STS-98 MISSION ARCHIVE (COMPLETE) Updated: 02/20/01 Space Station Assembly Mission 5A: U.S. Laboratory Module By William Harwood CBS News/Kennedy Space Center The following copy originally was posted on the Current Mission space page at http://cbsnews.cbs.com/network/news/space/current.html. Comments, suggestions and corrections welcome! TABLE OF CONTENTS -NASA assesses booster wiring repair (12/18/00) -Shuttle rollout likely off until after Christmas (12/19/00) -Rollout delayed (12/20/00) -Shuttle's move to launch pad delayed (01/02/01) -Atlantis hauled to pad; NASA targets Jan. 19 liftoff (01/04/01) -Shuttle crew arrival on tap; booster meetings planned (01/15/01) -Shuttle launch delayed; rollback ordered (01/15/01) -Shuttle chief explains launch delay (01/16/01) -NASA managers study revised shuttle launch schedule (01/24/01) -Shuttle launch delayed to Feb. 7 (01/25/01) -STS-98 mission preview (02/04/01) -Shuttle count on track; good weather expected (02/05/01) -Shuttle Atlantis cleared for launch (02/06/01) -Atlantis rockets into orbit (02/07/01) -Progress undocked from station; Atlantis closes in (02/08/01) -Atlantis docks with international space station (02/09/01) -Destiny module attached to station (02/10/01) -Astronauts enter, activate Destiny module (02/11/01) -PMA-2 attached to lab in second spacewalk (02/12/01) -Station shifts to gyroscope control (02/13/01) -Third spacewalk completes external lab outfitting (02/14/01) -Shuttle crew completes supply transfers (02/15/01) -Shuttle Atlantis undocks from space station (02/16/01) -Atlantis astronauts pack up for landing (02/17/01) -Landing delayed 24 hours by high winds (01/18/01) -Landing delayed for second straight day (02/19/01) =================================================================== NASA assesses booster wiring repair (12/18/00) Editor's Note... The following story also is posted on the Spaceflight Now web site. Launch of the shuttle Atlantis next month on the next space station assembly mission faces a potentially significant delay because of work required to fix a crumbling electrical cable in the shuttle's booster separation system. Shuttle mission STS-98 currently is targeted for launch at 2:44 a.m. EST on Jan. 18. The goal of the 102nd shuttle flight is to attach the U.S. laboratory module, Destiny, to the space station. But repairs to the shuttle's booster separation system could, in a worst-case scenario, require engineers to first remove Atlantis and its external tank from its two solid-fuel boosters to gain access to a damaged electrical cable. If "destacking" is, in fact, required, launch of mission STS-98 likely would be delayed at least a week and probably longer. But as of late Sunday evening, no such decisions had been made and launch remained officially targeted for Jan. 18. But a NASA spokesman said in a recorded status report that work to repair the cable in question "significantly threatens the STS-98 launch date of Jan. 18." Atlantis originally was scheduled to be hauled to launch pad 39A on Jan. 11, but the move was held up when engineers discovered a booster separation problem that occurred during launch of the shuttle Endeavour on Nov. 30. During Endeavour's launching, one of two explosive cartridges used to separate a strut holding the base of the orbiter's left-side solid-fuel booster to the ship's external fuel tank failed to fire. A redundant "NASA standard initiator," or detonator, inside the strut in question did fire, however, and the booster separated cleanly. As it turned out, a wiring problem prevented the detonation signal from reaching the initiator. But a shuttle could be lost if both detonators in a given booster attach strut failed to fire and NASA managers wanted to make sure the booster separation system used by Atlantis was healthy before moving the shuttle to the launch pad. As a result, Atlantis's rollout was delayed to give engineers time to X-ray wiring in the separation system and to review ground processing. "On Friday, a cable located in the lower strut of (Atlantis's) left-hand booster failed a standard (electrical) resistance check," NASA spokesman Joel Wells said in a recorded status report Sunday. "On Saturday, managers decided to replace a faulty connector on that cable. "Meanwhile, workers performing final X-rays on cables located in the SRB forward skirt identified a damaged outer shield on one ordnance cable. While replacing that cable connector, workers had to peel back an outer layer of shielding. During that process, technicians noticed a loss of integrity on an inner layer of cable shielding. "Further inspection revealed a crumbling effect on most of that shielding layer throughout that single cable," Wells said. "Engineers are now evaluating the cause of this cable issue and work planners are discussing plans to replace this entire cable." The spokesman said gaining access to the cable "may require the external tank to be demated in a worst-case scenario before the work can be done." To demate, or remove, the external tank, the shuttle itself first would have to be disconnected and lowered to the transfer aisle of the Vehicle Assembly Building. The tank then could be removed to give repair crews access to the booster separation system. =================================================================== Shuttle rollout likely off until after Christmas (12/19/00) Editor's Note... The following story also is posted on the Spaceflight Now web site. The shuttle Atlantis's rollout to pad 39A for launch on a critical space station assembly mission is expected to be delayed until after Christmas -- and possibly after the first of the year -- to complete booster wiring repairs and to give work crews holiday time off, sources say. NASA managers are meeting today to assess the repair work and to firm up the schedule. No formal decisions have been made as of this writing, but it appears launch of the 102nd shuttle mission will slip at least a few days beyond the current Jan. 18 target and possibly more, depending on how the repair work goes. The goal of mission STS-98 is to deliver the U.S. laboratory module, Destiny, to the international space station. The 32,000-pound module is scheduled to be delivered to the launch pad payload changeout room Jan. 3 for installation in Atlantis's cargo bay. While rollout options are still being assessed, one source said the move was off until at least Dec. 27 and another mentioned Jan. 2 as a possibility. Atlantis has been held up because of concern about crumbling shielding on cables in one area of the shuttle's booster separation system. Two repair options have been developed, both of which can be accomplished without "destacking" the shuttle and its external tank. A decision on which repair option will be implemented, along with a revised work schedule, are expected to be discussed at an afternoon engineering meeting. Atlantis originally was scheduled to be hauled to launch pad 39A on Jan. 11, but the move was held up when engineers discovered a booster separation problem that occurred during launch of the shuttle Endeavour on Nov. 30. During Endeavour's launching, one of two explosive cartridges used to separate a strut holding the base of the orbiter's left-side solid-fuel booster to the ship's external fuel tank failed to fire. A redundant "NASA standard initiator," or detonator, inside the strut in question did fire, however, and the booster separated cleanly. As it turned out, a wiring problem prevented the detonation signal from reaching the initiator. But analysis indicates a shuttle would fly out of control and begin breaking up in seconds if both detonators in a given booster attach strut failed to fire. As a result, NASA managers decided to make sure the booster separation system used by Atlantis was healthy before moving the shuttle to the launch pad. Atlantis's rollout then was delayed to give engineers time to X-ray wiring in the separation system and to review ground processing. "On Friday, a cable located in the lower strut of (Atlantis's) left-hand booster failed a standard (electrical) resistance check," NASA spokesman Joel Wells said in a recorded status report Sunday. "On Saturday, managers decided to replace a faulty connector on that cable. "Meanwhile, workers performing final X-rays on cables located in the SRB forward skirt identified a damaged outer shield on one ordnance cable. While replacing that cable connector, workers had to peel back an outer layer of shielding. During that process, technicians noticed a loss of integrity on an inner layer of cable shielding. "Further inspection revealed a crumbling effect on most of that shielding layer throughout that single cable," Wells said. "Engineers are now evaluating the cause of this cable issue and work planners are