RPM start window close
    10:42 PM...01...20...14...Russian arrays feathered
    10:46 PM...01...20...18...+V bar arrival 310 feet directly in front of ISS
    10:47 PM...01...20...19...Range: 300 feet
    10:49 PM...01...20...21...Sunset
    10:51 PM...01...20...23...Range: 250 feet
    10:55 PM...01...20...27...Range: 200 feet
    10:58 PM...01...20...30...Range: 170 feet
    10:59 PM...01...20...31...Range: 150 feet
    11:03 PM...01...20...35...Range: 100 feet
    11:06 PM...01...20...38...Range: 75 feet
    11:11 PM...01...20...43...Range: 50 feet
    11:14 PM...01...20...46...Range: 30 feet; start stationkeeping
    11:19 PM...01...20...51...End stationkeeping; push to dock
    11:23 PM...01...20...55...Range: 10 feet
    11:25 PM...01...20...57...Sunrise
    11:25 PM...01...20...57...DOCKING
    11:48 PM...01...21...20...Leak checks
    
    03/13/08
    12:08 AM...01...21...40...Docking video playback
    12:18 AM...01...21...50...Orbiter docking system prepped for ingress
    12:18 AM...01...21...50...Group B computer powerdown
    12:33 AM...01...22...05...Post docking laptop reconfig
    12:38 AM...01...22...10...Hatch open
    01:08 AM...01...22...40...Welcome aboard!
    01:13 AM...01...22...45...Safety briefing
    01:38 AM...01...23...10...Post-docking EVA transfer
    01:38 AM...01...23...10...Soyuz seatliner transfer to ISS
    01:38 AM...01...23...10...SRMS grapples SLP
    02:00 AM...01...23...32...Mission status briefing on NASA TV
    02:28 AM...02...00...00...SLP unberth and install
    02:28 AM...02...00...00...Soyuz seatliner installation
    02:53 AM...02...00...25...REBA checkout
    03:08 AM...02...00...40...Airlock preps
    03:18 AM...02...00...50...Transfer ops (JLP and VOK)
    03:33 AM...02...01...05...SLP ungrapple
    04:28 AM...02...02...00...EVA-1: Procedures review
    06:43 AM...02...04...15...EVA-1: Mask pre-breathe
    07:38 AM...02...05...10...EVA-1: Airlock 10.2 psi depress
    07:58 AM...02...05...30...ISS crew sleep begins
    08:28 AM...02...06...00...STS crew sleep begins
    09:00 AM...02...06...32...Daily video highlights reel on NASA TV
    01:00 PM...02...10...32...Flight director update on NASA TV
    04:28 PM...02...14...00...Crew wakeup
    


    03:40 AM, 3/12/08, Update: Astronauts inspect heat shield; no obvious damage seen; analysts not yet sure whether bird/debris might have struck shuttle's nose during ascent

    The Endeavour astronauts unlimbered the shuttle's robot arm overnight and inspected the ship's nose cap and wing leading edge panels with a laser scanner on the end of a 50-foot-long boom. The areas of the orbiter that experience the most extreme heating during re-entry appeared in good shape to the untrained eye, including the nose section where launch imagery indicates a possible bird or debris strike about 10 seconds after liftoff. Additional inspections are planned during final approach to the space station Wednesday night and lead Flight Director Mike Moses said early today it's too soon to say what, if anything, might have struck the shuttle.

    "I took a look at the video before I came over here," he told reporters during a mission status briefing. "It's really hard to tell. It looks like it's not coming from the orbiter and you can't really tell if it strikes the orbiter or not. You could go either way. You could say it hits somewhere on the nose or it passes behind the SRB (solid rocket booster) and doesn't actually come anywhere near us.

    "So, I guess the bottom line is we don't know what it is yet, we're still looking at it. ... The initial look at the still photos from ascent didn't show anything. We got some real quick flyby video today (during the heat shield inspection), nothing obvious showed up. But I'm certainly not the expert and the teams will take a look at that. We'll know in the next day or two if anything is on the nose we didn't expect."

    The fully fueled shuttle weighs 4.5 million pounds on the launch pad and accelerates - straight up - to a velocity of 120 mph in the first 10 seconds of flight. Moses said that's not fast enough to cause any major impact concern and "if we did have an impact there, it probably would be no problem." The foam insulation that struck the shuttle Columbia's left wing with catastrophic results in 2003 impacted with a relative velocity of some 530 mph.

    A bird was hit by the shuttle Discovery's external tank during launch of the first post-Columbia mission and Moses said it's possible a bird was involved in the incident 10 seconds after Endeavour lifted off. But, he added, "I can't even begin to speculate on what it could be. And to be honest, even speculating that it didn't come from the orbiter is maybe a little premature as well. We should let the experts do the math. We got some good video at least that shows it in multiple frames so they'll be able to do a trajectory analysis to see where that came from."

    During the climb to space early Tuesday, a signal processing card failed resulting in a loss of telemetry from a group of left-side aft rocket thrusters. Because flight controllers cannot detect possible fuel leaks in those jets, three primary thrusters in the left-side orbital maneuvering system rocket pod will not be used for the remainder of the flight. Engineers are working on a software patch that should recover the use of smaller left-side vernier jets in time for Endeavour's rendezvous with the space station Wednesday night.

    "That will give us back the vernier jets for rendezvous, which gives us the fine control we like to have," Moses said. "But bottom line, even if the verniers for some strange reason just did not recover again, no mission impact to mission duration. But our plan is to recover those with this software patch."

    One other glitch during launch involved the shuttle's flash evaporator cooling system, or FES. The FES is used primarily during launch and re-entry, when the shuttle's cargo bay doors are closed and radiator panels are not deployed, to get rid of the heat generated by the ship's electronics. During launch Tuesday, the primary A-channel FES controller failed to work properly, forcing an alternate controller to take over.

    "We actually have three separate controllers we can use for the FES," Moses said. "We switched over to the B controller and it worked fine. Once we got on orbit and opened up the payload bay doors, we went back to the A controller. It got really close to the control band, but couldn't quite keep up and shut itself down again. A little later we switched it to a different mode ... and again, we saw a similar signature, it just wasn't able to control.

    "It probably points to some kind of sensor problem in a controller, a feedback problem, it's hard to tell. The good news is, we saw no signs of icing, no problems at all with the FES system itself and FES pri B is working great. So at this time, we're going to go ahead and declare FES pri A failed and we're not going to do anymore troubleshooting with it. Pri B is working great for us and we don't expect any problems. So it's no mission impact with the FES."

    Along with inspecting the nose cap and wing leading edge panels late Tuesday and today, the astronauts checked out the spacesuits that will be used during five upcoming spacewalks. They also pre-staged equipment and supplies that will be moved over to the station after docking Wednesday.

    "Once we dock, we have a lot of gear we have to haul over to the ISS airlock in preparation for the EVAs we'll be doing out of the station's airlock," Moses said. "In addition to that, later on today the crew is going to continue on with the scans with the OBSS (orbiter boom sensor system) and to get us ready for rendezvous tomorrow (Wednesday night), they'll do a tools checkout of the systems they use up on the flight deck - the hand-held laser system, the laptop computer systems they use to help with rendezvous. They're also going to check out the docking system, power it up, extend the ring and have the docking system ready for docking."

    Finally, Moses said sensors mounted behind the wing leading edge panels worked as planned during launch Tuesday and did not detect any unusual vibrations that would indicate any significant debris strikes. He also said a new Nikon flash system worked as expected, allowing a camera in the belly of the shuttle to photograph the external tank after separation in orbital darkness. The imagery is under assessment.

    The astronauts are scheduled to go to bed around 8 a.m. Wakeup is expected shortly after 4 p.m. Rendezvous operations begin around 5:33 p.m. with the terminal phase initiation rocket firing on tap at 8:42 p.m. Docking is expected at 11:25 p.m. A detailed rendezvous timeline is posted on the CBS News STS-123 Quick-Look page.


    04:55 PM, 3/11/08, Update: Astronauts awakened for heat shield checkout; docking preps

    The Endeavour astronauts were awakened today at 4:29 p.m. to begin their first full day in space. Heat shield inspections are planned, along with spacesuit check outs, rendezvous preps and a pair of rocket firings to fine tune the shuttle's approach to the international space station. At crew wakeup, the shuttle was about 1,000 miles behind the lab complex, on course for docking Wednesday night.

    Engineers on the ground, meanwhile, are analyzing launch imagery to identify any possible ascent debris strikes from falling external tank foam insulation or other sources. Just before the crew went to bed earlier today, flight controllers reported a possible debris impact event about 10 seconds after launch. Another possible debris event was noted at 83 seconds into flight but no impact was observed.

    Endeavour took off at 2:28:14 a.m. and given the reduced lighting with a night launch, the astronauts will rely more on detailed orbital inspections to verify the health of the ship's heat shield than would be the case for a daylight ascent.

    The astronauts were awakened by a recording of "Linus and Lucy" from "A Charlie Brown Christmas" beamed up from mission control in Houston for shuttle flight engineer Mike Foreman.

    "Good morning, Endeavour. And a special good morning to you, Mike," astronaut Al Drew radioed from the Johnson Space Center.

    "Well good morning, Houston, we appreciate that song," Foreman replied. "We had an exciting trip to orbit yesterday morning and we're looking forward to our first full day in orbit."

    The major activity in space today is a detailed inspection of Endeavour's reinforced carbon carbon nose cap and wing leading edge panels, which experience the most extreme heating during re-entry. The astronauts also will use cameras on the shuttle's robot arm to inspect tiles protecting the upper surfaces of the shuttle, including two aft rocket pods.

    The possible impact event at T-plus 10 seconds occurred in the nose area of the shuttle, but nothing obvious could be seen in the launch video from NASA television.

    For today's inspections, commander Dominic Gorie, pilot Gregory Johnson and Japanese astronaut Takao Doi will use the shuttle's 50-foot-long robot arm and the equally long orbiter boom sensor system, or OBSS, mounted along the right side of Endeavour's cargo bay. The OBSS is equipped with a laser scanner and high-resolution cameras capable of spotting any significant impact damage to the critical nose cap and wing leading edge panels.

    "We're all operating the shuttle's robotic arm and we'll first grapple the OBSS, the Orbiter Boom Sensor System, and it about doubles the length of the arm," Johnson said in a NASA interview. "Then we can reach around and look underneath the orbiter and check out all the tiles and the reinforced carbon carbon and we can also reach around and look at the nose of the shuttle. It's an all-day task."

    While the heat shield inspection is going on, the other crew members will check out the spacesuits that will be used for station assembly spacewalks later in the mission, test the handheld lasers and other gear needed for the station rendezvous and rig the ship for docking. A mission status briefing is planned for 2 a.m. Wednesday on NASA television.

    Here is an updated timeline of today's activity (in EDT and mission elapsed time; supercedes revision A of the NASA television schedule; briefing times are unchanged):

    EDT........DD...HH...MM...EVENT
    
    Tue 04:28 PM...00...14...00...Crew wakeup
    Tue 06:33 PM...00...16...05...Shuttle robot arm (SRMS) checkout
    Tue 07:08 PM...00...16...40...Laptop computer setup (part 2)
    Tue 07:46 PM...00...17...18...NC-2 rendezvous rocket firing
    Tue 07:53 PM...00...17...25...SRMS unberths OBSS heat shield inspection boom
    Tue 08:08 PM...00...17...40...Spacesuit checkout preps
    Tue 08:28 PM...00...18...00...Ergometer setup
    Tue 08:38 PM...00...18...10...Spacesuit checkout
    Tue 09:08 PM...00...18...40...OBSS starboard wing survey
    Tue 10:28 PM...00...20...00...Crew meal
    Tue 11:03 PM...00...20...35...OBSS nose cap survey
    Tue 11:28 PM...00...21...00...Spacewalk equipment prepped for transfer to station
    
    03/12/08
    Wed 12:53 AM...00...22...25...OBSS port wing survey
    Wed 12:58 AM...00...22...30...Logistics transfer preps
    Wed 02:00 AM...00...23...32...Mission status briefing on NASA TV
    Wed 02:28 AM...01...00...00...OMS rocket pod survey
    Wed 02:28 AM...01...00...00...Centerline camera setup in docking system
    Wed 02:53 AM...01...00...25...SRMS berths OBSS
    Wed 02:58 AM...01...00...30...Orbiter docking system ring extension
    Wed 03:13 AM...01...00...45...Laser data downlink
    Wed 03:38 AM...01...01...10...Rendezvous tools checkout
    Wed 04:58 AM...01...02...30...NC-3 rendezvous rocket firing
    Wed 08:03 AM...01...05...35...Crew sleep begins
    Wed 09:00 AM...01...06...32...Daily video highlights reel on NASA TV
    
    Revision A of the NASA television schedule is posted on the CBS News STS-123 Quick-Look page, along with the latest rendezvous and docking timeline.


    3:08 AM, 3/11/08, Update: Shuttle Endeavour launched (UPDATED at 4:45 a.m. with cooling system details, debris report

    The space shuttle Endeavour, carrying a crew of seven, a Japanese space station module and a high-tech Canadian robot with 11-foot-long arms, vaulted into orbit early today, lighting up the pre-dawn sky for miles around as it knifed through low clouds and rocketed away on a 16-day space station assembly mission.

    "OK, Dom, the vehicle's in great shape, the weather is go, in fact it should be an interesting sight for you to punch through the clouds tonight," Launch Director Mike Leinbach radioed during a final hold in the countdown. "So on behalf of the KSC launch team, I'd like to wish you good luck, Godspeed and we'll see you back here in 16 days."

    "Well Mike, you've just made people smile around the world and you've got seven smiling faces on board here," commander Dom Gorie replied from the shuttle's cockpit. "We'd like to give a special thanks to our families, KSC's Endeavour crew, our friends in Houston and Canada and for JAXA (the Japanese space agency), we'd like to say konichwa, doomo arigatoo and banzai! God has truly blessed us with a beautiful night ... to launch, so let's light 'em up and give 'em a show."

    With its three hydrogen-fueled main engines roaring at full throttle, Endeavour's twin solid-fuel boosters ignited with a rush of fiery exhaust at 2:28:14 a.m., instantly pushing the spacecraft away from pad 39A atop twin pillars of 5,000-degree flame.

    Climbing straight up for the first 10 seconds, Endeavour wheeled about to put the crew in a heads-down orientation beneath the external tank and arced away to the northeast on a course paralleling the East Coast. It was only the second night launch since the 2003 Columbia disaster and Endeavour put on a spectacular, if brief, sky show as it passed through a deck of clouds about 6,300 feet above the launch pad and disappeared from view.

    Monitoring the computer-controlled ascent from Endeavour's upper flight deck were Gorie, pilot Gregory Johnson, flight engineer Michael Foreman and Robert Behnken. Strapped in on the shuttle's lower deck were Richard Linnehan, Japanese astronaut Takao Doi and space station flight engineer Garrett Reisman, hitching a ride to the lab complex to replace outgoing flight engineer Leopold Eyharts.

    Telemetry from the shuttle indicated a problem moments after liftoff with a loss of data from two of the ship's reaction control system maneuvering jets and a few minutes later, a glitch of some sort forced a switch to an alternate cooling system controller. The flash evaporator system, or FES, is primarily used during ascent and entry, when the shuttle's cargo bay doors are closed and Freon coolant loop radiators are not yet deployed.