discussing plans to replace this entire cable." After additional analysis, engineers developed two repair options that did not require destacking. Assuming no additional inspections will be required to check other cables in the booster separation system, Atlantis should be ready for launch within a few days of its original Jan. 18 target. But if analysis indicates additional inspections and/or repairs are required, the flight likely would slip into February. =================================================================== Rollout delayed (12/20/00) The shuttle Atlantis' rollout to pad 39A for launch on a critical space station assembly mission will be delayed at least until Jan. 2 to complete booster wiring repairs and to give work crews holiday time off, NASA officials announced today. The shuttle's launch, originally targeted for Jan. 18, is expected to slip a few days to Jan. 21 or 22 at the earliest. But the Air Force Eastern Range, which provides radar and tracking support for all rockets launched from the East Coast, currently is booked Jan. 21 through Jan. 23 for pre-launch tests of an Air Force Titan 4 rocket at the nearby Cape Canaveral Air Force Station. NASA managers plan to meet Wednesday to assess the shuttle repair plan, the processing schedule and range availability. A new launch target date could be set Wednesday afternoon. =================================================================== Shuttle's move to launch pad delayed (01/02/01) Editor's Note... The following story also is posted on the Spaceflight Now web site. The shuttle Atlantis's trip to launch pad 39A today was delayed 24 hours because of a computer glitch in the massive crawler-transporter used to haul the spaceplane and its mobile launch platform to NASA's seaside firing stand. The impact of the one-day rollout delay is not yet known. But it appears likely the flight will slip an additional day to Jan. 20 at the earliest. But the 102nd shuttle mission could slip out to Jan. 24 or thereabouts when all is said and done because of previously scheduled activity on the Air Force Eastern Range, the network of tracking systems used to support all Florida launchings. NASA managers planned to meet this afternoon to assess launch processing, but an official target date has not yet been set. The goal of long-awaited mission is to attach the U.S. laboratory module, Destiny, to the international space station, clearing the way for science operations to begin later this year. Shuttle engineers had hoped to get Atlantis to the pad today to preserve a chance of launching as early as Jan. 19. But after getting underway at 8:40 a.m., a computer system in the shuttle's crawler malfunctioned, bringing the transporter to a halt just a hundred meters or so from the Vehicle Assembly Building. A backup system continued to operate normally, but engineers decided to play it safe and return Atlantis to the VAB pending resolution of the computer problem. In the end, they decided to use a different crawler and rescheduled the move for Wednesday. The 32,000-pound Destiny module, meanwhile, will be moved to the pad an installed in a payload changeout room this evening for installation in the shuttle's cargo bay this weekend. Atlantis's four-man one-woman crew plans to fly to the Kennedy Space Center on Thursday to review safety procedures and to participate in a launch day rehearsal called a terminal countdown demonstration test, or TCDT. The astronauts - commander Kenneth Cockrell, pilot Mark Polansky, flight engineer Marsha Ivins and spacewalkers Thomas Jones and Robert Curbeam - are scheduled to field questions from reporters at the pad at 1:30 p.m. Friday and strap in for the countdown test Saturday. The TCDT is timed to end with a simulated ignition and shutdown of Atlantis's main engines at 11 a.m. But the TCDT schedule could slip a day or so depending on when Atlantis gets to the launch pad. The astronauts plan to participate in a final news conference at the Johnson Space Center in Houston, part of a series of briefings covering all aspects of shuttle mission STS-98. Atlantis originally was scheduled for rollout to the pad in December and launch at 2:44 a.m. on Jan. 18. But rollout was delayed to give engineers time to assess and correct potential problems with cables in the system used to separate the shuttle's two solid-fuel boosters two minutes after liftoff. That system has been repaired and before today's rollout delay, engineers said Atlantis could, in theory, be ready for launch on the 102nd shuttle mission around 2:19 a.m. on Jan. 19. But that schedule has no contingency time available to handle any problems that might crop up between now and then. The Air Force Eastern Range - the network of radars, tracking cameras and destruct systems that supports all launches from Florida - is free on Jan. 19 and 20. But it will be unavailable to the shuttle team Jan. 21 through 23 because of already scheduled pre-launch Titan 4 tests at the nearby Cape Canaveral Air Force Station. The range will open up again for possible shuttle launch tries on Jan. 24, 25 and 26. While NASA has no official policy to the contrary, it is considered highly unlikely the agency would attempt to launch Atlantis - or any shuttle, for that matter - between Jan. 27 and 29. The shuttle Challenger was lost on Jan. 28, 1986, and this year marks the 15th anniversary of history's worst space disaster. NASA is not a particularly superstitious agency, but Atlantis is not expected to fly within a day or so of the anniversary. =================================================================== Atlantis hauled to launch pad; NASA targets Jan. 19 liftoff (01/04/01) Editor's Note... The following story also is posted on the Spaceflight Now web site. The shuttle Atlantis was hauled to launch pad 39A Wednesday for work to ready the ship for launch Jan. 19 on a critical mission to attach the $1.38 billion U.S. laboratory module, Destiny, to the international space station. Running a day late because of computer problems with the shuttle's original crawler-transporter, engineers began Atlantis's 3.2-mile trip to the pad at 10:21 a.m. using a different Apollo-era crawler. This time, the five-and-a-half-hour trip proceeded smoothly and Atlantis's mobile launch platform was lowered onto its massive launch pad support jacks shortly after reaching the pad at 3:45 p.m. The 32,000-pound Destiny module, the scientific heart of the international space station, was moved to the launch pad overnight Tuesday and installed in the rotating service structure's payload changeout room. The Boeing-built lab will be loaded into Atlantis's cargo bay Saturday. Four members of the shuttle's crew, meanwhile - commander Kenneth Cockrell, pilot Mark Polansky and spacewalkers Thomas Jones and Robert Curbeam - flew to Florida today to participate in a dress-rehearsal countdown this weekend. Flight engineer Marsha Ivins was ill and was expected to join her crewmates at the Kennedy Space Center later today. After reviewing emergency procedures Friday and meeting briefly with reporters, the astronauts are scheduled to strap in aboard Atlantis early Saturday for the final hours of a mock countdown. An official launch date has not yet been set. But NASA managers believe Atlantis can be ready for launch on the 102nd shuttle mission by Jan. 19 if no problems develop between now and then. The launch window for Jan. 19 will open at 2:05:59 a.m. EST and close at 2:15:58 a.m. The preferred launch time within that window, that is, the moment Earth's rotation carries pad 39A into the plane of the space station's orbit, is 2:10:42 a.m. An on-time launching would result in a rendezvous and docking with the international space station on the third day of the mission. Should the flight slip to Jan. 20, the preferred launch time would be 1:48:06 a.m., setting up a flight-day four rendezvous. The Air Force Eastern Range, the network of tracking equipment that supports all launches from Florida, is already booked Jan. 21-23 for pre-launch tests of an Air Force Titan 4B rocket at the nearby Cape Canaveral Air Force Station. Additional shuttle launch opportunities are available Jan. 24, 25 and 26. =================================================================== Shuttle crew arrival on tap; booster meetings planned (01/15/01) The shuttle Atlantis's five-member crew flies to Florida today to prepare for launch this week on a critical space station assembly mission. The countdown is scheduled to begin at 5:30 a.m. EST Tuesday for a launch attempt at 2:11 a.m. Friday. But that assumes NASA managers clear Atlantis for flight after meetings today to discuss the health of the shuttle's solid-fuel booster separation system. During the most recent shuttle launching in late November, one of two pyrotechnic circuits in a booster attachment strut failed to fire. The other circuit worked normally, however, and the booster separated cleanly. But NASA held up Atlantis's planned trip to launch pad 39A last month to carry out detailed X-ray inspections of its booster separation system wiring. X-ray inspections showed one cable with a slightly frayed outer jacket. The cable was repaired, Atlantis was given a clean bill of health and the shuttle was moved to the launch pad Jan. 3. But engineers continued to study the issue, carrying out additional tests on other hardware to characterize electrical conductivity and overall performance. On Saturday, problems were found in a separation system cable used during a September shuttle flight. The cable in question passed a post-flight X-ray examination, sources said, but exhibited intermittent electrical continuity, or transmission, during a so-called "wiggle test" in which the wire is physically moved while power is applied. Senior NASA managers planned to meet at 4 p.m. today to review the booster separation system issue. If program managers decide Atlantis' separation system needs additional inspections or repairs, the spacecraft would have to be moved back to the Vehicle Assembly Building. And that would delay launch to early February at the earliest, sources said. One source said "this is a serious issue" and that NASA management is treating it as such. But another source said he believes Atlantis is safe to launch as is and that program managers likely will come to that conclusion. The goal of the 102nd shuttle mission is to deliver and attach the $1.38 billion Destiny laboratory module to the international space station. Commander Kenneth Cockrell, pilot Mark Polansky, flight engineer Marsha Ivins and spacewalkers Thomas Jones and Robert Curbeam are scheduled to fly to Florida this evening for the start of the countdown at 5:30 a.m. Tuesday. =================================================================== Shuttle launch delayed; rollback ordered (01/15/01) NASA managers late today ordered engineers to haul the shuttle Atlantis off its oceanside launch pad and back to the Vehicle Assembly Building for additional tests to confirm the health of cables in the ship's critical booster separation system. As a result, launch of the 102nd shuttle mission - a showcase flight to deliver the $1.38 billion Destiny laboratory module to the international space station - will be delayed from Friday to at least Feb. 6. Engineers at the Kennedy Space Center had planned to start Atlantis's countdown at 4:30 a.m. Tuesday. The shuttle's crew - commander Kenneth Cockrell, pilot Mark Polansky, flight engineer Marsha Ivins and spacewalkers Thomas Jones and Robert Curbeam - planned to fly to Florida from Houston early this evening. But the astronauts delayed their departure while NASA managers assessed the booster separation system issue and ultimately cancelled the trip altogether when the decision was made to delay the launch. The preliminary schedule calls for Destiny to be removed from Atlantis's cargo bay Thursday. The shuttle then will be moved back to the Vehicle Assembly Building on Friday for three days of tests to confirm the health of wires in the booster separation system. Assuming no problems are found, the Atlantis will be hauled back to pad 39A next Wednesday for a launch attempt no earlier than Feb. 6. NASA originally planned to move Atlantis to the pad in mid December for a launch on Jan. 18. But the move was held up after engineers discovered problems with booster separation hardware used in the late November launch of shuttle Endeavour. One of two pyrotechnic circuits in Endeavour's left-side booster attachment strut failed to fire. The other circuit worked normally and the booster separated cleanly. But booster separation is a critical event - the shuttle would be destroyed if even one strut failed to separate properly - and NASA managers ordered X-ray inspections of Atlantis' booster wiring to make sure its separation system was healthy and fully redundant. One cable with a slightly frayed outer jacket was replaced, Atlantis was given a clean bill of health and the shuttle was moved to the launch pad Jan. 3. Taking holiday downtime into account, the launch only slipped one day, to Jan. 19. In the meantime, engineers continued to assess the wear and tear on the cables while carrying out additional tests on other hardware in the shuttle inventory to characterize electrical conductivity and overall performance. Over the past week, engineers discovered problems in four separation system cables taken from the shuttle inventory. At least one of the cables in question passed a post-flight X-ray examination, sources said, but exhibited intermittent continuity, or electrical transmission, during a so-called "wiggle test" that simulates launch vibrations. Engineers plan to perform similar wiggle tests on all the cables in Atlantis' boosters to make sure continuity is solid. =================================================================== Shuttle chief explains launch delay (01/16/01) Editor's Note... The following story also is posted on the Spaceflight Now web site. Worried about possible problems in shuttle booster wiring, engineers tested 194 cables containing 3,028 electrical conductors. They found electrical continuity problems in just four of those conductors. Given that more than one such loss of continuity in a single system would be required to trigger a catastrophic failure during launch, the odds are that shuttle Atlantis could have been safely launched this week on a long-awaited space station assembly mission. Instead, shuttle program manager Ronald Dittemore ordered engineers to haul Atlantis off its launch pad and back to the Vehicle Assembly Building for additional inspections to verify the integrity of 36 multi-wire cables in the shuttle's two solid-fuel boosters. Launch will be delayed from Friday to no earlier than Feb. 6. While the delay marks a frustrating start to a busy 2001 launch campaign, Dittemore said in the end, the launch team had little choice. "I've been doing this job for almost two years and I think I've been fairly consistent," he said. "I guard against the phenomena of 'go fever' like it was the plague. And you have to be very sensitive as you get closer to launch. "I will assure you that this program and the people in this program are extremely sensitive to the fact that we need clear evidence to overcome a challenge or an anomaly that we don't fully understand." Dittemore made the decision after a three-hour teleconference Monday with engineers and managers at the Johnson Space Center, the Kennedy Space Center and the Marshall Space Flight Center in Huntsville, Ala., where the booster project is managed. Unlike an infamous teleconference the night before shuttle Challenger's final launch 15 years ago this month, the Marshall booster team recommended delaying launch for additional testing despite a statistical analysis indicating the odds of a catastrophic failure were slim. "In this instance, we had some statistical analysis that we had performed that indicated, based on statistics alone, that you might be comfortable proceeding with flight," Dittemore said. "And there were a number of folks who felt comfortable with just a statistical analysis. "There was a another camp that felt ... the hardware was telling us something. We had four failures here that we discovered in our testing, we don't quite understand yet why, and we ought to listen to what the hardware may be trying to tell us and do further inspections." In the end, Dittemore said, "the prudent thing to do was to go back an inspect." Engineers plan to move Atlantis from pad 39A back to the Vehicle Assembly Building on Friday. Cable inspections will begin Saturday and if no problems are found, the shuttle will be moved back out to the pad Jan. 25 for a launch attempt Feb. 6. The shuttle's twin solid-fuel boosters provide most of the shuttle's power during the first two minutes of flight. The boosters then are jettisoned, recovered in the Atlantic Ocean and reused. Each booster is equipped with 105 multi-conductor electrical cables that control a variety of critical functions, including booster separation and self-destruct. Twenty-four cables in each booster are water tight and reusable, 41 are not waterproof but are reusable and 40 are used only once. Of the 24 waterproof cables, five are located in the external tank attachment ring and 19 are located in a long systems tunnel that runs the length of each rocket. During the shuttle Endeavour's launch in late November, one of two pyrotechnic circuicts in the left-hand booster's separation system failed to fire. The other circuit fired normally and