    LeRoy Cain, chairing NASA's Mission Management Team, described the problems as "minor" and said neither was expected to have any impact on Endeavour's mission.

    "It's a fully redundant system," he said. "It's the kind of thing we have seen fail in this way during powered flight a number of times. ... I fully expect we'll be able to resolve it. It's a loss of redundancy in the very worst case."

    As with all space station flights, today's launching was timed to roughly coincide with the moment Earth's rotation carried the launch pad into the plane of the lab's orbit. As a result, takeoff occurred in darkness and even with a camera mounted on the side of the shuttle's external tank, there was little to see after Endeavour's solid-fuel boosters separated two minutes and five seconds into flight.

    Eight-and-a-half minutes after liftoff, the shuttle's main engines shut down and seconds later, the spaceplane separated from its external tank. As Endeavour pulled away, live television views from the tank camera showed periodic flashes as a digital camera in the belly of the shuttle used a new Nikon flash system to illuminate the tank. The goal was to collect detailed digital pictures to help engineers assess the condition of the tank's foam insulation even in orbital darkness.

    A quick look at the limited video available from ground cameras indicated at least one piece of debris separated and fell away 83 seconds after liftoft. The incident occurred while the shuttle was still in the thicker, lower atmosphere, which can produce higher impact velocities, But astronaut James Dutton in mission control told the crew the debris, whatever it might have been, did not appear to strike the orbiter.

    "We did track one piece of debris that appeared to move past the right wing at 83 seconds," Dutton said. "There was no impact seen. ... Overall, it looked really nice."

    The astronauts will carry out their own heat shield inspection later this evening, using a sensor boom on the end of the shuttle's robot arm to check the condition of the ship's nose cap and wing leading edge panels, which experience the most extreme heating during re-entry. if all goes well, Gorie will guide the shuttle to a docking with the space station around 11:30 p.m. Wednesday.

    The primary goals of the 122nd shuttle mission are to install a Japanese equipment module atop the forward Harmony module; to assemble Canada's special purpose dexterous manipulator robot, known informally as "Dextre;" to deliver spare parts and supplies; and to test a new heat shield repair technique, one of the final steps in NASA's recovery from the Columbia disaster.

    Five spacewalks are planned - the most of any station assembly flight to date - over 12 docked days. That's the longest shuttle stay at the station since construction began in 1998. Endeavour is equipped with a new station-to-shuttle power transfer system that lets it tap into the lab's solar power grid, permitting longer stays than possible with the shuttle's fuel cells alone.

    The Japanese module mounted in Endeavour's cargo bay is the first of two that will make up an entire wing of the space station, a state-of-the-art addition that will complement U.S. and European research modules. But the assembly of Canada's $209 million Dextre represents the most complex task of Endeavour's mission.

    Capable of manipulating objects as big as a phone booth and as small as a phone book, Dextre is an attachment for the station's Canadian-built robot arm that, in effect, will give it a pair of hands capable of positioning components to within 2 millimeters and gripping them with as little as 1.5 pounds of force.

    "If you could picture what a praying mantis would look like, that's what I liken Dextre to," Linnehan said in a NASA interview. "I grew up with cartoons and sci-fi and there used to be this show on when I was a kid called 'Gigantor, the Space Age Robot' and so, you know, my pet name for Dextre is 'Gigantor.' It's this giant robot with arms and out-riggers and all this equipment, with wrists and hands that actually move and can articulate itself all over the station."

    Once assembled and attached to the station's robot arm, Dextre, equipped with force-sensing grippers for hands, TV eyes, a tool pouch and sophisticated control software, can be operated by astronauts or flight controllers on the the ground to perform equipment swap outs that otherwise would require a spacewalk.

    "This is something we haven't attempted before so it kind of goes toward exploration and new technology development," said Dana Weigel, lead space station flight director at the Johnson Space Center in Houston. "But the other piece of it is it will save EVA time. If you look at it, EVAs are risky. This will buy down some risk. If this buys back one or two EVAs, that's certainly a good trade."

    Joked Foreman, who will help Linnehan build the robot: "As spacewalkers, we don't want to put ourselves out of a job! But I think Dextre will be a boon to the space station when it gets built and put into work."

    Installation of the Japanese module, assembly of Dextre and the transfer of spare parts to the station will take up the first three spacewalks. In a milestone test scheduled for the crew's fourth excursion, Foreman and Behnken plan to test a caulk gun-like device, squirting a thick, heat-resistant pink goo known as STA-54 into deliberately damaged heat shield tiles. The goal is to demonstrate a repair technique that could help a crippled shuttle make it through the heat of re-entry.

    The demonstration is one of the final in-flight tests of procedures developed in the wake of the 2003 Columbia disaster to give astronauts a fighting chance in case of major heat shield damage that might otherwise prevent a safe descent to Earth.

    "I consider it to be kind of the last thing we're going to do on the return to flight tile and (wing leading edge) repair tasks that we took on," said shuttle program manager John Shannon. "We have high confidence in it, but this will just be the final activity that we'll do to verify that's indeed a good repair capability."

    While not a requirement, a successful test would give NASA added confidence about launching the shuttle Atlantis in late August on a final Hubble Space Telescope servicing mission, a flight that cannot take advantage of safe haven aboard the space station if major heat shield damage occurs.

    Along with transferring fresh water and supplies to the space station, the Endeavour astronauts also will temporarily store the shuttle's 50-foot-long heat-shield inspection boom on the forward face of the station's solar power truss for use by the crew of the next assembly mission. That flight will deliver the huge Japanese experiment module, or JEM, to the station and there is not enough room for the lab and the boom in Discovery's cargo bay.

    "If you had to go to a drawing board and describe an exciting mission from scratch, I think you would come up with STS-123," Gorie said of Endeavour's flight. "We've got everything on this mission that you can imagine, going to the space station, taking Garrett up there and dropping him off for another crew member, 16 days on orbit, five spacewalks, international hardware, a night launch, a night landing. It's all there."

    If all goes well, Endeavour will undock from the space station around 8 p.m. on March 24 and land back at the Kennedy Space Center around 8:33 p.m. on March 26.


    8:30 PM, 3/10/08, Update: Shuttle fueled for flight

    The space shuttle Endeavour's external tank has been loaded with a half-million gallons of liquid oxygen and hydrogen rocket fuel. The engine cutoff - ECO - sensors at the base of the hydrogen tank are performing normally, there are no technical problems of any significance and forecasters continue to predict good weather for a launch attempt at 2:28:14 a.m. Tuesday.

    Fueling began at 5:04 p.m. and the tank was full exactly three hours later, transitioning to stable replenish mode. Endeavour's crew is expected to suit up and head for launch pad 39A around 10:38 p.m. to begin strapping in for launch shortly after 11 p.m.


    5:15 PM, 3/10/08, Update: Shuttle fueling begins

    Working by remote control, engineers began pumping a half-million gallons of liquid oxygen and liquid hydrogen rocket fuel into the shuttle Endeavour's external tank today just after 5 p.m. , setting the stage for a sky-lighting launch on a space station assembly mission at 2:28:14 a.m. Tuesday.

    There are no major technical problems at pad 39A and forecasters say they expect the weather to cooperate. As usual, engineers will be paying close attention to low-level hydrogen sensors at the base of the external tank that have caused problems in recent countdowns. A fix ordered in the wake of open circuits that derailed a December launch worked flawlessly during the shuttle Atlantis' launch campaign in February and NASA managers are confident the sensors in Endeavour's tank will work properly as well.

    But now-standard tests will be carried out to make sure. The three-hour fueling process started at 5:04 p.m. with propellant transfer line chilldown and the sensors will be submerged in liquid hydrogen around 5:50 p.m. The circuits will be monitored throughout the remainder of the countdown.

    If all goes well, fueling will be complete by around 8 p.m. and Endeavour's crew - commander Dominic Gorie, pilot Gregory Johnson, flight engineer Michael Foreman, Richard Linnehan, Robert Behnken, Japanese astronaut Takao Doi and space station flight engineer Garrett Reisman - will begin strapping in just after 11 p.m. to await launch.


    10:45 AM, 3/10/08, Update: Comm cable swapped out; countdown on track for Tuesday launch

    Rollback of a protective gantry from the shuttle Endeavour was delayed today while engineers replaced a suspect cockpit audio cable that will be used by flight engineer Mike Foreman during the climb to space early Tuesday. Tower rollback was delayed about three hours, but by 9 a.m., the huge gantry was in its launch position and engineers said the snag would not have any impact on the remainder of Endeavour's countdown.

    Launch is targeted for 2:28:14 a.m. and forecasts are continuing to predict a 90 percent chance of acceptable weather. Other than the cable replacement and work overnight to repair minor tile damage near a nose rocket thruster, the countdown is proceeding smoothly with no technical issues of any significance.

    NASA's Mission Management Team plans to meet late this afternoon to assess the weather and any outstanding technical issues before giving the launch team permission to begin loading a half-million gallons of liquid oxygen and hydrogen rocket fuel into Endeavour's external tank. The three-hour remotely controlled procedure is scheduled to begin around 5 p.m.

    Endeavour's crew - Foreman, commander Dominic Gorie, pilot Gregory Johnson, Richard Linnehan, Robert Behnken, Japanese astronaut Takao Doi and space station flight engineer Garrett Reisman - plans to don their pressure suits and head for the pad to strap in around 10:38 p.m.

    Endeavour's trajectory for the second night launch of the post-Columbia era will carry it along a path paralleling the East Coast of the United States, a dramatic sight for viewers with clear weather. T.S. Kelso, a noted satellite tracking analyst, provides a very useful visualization tool illustrating the shuttle's flight path and visibility from various locations. Interested readers can find the STS-123 data file, and the free Analytical Graphics viewer software necessary to play it, here:

    Here is a timeline for the remainder of today's countdown, major ascent events and the crew's post-launch timeline (in EDT; best viewed with fixed-width font):

    EDT...........EVENT
    
    03:03 PM......Begin 2-hour built-in hold (T-minus 6 hours)
    03:58 PM......Crew wakeup
    04:03 PM......External tank ready for loading
    04:18 PM......Mission management team tanking meeting
    05:03 PM......Resume countdown (T-minus 6 hours)
    
    05:03 PM......Liquid oxygen (LO2), liquid hydrogen (LH2) transfer line chilldown
    05:13 PM......Main propulsion system chill down
    05:13 PM......LH2 slow fill
    05:43 PM......LO2 slow fill
    05:48 PM......Hydrogen ECO sensors go wet
    05:53 PM......LO2 fast fill
    06:03 PM......LH2 fast fill
    07:58 PM......LH2 topping
    08:03 PM......LH2 replenish
    08:03 PM......LO2 replenish
    
    08:03 PM......Begin 2-hour 30-minute built-in hold (T-minus 3 hours)
    08:03 PM......Closeout crew to white room
    08:03 PM......External tank in stable replenish mode
    08:18 PM......Astronaut support personnel comm checks
    08:48 PM......Pre-ingress switch reconfig
    08:55 PM......Crew breakfast/photo op (recorded)
    09:30 PM......NASA television launch coverage begins
    09:58 PM......Final crew weather briefing
    10:08 PM......Crew suit up begins
    10:33 PM......Resume countdown (T-minus 3 hours)
    
    10:38 PM......Crew departs O&C building
    11:08 PM......Crew ingress
    11:58 PM......Astronaut comm checks
    
    Tue  03/11/08
    
    12:13 AM......Hatch closure
    12:53 AM......White room closeout
    
    01:13 AM......Begin 10-minute built-in hold (T-minus 20m)
    01:23 AM......NASA test director countdown briefing
    01:23 AM......Resume countdown (T-minus 20m)
    
    01:24 AM......Backup flight computer to OPS 1
    01:28 AM......KSC area clear to launch
    
    01:34 AM......Begin final built-in hold (T-minus 9m)
    02:04 AM......NTD launch status verification
    02:19:14 AM...Resume countdown (T-minus 9m)
    
    02:20:44 AM...Orbiter access arm retraction
    02:23:14 AM...Launch window opens
    02:23:14 AM...Hydraulic power system (APU) start
    02:23:19 AM...Terminate LO2 replenish
    02:24:14 AM...Purge sequence 4 hydraulic test
    02:24:14 AM...Inertial measurement units to inertial
    02:24:19 AM...Elevons, speed brake steering check
    02:24:44 AM...Main engine steering test
    02:25:19 AM...LO2 tank pressurization
    02:25:39 AM...Fuel cells to internal reactants
    02:25:44 AM...Clear caution-and-warning memory
    02:26:14 AM...Crew closes visors
    02:26:17 AM...LH2 tank pressurization
    02:27:24 AM...Booster joint heater deactivation
    02:27:43 AM...Shuttle flight computers take control of countdown
    02:27:53 AM...Booster steering test
    02:28:07 AM...Main engine start (T-6.6 seconds)
    
    02:28:14 AM...LAUNCH
    
    ..............Return to Launch Site abort option available (1 engine out)
    
    02:28:24 AM...(T+00:10) Start roll maneuver
    02:28:32 AM...(T+00:18) Start throttle down (72%)
    02:29:03 AM...(T+00:49) Max q (686 pounds per square foot)
    02:29:07 AM...(T+00:53) Start throttle up (104.5%)
    02:30:19 AM...(T+02:05) Booster separation
    02:30:29 AM...(T+02:15) Start OMS assist rocket firing (1:54 duration)
    
    ..............Trans-Atlantic Landing abort option available (1 engine out)
    
    02:30:47 AM...(T+02:33) 2 Engine TAL Moron (104.5%, 2S)
    02:30:52 AM...(T+02:38) 2 Engine TAL Zaragoza (104.5%, 2S)
    02:31:03 AM...(T+02:49) 2 Engine TAL Istres (104.5%, 2S)
    02:32:01 AM...(T+03:47) Negative return (KSC) (104.5%, 3S)
    
    ..............Abort to Orbit option available (1 engine out)
    
    02:33:16 AM...(T+05:02) Press to ATO (104.5%, 2S, 160 u/s)
    02:33:38 AM...(T+05:24) Droop Zaragoza (109%,0s)
    02:33:40 AM...(T+05:26) Single engine ops-3 Zaragoza (109%,0s,2eo simo)
    02:34:01 AM...(T+05:47) Roll to headsup
    
    ..............Normal orbit available (1 engine out)
    
    02:34:17 AM...(T+06:03) Press to MECO (104.5%, 2S, 160 u/s)
    02:34:18 AM...(T+06:04) Single engine TAL Zaragoza (104.5%,2S,2eo simo)
    02:34:18 AM...(T+06:04) Single engine TAL Moron(109%,0s,2eo seq,1st eo @ 5780 vi)
    02:34:18 AM...(T+06:04) Single engine TAL Istres(109%,0s,2eo seq,1st eo @ 6150 vi)
    02:35:09 AM...(T+06:55) Single engine press-to-MECO (104.5%, 2S, 566 u/s)
    02:35:34 AM...(T+07:20) Negative Moron (2@67%)
    02:35:36 AM...(T+07:22) 3G limiting
    02:35:55 AM...(T+07:41) Last 2 eng pre-MECO TAL Zaragoza (67%)
    02:35:55 AM...(T+07:41) Negative Istres (2@67%)
    02:36:02 AM...(T+07:48) Last single eng pre-MECO TAL Zaragoza (104.5%)
    02:36:07 AM...(T+07:53) 23K
    02:36:07 AM...(T+07:53) Last 3 eng pre-meco TAL Zaragoza (67%)
    02:36:32 AM...(T+08:18) Last TAL Diego Garcia
    02:36:37 AM...(T+08:23) Engine cutoff command (MECO)
    02:36:43 AM...(T+08:29) Zero thrust
    03:06:00 AM...OMS-2 rocket firing to raise perigee
    03:18:00 AM...Post insertion timeline begins
    04:58:00 AM...Laptop computer setup (part 1)
    05:08:00 AM...Robot arm powerup
    05:50:00 AM...NC-1 rendezvous rocket firing
    06:03:00 AM...Robot arm checkout
    06:18:00 AM...External tank umbilical camera downlink
    07:08:00 AM...Group B computer powerdown
    08:28:00 AM...Crew sleep begins
    


    9:40 PM, 3/9/08, Update: STS-123 mission preview

    The space shuttle Endeavour, carrying a crew of seven, a Japanese storage module and a high-tech Canadian robot with 11-foot-long arms, is on track for a sky lighting pre-dawn launch March 11 to kick off a marathon five-spacewalk mission to the fast-growing international space station.