the booster separated cleanly. But the failure triggered an engineering probe to make sure Atlantis' boosters were good to go. As it turned out, the cable that failed in November, located in the external tank attachment ring, showed clear signs of wear and tear. Engineers inspected all of the ETA cables in each of Atlantis' boosters. One cable was replaced and the shuttle was moved to pad 39A on Jan. 4 for launch Jan. 19. In the meantime, engineers continued testing cables in the booster inventory. And they found four instances where connectivity was lost during testing. All four of the cables in question were 14 to 16 years old. Complicating the picture, the four inventory failures were not due to wear and tear or ground processing. The cause has not yet been determined. And that unknown played a critical role in Dittemore's decision. "Our understanding of it and our comfort level with what caused it and us believing or not whether or not we had a good set of cables on (Atlantis) were all called in question, independent of the math," he said. While engineers tested the 10 ETA ring cables in Atlantis' boosters, they did not test cables in the systems tunnels. Once the shuttle is back in the Vehicle Assembly Building, engineers will do just that, carrying out "wiggle tests" to verify continuity. In the wiggle test, a cable is physically moved from side to side and up and down while power is applied. Dittemore described it as a "fairly severe test" that subjects each cable to more extreme bending than it would experience during an actual launch. Only 36 of the 38 systems tunnel cables will be tested. The other two are used in systems that operate after booster separation. "We do know we can screen the cables to be functional and safe to fly even though we don't understand the root cause," Dittemore said. "So even though we have some more work to do, we do know we're safe to fly given that we screen then properly." It is not yet known what impact any cable replacement work might have on Atlantis' eventual launch date. The current Feb. 6 target assumes no problems are found. =================================================================== NASA managers study revised shuttle launch schedule (01/24/01) Editor's Note... The following story also is posted on the Spaceflight Now web site. NASA managers are assessing a revised shuttle launch schedule that delays two space station assembly flights by several weeks and pushes one flight by the veteran shuttle Columbia into next year. The schedule is not yet official, but the plan was reviewed by shuttle program manager Ronald Dittemore on Monday. While exact target dates may change slightly, the general outline is expected to win approval. The new launch schedule calls for seven flights in 2001, all devoted to space station assembly except a lone flight by Columbia in mid November. And it's not yet clear what Columbia will be carrying. Currently undergoing repairs and refurbishment in Palmdale, Calif., NASA had hoped to launch Columbia on a science mission - STS-107 - in August and then on Hubble Space Telescope Servicing Mission 3B in early December, a flight known as mission STS-109. As it now stands, Columbia will make just one flight this year, in mid November, and NASA is still assessing whether STS-107 or STS-109 will get the nod. In the near term, NASA is gearing up to launch shuttle Atlantis and the U.S. laboratory module, Destiny, on Feb. 6. Originally scheduled for launch Jan. 18, STS-98 was delayed twice, first to Jan. 19 and then to no earlier than Feb. 6, by work to inspect suspect cables in the ship's two solid-fuel boosters. As it turns out, the flight likely will slip an additional day to Feb. 7, which would permit a rendezvous and docking on the third day of the mission. A launch on Feb. 6 would require a flight-day four rendezvous, which NASA wants to avoid if possible. The next flight in the sequence, STS-102 with shuttle Discovery, had been targeted for launch March 1 to carry the station's second full-time crew into orbit along with supplies and additional equipment for the lab's outfitting. But given Atlantis' delay to Feb. 6, STS-102 is expected to be delayed to around March 8 to allow more time between the end of Atlantis' mission and the start of Discovery's. Shuttle mission STS-100 with Endeavour is next up and remains on track for launch April 19 as already planned to ferry the station's Canadian-built robotic arm into orbit. But the next flight in the sequence, STS-104, is expected to slip from May 17 to no earlier than June 7. The goal of the mission, carried out with shuttle Atlantis, is to attach the station's main airlock. The primary reason for the slip is the delay getting Atlantis off the ground for STS-98 and to avoid what NASA calls a "beta angle cutout," a period when the angle between the station's orbit and the sun is not favorable for solar power generation. In domino fashion, the next station assembly flight - STS-105 - is expected to slip from June 21 to at least July 12. And because of another beta angle cutout that begins on July 17, the flight ultimately could be delayed into early August. The shuttle Endeavour returns to space Oct. 4 as previously scheduled for mission STS-108, the first in a series of space station utilization flights. Columbia then will close out the year with a flight in mid November. Columbia is scheduled to return to the Kennedy Space Center from Palmdale around Feb. 23. Engineers say they will need 210 days of horizontal processing to prepare the ship for its next mission and that a launch will not be possible before Nov. 15. But that date does not take other shuttle processing "flows" and launches into account or a potentially dangerous meteor shower in November. As a result, NASA has not yet settled on a target date for Columbia's return to space. =================================================================== Shuttle launch delayed to Feb. 7 (01/25/01) Editor's Note... The following story also is posted on the Spaceflight Now web site. As expected, NASA managers Thursday agreed on a revised near-term shuttle launch schedule, delaying the next flight one day to Feb. 7 and the flight after that from March 1 to March 8. Other downstream flights face delays of several weeks and two space station crew rotation missions are under review. Engineers at the Kennedy Space Center are gearing up to move the shuttle Atlantis from the Vehicle Assembly Building back out to pad 39A Friday for work to ready the ship for blastoff Feb. 7 on a long-awaited flight to attach the U.S. laboratory module, Destiny, to the international space station. Liftoff is targeted for 6:11:14 p.m. on Feb. 7 with a backup opportunity at 5:48:38 p.m. on Feb. 8. A launch on either day would result in a flight day three rendezvous with the space station. NASA originally hoped to send Atlantis into orbit Jan. 18, but the flight was delayed twice - first to Jan. 19 and then to Feb. 6 - by work to inspect suspect electrical wiring in the ship's two solid-fuel boosters. An additional one-day delay was ordered today because of a conflict with the Feb. 3 launch of an Air Force Titan 4 rocket from the nearby Cape Canaveral Air Force Station and because a launch on Feb. 6 would have required a flight day four rendezvous with the space station. NASA managers on Monday discussed potential delays for downstream flights and today, they agreed on a revised near-term flight schedule. But additional meetings are planned next week to resolve open questions with at least two flights. STS-102 will carry the space station's second full-time crew into orbit. The Expedition Three crew will go up on STS-105 while their replacements, Expedition Four, will launch aboard STS-108. Because STS-105 faces a delay of several weeks - and possibly longer because of required maintenance on Discovery and issues involving the station's orbit - launch of STS-108 could slip beyond Oct. 4 to ensure adequate separation between the two crew rotations. NASA's most recent space station assembly schedule called for the Expedition Three crew to spend 113 days in space from launch on STS-105 to space station undocking on STS-108. Under that scenario, STS-108 would take off in late October for a station undocking around Nov. 2. Senior NASA managers will review planning for both flights next Thursday and possibly set new launch targets. In addition, NASA is still debating what to do about shuttle Columbia, currently undergoing modifications and repairs at Boeing's Palmdale, Calif., processing facility. Columbia had been scheduled for two flights this year, one in August to carry out a suite of science experiments, and another at the end of the year to service the Hubble Space Telescope. But Columbia will not get back to the Kennedy Space Center until late next month and engineers now say the veteran spaceplane will not be ready for flight until mid November. Whether the science mission - STS-107 - or Hubble Space Telescope Servicing Mission 3B, known as STS-109, will get the nod is not yet known. =================================================================== STS-98 mission preview (02/04/01) SHUTTLE ATLANTIS SET FOR LAUNCH ON CRITICAL STATION MISSION The shuttle Atlantis is set for launch Wednesday on a critical mission to deliver the $1.38 billion U.S. laboratory module, Destiny, to the international space station, finally clearing the way for the start of orbital research later this year. Atlantis' crew - commander Kenneth Cockrell, pilot Mark Polansky, flight engineer Marsha Ivins and spacewalkers Thomas Jones and Robert Curbeam - flew to the Kennedy Space Center on Sunday for the start of the countdown to launch on the 102nd shuttle mission. If all goes well, Atlantis will blast off from pad 39A at 6:11 p.m. Wednesday, Feb. 7, at the precise moment Earth's rotation carries the launch pad into the plane of the international space station's orbit. Assuming an on-time liftoff, Cockrell will guide Atlantis to a docking with the space station around noon on Feb. 9. Awaiting their arrival will be station commander William Shepherd and cosmonauts Yuri Gidzenko and Sergei Krikalev, launched Oct. 31 aboard a Russian Soyuz spacecraft and now working through their fourth month in space. The long-awaited and oft-delayed Destiny module will be attached to the station the day after docking during the first of three planned spacewalks by Jones and Curbeam. The 32,000-pound Boeing-built lab module, the scientific heart of the international space station, was designed to serve as a world-class orbital research facility, allowing scientists to carry out long-term experiments in the microgravity environment of space. It also will serve as the "bridge" of the space station, providing the central computers and communications gear necessary to monitor and control critical systems throughout the complex. "The lab is really the guts of the space station's research and command and control capabilities," Jones said in a NASA interview. "It becomes possible to do science and to make the science quality science because of the arrival of the lab." He said the massive laboratory represents "a quantum jump for the space station's maturity as a research facility." "We're really getting into the serious growth phase of the space station," he said. "And we can leapfrog from the lab to doing some really valuable work there." More poetically, perhaps, veteran shuttle commander Robert Cabana, a senior space station manager, said the lab "fulfills the destiny of the space station." "It's going to be what gives us hopefully those breakthroughs we're looking for in the future, a real place to do science and a world-class microgravity lab," Cabana said. "It's going to be something." Measuring 24 feet long and 14 feet wide, the Destiny module is the most complex space station component, U.S. or Russian, ever built. And at $1.4 billion, it is certainly the most expensive." The lab can accommodate 12 removable refrigerator-size racks for high-tech experiment hardware and another dozen system racks housing computers, environmental control systems and communications equipment. It also features a large Earth-facing window in an open rack bay made with optically pure, telescope-quality glass. Along with serving as the station's main research center, computers in the Destiny module will be used to monitor and control all aspects of station operation, including a quartet of massive stabilizing gyroscopes attached to the station last year. By changing the spin rate of the gyros, the lab computers can change the orientation of the entire space station as required by the research agenda and the arrival and departure of space shuttles, Soyuz crew ferry ships or unmanned Progress supply craft. By using the gyros to control the station's orientation, NASA and its Russian partners can avoid experiment-jarring rocket firings that burn up precious on-board supplies of rocket fuel. "For command and control, right now we're in sort of a crude mode where we use thruster control to maintain attitude on the space station and that's a very fuel-intensive activity," Jones said in the NASA interview. "We want to get the gyros that went up there on (assembly flight) 3A to control the station's attitude, and the software and commanding, the computers that make that possible, are all in the laboratory. So, that enables a more fuel-efficient mode of operation. "And the control moment gyros are much less disturbing to a microgravity environment than thruster firings are," he added. "So, that makes a good quality research environment available on the station." Up until this point, orientation, or attitude, control has been provided by thrusters on the Russian Zarya and Zvezda modules. Likewise, the station's primary communications - telemetry and voice circuits - have been routed through Russian ground sites and control centers. As such, the Russian mission control center near Moscow - MCC-M in NASA-speak - has been designated the station's "lead" flight center. But with arrival of the Destiny module, activation of the station's NASA-supplied control moment gyros and two high-data-rate S-band radio links that will operate through U.S. communications satellites, NASA's mission control center at the Johnson Space Center in Houston will formally become the station's lead center. Russian flight controllers will continue to monitor and control operations in the Russian segment of the station, handling Russian-language communications and orchestrating arrivals and departures of Progress and Soyuz spacecraft carrying cosmonauts and, in at least one case, presumably, a private citizen. But with Destiny's arrival and activation during Atlantis' mission, flight controllers in Houston - MCC-H - will finally be in charge, in a formal sense at least, of the $60 billion space station complex. "After (station assembly flight) 5A, control shifts primarily from MCC-Moscow to MCC-Houston," Cabana said. "We're working with the Russian control team, our control folks, to lay out the criteria for that shift and the process by which it happens. "That doesn't mean the Russians won't have control of their vehicle," he added. "They'll still be talking to the crew in Russian and exercising the authority and control that they need to ensure their systems are up and operating." Cabana said both sides are working to ensure an orderly handover, but "I'm sure it's not going to be without some growing pains." Shuttle program manager Tommy Holloway downplayed the significance of the changing roles of the two control centers. "This is a joint operation," he insisted. "And when we talk about who's in control we really mean is who is the leader of the band and who is providing the overall integration and overall planning. And indeed, each side is in control and in charge of their particular part of the operation." RENDEZVOUS MORE ART THAN SCIENCE NASA had hoped to launch Atlantis on Jan. 18. But the flight was delayed twice, first to Jan. 19 and then to Feb. 6, by inspections to verify the integrity of critical wiring in the ship's booster separation system. A subsequent one-day delay was ordered to permit a flight-day-three rendezvous with the space station. As with all space station assembly missions, Atlantis' theoretical launch window is just 10 minutes long, five minutes to either side of the moment the pad is directly in the station's orbital plane. The countdown targets the opening of this 10-minute "planar" window. But NASA actually targets launch for the moment the pad is "in plane" with the station, which occurs five minutes later. By launching directly into the station's orbital plane, the shuttle crew can improve certain abort options and save fuel. To hit the preferred in-plane launch time of 6:11 p.m., a final built-in hold at the T-minus nine-minute mark in the countdown will be extended as required. It will take Atlantis' crew two days to catch up with the space station for a docking on Feb. 9. Cockrell will begin final approach to the complex with a critical rocket firing known as the TI burn at a point about 9.2 miles directly behind the target. To visualize the shuttle's approach, it helps to keep the station's current configuration and orientation in mind. The outpost currently consists of three pressurized modules attached end to end: The Russian command module, Zvezda, on one end; the multi-hatch U.S. Unity node on the other; and the Russian-built, NASA-financed Zarya module sandwiched in between. The Soyuz spacecraft that ferried Shepherd's