    The Japanese module is the first of two that will make up an entire wing of the space station, a state-of-the-art addition that will complement U.S. and European research modules. But the assembly of Canada's $209 million special purpose dextrous manipulator, or "Dextre," represents the most complex task of Endeavour's mission.

    Capable of manipulating objects as big as a phone booth and as small as a phone book, Dextre is an attachment for the station's Canadian-built robot arm that, in effect, will give it a pair of hands capable of positioning components to within 2 millimeters and gripping them with as little as 1.5 pounds of force.

    "If you could picture what a praying mantis would look like, that's what I liken Dextre to," Linnehan said in a NASA interview. "I grew up with cartoons and sci-fi and there used to be this show on when I was a kid called 'Gigantor, the Space Age Robot' and so, you know, my pet name for Dextre is 'Gigantor.' It's this giant robot with arms and out-riggers and all this equipment, with wrists and hands that actually move and can articulate itself all over the station."

    Once assembled and attached to the station's robot arm, Dextre, equipped with force-sensing grippers for hands, TV eyes, a tool pouch and sophisticated control software, can be operated by astronauts or flight controllers on the the ground to perform equipment swap outs that otherwise would require a spacewalk.

    "This is something we haven't attempted before so it kind of goes toward exploration and new technology development," said Dana Weigel, lead space station flight director at the Johnson Space Center in Houston. "But the other piece of it is it will save EVA time. If you look at it, EVAs are risky. This will buy down some risk. If this buys back one or two EVAs, that's certainly a good trade."

    Joked astronaut Michael Foreman, who will help Linnehan build the robot: "As spacewalkers, we don't want to put ourselves out of a job! But I think Dextre will be a boon to the space station when it gets built and put into work."

    Along with installing the Canadian robot and Japan's pressurized logistics module, the Endeavour astronauts also plan to ferry space station flight engineer Garrett Reisman to the lab complex and bring European Space Agency astronaut Leopold Eyharts back to Earth after six weeks in space.

    And in a milestone test scheduled for the crew's fourth spacewalk, Foreman and Robert Behnken plan to test a caulk gun-like device, squirting a thick, heat-resistant pink goo known as STA-54 into deliberately damaged heat shield tiles to demonstrate a repair technique that could help a crippled shuttle make it through the heat of re-entry.

    The demonstration is one of the final in-flight tests of procedures developed in the wake of the 2003 Columbia disaster to give astronauts a fighting chance in case of major heat shield damage that might otherwise prevent a safe descent to Earth.

    "I consider it to be kind of the last thing we're going to do on the return to flight tile and (wing leading edge) repair tasks that we took on," said shuttle program manager John Shannon. "We have high confidence in it, but this will just be the final activity that we'll do to verify that's indeed a good repair capability."

    While not a requirement, a successful test would give NASA added confidence about launching the shuttle Atlantis in late August on a final Hubble Space Telescope servicing mission, a flight that cannot take advantage of safe haven aboard the space station if major heat shield damage occurs.

    Along with transferring fresh water and supplies to the space station, the Endeavour astronauts also will temporarily store the shuttle's 50-foot-long heat-shield inspection boom on the forward face of the station's solar power truss for use by the crew of the next assembly mission. That flight will deliver the huge Japanese experiment module, or JEM, to the station and there is not enough room for the lab and the boom in Discovery's cargo bay.

    "If you had to go to a drawing board and describe an exciting mission from scratch, I think you would come up with STS-123," commander Dom Gorie said of Endeavour's flight. "We've got everything on this mission that you can imagine, going to the space station, taking Garrett up there and dropping him off for another crew member, 16 days on orbit, five spacewalks, international hardware, a night launch, a night landing. It's all there."

    Launch is targeted for 2:28:12 a.m. EDT Tuesday, roughly the moment Earth's rotation carries launch pad 39A into the plane of the space station's orbit. Assuming an on-time launching, Gorie and pilot Gregory Johnson will guide Endeavour to a docking with the space station around 11:30 p.m. Wednesday.

    The next day, Linnehan and Reisman will stage the first of the crew's five planned spacewalks - a record for station assesmbly during a single shuttle flight - to prepare the new Japanese logistics module for installation and to begin putting Dextre together.

    Japan is supplying three critical components to the station, known collectively as Kibo, or Hope, in English. The centerpiece of the Japanese addition is the huge Japanese Experiment Module that will be bolted to the left side of the Harmony connecting module in late May. The smaller pressurized module carried aloft by Endeavour will serve as a logistics depot and ultimately will be mounted to a port on the lab module's outboard upper end.

    Finally, a porch-like deck will be added next year for experiments that need access to the space environment. An airlock on the far end of the JEM, along with a sophisticated robot arm, will permit researchers to move experiments inside and out as required.

    Because of its sheer size, NASA is launching Kibo in stages. The pressurized logistics module delivered by Endeavour's crew will be temporarily mounted on the Harmony module's upper port the day after docking. Linnehan and Reisman will prepare the module for attachment to Harmony before beginning assembly of Dextre.

    Linnehan will be joined by Foreman for the Endeavour crew's second spacewalk on March 15 and by Behnken for the third on March 17. The first two spacewalks are devoted to Dextre assembly while the third will be used to complete any unfinished work and to store spare parts on the station, including a joint for the station's main robot arm and two power switching units.

    Behnken and Foreman will carry out the final two spacewalks on March 20 and 22 to replace a critical circuit breaker, test the "T-RAD" heat shield repair tool and to help mount the shuttle's heat shield inspection boom on the station.

    Linnehan, a large animal veterinarian before becoming an astronaut, last flew in space aboard Columbia in 2002 when he helped service the Hubble Space Telescope. Working on Hubble, he said, was like performing surgery, "operating on a big beast and you go in and open it up. It's like playing 'Operation' on a large scale, if you can remember that game we used to play when you were a kid."

    "With this mission, it's much more physically strenuous," he said. "This is like being a longshoreman in terms of the physical exertion and what happens with moving big pieces of the station around robotically and with humans. I would have to say this is a much more complicated mission than the Hubble mission was."

    If all goes well, Endeavour will undock from the space station around 8 p.m. on March 24 and land back at the Kennedy Space Center around 8:35 p.m. on March 26.

    Endeavour's mission is just the latest in a series of critical flights to the fast-growing space station.

    In a dramatic prelude, the European Space Agency successfully launched the Jules Verne Automated Transfer Vehicle, or ATV, Saturday evening from Kourou, French Guiana, atop powerful Ariane 5 rocket. The ATV, carrying more than 10,000 pounds of equipment and supplies - about three times the cargo of an unmanned Russian Progress freighter - is scheduled to dock at the station April 3, after Endeavour is back on Earth.

    The Jules Verne is the first of at least five ATVs being built by EADS-Astrium for the European Space Agency as part of a $7 billion investment in the international space station project. That figure includes the cost of the ATV, ESA's Columbus research module and the ground infrastructure required to operate them.

    "The ATV as a logistics vehicle carries almost three times the hardware and fuel and water and oxygen that a Progress can carry for us," said Mike Suffredini, space station program manager for NASA. "So it is a major contribution to the program. Probably more significantly will be post 2010 when the shuttle is no longer available for us to do much of the logistics work it does. To me, that's a key part of what the automated transfer vehicle brings to the program."

    Said Daniel Sacotte, ESA's Director for Human Spaceflight, Microgravity and Exploration: "Last month, with the docking of Columbus, Europe got its own flat in the ISS building. With the launch of the first ATV, we now have our own delivery truck. We have become co-owners of the ISS, now we are about to become fully-fledged partners in running it."

    The Russians plan to follow the ATV docking with launch of a Soyuz spacecraft from the Baikonur Cosmodrome in Kazakhstan on April 8 to deliver two Russian cosmonauts - Sergey Volkov and Oleg Kononenko - to the space station to replace Expedition 16 commander Peggy Whitson and flight engineer Yuri Malenchenko.

    Reisman will take Eyharts' place in the Expedition 16 crew and then serve with Volkov and Kononenko after Whitson and Malenchenko return to Earth April 19 along with a South Korean guest cosmonaut who will launch with Volkov and Kononenko. If all goes well, Reisman's replacement - NASA astronaut Gregory Chamitoff - will be launched aboard the shuttle Discovery at the end of May when the Japanese Experiment Module is launched.

    At that point, the pressurized logistics module carried up by Endeavour and temporarily mounted atop the Harmony connecting module, will be moved and mounted on the far end of the JEM to serve as a sort of storage locker for the larger lab module.

    "We're having kind of a growth spurt right now in terms of we're finally getting the international partners on-line," Linnehan said in a NASA interview. "It's almost an exponential growth in space aboard the ISS in terms of scientific capability and also bringing in a larger crew with larger space, larger power capability with the new arrays that are up there. We're able to put more modules (up) and we're able to open up space. I think the JEM itself is about the size of a Greyhound bus. It's a really big module. It's going to give us a lot more operational space and I think once we have that happening with Columbus and all that, that's when we're going to be looking at increasing crew size and bringing people up and we'll have a true multi-national crew on ISS."

    The international nature of the space station project reflects a partnership that Reisman described as "really one of the most remarkable stories in the whole history of the space station program."

    "It's a fantastic engineering feat, something unparalleled, really, in the history of engineering," he said. "But on top of that, it's also an amazing political achievement. The fact that we've gone through so many different administrations here in the United States, over in Russia and in Japan, Canada, it survived all of that, it held together, and it's only strengthened over time as we've learned to work together.

    "So it's very exciting now that we're bringing in more partners on a day to day basis. These partners have always been with us, but now they're getting their hands really dirty and being a real big contributor to the whole program. It's a very exciting time."

    Reisman, Gorie, Linnehan, Foreman and Behnken will be joined by pilot Gregory Johnson and Japanese astronaut Takao Doi, a shuttle veteran responsible for activating the new Japanese pressurized logistics module. Gorie is making his fourth shuttle flight as is Linnehan. Foreman, Behnken, Johnson and Reisman are space rookies.

    "The highlight of my whole spaceflight is going to be being part of this crew," Reisman said. "For me, since I'll be doing robotics and space walking and assisting all these guys in their tasks, for me it's kind of like playing the Super Bowl and then going about the regular season for another two months. I've had such a good time as far as this crew, I think when it's time to close the hatches I'm going to be looking around saying, 'where are you guys going? Why are you leaving me here?'"

    AFTER A RARE NIGHT LAUNCH, A STANDARD STATION RENDEZVOUS

    To reach the international space station, shuttles must blast off within five minutes of the moment the pad is in the plane of the lab's orbit. For March 11, a night launch is required, only the second in eight post-Columbia flights.

    As usual, a battery of film, video and still cameras will photograph Endeavour's climb to space, including cameras mounted on the shuttle's twin solid-fuel boosters, on its external fuel tank and inside an umbilical well in the shuttle's belly where external tank propellant lines enter the orbiter.

    Tank separation will occur in orbital darkness, but Endeavour is equipped with Nikon flash units for the umbilical well camera to help engineers document the condition of the tank's foam insulation. The flash system, which is powerful enough to illuminate the tank at distances up to 130 feet, will fire every two seconds starting eight seconds after separation. Twenty three flashes are expected before the tank drifts too far away.

    The umbilical well imagery will be downlinked as soon as possible, along with data from impact sensors mounted behind Endeavour's reinforced carbon carbon wing leading edge panels. While analysis of the imagery and radar data is going on at the Johnson Space Center in Houston, the astronauts will spend their second day in space carrying out a now-standard inspection of the ship's nose cap and RCC panels, which experience the most extreme heat during re-entry.

    Gorie, Johnson and Doi will use the shuttle's 50-foot-long robot arm to latch onto the equally long orbiter boom sensor system, or OBSS, mounted along the right side of Endeavour's cargo bay. The OBSS is equipped with a laser scanner and high-resolution cameras capable of spotting any significant impact damage to the critical nose cap and wing leading edge panels.

    "We're all operating the shuttle's robotic arm and we'll first grapple the OBSS, the Orbiter Boom Sensor System, and it about doubles the length of the arm," Johnson said in a NASA interview. "Then we can reach around and look underneath the orbiter and check out all the tiles and the reinforced carbon carbon and we can also reach around and look at the nose of the shuttle. We basically will be inspecting in great detail every little, tiny little patch of thermal protection system on the shuttle. So it's an all-day task."

    DATE/EDT.......DD...HH...MM...EVENT
    
    03/11/08
    Tue 02:28 AM...00...00...00...Launch
    Tue 03:06 AM...00...00...38...OMS-2 rocket firing
    Tue 03:18 AM...00...00...50...Post insertion timeline begins
    Tue 04:58 AM...00...02...30...Laptop computer setup (part 1)
    Tue 05:08 AM...00...02...40...Shuttle robot arm (SRMS) powerup
    Tue 05:52 AM...00...03...24...NC-1 rendezvous rocket firing
    Tue 06:03 AM...00...03...35...SRMS checkout
    Tue 06:18 AM...00...03...50...ET umbilical camera downlink
    Tue 06:38 AM...00...04...10...Wing leading edge sensors activated
    Tue 07:08 AM...00...04...40...Group B computer powerdown
    Tue 08:28 AM...00...06...00...Crew sleep begins
    Tue 04:28 PM...00...14...00...Crew wakeup
    Tue 07:08 PM...00...16...40...Laptop computer setup (part 2)
    Tue 07:37 PM...00...17...09...NC-2 rendezvous rocket firing
    Tue 07:38 PM...00...17...10...SRMS unberths OBSS
    Tue 08:08 PM...00...17...40...Spacesuit checkout preps
    Tue 08:28 PM...00...18...00...Ergometer setup
    Tue 08:38 PM...00...18...10...Spacesuit checkout
    Tue 08:53 PM...00...18...25...OBSS starboard wing survey
    Tue 10:28 PM...00...20...00...Crew meal
    Tue 10:48 PM...00...20...20...OBSS nose cap survey
    Tue 11:28 PM...00...21...00...Spacewalk equipment prepped for transfer
    
    03/12/08
    Wed 12:33 AM...00...22...05...Transfer preps
    Wed 12:38 AM...00...22...10...OBSS port wing survey
    Wed 12:58 AM...00...22...30...OMS rocket pod survey
    Wed 02:38 AM...01...00...10...SRMS berths OBSS
    Wed 02:58 AM...01...00...30...Laser data downlink
    Wed 03:38 AM...01...01...10...Rendezvous tools checkout
    Wed 04:38 AM...01...02...10...Centerline camera setup
    Wed 04:58 AM...01...02...30...NC-3 rendezvous rocket firing
    Wed 08:13 AM...01...05...45...Crew sleep begins
    
    While the heat shield inspection is going on, the other crew members will check out the spacesuits that will be needed later in the mission, test the handheld lasers and other gear needed for the station rendezvous and rig the ship for docking.