crew to the station is docked to Zvezda's aft port. The Unity module features six hatches or ports: One on each end and four around its circumference. Attached to one of the end hatches is a pressurized mating adapter - PMA-1 - that connects to the Zarya module. Another mating adapter, PMA-2, is attached to the other end hatch while a third, PMA-3, is attached to Unity's downward-facing, or nadir, port. A large structural component known as the Z1 truss is bolted to Unity's upward-facing, or zenith, port. The Z1 truss houses the four control moment gyroscopes that will be used to maintain the station's orientation. A huge set of solar arrays is bolted to the top of the Z1 truss. Its two wings, oriented at right angles to the long axis made up of the three pressurized modules, stretch 240 feet from tipi to tip. Installed during the most recent shuttle flight last December, the P6 solar array truss also includes large radiator panels to dissipate the heat generated by the Destiny module's electronics systems. As Atlantis approaches the station, the complex will be oriented with its long axis - the Unity/Zarya/Zvezda axis - in the direction of its orbital motion with Unity in front and Zvezda behind. The Z1 truss and the P6 array will be facing deep space while PMA-3 will be facing Earth. The Destiny laboratory module, which features a hatch on each end, must be installed on the Unity end hatch currently occupied by PMA-2. PMA-2 will be removed and reattached to the lab's far hatch during Atlantis' mission. But first, Cockrell must guide the shuttle to a docking with Unity's downward-facing PMA-3. The terminal rendezvous sequence will begin about two-and-a-half hours before docking with the TI burn. Final approach is set up to bring Atlantis, in a nose-forward, wings-level, belly-to-Earth orientation, to a point about 600 feet directly below the station. The imaginary line connecting the station to the center of the Earth is known as the "r-bar," or radius vector. By convention, points below the station are considered positive while points above are considered negative. Cockrell will approach the station along the plus r-bar for a docking at the downward-facing PMA-3. But given the station's orientation, he first will have to yaw the shuttle 180 degrees so it is flying tail first below the station. Otherwise, PMA-1 and the Zarya module would prevent the crew from removing Destiny from the shuttle's cargo bay after docking. The yaw maneuver is fairly tricky, combining two different types of orbiter motion at the same time. "It's called the tail forward maneuver," Cockrell said. "And when I was first presented with this, I thought, 'Okay, tail forward maneuver. Put in some control inputs and the orbiter swings around.' "It turns out, it's a little more of an art than it is of a science and it's taken a lot of practice for us to begin the tail forward maneuver so that we come out of it at the appropriate place and don't require a lot of thruster firings that waste fuel. "And so, if there's a point you want to key into the rendezvous and note our response to something we've done, that would be one of them," Cockrell said. "Because it can either go well or it can go bad. It won't ruin the rendezvous. But, if it goes badly, we may not have as much fuel as we'd like (left over)." The tail forward maneuver should be complete by the time Atlantis is 360 feet or so below the station. That will prevent any chance of possible thruster exhaust plume damage to the space station. "From that point on, we drive in to 170 feet," Cockrell said. "If there's any timing we need to do to make the docking occur at a specific point over the Earth, then we wait at 170 feet to make that timing come true. "From there, we drive in to 30 feet. And at 30 feet, we zoom the camera that's looking at the station right up through our docking adapter, zoom it all the way in, look at the target ... and determine whether there's any error in pitch, yaw or roll of the station. "And if there is, we just, by visually using a little scale and ruler, measure how much error there is, apply it to a formula, put it into the autopilot ... so that we can then manually fly it on up to the station. That happens at 30 feet. "Once the pointing is done and then when the timer counts down to the right amount if we're trying to hit a specific spot over the Earth at docking time, we push on in." From that point, he said, "it's just trying to keep your 200,000-pound vehicle lined up with (the station) to an accuracy of about three inches." "We need to be no less, no more, than three inches off in our position," Cockrell said. While the job is no doubt challenging, Curbeam said in a NASA interview that Cockrell - known as "Taco" - has no problem pulling it off to perfection in NASA's shuttle simulators. "Space rendezvous is an absolutely amazing thing to me," Curbeam said. "You have these two objects sitting in orbit, moving at over 17,000 miles an hour. But yet, you've got to control these two vehicles so you get closure between them to less than a tenth of a foot per second. "So it's a pretty amazing feat in itself," he said. "And I bow down to Taco every time I see him do it when we're in the simulator and do it so well. If all goes well hooks and latches in the docking system will pull the two spacecraft together a few minutes before noon on Feb. 9. A vestibule between the shuttle's hatch and a hatch on the end of PMA-3 then will be pressurized and after leak checks, the hatches will be opened and the two crews will finally greet each other. A brief welcoming ceremony is planned that will be carried live on NASA television. "I'm sure they'll be happy to see us because we'll have some fresh food and some gifts and maybe some chocolate, or whatever they'd like, we'll be bringing to them," Cockrell said. "And then, we'll get straight to work." LAB INSTALLATION A COMPLEX BALLET After completing initial equipment and supply transfers from the shuttle to the space station, the two crews will close the hatches between the two vehicles and go to bed to wrap up the shuttle crew's third flight day. The next "morning," Ivins will unlimber the shuttle's 50-foot-long robot arm while Jones and Curbeam prepare for the first of three planned spacewalks, or EVAs. Before Destiny can be attached to the Unity node's end hatch, Ivins must remove PMA-2 and temporarily mount it on the Z1 truss. The pressurized mating adapter is attached to Unity with a system of motor-driven bolts making up a common berthing mechanism, or CBM. After Ivins locks the end of the arm on PMA-2's grapple fixture, computer commands will be sent to open all the CBM bolts holding the mating adapter in place. About one hour before the spacewalk begins, PMA-2 will be detached from Unity and moved to a point just a few feet away from its temporary mounting point on the Z1 truss. No problems are expected at this stage. If all goes well, that is. While the station's CBMs have been used to successfully lock components together, the removal of PMA-2 marks the first time the system will have been used to detach a component. In any case, Ivins should have PMA-2 in the "pre-install position" aside the Z1 truss just about the time Jones and Curbeam are floating out of Atlantis' airlock. "We have to remove PMA-2, and we don't even want the EVA guys to come out of the airlock until we've successfully unbolted PMA-2, using computer commands from the shuttle, and pulled it away from the node," Cockrell said. "And then, we're going to allow the guys to open the hatch and start their work." Jones will make his way up to the Z1 to assist Ivins in precisely positioning PMA-2 on the side of the truss. He then will use a power tool to drive four bolts closed, temporarily locking PMA-2 in place. Curbeam, meanwhile, will float to the far end of Atlantis' payload bay to remove contamination shields protecting the common berthing mechanism interface that will connect to the Unity module's hatch. He then will disconnect umbilicals providing power for the lab's heaters. Once that work is complete, the two spacewalkers will move up the station "stack" to the P6 solar array truss where they will unlock restraints holding a cooling radiator in place. The radiator will be deployed later in the mission. After unlatching the radiator restraints, Jones and Curbeam will remove a locking pin holding the steering system of the station's main Ku-band dish antenna in place. The antenna will not be used, however, until after the next station assembly mission. Ivins, meanwhile, will be using the robot arm to pull Destiny out of Atlantis's cargo bay. She will have to be very, very careful: There are only two-and-a-half inches of clearance between the sides of the lab at its widest point and the walls of the shuttle's payload bay. Keeping the lab properly oriented and within this tight tolerance would be a challenge to any arm operator. But it's even more so for Ivins because she will not be able to directly see the lab and its attachment fittings. "When we attach to the station, when you look out the aft window and the overhead window of the flight deck, all you see is station," she said in a NASA interview. "I mean, the station is six feet (away) out the window. "So unlike most flights where there is a robotics operator who's manipulating a large structure in the payload bay, we have no direct eye contact with the payload. We can't see it at all." Instead, she will use two television monitors on the shuttle's aft flight deck to display the output of four television cameras mounted in each corner of the cargo bay. "The lab is about as wide as the payload bay is," Ivins said. "I'm going to pull it out of the bay at about a tenth of a foot per second. So, it will take 20 minutes to get this thing out of the bay. "Then I have to flip it 180 degrees. Now, as it turns out, there is a keel pin on the bottom of the lab that holds it into the payload bay when we launch. I have to flip it over because a few flights from ours they will attach something to that keel pin." Because of limitations on the range of movement of each joint in the robot arm, Ivins cannot simply flip the lab over. She must move the arm through a complex pattern to accomplish her goal. "It's taken us about a year and a half to figure out what that path is," she said. "I can do that. So we flip this thing over and bring it down to the position of the node." At this point, Ivins will be able to take advantage of the view from a camera mounted by the station crew in Unity's hatch. She will see the lab from Unity's perspective, allowing her to fine-tune the final approach. If the lab is properly aligned, the cockpit crew will see four "ready to latch" indicators light up. At that point, the CBM mechanism will be activated via computer link to begin locking Destiny to the Unity module. "We will throw the latches and we will drive the bolts and I will start to breathe again," Ivins said. And what if one of the critical cameras breaks down? "I wake up at night in a cold sweat thinking about this," Ivins said in a pre-flight news conference. 'This flight and most of the other station assembly flights to follow are very highly dependent on these cameras because you have no direct view out the back windows. "There are some cameras that if we lose we are going to ask the EVA guys to go out and replace with another payload bay camera. We're really hoping that doesn't happen." With Destiny in place, Curbeam and Jones will move to a panel on the Z1 truss that provides connections for electrical and fluid lines running between the P6 solar array truss and the rest of the station. The spacewalkers will hook up nine electrical connectors between the lab and the Z1 truss and four fluid jumpers that will allow ammonia coolant to flow between Destiny and the P6 radiators. The nine electrical cables carry power from the solar arrays, computer commands and telemetry and electricity to repower the lab's launch-to-activation heaters, which were disconnected from shuttle power earlier in the spacewalk. "The ammonia lines - the fluid lines - are circulating cooling ammonia all the way up to the radiators on the P6 truss," Jones said. "And that provides an outlet for the lab's heat. The electrical power is flowing down from the solar panels down P6 through Z1, and that power is available at the end of these umbilicals that we then hook into the laboratory's connections. "And now we distribute this 120-volt electrical power into the laboratory so it can be distributed to the various life support, command and control and scientific functions later on. So we actually have a little fold-down tray on the end of Z1 that lays out these lines in a nice, orderly fashion. "We have to bend them across a few feet of space and then mate them to the laboratory," he said. "And both Bob and I reach in from opposite sides of this tray and spend about an hour doing all those critical connections." If the spacewalkers run into problems getting the power lines connected on the Z1 tray, a smaller set of cables will be hooked up between Destiny and Unity to provide emergency power to operate the lab's heaters until the other problem is resolved. Getting power to the lab is critical. While ammonia coolant carries heat up to the P6 radiators, water is used in the lab's internal cooling loops and without heaters, that water could freeze. The ammonia coolant lines are just as critical at the other end of the temperature extreme. In a sort of "Catch-22," the crew most power up the lab's computers and avionics system, which generate heat, to activate the cooling system necessary to remove it. "There's about a four-hour window to accomplish this lab activation," said station flight director Andrew Algate. "When we start turning on the avionics, they require cooling. But to turn the cooling system on, we need to have the avionics on. "But we estimate the procedure here will only take about an hour and a half so we have a fair window here to get the job done." The spacewalk is scheduled to last six-and-a-half hours. The hatches between Atlantis and the ISS will be reopened about an hour after Curbeam and Jones repressurize Atlantis' airlock and internal electrical grounding straps will be hooked up between Destiny and the Unity module. Avionics powerup and coolant system activation will begin shortly thereafter. "The first thing that we do is we turn on the DC-to-DC converter units that are providing power to the systems in the lab," Algate said. "As soon as those units start converting power, they require cooling. "As we turn on subsequent components in the lab, the various computer systems required to turn on the thermal cooling loops, those systems also require cooling. So there's a period of time that's estimated to be four to five hours before some of those components start to overheat. "So the key is that within that window of time we start the coolant water flowing in the thermal control loops." The equipment is fully redundant. While no problems are expected, flight controllers are prepared for a variety of contingencies. "It's always possible just to shut things down" if cooling cannot be established in time, Algate said. "There's a separate heater system ... that will keep it warm while we troubleshoot any problems that we have." Flight controllers in Houston will continue Destiny's initial activation and checkout while the crew sleeps. The next day, the astronauts and cosmonauts will finally float inside and lab activation will begin in earnest. THE MOMENT OF TRUTH: DESTINY COMES TO LIFE Destiny's initial activation is primarily the responsibility of the shuttle crew members, who have received more recent training than Shepherd and his crewmates. But all eight space fliers will participate in one form or another. "It's really a housewarming party for the whole second day, where we open up the closets, we turn on the lights, we enable the fan and air-conditioning systems to come on," Jones said. "And by the end of that day, we should have laptop (computer) control of the lab systems from inside. We should have all the air circulating. We should have the thermal control (system) activated so that everything's humming for making that a habitable space for the crew. And that doubles their working space. "So I think they're going to be as motivated as we are to get it going," Jones said. The interior of the Destiny laboratory module is rectangular and divided into four zones called "rack faces." Each rack face can accommodate six racks of science gear or systems equipment. Each refrigerator-size equipment rack pivots at its base to rotate outward for access to the interior. The racks can be removed and replaced by on-board crews as required to support new experiments or maintenance. Because of shuttle weight limitations, Destiny will be launched with just five of its two dozen racks in place, all of them devoted to support equipment. Eight empty rack bays are equipped with flexible curtains to provide 288 cubic feet of temporary stowage space. The first science rack, a package of medical experiment hardware, is scheduled for delivery during the next shuttle mission in March. "They can be anything," Jones said of the racks in his NASA interview. "They can be life support setups. They can be racks full of avionics and computers. They can be research facilities. And anything from a microgravity furnace to a biological containment facility for small laboratory animals." While Atlantis is launching with just five systems racks