    The final phase of the two-day orbital chase will begin around 8:42 p.m. Wednesday with a critical rocket firing as Endeavour trails the station by about 9.2 miles. After reaching a point about 600 feet directly below the lab complex, Gorie will fire maneuvering jets to put the shuttle in a slow back flip, exposing the ship's heat shield while the station crew snaps dozens of high-resolution photos with digital cameras equipped with 400- and 800-millimeter lenses.

    "The rendezvous pitch maneuver is a 360 degree pitch almost like a loop where we expose the bottom of the orbiter to the space station where they have some very powerful cameras ... like you see out at the end of the football field in the end zone with people taking pictures of a football game," Gorie said. "And with those cameras, they are able to detect whether there's any white tile showing on the surface of the orbiter and that would mean that the black coating on the belly tiles has been damaged.

    "During the RPM, the commander is in charge of the orbiter and flying the vehicle, so I'll be at the aft station of the space shuttle flight deck and we'll be looking out through the overhead windows as we start this maneuver and make sure that we are in the right position with the right rates. We'll start that off with an auto pilot maneuver that takes us through this hands-off pitch at that point. It's sort of different than anything we've done before as, as astronauts, to be hands-off of the orbiter as we cannot see the space station any more. But the last couple flights that have done this have had great luck and it's worked very well for us."

    DATE/EDT.......DD...HH...MM...EVENT
    
    03/12/08
    Wed 04:13 PM...01...13...45...STS crew wakeup
    Wed 04:28 PM...01...14...00...ISS crew wakeup
    Wed 05:13 PM...01...14...45...Group B computer powerup
    Wed 05:18 PM...01...14...50...ISS daily planning conference
    Wed 05:33 PM...01...15...05...Rendezvous timeline begins
    Wed 06:18 PM...01...15...50...NH rendezvous rocket firing
    Wed 07:08 PM...01...16...40...NC-4 rendezvous rocket firing
    Wed 07:58 PM...01...17...30...Spacesuits removed from airlock
    Wed 08:40 PM...01...18...12...TI rocket firing (range to ISS: 9.2 sm)
    Wed 09:08 PM...01...18...40...ISS crew meal
    Wed 09:28 PM...01...19...00...Hand-held laser ops
    Wed 09:53 PM...01...19...25...Approach timeline begins
    Wed 10:20 PM...01...19...52...RPM photography
    Wed 11:27 PM...01...20...59...DOCKING
    Wed 11:48 PM...01...21...20...Leak checks
    
    03/13/08
    Thu 12:08 AM...01...21...40...Docking video playback
    Thu 12:18 AM...01...21...50...Orbiter docking system prepped for ingress
    Thu 12:28 AM...01...22...00...Group B computer powerdown
    Thu 12:33 AM...01...22...05...Post docking laptop reconfig
    Thu 12:38 AM...01...22...10...Hatch open
    Thu 01:08 AM...01...22...40...Welcome aboard!
    Thu 01:13 AM...01...22...45...Safety briefing
    Thu 01:38 AM...01...23...10...Post-docking EVA transfer
    Thu 01:38 AM...01...23...10...Soyuz seatliner transfer to ISS
    Thu 01:38 AM...01...23...10...SRMS grapples Dextre Spacelab pallet (SLP)
    Thu 02:28 AM...02...00...00...SLP unberth and install
    Thu 02:28 AM...02...00...00...Soyuz seatliner installation
    Thu 03:18 AM...02...00...50...Logistics transfers
    Thu 03:33 AM...02...01...05...SLP ungrapple
    Thu 03:38 AM...02...01...10...Airlock preps
    Thu 04:28 AM...02...02...00...EVA-1: Procedures review
    Thu 07:38 AM...02...05...10...EVA-1: Airlock 10.2 psi depress
    Thu 08:28 AM...02...06...00...STS crew sleep begins
    
    With the RPM complete, Gorie will guide Endeavour to a point about 400 feet directly in front of the space station with the shuttle's tail pointed toward Earth and its open payload bay facing pressurized mating adapter No. 2 on the front end of the Harmony module.

    "We slowly back into the space station with the commander at the controls and flying it manually," Gorie said. "That is one of the most exciting parts of the mission for me. You get to fly formation with the space ship being framed by creation underneath you, that's just spectacular. So it's very easy to get distracted by the beauty of what's going on underneath and the beauty of the space station. Flying formation at that time is a really, really exciting thing that demands everybody on the flight deck to be participating. Everybody has a role in that process so it really relies a lot on teamwork and training."

    The actual docking, Gorie said, "is really exciting. ... The docking system is a very elaborate beautifully designed piece of equipment that can connect the two vehicles together after a very slow collision. There are hooks that grab onto the space station, once all of the motions are damped out, with springs like shock absorbers on this extended ring. We slowly draw the two vehicles together with the screw drives that pull it together and after an hour of pressure checks and docking system checks we are able then to open the hatch. But knowing that there's this space station crew on the other side waiting for our arrival, eager to have a replacement for one of their folks and, and some of the re-supply items that we're bringing, it makes it a really an exciting time as well."

    Whitson, Malenchenko and Eyharts will welcome the shuttle crew into the Harmony module. After a mandatory safety briefing to familiarize the visiting astronauts with emergency procedures, the crews will get busy transferring spacesuits and other equipment to the station's Quest airlock to prepare for the first spacewalk the following day.

    The disassembled Dextre robot, designed to operate in weightlessness, has been tested but never fully assembled on Earth. It will make the climb to space in pieces bolted to a Spacelab pallet in the shuttle's cargo bay. After docking, Behnken and Johnson, operating the station's robot arm from inside the Destiny lab module, plan to pull the pallet out of the cargo bay. It will be attached to a grapple fixture on the side of the mobile base system normally used to move the station arm along the front face of the main solar power truss.

    The robot cannot be assembled in the cargo bay because of its sheer size. If an emergency developed requiring a quick separation from the station, Endeavour's cargo bay doors could not be closed due to interference with Dextre. As a result, NASA flight planners decided to have the crew anchor the Spacelab pallet to the mobile base system and to build the robot on the station's power truss. After assembly is complete, Dextre will be mounted on the hull of the Destiny module and the pallet will be reberthed in Endeavour's cargo bay for return to Earth.

    "Right after we rendezvous we're going to take that SLP and install it in a temporary location on the ISS," Johnson said. "Then through the next three or four days, actually five or six days, we're going to assemble Mr. Dextre on the various spacewalks and that's a pretty involved process."

    SPACEWALKS 1 and 2: JAPANESE MODULE INSTALLATION AND Dextre ASSEMBLY

    As with all spacewalks staged from the Quest airlock module, Linnehan and Reisman will spend the night in the airlock at a reduced pressure of 10.2 pounds per square inch as part of a standard, though lengthy, procedure to purge nitrogen from their bloodstreams. This helps prevent the bends after a day spent wearing NASA's 5 psi spacesuits.

    After exiting the airlock around 9:30 p.m. the day after docking, Linnehan and Reisman will make their way to Endeavour's cargo bay where they first will remove eight thermal blankets protecting the Japanese logistics module's common berthing mechanism. Moving to the front of the module, Reisman will unplug an electrical cable that supplied shuttle power to internal heaters.

    "Our job is to prepare the JLP for installation on the space station," Reisman said. "There are covers, kind of blankets that keep it warm in the coldness of space, that need to be removed before it gets installed. So we have to take off those covers and blankets. Then we also have to unplug (an) electrical cable that is used to keep it warm while it's inside the payload bay and that cable needs to be unplugged before it's lifted out, installed on the space station."

    Once that is completed, Doi, operating Endeavour's robot arm, will pull the module out of the cargo bay and begin the slow process of moving it to Harmony's upward-facing port. Linnehan and Reisman, meanwhile, will move up to the front of the station's power truss, make their way to the mobile base system to begin assembling Dextre.

    "We'll be focused on our work but, out of the corner of our eye, we'll see them taking this big module outside the payload bay," Reisman said. "It should be quite a sight watching that get installed as we go over to do the beginning, the first assembly work on Dextre. Our job is basically to put Dextre's hands on his arms."

    DATE/EDT.......DD...HH...MM...EVENT
    
    03/13/08
    Thu 04:28 PM...02...14...00...Crew wakeup
    Thu 05:08 PM...02...14...40...EVA-1: 14.7 psi repress/hygiene break
    Thu 05:53 PM...02...15...25...EVA-1: Airlock depress to 10.2 psi
    Thu 06:18 PM...02...15...50...EVA-1: Campout EVA preps
    Thu 07:48 PM...02...17...20...EVA-1: Spacesuit purge
    Thu 08:03 PM...02...17...35...EVA-1: Spacesuit prebreathe
    Thu 08:53 PM...02...18...25...EVA-1: Crew lock depressurization
    Thu 09:23 PM...02...18...55...EVA-1: Spacesuits to battery power
    Thu 09:28 PM...02...19...00...EVA-1: Airlock egress
    Thu 10:08 PM...02...19...40...EVA-1: JLP unberth prep
    Thu 11:23 PM...02...20...55...EVA-1: OTCM 2 install
    
    03/14/08
    Fri 01:23 AM...02...22...55...EVA-1: OTCM 1 install
    Fri 01:58 AM...02...23...30...JLP unberth
    Fri 02:38 AM...03...00...10...SODF deploy
    Fri 02:43 AM...03...00...15...SPDM assembly preps
    Fri 03:08 AM...03...00...40...EVA-1: Cleanup
    Fri 03:33 AM...03...01...05...EVA-1: Airlock ingress
    Fri 03:53 AM...03...01...25...CBM first stage bolts
    Fri 03:53 AM...03...01...25...EVA-1: Airlock repressurization
    Fri 04:08 AM...03...01...40...Spacesuit servicing
    Fri 04:13 AM...03...01...45...CBM second stage bolts
    Fri 04:28 AM...03...02...00...Soyuz seatliner transfer to station
    Fri 05:08 AM...03...02...40...Alignment camera removed
    Fri 05:58 AM...03...03...30...JLP leak checks
    Fri 06:03 AM...03...03...35...JLP ungrapple
    Fri 07:58 AM...03...05...30...ISS crew sleep begins
    Fri 08:28 AM...03...06...00...STS crew sleep begins
    
    "The business end of Dextre if you like, Dextre's hands, also called the ORU tool changeout mechanisms (OTCMs), are equipped with force moment sensors," said Daniel Rey, Dextre integration manager for the Canadian Space Agency. "What makes Dextre able to perform these human scale tasks is the sense of touch it has and the automatic control that allows it to compensate for sets of forces, or moments, so that despite the crews commands, since they have no direct view and no direct force feedback except what's on their graphical display, Dextre will be able to prevent something from jamming."

    Replacing a failed space station component, he said, is similar to pulling out and re-inserting a drawer.

    "An insertion or an extraction is quite a delicate task, it's like trying to remove an old drawer from a chest that maybe is a bit damp and it requires that sense of touch that Dextre has built into it," Rey said. "Other features of the hand are the grippers ... and in the middle of the grippers, you notice there's a socket that can be extended identical to what you'd find on the EVA crew member's pistol grip tool. So it's a seven-sixteenths socket and that extends to unbolt an ORU."

    When fully assembled and attached to the station's robot arm, Dextre can be positioned next to a failed component. Using one of its hands to lock onto the station to provide rigidity, the other hand's grippers can lock onto the component, the socket wrench can unbolt it, the unit can be withdrawn and a replacement inserted.

    "There's a choreography that goes on with Canadarm2 to place Dextre in front of the work site," Rey said. "One arm will then be used to advance and stabilize the system. Since it's at the very end of a large, flexible arm 17 meters long, it's required to stabilize to avoid too many oscillations for the delicate maintenance tasks. So once the stabilization arm has acquired the stabilization fixture, the other arm is advanced.

    "We're looking forward to being used on orbit," Rey said. "We have every reason to believe that Dextre will meet and exceed its specifications the same as Canadarm2 did.

    But first, it has to be assembled. Dextre's two arms are mounted on either side of the Spacelab pallet with the robot's central torso in the center. After setting up their tools, Reisman will mount a foot restraint on the pallet while Linnehan clips his boots into a foot restraint on the end of the station's robot arm. He then will release two clamps to free the first OTCM, which will be attached to its arm with four mechanical fasteners and two electrical cables.

    To provide plenty of clearance for Doi, who will still be maneuvering the Japanese module into place using the shuttle's robot arm, Linnehan will get off the station arm and the second OTCM will be install while he and Reisman are free floating.

    The next day, the crew's flight day five, the astronauts will open the Japanese module and float inside to continue activation and outfitting. A block of time also is set aside for any focused heat shield inspections that might be required if any damage is spotted in the analysis of launch imagery and data.

    DATE/EDT.......DD...HH...MM...EVENT
    
    03/14/08
    Fri 04:28 PM...03...14...00...Crew wakeup
    Fri 06:28 PM...03...16...00...ISS daily planning conference
    Fri 06:43 PM...03...16...15...Reisman's SOKOL suit leak check
    Fri 06:53 PM...03...16...25...JLP vestibule outfitting (part 1)
    Fri 07:13 PM...03...16...45...SOKOL suit drying
    Fri 07:28 PM...03...17...00...SSRMS grapples OBSS
    Fri 07:58 PM...03...17...30...SSMRS unberths OBSS
    Fri 08:13 PM...03...17...45...SSMRS hands OBSS off to SRMS
    Fri 08:48 PM...03...18...20...JLP outfitting (part 2)
    Fri 08:58 PM...03...18...30...SRMS grapples OBSS
    Fri 09:18 PM...03...18...50...SSRMS releases OBSS
    Fri 10:03 PM...03...19...35...Logistics transfers
    Fri 10:48 PM...03...20...20...EVA-2: Tool config
    Fri 10:58 PM...03...20...30...Crew meals begin
    
    03/15/08
    Sat 12:18 AM...03...21...50...JLP ingress
    Sat 01:48 AM...03...23...20...PAO event
    Sat 01:53 AM...03...23...25...Airlock preps
    Sat 03:58 AM...04...01...30...EVA-2: Procedures review
    Sat 06:38 AM...04...04...10...EVA-2: Airlock depress to 10.2 psi
    Sat 07:28 AM...04...05...00...STS crew sleep begins
    
    Linnehan will be joined by Foreman for the mission's second spacewalk, an excursion expected to take about seven hours to complete. The goal is to attach both arms to Dextre's central torso, no small task when one considers each hand/arm unit would weigh about 775 pounds on Earth.

    After exiting the Quest airlock, Linnehan and Foreman will make their way back to the front side of the port 1 solar power truss and remove electrical cables that provided heater power. Each 11-foot-long arm features seven joints and thermal covers protection those joints must be removed, along with the clamps holding the arms and joints in place. Each arm will be temporarily stowed on a pallet fitting during work to ready them for attachment to the torso.

    At this point, Linnehan will get back on the station arm while Foreman assists as a free floater.

    "On the second EVA Mike and I will take the constructed arms that Garrett and I built from the previous EVA, which are still positioned on the sides of the SLP, but constructed so that the wrists and the hands, so to speak, are on the arms," Linnehan said. "At that point, Mike and I will take each of those arms off the sides of the pallet and we'll have to rotate the main body of the (robot) up and then plug those arms in on these giant outriggers.

    "And as I said before, it kind of looks like a mantis. That's when it takes on its big mantis kind of robot look. Once those arms are on, we have several other things that we have to do, such as install cameras, go down and put these special tool platforms and adaptors that allow it to hold equipment from the space station on the lower part of it and actually plug in and interface its own tools, take them out and work on things. All that takes a little bit more time at the end of the EVA and some of it involves me on the end of the arm, the robot arm flying around doing it and at other times both of us will be free floating, moving around all over the pallet and building stuff that way.

    "And we hope to finish all of that in two EVAs and, as I said, if for some reason we're slow or something doesn't go the way we like, then on the third EVA Bob Behnken and I would be able to finish most of that."

    The torso of the robot will be pivoted up about 60 degrees for the attachment of the arms and hands.

    DATE/EDT.......DD...HH...MM...EVENT
    
    03/15/08
    Sat 03:28 PM...04...13...00...Crew wakeup
    Sat 04:08 PM...04...13...40...EVA-2: 14.7 psi repress/hygiene break
    Sat 04:53 PM...04...14...25...EVA-2: Airlock depress to 10.2 psi
    Sat 05:18 PM...04...14...50...EVA-2: Campout EVA preps
    Sat 06:23 PM...04...15...55...JLP outfitting
    Sat 06:48 PM...04...16...20...EVA-2: Spacesuit purge
    Sat 07:03 PM...04...16...35...EVA-2: Spacesuit prebreathe
    Sat 07:08 PM...04...16...40...SSRMS setup
    Sat 07:53 PM...04...17...25...EVA-2: Crew lock depressurization
    Sat 08:23 PM...04...17...55...EVA-2: Spacesuits to battery power
    Sat 08:28 PM...04...18...00...EVA-2: Airlock egress
    Sat 08:48 PM...04...18...20...EVA-2: Setup
    Sat 09:08 PM...04...18...40...EVA-2: SPDM arm 2 stow
    Sat 10:38 PM...04...20...10...EVA-2: SPDM arm 1 stow
    Sat 11:38 PM...04...21...10...EVA-2: SPDM arm install
    
    03/16/08
    Sun 01:28 AM...04...23...00...EVA-2 (Foreman): Cover removal; SLP cleanup
    Sun 01:28 AM...04...23...00...EVA-2 (Linnehan): SPDM cover removal
    Sun 02:38 AM...05...00...10...EVA-2: Cleanup
    Sun 03:08 AM...05...00...40...EVA-2: Airlock ingress
    Sun 03:28 AM...05...01...00...EVA-2: Airlock repressurization
    Sun 03:43 AM...05...01...15...Spacesuit servicing
    Sun 07:28 AM...05...05...00...STS crew sleep begins
    
    "I personally am going to be sighing a big sigh of relief at the end of EVA-2 when we get the OPCMs and both the arms installed," said Zeb Scoville, lead spacewalk officer. "There's a lot of really complex EVA activities going on there and coordination with some very fine robotics maneuvers required to get those installed. There have definitely been some challenges in ground training."

    DEXTRE TESTING, MODULE OUTFITTING AND HEAT SHIELD REPAIR TESTS

    The day after the second spacewalk, the astronauts and flight controllers will carry out tests to make sure Dextre's assembled appendages are working properly, participate in media interviews and prepare for spacewalk No. 3 the following day.

    DATE/EDT.......DD...HH...MM...EVENT
    
    03/16/08
    Sun 03:28 PM...05...13...00...Crew wakeup
    Sun 04:58 PM...05...14...30...JAXA PAO event
    Sun 05:18 PM...05...14...50...ISS daily planning conference
    Sun 05:43 PM...05...15...15...Brake run in arm 1
    Sun 06:43 PM...05...16...15...Brake run in arm 2
    Sun 07:48 PM...05...17...20...JLP outfitting
    Sun 08:48 PM...05...18...20...Spacesuit swap
    Sun 09:18 PM...05...18...50...Joint crew meal
    Sun 10:18 PM...05...19...50...PAO event (all)
    Sun 10:38 PM...05...20...10...JLP outfitting
    Sun 10:58 PM...05...20...30...EVA-3: Tool config
    Sun 11:48 PM...05...21...20...SPDM arm 1 SLP stow
    
    03/17/08
    Mon 12:58 AM...05...22...30...Airlock preps
    Mon 03:28 AM...06...01...00...EVA-3: Procedures review
    Mon 05:38 AM...06...03...10...EVA-3: Airlock depress to 10.2 psi
    Mon 06:28 AM...06...04...00...STS crew sleep begins
    
    Linnehan and Behnken will spend the night in the Quest airlock module to prepare for the mission's third spacewalk. With Linnehan once again on the end of the station's robot arm, the astronauts will wrap up the Dextre assembly work by removing a final set of thermal covers and installing the robot's tool carrier. Behnken also will install a camera pan and tilt unit and prepare the Spacelab pallet for its eventual reberthing in the shuttle for the return to Earth.

    Linnehan, meanwhile, will move back to the shuttle's cargo bay, collect an experiment mounting platform and attach it to the outboard end of the European Columbus research module. He then will move a spare robot arm yaw joint and two spare electronic power units, called direct current switching units, or DCSUs, from the shuttle to an external storage platform on the station.

    At that point, Linnehan will be done. As he is winding up his work, Behnken will retrieve a materials exposure experiment, known as MISSE-6, and attach it to the mounting fixture Linnehan earlier bolted to the Columbus module. After the astronauts return to the Quest airlock module, the station's robot arm will lock onto Dextre to prepare for its move the next day to a mounting point on the Destiny lab module.

    DATE/EDT.......DD...HH...MM...EVENT
    
    03/17/08
    Mon 02:28 PM...06...12...00...Crew wakeup
    Mon 03:08 PM...06...12...40...EVA-3: 14.7 psi repress/hygiene break
    Mon 03:53 PM...06...13...25...EVA-3: Airlock depress to 10.2 psi
    Mon 04:18 PM...06...13...50...EVA-3: Campout EVA preps
    Mon 05:48 PM...06...15...20...EVA-3: Spacesuit purge
    Mon 05:58 PM...06...15...30...SSRMS setup
    Mon 06:03 PM...06...15...35...EVA-3: Spacesuit prebreathe
    Mon 06:53 PM...06...16...25...EVA-3: Crew lock depressurization
    Mon 07:23 PM...06...16...55...EVA-3: Spacesuits to battery power
    Mon 07:28 PM...06...17...00...EVA-3: Airlock egress
    Mon 07:48 PM...06...17...20...EVA-3: Setup
    Mon 07:58 PM...06...17...30...EVA-3 (Behnken): Tool holder removal; pallet install
    Mon 08:08 PM...06...17...40...EVA-3 (Linnehan): Pallet install
    Mon 09:23 PM...06...18...55...EVA-3 (Behnken): Spacelab pallet cleanup
    Mon 09:23 PM...06...18...55...EVA-3 (Linnehan): Arm 2 blanket removal
    Mon 09:53 PM...06...19...25...EVA-3 (Linnehan): MISSE-6 mounting bracket transfer
    Mon 10:38 PM...06...20...10...EVA-3 (Behnken): Camera pan/tilt unit install (2)
    Mon 10:53 PM...06...20...25...EVA-3 (Linnehan): Yaw joint transfer to station
    Mon 11:18 PM...06...20...50...EVA-3 (Behnken): MISSE experiment relocate/deploy
    Mon 11:38 PM...06...21...10...EVA-3 (Linnehan): DCSU 1 transfer to station
    
    03/18/08
    Tue 12:23 AM...06...21...55...EVA-3 (Linnehan): DCSU 2 transfer to station
    Tue 01:13 AM...06...22...45...EVA-3: Cleanup
    Tue 01:28 AM...06...23...00...SSRMS Dextre grapple maneuver
    Tue 01:28 AM...06...23...00...EVA-3: Airlock ingress
    Tue 01:53 AM...06...23...25...EVA-3: Airlock repressurization
    Tue 02:08 AM...06...23...40...SSRMS grapples Dextre
    Tue 02:28 AM...07...00...00...Spacesuit servicing
    Tue 03:28 AM...07...01...00...Dextre release
    Tue 03:48 AM...07...01...20...Dextre overnight park
    Tue 06:28 AM...07...04...00...STS crew sleep begins
    
    The day after spacewalk No. 3, the astronauts will move Dextre to a mounting point on Destiny and move the Spacelab pallet back to the shuttle's cargo bay for return to Earth.

    DATE/EDT.......DD...HH...MM...EVENT
    
    03/18/08
    Tue 02:28 PM...07...12...00...Crew wakeup
    Tue 04:28 PM...07...14...00...ISS daily planning conference
    Tue 04:43 PM...07...14...15...Dextre arm 1 stow
    Tue 05:43 PM...07...15...15...Dextre arm 2 stow
    Tue 06:23 PM...07...15...55...Module outfitting
    Tue 06:43 PM...07...16...15...Dextre roll
    Tue 06:53 PM...07...16...25...Dextre stow on lab module
    Tue 07:53 PM...07...17...25...Crew meals begin
    Tue 09:03 PM...07...18...35...SSRMS releases Dextre
    Tue 09:08 PM...07...18...40...SLP grapple
    Tue 09:18 PM...07...18...50...Spacesuit swap and reconfig
    Tue 09:53 PM...07...19...25...SLP release
    Tue 10:08 PM...07...19...40...SLP berthing
    Tue 11:38 PM...07...21...10...SLP ungrapple
    Tue 11:53 PM...07...21...25...SSRMS walkoff Harmony to mobile base system
    
    03/19/08
    Wed 12:28 AM...07...22...00...Crew off duty
    Wed 01:28 AM...07...23...00...SSRMS releases node 2
    Wed 01:38 AM...07...23...10...SSRMS translation
    Wed 05:28 AM...08...03...00...STS crew sleep begins
    Wed 01:28 PM...08...11...00...Crew wakeup
    Wed 02:58 PM...08...12...30...ISS crew off duty
    Wed 04:28 PM...08...14...00...STS crew off duty
    Wed 09:08 PM...08...18...40...Joint crew news conference
    Wed 09:28 PM...08...19...00...Joint crew meal
    Wed 11:13 PM...08...20...45...T-RAD prep
    Wed 11:58 PM...08...21...30...EVA-4: Tools configured
    
    03/20/08
    Thu 01:28 AM...08...23...00...EVA-4: Procedures review
    Thu 04:38 AM...09...02...10...EVA-4: Airlock depress to 10.2 psi
    Thu 05:28 AM...09...03...00...STS crew sleep begins
    
    The mission's fourth spacewalk, by Behnken and Foreman, has two primary goals: Replacement of a faulty circuit breaker in the station's main power truss; and tests of the heat shield repair caulk gun. The former will require flight controllers to first power down critical station systems, including one of its two ammonia cooling loops.

    Behnken will change out the circuit breaker, called a remote power control module, or RPCM, while Foreman moves to the Z1 truss atop the central Unity module to reconfigure an electrical panel to provide redundant power to one of the station's stabilizing gyroscopes while the powerdowns are in force.

    With the RPCM installed, flight controllers will reactivate the powered down systems while Behnken and Foreman make their way back to the airlock to retrieve the equipment needed for the heat shield repair test. The work will be conducted on the bottom of the Destiny module, in view of the shuttle's payload bay cameras.

    "We'll actually take a couple of bags of equipment with us, all the things that you might have in your garage if you were going to do some spackling and some dry-wall repair," Behnken said in a NASA interview. "We'll have that stuff in the bag. We'll have scrapers and brushes and all that sort of equipment. We'll also have some engineering equipment. If you wanted to really understand how well of a repair job you're doing, we're taking some thermometers and a camera and things like that so that we can actually assess the progress of the repair material and our repair technique and see how we're doing with it.

    The idea is to use the tool, called a tile repair ablator dispenser, or T-RAD, to fill in deliberately damaged heat shield tiles to find out if the repair material, STA-54, will set up and adhere properly in the vacuum and weightlessness of space.

    "There are a number of different sizes and shapes of samples and really, this correlates to the different objectives we're trying to get out of this test," Scoville said. "Some of of our tests are going to be involving a study of the material itself, how it adheres to tile substrates, how it expands, if it bubbles, what sort of density it's going to have. Other objectives of this test are really to focus on how well the crew can operate and perform. It's one thing to be able to repair a very evenly machined sample. It's another thing to have a divot or pock mark that's been cut by an ice impact or foam damage. So we've modeled a couple of tile damage samples to represent things we've seen on previous missions or on ground testing.

    "There's really one main reason why we're trying to perform this test," Scoville said. "On the ground, we were able to develop techniques in a vacuum chamber to see how the material would react and then we performed tests on NASA's zero gravity airplane to understand how the repair process works in a zero gravity environment, albeit for a short period of time. But being able to combine both the vacuum and the zero gravity aspects of these together is what we're trying to figure out here."

    When the two compounds making up STA-54 are mixed in the gun applicator, a chemical reaction causes bubbles to form. On Earth, those bubbles typically rise to the top. In space, they may be more evenly distributed throughout the material. This is a critical question because it could affect the material's ability to protect damaged tiles from the heat of re-entry.

    "One of the big questions we have, in zero gravity are those bubbles going to rise to the surface or are they going to act more like a bread loaf as it bakes with the gas expanding in the material and being evenly distributed bubbles that then cause the surface to rise up over the top?" Scoville explained.

    "The surface smoothness is a big key in understanding how this will react during a re-entry scenario. If you have a lot of bubbles and expanded ridges and what not, this can disrupt the airflow ... and cause a turbulent flow transition, which can cause downstream heating and damage the orbiter on re-entry. So being able to understand how this material's going to react and expand and what we can do to control that is really one of our primary objectives of this test."