in place, each one is critical to lab operation. "There are a couple of thermal control racks which cool the interior of the lab and exchange heat from the inside of the laboratory out to the radiators on the outside of the station," Jones said. "They also condition the air that flows through the lab and cool it at the right temperature, for example. "We have a couple of avionics racks, which contain the command and control computers that establish this attitude and motion control function." But the control moment gyroscopes in the Z1 truss will not be turned on, spun up and tested by flight controllers until the next day, during the crew's second spacewalk. Other systems will, however, be tested during initial lab activation. The avionics systems, Jones said, "deliver commands down to the lower tiers of computers that will monitor the various subsystems on the space station, from photovoltaic power to life support to some of the laboratory data handling equipment." One rack is particularly valuable: The Air Revitalization System. The ARS equipment "will scrub carbon dioxide out of the air and then condition it and blow it to the rest of the laboratory," Jones said. "We make use of the lab's power and command and control capabilities to sort of make it a habitable volume that's a good place to work." For launch, the ARS rack was mounted in a specific rack bay capable of handling the vibrationss of ascent. One of the first items on the agenda for the crew during initial activation will be to move the rack to its proper location in a different bay. "It doesn't take over this life support function of scrubbing CO2 and conditioning the air and filtering it until it moves to its actual orbital location," Jones said. "That's one of the major tasks inside that activation day. "We also have some mundane chores, like swapping out valves that were needed only for the launch phase that now are needed for later connections to the front of the laboratory that permit the pressure to be equalized on either side of the hatch. "We have to make some electrical connections inside that deal with providing the laboratory users, the astronaut crew, communications capability back to the Russian segment comm system so that they can talk to mission control through the Russian segment and even just use intercom throughout the length of the station. "The stack's going to be 160 feet long or so by then, and you can't shout down the hallway. So this jumper connection will enable Sergei, using the U.S. lab audio terminal unit, to talk to somebody back in the service module." In addition, Jones said, "we've got some set up to do on the stowage racks in the laboratory that enable the crew to actually put things in there and keep them stowed in an orderly fashion." Lab activation will be filmed by the station crew using a large-format IMAX camera. The shuttle crew also plans the first in a series of rocket firings to boost the station's altitude by 15 miles or so, fuel permitting. At the end of the day, the hatches between Atlantis and the station will be closed again and the shuttle's cabin air pressure will be lowered to 10.2 psi, setting the stage for the crew's second spacewalk the next day. TWO MORE SPACEWALKS, MORE LAB OUTFITTING ON TAP The primary goal of the mission's second spacewalk is to move pressurized mating adapter No. 2 from its temporary mounting point on the Z1 truss and to attach it to the far end of the Destiny module to permit subsequent shuttle dockings. Jones and Curbeam also plan to install a so-called power and data grapple fixture to Destiny's hull that later will serve as the mounting point for the space station's Canadian-built robot arm. Other tasks include attachment of a slidewire for use by future spacewalkers and installation of thermal covers over the massive trunnion pins used to mount the lab in the shuttle's cargo bay. While the spacewalk is going on, flight controllers will begin testing the control moment gyroscopes, making for another busy day in space for the astronauts and ground crews alike. "The first spacewalk is basically to prepare Destiny for activation," Curbeam said. "The second spacewalk is basically to get ready for the rest of the assembly sequence." A half-hour or so before Jones and Curbeam exit Atlantis' airlock, Ivins will grapple PMA-2 with the robot arm. But the common berthing mechanism on the temporary attachment fitting is a manually operated system. "We have to get Tom up there first before we can do anything," Cockrell said. "He has to come up and be ready to unlatch PMA-2 from the Z1. Marsha grapples PMA 2. Tom unlatches it. And then she takes it down to the end of the lab and installs it on the leading edge of the front-end cone of the lab. "PMA 2, on the front of the lab, will be where the next several flights dock to. So, it's important that it gets installed there; otherwise, there's a break in the assembly process." But the crew will take its time tightening the 16 bolts in the lab's active common berthing mechanism. "Because it's been in a different thermal condition up on Z1 than the front of the lab has been, we will only partially bolt it down," Cockrell said. "We'll bolt it down tight enough to where she can let go of it with the arm, but then it needs to sit there and wait 12 hours while the temperatures equalize on the two interfaces. "We'll come back to it later and do the final torquing of those bolts," he added. "It depends on how smoothly that goes what else we get done on EVA two." Once PMA-2 is attached to the lab, Ivins will be free to help Jones and Curbeam attach the power and data grapple fixture to Destiny's hull. Jones, anchored to the end of the arm, will retrieve the grapple fixture from its mounting point in the cargo bay while Curbeam peels back micrometeoroid shielding protecting Destiny's outer skin where the PDGF will be installed. "It's just a grapple fixture that you've seen on all sorts of payloads on shuttle and space station elements," Jones said. "But this one's a little bit more capable in that it provides electrical connections into the laboratory from the outside. "And not only electrical connections but a video feed so that the cameras on the arm can be monitored from inside the laboratory and later from other workstations inside the station cupola, for example." It will take the spacewalkers two hours or so to complete the installation, attaching power lines, installing a video signal converter for a fiber optic link to the interior of the station and then re-installing the debris shielding. "There are a number of other minor outfitting chores on the EVA and installing a slide wire for translation safety up and down the lab, installing foot restraints for other work that we're going to be doing and other crews will be doing on the spacewalk. "But the major tasks are getting that docking port relocated and then providing the foundation for the robotic operations outside." The spacewalk is scheduled to last about six hours. Overnight, while the crews sleep, flight controllers in Houston will send commands to complete the tightening of the bolts in the lab's forward common berthing mechanism to firmly lock PMA-2 in place. Hatches between Atlantis and the space station will remain closed throughout the next day. The astronauts will enjoy a bit of off-duty time and carry out another in the series of reboost operations to increase the station's altitude. The third and final spacewalk of the mission - the 100th in U.S. space history - will begin the following day. "We'll have left the lab in good shape," Jones said. "It'll have all of its power and cooling capability. We'll have relocated the docking port so future crews can come to the right docking port. ... Those are the key things. "Then on the third EVA, we're going to set our sights on just enhancing the situation of the space station with regard to spares." First, Jones and Curbeam will mount a spare S-band antenna array on the Z1 truss to provide a backup in case the station's main S-band antenna package malfunctions at some point. The spacewalkers then will install a frying pan-like shutter on the lab's Earth-facing window and connect power and data lines between the lab and PMA-2. "Those power lines will provide both electricity flow to the heaters on the PMA and then also some data feedback into the station so that, when an orbiter docks, you can transfer information and commanding from the orbiter through to the rest of the space station via these lines," Jones said. With their primary tasks complete, Jones and Curbeam will make their way all the way up the Z1 and P6 trusses - a point more than nine stories above the cargo bay - to inspect the linkages in a system used earlier to extend the two deployable solar arrays.