    DATE/EDT.......DD...HH...MM...EVENT
    
    03/20/08
    Thu 01:28 PM...09...11...00...Crew wakeup
    Thu 02:28 PM...09...12...00...EVA-4: 14.7 psi repress/hygiene break
    Thu 03:03 PM...09...12...35...EVA-4: Airlock depress to 10.2 psi
    Thu 03:23 PM...09...12...55...EVA-4: Campout EVA preps
    Thu 04:53 PM...09...14...25...EVA-4: Spacesuit purge
    Thu 05:08 PM...09...14...40...EVA-4: Spacesuit prebreathe
    Thu 05:58 PM...09...15...30...EVA-4: Crew lock depressurization
    Thu 06:28 PM...09...16...00...EVA-4: Spacesuits to battery power
    Thu 06:33 PM...09...16...05...EVA-4: Airlock egress
    Thu 06:53 PM...09...16...25...EVA-4: Setup
    Thu 06:58 PM...09...16...30...EVA-4 (Behnken): RPCM replacement
    Thu 06:58 PM...09...16...30...EVA-4 (Foreman): Z1 patch panel reconfig
    Thu 07:28 PM...09...17...00...EVA-4: T-RAD worksite setup
    Thu 08:48 PM...09...18...20...EVA-4: T-RAD demonstration
    Thu 10:33 PM...09...20...05...EVA-4: Tool cleanup
    Thu 11:38 PM...09...21...10...EVA-4: Cleanup
    
    03/21/08
    Fri 12:38 AM...09...22...10...EVA-4: Airlock ingress
    Fri 12:58 AM...09...22...30...EVA-4: Airlock repressurization
    Fri 01:13 AM...09...22...45...Spacesuit servicing
    Fri 04:58 AM...10...02...30...ISS crew sleep begins
    Fri 05:28 AM...10...03...00...STS crew sleep begins
    
    A FINAL SPACEWALK, UNDOCKING AND RETURN TO EARTH

    The Japanese Experiment Module was designed before th Columbia disaster and before NASA built the heat shield inspection boom that now is a standard fixture on the right side of the shuttle's cargo bay. The JEM is so large, the orbiter boom sensor system cannot be carried by Discovery when the big module is launched in late May. To make sure that crew has the ability to inspect their tiles and wing leading edge panels, Endeavour's boom will be left behind on the space station.

    Because of that, Endeavour's crew will not be able to conduct a post-undocking inspection to look for signs of damage from space debris or micrometeoroids. As a result, they plan to use the boom on the day between the fourth and fifth spacewalks to carry out what would normally be termed a late inspection.

    DATE/EDT.......DD...HH...MM...EVENT
    
    03/21/08
    Fri 01:28 PM...10...11...00...Crew wakeup
    Fri 04:03 PM...10...13...35...OBSS starboard wing survey
    Fri 05:28 PM...10...15...00...Experiment rack 3 transfer
    Fri 06:33 PM...10...16...05...Crew meals begin
    Fri 06:43 PM...10...16...15...LDRI downlink
    Fri 07:43 PM...10...17...15...OBSS nose cap survey
    Fri 07:43 PM...10...17...15...OBSS KAU assembly
    Fri 09:13 PM...10...18...45...OBSS port wing survey
    Fri 10:23 PM...10...19...55...EVA-5: Tool config
    Fri 11:13 PM...10...20...45...LDRI downlink
    Fri 11:18 PM...10...20...50...Airlock prep
    
    03/22/08
    Sat 12:58 AM...10...22...30...EVA-5: Procedures review
    Sat 03:33 AM...11...01...05...EVA-5: Airlock depress to 10.2 psi
    Sat 04:28 AM...11...02...00...STS crew sleep begins
    
    The next day, Behnken and Foreman will venture back outside for a fifth and final spacewalk to mount the OBSS on the forward face of the station's power truss. Electrical connections will provide power for heaters needed to keep the boom's laser sensor and camera package from getting too cold.

    "That sensor boom is going to be left on station because the following mission is going to deliver the next portion of the Japanese laboratory," Behnken said. "That module is a very large module and there's actually not room in the shuttle payload bay to launch both that module and this sensor boom on the same shuttle flight. So to provide the inspection capability to allow that next shuttle mission to be able to inspect their thermal protection system before they come back for re-entry, they're going to need to have a sensor boom. They can't bring their own and so our flight is going to do an inspection late in the mission and then we'll stow the boom during our EVA 5 on the ISS and hook up the power to it and it'll be all ready for those guys when they actually arrive and install the Japanese module."

    While the spacewalkers are setting up their tools and running a 30-foot-long power cord down the truss, the shuttle's robot arm will hand the sensor boom to the station arm. As soon as possible, Behnken will plug the power cable into the boom to activate the heaters. The arm then will release the boom so Behnken and Foreman can bolt it in place.

    With the OBSS mounted on the station, Behnken and Foreman will turn their attention to the station's right side solar alpha rotary joint, or SARJ, a massive 10-foot-wide motor-driven gear system that turns outboard solar arrays like a giant paddle wheel to keep them face on to the sun.

    Last fall, engineers because concerned about high vibration levels and power usage and ordered an inspection. To their dismay, spacewalking astronauts reported metal shavings covering the interior of the bearing race ring and damage to the ring itself. Engineers are still not sure what is causing the damage, and the joint is locked down pending additional analysis.

    Engineers are considering a plan to remove 12 bearing assemblies and move them to an identical race ring that is available as a backup. But the work would require multiple spacewalks and flight planners don't want to take that step until they have a better idea of what might be wrong.

    Behnken and Foreman will replace a bearing assembly that was removed during an earlier spacewalk and returned to Earth for analysis. They also plan to carry out additional inspections to help engineers collect more data on the contaiminated race ring's current condition. Finally, to pave the way for attachment of the JEM module, the astronauts will remove launch locks on the Harmony module's left-side and downward-facing ports.

    DATE/EDT.......DD...HH...MM...EVENT
    
    03/22/08
    Sat 12:28 PM...11...10...00...Crew wakeup
    Sat 01:08 PM...11...10...40...EVA-5: 14.7 psi repress/hygiene break
    Sat 01:58 PM...11...11...30...EVA-5: Airlock depress to 10.2 psi
    Sat 02:28 PM...11...12...00...EVA-5: Campout EVA preps
    Sat 02:28 PM...11...12...00...SSRMS EVA-5 setup
    Sat 03:48 PM...11...13...20...EVA-5: Spacesuit purge
    Sat 04:03 PM...11...13...35...EVA-5: Spacesuit prebreathe
    Sat 04:53 PM...11...14...25...EVA-5: Crew lock depressurization
    Sat 05:23 PM...11...14...55...EVA-5: Spacesuits to battery power
    Sat 05:28 PM...11...15...00...EVA-5: Airlock egress
    Sat 05:33 PM...11...15...05...SSRMS grapples OBSS
    Sat 05:48 PM...11...15...20...EVA-5: Setup
    Sat 06:03 PM...11...15...35...SRMS releases OBSS
    Sat 06:08 PM...11...15...40...EVA-5: OBSS power cable install
    Sat 06:18 PM...11...15...50...OBSS handoff to EVA
    Sat 07:28 PM...11...17...00...Crew meals begin
    Sat 07:43 PM...11...17...15...EVA-5: OBSS stow
    Sat 08:58 PM...11...18...30...EVA-5: Trundle bearing assembly No. 5 install
    Sat 10:13 PM...11...19...45...EVA-5 (EV1): JLP trunnion covers
    Sat 10:13 PM...11...19...45...EVA-5 (EV2): Harmony port and nadir launch locks
    Sat 11:08 PM...11...20...40...EVA-5: Cleanup
    Sat 11:33 PM...11...21...05...EVA-5 Airlock ingress
    Sat 11:53 PM...11...21...25...EVA-5: Airlock repressurization
    
    03/23/08
    Sun 12:28 AM...11...22...00...SRMS powerdown
    Sun 03:58 AM...12...01...30...ISS crew sleep begins
    Sun 04:28 AM...12...02...00...STS crew sleep begins
    
    The day after the fifth and final spacewalk, the astronauts will hold a joint crew news conference and begin moving spacesuits and other equipment from the station to the shuttle for return to Earth. Undocking is planned the day after that, around 7:55 p.m. on March 24. As usual with shuttle departures, pilot Johnson will be at the controls for a lap-and-a-quarter fly-around.

    "That's going to be a great thing for a pilot," he told CBS News. "Undocking is about the opposite of docking, you're leaving the space station at a pretty controlled rate. And then at the end of the undocking timeline, when we get about 300 to 400 feet away, then we start what's called a fly-around and that's where you take the orbiter and go 360 degrees all the way around the station, about 45 minutes of flying. You get to see angles of space station that aren't normally observed and just a great, exciting period for the whole crew."

    Here is the timeline for the remainder of Endeavour's mission:

    DATE/EDT.......DD...HH...MM...EVENT
    
    03/23/08
    Sun 12:28 PM...12...10...00...Crew wakeup
    Sun 01:58 PM...12...11...30...Crews off duty
    Sun 07:03 PM...12...16...35...ISS crew meal
    Sun 08:18 PM...12...17...50...STS crew meal
    Sun 09:23 PM...12...18...55...EVA prep for transfer to shuttle
    Sun 10:48 PM...12...20...20...Rendezvous tools checkout
    Sun 11:58 PM...12...21...30...Joint crew photo
    
    03/24/08
    Mon 12:18 AM...12...21...50...Joint crew news conference
    Mon 03:28 AM...13...01...00...ISS crew sleep begins
    Mon 03:58 AM...13...01...30...STS crew sleep begins
    Mon 11:58 AM...13...09...30...Crew wakeup
    Mon 04:13 PM...13...13...45...Oxygen system teardown
    Mon 04:58 PM...13...14...30...Farewell ceremony
    Mon 05:13 PM...13...14...45...Hatch closure
    Mon 05:18 PM...13...14...50...Group B computer powerup
    Mon 05:43 PM...13...15...15...Leak checks
    Mon 06:28 PM...13...16...00...Centerline camera setup
    Mon 06:58 PM...13...16...30...Undocking timeline begins
    Mon 07:55 PM...13...17...27...UNDOCKING
    Mon 09:10 PM...13...18...42...Separation burn No. 1
    Mon 09:23 PM...13...18...55...PMA-2 depressurization
    Mon 09:28 PM...13...19...00...Post undocking computer reconfig
    Mon 09:38 PM...13...19...10...Separation burn No. 2
    Mon 09:53 PM...13...19...25...SRMS powerdown
    Mon 10:13 PM...13...19...45...Group B computer powerdown
    Mon 10:28 PM...13...20...00...Spacesuit install
    Mon 10:58 PM...13...20...30...EVA unpack and stow
    Mon 11:03 PM...13...20...35...Undocking video replay
    
    03/25/08
    Tue 03:28 AM...14...01...00...Crew sleep begins
    Tue 11:28 AM...14...09...00...Crew wakeup
    Tue 02:28 PM...14...12...00...Cabin stow begins
    Tue 03:13 PM...14...12...45...FCS checkout
    Tue 04:23 PM...14...13...55...RCS hotfire
    Tue 04:38 PM...14...14...10...PILOT operations
    Tue 06:48 PM...14...16...20...Crew meals begin
    Tue 07:13 PM...14...16...45...Orbit adjust rocket firing
    Tue 08:33 PM...14...18...05...PAO event
    Tue 08:53 PM...14...18...25...Cabin stow resumes
    Tue 10:03 PM...14...19...35...Entry video setup
    Tue 10:28 PM...14...20...00...Launch/entry suit checkout
    Tue 11:28 PM...14...21...00...Recumbent seat setup
    Tue 11:38 PM...14...21...10...Wing leading edge sensors deactivated
    Tue 11:58 PM...14...21...30...Laptop computer teardown (part 1)
    
    03/26/08
    Wed 12:28 AM...14...22...00...Deorbit review
    Wed 03:28 AM...15...01...00...Crew sleep begins
    Wed 11:28 AM...15...09...00...Crew wakeup
    Wed 02:13 PM...15...11...45...Group B computer powerup
    Wed 02:28 PM...15...12...00...IMU alignment
    Wed 03:18 PM...15...12...50...Deorbit timeline begins
    Wed 07:31 PM...15...17...03...Deorbit ignition (rev. 249)
    Wed 08:33 PM...15...18...05...Landing
    


    09:25 AM, 3/9/08, Update: Fuel cells loaded; weather still 90 percent 'go'

    Engineers pumped liquid oxygen and hydrogen into the shuttle Endeavour's fuel cell system early today in preparation for launch Tuesday on a space station assembly mission. There are no technical problems of any significance launch complex 39A and forecasters say the weather is behaving as expected with a 90 percent chance of acceptable conditions at launch time.

    "All of our systems are in great shape, our teams are ready to go, they're very excited to be back again in this posture where we're able to launch just a little over a month or so since the last launch," said NASA Test Director Jeff Spaulding. "We're going to be ready ... Tuesday."

    Payload Manager Scott Higginbotham said "this has been a long campaign for us, but both my team and our international partners are excited for the opportunity to finally see our hardware do it's thing in space."

    Liftoff is targeted for 2:28:12 a.m. Tuesday, the middle of a 10-minute launch window and roughly the moment Earth's rotation carries the pad into the plane of the international space station's orbit.

    The goals of the 122nd shuttle mission are to ferry a Japanese logistics module to the station; to assemble and install a Canadian maintenance robot; to deliver critical spare parts and supplies; to test a new heat shield repair technique; and to carry up a replacement - Garrett Reisman - for European Space Agency astronaut Leopold Eyharts. Eyharts is wrapping up six weeks of work in space activating and checking out ESA's new Columbus research module. Five spacewalks are planned over the course of Endeavour's 16-day mission.

    NASA will have two shots at getting Endeavour off the pad this week. If the shuttle is not off the ground by Wednesday, when forecasters expect a 70 percent chance of good weather, NASA will stand down to make way for launch Saturday of an Air Force Delta 2 rocket carrying a new Global Positioning System navigation satellite. The next opportunity for Endeavour would be March 17.

    The forecast for Tuesday calls for winds out of the northeast at 8 knots with gusts up to 12 knots, well within NASA's safety limits. Scattered clouds are expected, but there's a slight chance a more extensive deck of low clouds could move into the area from offshore that could cause problems. The weather at NASA's emergency runways in California, New Mexico, Spain and France is expected to be acceptable for flight.

    If launch is delayed 24 hours, conditions will deteriorate somewhat with a better chance of low clouds and showers in the launch area. Forecasters expect a 70 percent chance of good weather Wednesday, with winds gusting to 15 knots at the shuttle's runway.

    NASA managers will provide a traditional launch-minus two-day status briefing at 11 a.m. today, followed at 1 p.m. by a Canadian Space Agency briefing on the special purpose dextrous manipulator payload, a high-tech space station maintenance robot known informally as Dextre.

    In the nearby launch control center, meanwhile, engineers will carry out extensive checks of Endeavour's main engines starting around noon, followed by a more general avionics system checkout. At 8 p.m. this evening, a 14-hour three-minute "hold" in the countdown will begin, during which the orbiter's communications systems will be activated and tested.

    At 5 a.m. Monday, a protective gantry known as the rotating service structure will be pulled away from Endeavour, exposing the shuttle to view and setting the stage for fueling. After hydraulic system tests, fuel cell activation and other preparations, engineers plan to begin pumping a half-million gallons of liquid oxygen and hydrogen rocket fuel into Endeavour's external tank starting around 5:03 p.m.

    Fueling should be complete by 8 p.m. and Endeavour's crew - commander Dominic Gorie, pilot Gregory Johnson, flight engineer Michael Foreman, Richard Linnehan, Robert Behnken, Japanese astronaut Takao Doi and Reisman - is expected to begin strapping in for launch just after 11 p.m. Monday.

    A detailed flight plan, countdown timeline, ascent abort boundaries, the NASA TV schedule and other useful data are posted on the CBS News STS-123 Quick-Look page.


    11:30 AM, 3/8/08, Update: Shuttle countdown on track

    The shuttle Endeavour's countdown is ticking smoothly through its initial stages, with engineers checking out the ship's avionics systems and gearing up to pump liquid oxygen and hydrogen aboard early Sunday to power the orbiter's electricity generating fuel cells. With forecasters predicting a 90 percent chance of good weather, launch remains on track for 2:28:12 a.m. Tuesday.

    The only technical issue going into the countdown was trouble with the shuttle's high-power UHF radio, which serves as a backup to the ship's S-band satellite communications system. Overnight, engineers isolated the problem to an amplifier in the high-power section of the UHF transmitter. Because two low-power UHF amplifiers are fully operational, NASA managers cleared Endeavour for launch as is.

    "All of our systems are in good shape, our countdown work is on schedule, I have no real issues to report," said NASA Test Director Charlene Blackwell-Thompson. "Our team is ready and we're all looking forward to Tuesday's launch."

    A cold front swept across the spaceport early today, bringing torrential rain and high winds. But the clouds began clearing out this morning as the front pushed through and while shuttle weather officers expected breezy conditions throughout the day, the forecast for launch early Tuesday remains 90 percent "go."

    "We've had some interesting weather over the past 24 hours," said forecaster Todd McNamara. "We had thunderstorms on and off until about (3 a.m.) local this morning. As they passed through, we experienced about a quarter to an inch of rain from the northern to the southern portions of Kennedy Space Center and we've seen gusts up to around 39 knots on some of our local wind towers.

    "Now that that system has pushed through, we're going to see high pressure build back in. Over the next 24 to 48 hours, that high pressure system back behind the front will continue to move through the area and kind of dominate our region and by launch day ... we'll be under very favorable conditions."

    With only a slight chance of low ceilings, forecasters are predicting a 90 percent chance of good weather, with scattered clouds at 3,000 and 20,000 feet and winds out of 40 degrees at eight knots with gusts up to 12 knots. Crosswinds at the shuttle's emergency runway are expected to be well within limits and good conditions are expected at emergency landing sites in Europe.

    The forecast for Wednesday is 70 percent go with a 60 percent chance of acceptable conditions on Thursday.

    Here are countdown highlights leading up to Tuesday's launch (in EST/EDT):

    EDT...........EVENT
    
    Sat 03/08/08
    
    02:30 AM......Call to stations
    03:00 AM......Countdown begins
    01:00 PM......Fuel cell reactant load preps
    06:40 PM......MEC/SRB power up
    07:00 PM......Clear crew module
    
    07:00 PM......Begin 4-hour built-in hold
    07:45 PM......Clear blast danger area
    07:45 PM......Orbiter pyro-initiator controller test
    07:55 PM......SRB PIC test
    08:55 PM......Master events controller pre-flight test
    11:00 PM......Resume countdown
    
    Sun 03/09/08
    
    12:30 AM......Fuel cell oxygen loading begins
    02:00 AM......Switch to Eastern Daylight Time (GMT-4)
    04:00 AM......Fuel cell oxygen load complete
    04:00 AM......Fuel cell hydrogen loading begins
    06:30 AM......Fuel cell hydrogen loading complete
    07:30 AM......Pad open; ingress white room
    
    08:00 AM......Begin 4-hour built-in hold
    08:00 AM......Crew module clean and vacuum
    08:30 AM...... Fuel cell loading boom disconnected
    10:00 AM......Secure mobile launch platform interior
    12:00 PM......Countdown resumes
    
    12:00 PM......Main engine preps
    12:30 PM......Master event controllers 1 and 2 on; avionics system checkout
    01:00 PM......Remove OMS engine covers, throat plugs
    01:30 PM......Deflate rotating gantry dock seals; tile inspection
    02:00 PM......Tile inspection
    06:00 PM......Tail service mast prepped for fueling
    
    08:00 PM......Begin 14-hour 3-minute hold
    09:30 PM......OIS communications check
    10:15 PM......Crew weather briefing
    10:20 PM......JSC flight control team on station
    11:30 PM......Comm system activation
    
    Mon 03/10/08
    
    12:00 AM......Crew module voice checks
    12:30 AM......Launch pad debris inspection
    01:00 AM......Flight crew equipment late stow
    05:00 AM......Service gantry rotated to park position
    06:00 AM......Final heat shield inspection
    07:00 AM......Ascent switch list
    10:03 AM......Resume countdown
    
    10:03 AM......Astronaut support personnel cockpit config
    10:23 AM......Pad clear of non-essential personnel
    10:23 AM......Hydraulic power system avionics test
    11:13 AM......Fuel cell activation
    12:03 PM......Booster joint heater activation
    12:33 PM......MEC pre-flight bite test
    12:48 PM......Tanking weather update
    01:33 PM......Final fueling preps; launch area clear
    02:03 PM......Red crew assembled
    02:48 PM......Fuel cell integrity checks complete
    
    03:03 PM......Begin 2-hour built-in hold (T-minus 6 hours)
    03:13 PM......Safe-and-arm PIC test
    03:58 PM......Crew wakeup
    04:03 PM......External tank ready for loading
    04:18 PM......Mission management team tanking meeting
    05:03 PM......Resume countdown (T-minus 6 hours)
    
    05:03 PM......Liquid oxygen (LO2), liquid hydrogen (LH2) transfer line chilldown
    05:13 PM......Main propulsion system chill down
    05:13 PM......LH2 slow fill
    05:43 PM......LO2 slow fill
    05:48 PM......Hydrogen ECO sensors go wet
    05:53 PM......LO2 fast fill
    06:03 PM......LH2 fast fill
    07:58 PM......LH2 topping
    08:03 PM......LH2 replenish
    08:03 PM......LO2 replenish
    
    08:03 PM......Begin 2-hour 30-minute built-in hold (T-minus 3 hours)
    08:03 PM......Closeout crew to white room
    08:03 PM......External tank in stable replenish mode
    08:18 PM......Astronaut support personnel comm checks
    08:48 PM......Pre-ingress switch reconfig
    08:55 PM......Crew breakfast/photo op (recorded)
    09:30 PM......NASA television launch coverage begins
    09:58 PM......Final crew weather briefing
    10:08 PM......Crew suit up begins
    10:33 PM......Resume countdown (T-minus 3 hours)
    
    10:38 PM......Crew departs O&C building
    11:08 PM......Crew ingress
    11:58 PM......Astronaut comm checks
    
    Tue 03/11/08
    
    12:13 AM......Hatch closure
    12:53 AM......White room closeout
    
    01:13 AM......Begin 10-minute built-in hold (T-minus 20m)
    01:23 AM......NASA test director countdown briefing
    01:23 AM......Resume countdown (T-minus 20m)
    
    01:24 AM......Backup flight computer loads OPS 1 software
    01:28 AM......KSC area clear to launch
    
    01:34 AM......Begin final built-in hold (T-minus 9m)
    02:04 AM......NTD launch status verification
    02:19:12 AM...Resume countdown (T-minus 9m)
    
    02:20:42 AM...Orbiter access arm retraction
    02:23:12 AM...LAUNCH WINDOW OPENS
    02:23:12 AM...Hydraulic power system (APU) start
    02:23:17 AM...Terminate LO2 replenish
    02:24:12 AM...Purge sequence 4 hydraulic test
    02:24:12 AM...Inertial measurement navigation units to inertial
    02:24:17 AM...Control surfaces steering test
    02:24:42 AM...Main engine steering test
    02:25:17 AM...LO2 tank pressurization
    02:25:37 AM...Fuel cells to internal reactants
    02:25:42 AM...Clear caution-and-warning memory
    02:26:12 AM...Crew closes visors
    02:26:15 AM...LH2 tank pressurization
    02:27:22 AM...SRB joint heater deactivation
    02:27:41 AM...Shuttle flight computers take control of countdown
    02:27:51 AM...SRB steering test
    02:28:05 AM...Main engine start (T-6.6 seconds)
    02:28:12 AM...Booster ignition (LAUNCH)
     


    3:15 AM, 3/8/08, Update: Astronauts arrive for launch; countdown begins

    Delayed by heavy rain, the shuttle Endeavour's crew arrived at the Kennedy Space Center early Saturday for the start of the countdown to launch Tuesday on a 16-day space station assembly mission. Commander Dom Gorie, standing with his crewmates on the rain-soaked shuttle runway, spoke briefly to waiting reporters.

    "Good evening. Thank you all for coming out and welcoming us here in this wonderful weather we've got," Gorie said around 1:30 a.m., a few minutes after touching down in a NASA jet. "I think when we get the weather done with today we're going to have a nice shot at launching here this week.

    "We all just wanted to convey how excited we are to be here for launch week. We've got a great training team, they've got us ready. We've got multiple shifts of folks at mission control waiting to run this 16-day mission with us. And we've got a very, very ambitious flight schedule. But with a great orbiter waiting for us and this great crew, we're going to have a great mission. Thank you very much. You all have a nice evening."

    Gorie and his crewmates - pilot Greg Johnson, flight engineer Mike Foreman, Richard Linnehan, Robert Behnken, Japanese astronaut Takao Doi and space station flight engineer Garrett Reisman - then left the runway as rain from a passing frontal system continued to fall.

    An hour-and-a-half later, at 3 a.m., engineers at the nearby launch control center started Endeavour's carefully choreographed countdown at the T-minus 43-hour mark (launch minus 70 hours and 23 minutes, including hold time). Liftoff is targeted for 2:28:12 a.m. Tuesday, roughly the moment Earth's rotation carries launch pad 39A into the plane of the space station's orbit.

    The primary goals of the year's second shuttle mission are to deliver a Japanese module to the international space station; to assemble and install a sophisticated Canadian robot capable of performing maintenance that otherwise might require a spacewalk; to deliver Reisman to the station and to return outgoing flight engineer Leopold Eyharts to Earth after six weeks in orbit.

    The astronauts also plan to test a new heat shield repair technique, one of the final steps in NASA's recovery from the 2003 Columbia disaster.

    A detailed flight plan, countdown timeline, ascent abort boundaries, the NASA TV schedule and other useful data are posted on the CBS News STS-123 Quick-Look page.


    11:00 AM, 3/7/08, Update: Weather 90 percent 'go' for Tuesday launch; UHF radio issue not a constraint

    The shuttle Endeavour's seven-member crew flies to Florida this evening to prepare for a sky lighting night launch early Tuesday on a quick-turnaround space station assembly mission. The countdown is scheduled to begin at 3 a.m. EST Saturday and forecasters are predicting a 90 percent chance of good weather for launch, targeted at 2:28:12 a.m. EDT Tuesday.

    NASA has two opportunities to launch Endeavour, on March 11 and 12, before standing down to make way for the March 15 launch of an Air Force Delta 2 rocket carrying a Global Positioning System navigation satellite. Shuttles and unmanned rockets launched from the nearby Cape Canaveral AIr Force Station share tracking, imagery and self-destruct systems.

    "Because of turnaround constraints between one launch and the next, we would attempt launches on the 11th and 12th and then stand down, let the Delta rocket play through - it has two attempts if it needs it - and then we could re-attempt, the earliest would be on the 17th, late in the evening," said NASA Test Director Steve Payne. "After that, we'd have opportunities through March 22 if we needed them."

    The primary goals of Endeavour's flight are to ferry flight engineer Garrett Reisman to the space station and bring European Space Agency astronaut Leopold Eyharts back to Earth; to install the first of two Japanese modules; and to assemble a sophisticated Canadian robot capable of maintenance tasks that normally require spacewalking astronauts. The astronauts also plan to test a heat shield repair tool that represents one of the final steps in NASA's recovery from the 2003 Columbia disaster.

    A launch on March 11 would result in a docking with the international space station around 11:30 p.m. on March 12. Five spacewalks are planned before undocking March 24. Landing back at the Kennedy Space Center is expected around 8:35 p.m. on March 26.

    Endeavour's mission is just one in a series of critical flights to the fast-growing space station.

    The European Space Agency is gearing up to launch an Ariane 5 rocket Saturday night, at 11:03 p.m. EST, from Kourou, French Guiana, to boost the Jules Verne Automated Transfer Vehicle, or ATV, into orbit on its long-awaited maiden flight. The ATV, capable of carrying about three times the cargo of an unmanned Russian Progress freighter, is making its maiden flight, with docking at the space station expected April 3, after Endeavour is back on Earth.

    The Russians plan to follow the ATV docking with launch of a Soyuz spacecraft from the Baikonur Cosmodrome in Kazakhstan to deliver two Russian cosmonauts to the space station to replace Expedition 16 commander Peggy Whitson and flight engineer Yuri Malenchenko. If all goes well, the shuttle Discovery will take off May 25 to deliver Japan's huge Kibo lab module to the station.

    Going into Endeavour's countdown, Payne said the only technical issue at pad 39A is trouble with a high-power amplifier in the shuttle's UHF radio system. NASA typically uses S-band and Ku-band communications links through a satellite relay system, but the UHF radio provides a secondary capability.

    "We have the option of flying it as is, because there's redundant capability inside the radio," Payne said. "There are two good low-power amplifiers with redundant power coming to them and that is sufficient to satisfyļ the flight rules. The other option is to remove and replace. That involves some work. Either way, both of those options support launch on the 11th, so we're still good."

    Other than that, "we have no other issues to report," Payne said. "Systems are clean, it appears it's going to be a good day for us Tuesday early morning and Endeavour and her crew are ready to launch."

    Endeavour commander Dominic Gorie, pilot Gregory Johnson, flight engineer Michael Foreman, Richard Linnehan, Robert Behnken, Japanese astronaut Takao Doi and Reisman are expected to land at the Kennedy Space Center around 9 p.m. this evening.

    But a front with potentially severe thunderstorms is expected to move through the central Florida area later today and the crew's arrival time could change depending on conditions at the time. But shuttle weather officer Todd McNamara said "it won't be totally socked in and they should be able to make their way in."

    After the front passes through, conditions are expected to improve. The forecast for Tuesday calls for a 90 percent chance of good weather with scattered clouds and light winds. The odds drop to 80 percent "go" if launch is delayed to Wednesday.

    A detailed flight plan and countdown timeline are posted on the CBS News STS-123 Quick-Look page.


    02:20 PM, 2/29/08, Update: Endeavour cleared for March 11 launch

    NASA managers completed a two-day flight readiness review today and formally cleared the shuttle Endeavour for blastoff March 11 on a 16-day space station assembly mission featuring five spacewalks, delivery of a new Japanese module and assembly of a complex Canadian hand-like attachment for the station's robot arm.

    Endeavour's seven-member crew - commander Dominic Gorie, pilot Gregory Johnson, flight engineer Michael Foreman, Richard Linnehan, Robert Behnken, Japanese astronaut Takao Doi and space station flight engineer Garrett Reisman - plans to fly to the Kennedy Space Center next Friday night for the 3 a.m. Saturday (March 8) start of the countdown to launch.

    Liftoff is targeted for 2:28:10 a.m. on March 11, roughly the moment Earth's rotation carries launch complex 39A into the plane of the space station's orbit.

    "We had a very thorough review over the last day and a half," said Bill Gerstenmaier, manager of space operations at NASA headquarters. "The teams are ready to go launch here on March 11. We're really not working very many open items, and that's a tribute to the team and the great performance of Atlantis (on the recently concluded STS-122 mission).

    "There wasn't a lot of work that we're carrying forward out of this review into the next review at L-minus 2 (days) and that's a tribute to the team and it's also evidence that we're really ready to go fly and we're not rushing things."

    Gerstenmaier said analysis of debris from a disabled spy satellite that was blown apart by a Navy missile last week in a dramatic shoot down showed no significant additional risk for Endeavour's crew.

    "We took a look at that, we had our analysts take a look at the latest predictions of what debris is remaining from that event, we've calculated it and it really poses no risk to the shuttle with where we are. There's just a small change in risk over the mission, I think we went from 1-in-269 to 1-in-259, which is just a minor, trivial change. We probably don't know the debris model that well to see that kind of difference. So we looked at it, we reviewed it, we'll continue to talk to folks to make sure there's nothing, but we don't see any concerns."

    The numbers, he said, refer to the odds of a "critical penetration" of the shuttle by space debris over the course of the 16-day mission.

    NASA will have two days to get Endeavour off the ground before standing down to make way for the launch of an Air Force Delta 2 rocket carrying a new Global Positioning System navigation satellite. Launch is scheduled for March 15 at 2:09 a.m.

    "In order to turn around the range from our launch attempts to theirs requires 48 hours," said shuttle Launch Director Mike Leinbach. "So we have two launch attempts for the shuttle program, the 11th and 12th. If we don't launch by the 12th we have to stand down for the Delta program. And that's about a five-day stand down when you add all the factors together. Our next launch attempt would be the 17th."

    Assuming an on-time launch, Endeavour will dock with the space station around 11:27 p.m. on March 12. The Japanese logistics module will be installed the next day during the first of five planned spacewalks. Linnehan and Reisman will carry out the first excursion, Linnehan will be joined by Foreman for the second on March 15 and by Behnken for the third on March 17. All three will be devoted primarily to assembling the new Canadian special purpose dexterous manipulator, or DEXTRE, a mechanical hand of sorts that can be attached to the station's robot arm.

    Benkhen and Foreman will carry out the final two spacewalks on March 20 and 22 to test a heat shield repair tool and to help mount the shuttle's heat shield inspection boom on the station. The 50-foot-long boom will be left behind when Endeavour departs because of interference issues when a second, much larger Japanese module is launched on the next assembly mission in late May.

    If all goes well, Endeavour will undock from the space station around 8 p.m. on March 24 and land back at the Kennedy Space Center around 8:35 p.m. on March 26.

    Endeavour's flight is the longest yet for a shuttle visiting the international space station. The long duration is possible because of a new station-to-shuttle power transfer system that will let Endeavour tap into the lab's solar power grid.

    New shuttle Program Manager John Shannon said there are no plans at present to extend Endeavour's mission beyond 16 days, although that option is available if problems develop or if the crew needs additional time to accomplish major mission objectives.

    "Right now, we have 16 days, we have one extension day that we could add to the flight," Shannon said. "Right now, the entire mission fits inside those 16 days. But it is very complicated, it's a very complex mission, we're doing a lot of different things. So I wouldn't say absolutely we won't extend or not. We have that option available to us."

    Adding to the complexity of the operation, the European Space Agency is scheduled to launch the "Jules Verne," its new Automated Transfer Vehicle, or ATV, next Friday night from Kourou, French Guiana. The ATV, a large, unmanned cargo carrier designed to ferry critical supplies and equipment to the space station, is scheduled to dock at the aft port of the station's Russian Zvezda module at 10:20 a.m. on April 3. It will be "parked" in orbit some some 1,200 miles from the station during Endeavour's mission.

    Because the shuttle, station and ATV all rely on NASA communications satellites, "there will be some times during the mission where we may not have comm with the orbiter like we normally do," Gerstenmaier said. "We'll have comm periodically during an orbit, not all the time. So we discussed that (today). if we really need comm with all three vehicles - ATV, shuttle and station - we can do that, we can set it up. But from a scheduling standpoint, we'd like to minimize those periods where we need high-rate communications with all three vehicles."

    A detailed flight plan, updated launch windows and a countdown timeline are available on the CBS News STS-123 Quick-Look page.


    02:00 PM, 2/25/08, Update: Astronauts strap in for practice countdown

    The crew of the shuttle Endeavour strapped in today at pad 39A for a dress-rehearsal countdown that sets the stage for launch March 11 on a 16-day space station assembly mission featuring five spacewalks, installation of a Japanese logistics module and assembly of a complex hand-like attachment for the lab's robot arm.

    Commander Dominic Gorie, pilot Gregory Johnson, flight engineer Michael Foreman, Richard Linnehan, Robert Behnken, Japanese astronaut Takao Doi and space station flight engineer Garrett Reisman boarded Endeavour early today and worked through the final hours of a terminal countdown demonstration test, or TCDT, that ended with the simulated ignition and shutdown of the ship's main engines.

    The astronauts hope to strap in for real the night of March 10 for a launch at 2:28:10 a.m. on March 11. As it now stands, NASA will have two shots at getting Endeavour off the ground, on March 11 or 12, before standing down a few days to make way for the already planned launch of an unmanned Delta 2 rocket carrying an Air Force Global Positioning System satellite.

    Endeavour's planned launching comes just three weeks after the shuttle Atlantis landed at the spaceport to close out the first of six missions planned for 2008.

    "We're really excited to be here during this dry count practice run for launch here in a couple of weeks," Gorie told reporters Sunday. "The Kennedy Space Center is running at a pretty fast pace as you can imagine with two launches like this back to back. They've got a great thing going, we're going to keep it going with Endeavour's launch here on March 11. Endeavour's in great shape and is ready for us to go."

    Bill Gerstenmaier, head of space operations at NASA headquarters, will chair a two-day flight readiness review Thursday and Friday. Assuming no problems develop, NASA plans to start Endeavour's countdown at 3 a.m. EST on March 8 (note: the United States switches to daylight savings time (GMT-4 hours) at 2 a.m. on March 9).

    As usual with space station missions, the shuttle can take off roughly five minutes to either side of the moment Earth's rotation carries the launch pad into the plane of the lab's orbit. NASA typically targets the middle of the window, known as the "in-plane" time, a strategy that improves performance but effectively reduces the launch window to just five minutes.

    Here are the latest launch windows for the STS-123 mission (in EDT; dates refer to the "in-plane" launch times; launch day is flight day 1):

    (Editor's Note: This chart was updated 2/26)

    DATE/GMT...WINDOW OPEN...IN-PLANE......WINDOW CLOSE..DOCKING
    
    03/11/08...02:23:10 AM...02:28:10 AM...02:33:10 AM...FD 3
    
    03/12/08...01:57:28 AM...02:02:28 AM...02:07:28 AM...FD 3
    .......................................02:10:38 AM...FD 4
    
    03/13/08...01:34:56 AM...01:39:56 AM...01:44:56 AM...FD 3
    
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    The primary goals of mission STS-123 are to deliver Japan's pressurized logistics module; to install a sophisticated Canadian robotic manipulator for the station's main robot arm; to test a new heat-shield repair technique; to ferry Reisman to the station to join the Expedition 16 crew; and to bring European Space Agency astronaut Leopold Eyharts back to Earth after six weeks in orbit.

    The Japanese module will be temporarily attached to the upper port of the forward multi-hatch Harmony connecting module. During a shuttle flight in late May, the much larger Kibo laboratory module will be mounted on Harmony's left-side port and the logistics module carried aloft aboard Endeavour will be moved to an upper hatch on the far end of the new lab.

    Assuming an on-time launch, Gorie will guide Endeavour to a docking with the space station around 11:27 p.m. on March 12. The Japanese logistics module will be installed the next day during the first of five planned spacewalks. Linnehan and Reisman will carry out the first excursion, Linnehan will be joined by Foreman for the second on March 15 and by Behnken for the third on March 17. All three will be devoted primarily to assembling the new Canadian special purpose dexterous manipulator, or DEXTRE, a mechanical hand of sorts that can be attached to the station's robot arm.

    Benkhen and Foreman will carry out the final two spacewalks on March 20 and 22 to test a heat shield repair tool and to help mount the shuttle's heat shield inspection boom on the station. The 50-foot-long boom will be left behind when Endeavour departs because of interference issues when the large Kibo module is launched on the next assembly mission.

    If all goes well, Endeavour will undock from the space station around 8 p.m. on March 24 and land back at the Kennedy Space Center around 8:35 p.m. on March 26.

    A detailed flight plan is posted on the STS-123 Quick-Look page, along with text versions of the launch windows chart, the countdown and the trajectory timeline. Additional updates will be posted as the data become available.


    09:30 AM, 2/20/08, Update: Space shuttle Atlantis returns to Earth (UPDATED at 12:30 p.m. with quotes from Frick; news conference; bad weather in Pacific may delay satellite shoot down)

    Taking advantage of calm weather, the shuttle Atlantis dropped out of orbit and glided to a smooth Florida landing today, closing out an extended 13-day mission to deliver a new European research lab and a French astronaut to the international space station.

    Bringing outgoing space station flight engineer Dan Tani back to Earth after 120 days in space, Atlantis commander Steve Frick guided Atlantis through a sweeping 235-degree left overhead turn, lined up on runway 15 at the Kennedy Space Center and swooped to a picture-perfect touchdown at 9:07:10 a.m.

    "Houston, Atlantis, wheels stopped," Frick radioed as the shuttle rolled to a halt.

    "Copy, wheels stopped," astronaut Jim Dutton replied from mission control in Houston. "Welcome home, Atlantis, welcome home, Dan, and congrats on delivering (the) Columbus (module) to its new world."

    "It's been a great mission," Frick said. "We're extremely happy to be home, it's such a beautiful day in Florida. We can't wait to see our families, who hopefully were all at the (grand)stands here watching. We appreciate all the great help and support from the folks here at Kennedy and all over NASA, and especially at Johnson Space Center, mission control, for keeping us safe when we were airborne and bringing us safely home,"

    "We really appreciate those words, Steve," replied astronaut Jim Dutton in mission control.

    Mission duration was 12 days 18 hours 21 minutes and 40 seconds, covering 202 complete orbits and 5.3 million miles since blastoff Feb. 7. Bill Gerstenmaier, director of space flight operations at NASA headquarters in Washington. said Tani came through re-entry and the return to Earth's gravity in good shape.

    "He's doing great," Gerstenmaier said. "He'll go back to Houston and start some rehabilitation, start doing some weight training, some water training, those kind of things, and eventually get back into a pretty routine lifestyle."

    With Atlantis and its seven-member crew safely home, the Pentagon was clear to proceed with plans to destroy a falling spy satellite with a dramatic missile shot from a Navy cruiser west of Hawaii.

    The unprecedented intercept had been planned for this evening, but Pentagon officials said this morning high seas near Hawaii threatened to delay the launching. A second opportunity was available Thursday.

    Launched in December 2006, the classified National Reconnaissance Office satellite, believed to be an experimental spacecraft intended to test new sensor technologies, suffered a catastrophic malfunction shortly after reaching orbit. It has been out of contact and out of control ever since, slowly falling back to Earth due to the long-term affects of atmospheric friction.

    Left on its own, the 5,000-pound NROL-21 spacecraft would re-enter the atmosphere and break apart in mid March. About 2,400 pounds of debris could be expected to survive re-entry and make it all the way to the surface. The risk of injury from satellite debris is considered minimal, but the Bush administration, worried the satellite's full load of toxic, now-frozen hydrazine rocket fuel might make it to the ground, ordered the Navy to attempt a shoot down.

    The avoid any risk of debris that might threaten Atlantis and its crew, the shot was held up until Atlantis could return to Earth. Playing it safe, NASA staffed a backup landing site at Edwards Air Force Base, Calif., to get the shuttle down today, on one coast or the other. As it turned out, the weather cooperated in Florida and Edwards wasn't needed.

    Flying upside down and backward 212 miles above the Indian Ocean, Frick and pilot Alan Poindexter fired Atlantis' twin braking rockets at 7:59:52 a.m. for two minutes and 43 seconds, slowing the ship by about 198 mph to drop out of orbit (ground-track mapss).

    A half hour later, descending through 76 miles above the south Pacific Ocean, Atlantis plunged back into the discernible atmosphere around 8:36 a.m., entering the zone of peak heating a few minutes later.

    Following a southwest-to-northeast trajectory that carried the ship high above central America just south of the Yucatan Peninsula, Atlantis skirted the western tip of Cuba before crossing the southwest coast of Florida near Fort Myers.

    Frick took over manual control as the shuttle descended through 51,000 feet and dropped below the speed of sound around 9:03 a.m. Approaching the Kennedy Space Center the southwest, he and Poindexter guided the ship through a sweeping left overhead turn to line up on runway 15.

    Frick, Poindexter, flight engineer Rex Walheim, Leland Melvin, Stan Love and European Space Agency astronaut Hans Schlegel were expected to doff their pressure suits and climb out of the shuttle an hour or so after touchdown. Tani made the return to Earth strapped into a reclining seat on the shuttle's lower deck and flight surgeons were standing by to provide assistance as needed.

    After medical exams and reunions with friends and family members, all seven astronauts were expected to fly back to the Johnson Space Center in Houston on Thursday.

    Tani was launched to the space station aboard the shuttle Discovery last October to help commander Peggy Whitson and flight engineer Yuri Malenchenko prepare the outpost for the attachment of the European Space Agency's Columbus research module. The new lab module was scheduled to be carried aloft aboard Atlantis in December along with Tani's replacement, French astronaut Leopold Eyharts.

    But Atlantis was grounded by problems with hydrogen fuel sensors, Columbus' delivery was held up and Tani's stay in space ultimately was extended for two months. As such, he missed the holidays with his family and was off the planet when his 90-year-old mother was killed in a Dec. 19 car wreck.

    After extensive modifications to a suspect fuel sensor wiring connector, Atlantis blasted off at 2:45:30 p.m. on Feb. 7 to kick off the delayed assembly mission.

    Over the next 13 days, the astronauts staged three spacewalks, delivered and installed the 26,627-pound Columbus module, two external experiment packages totaling 1,409 pounds and a fresh tank of high-pressure nitrogen for the station's ammonia cooling system that tipped the scales at 1,.069 pounds.

    The shuttle brought 2,242 pounds of station hardware back to Earth in its cargo bay, including a spent nitrogen tank and a faulty control moment gyroscope. Some 1,299 pounds of supplies and equipment were transferred from the shuttle cabin to the space station, including a new solar alpha rotary joint drive motor, and 1,343 pounds of equipment was moved from the station to the shuttle's cabin for return to Earth.

    The astronauts transferred 1,386 pounds of fresh water to the space station, 95 pounds of oxygen and 27 pounds of nitrogen.

    "It's great... to be back on the ground here at the Kennedy Space Center on our first try," Frick said from the runway. "As you can see, the weather is gorgeous and it looked just as nice from up high as it does down here. Atlantis is a great ship, it brought us home without any troubles, everything worked just beautifully. We're obviously very excited that our mission is complete and successful, we got everything done that we had hoped to get done."

    With Atlantis safely home, NASA engineers will set their sights on launching the shuttle Endeavour March 11 on a marathon 16-day five-spacewalk mission to attach the first of two Japanese research modules to the space station. Endeavour's crew is scheduled to fly to the Florida space center Saturday to participate in a dress-rehearsal countdown Monday.

    If all goes well, Endeavour will rocket away around 2:28 a.m. on March 11 and return to Earth around 7:40 p.m. on March 26.

    The next flight in the sequence, a mission by Discovery to carry Japan's huge Kibo module to the station, has slipped from the end of April to around May 25 because of unfavorable orbital conditions and time needed to complete external tank processing.

    After that, Atlantis is scheduled to return to space Aug. 28 on a long-awaited flight to service the Hubble Space Telescope. Two more flights, by Endeavour and Discovery in October and December, will ferry supplies to the space station and a final set of solar arrays.