STS-99 MISSION ARCHIVE Updated: 02/23/00 The Shuttle Radar Topography Mission (COMPLETE) By William Harwood CBS News/Kennedy Space Center The following copy originally was posted on the Current Mission space page at http://www.cbs.com/network/news/space/current.html. Comments, suggestions and corrections welcome! TABLE OF CONTENTS NASA to launch radar mission Nov. 19 (09/09/99) NASA reconsiders flight sequence (09/17/99) Radar mission re-targeted for December launch (09/24/99) Radar flight slips to Jan. 13 (10/07/99) Endeavour launch slips to end of January (12/29/99) NASA managers target Jan. 31 launch date for Endeavour (01/03/00) No decision yet on launch dates (01/10/00) NASA, Air Force remain at loggerheads on launch date issue (01/12/00) NASA, Air Force agree on launch dates for shuttle Endeavour (01/13/00) NASA managers order tile bonding review (01/19/00) Radar mast to be retracted one day early; dataset reduced (01/20/00) NASA managers study ways to increase science return (01/24/00) Science extension appears unlikely (01/25/00) STS-99 Mission Preview (01/26/00) Astronauts arrive for launch; engine issue discussed (01/27/00) Engine issue assessed; countdown set to begin (01/28/00) Countdown begins (01/28/00) NASA managers await word on engine issue (01/29/00) NASA defers engine decision; countdown continues (01/29/00) Weather forecast worsens; no word yet on engine issue (01/30/00) Endeavour cleared for launch (01/30/00) Shuttle Endeavour grounded by weather, avionics problem (01/31/00) MEC replacement ordered; launch delayed to at least Feb. 9 (02/01/00) Shuttle Endeavour rescheduled for Feb. 11 launch (02/02/00) NASA develops strategy to maximize odds of launching Endeavour (02/03/00) Astronauts return for launch (02/07/00) Weather 'go' for launch; booster issue assessed, resolved (02/08/00) Endeavour set for blastoff (02/09/00) Weather improves for Friday launch (02/10/00) Shuttle Endeavour rockets into orbit (02/11/00) Radar mapping operations commence; mission managers elated (02/12/00) Radar mapping continues; boom thruster anomaly studied (02/13/00) NASA managers downplay impact of ineffective thruster (02/14/00) NASA managers optimistic thruster issue can be resolved (02/15/00) Radar mast thruster issue appears resolved (02/16/00) Scientists elated with initial mapping results (02/17/00) Radar mapping extension approved (02/18/00) Extra nine hours means big boost for science (02/19/00) NASA says radar data exceeded expectations (02/20/00) Astronauts complete radar mapping; retract mast on fourth try (02/21/00) Shuttle Endeavour returns to Earth (02/22/00) Astronauts pleased with mission success (02/23/00) =================================================================== NASA to launch Hubble repair mission Oct. 28; radar mission Nov. 19 (09/09/99) Struggling to get the shuttle program back on track after work to repair dozens of wiring defects, NASA managers today agreed to flip-flop the next two shuttle missions, launching a high-profile Hubble Space Telescope repair mission aboard the shuttle Discovery Oct. 28 and an Earth mapping mission aboard Endeavour on Nov. 19. The radar mapping mission will come one week after launch of a critical Russian service module to the international space station and one day after the potentially dangerous Leonids meteor shower Nov. 17-18. The radar mission will be the final shuttle flight of 1999. Shuttle managers said the new launch dates are targets only and subject to change depending on the progress of work to repair wiring defects in both space shuttles. "We've established these planning dates so that those involved in flight preparations can establish the proper order of priority for work on each mission," space shuttle program manager Ron Dittemore said in a NASA status report. "However, we are continuing to review the progress of wiring inspections and repairs on Endeavour and Discovery and, as part of our continuing evaluations of those activities, we may need to revisit the subject and further adjust our target launch dates as those repairs progress," he said. "We will not fly any mission until we are satisfied that we have safely resolved the all wiring problems we have found." A short circuit five seconds after the shuttle Columbia's liftoff July 23 caused two main engine computers to shut down. The veteran shuttle made it safely into orbit using backup computers but after the flight, Dittemore ordered fleet-wide inspections to make sure no other wiring problems lurked unnoticed. Both Endeavour and Discovery were found to have dozens of wiring defects, primarily in areas, like those in Columbia's cargo bay, where workers could have caused inadvertent damage during normal between-flight processing. Endeavour was found to have more such defects than Discovery. Detailed inspections of Columbia and Atlantis are not yet complete. Hubble managers have been waging a vigorous campaign to fly as close to their original launch date as possible because three of Hubble's six stabilizing gyroscopes have failed, leaving the telescope one failure away from scientific shutdown. The primary goal of the servicing mission is to install a full suite of six new gyroscopes, a new computer, six battery conditioners, a new solid-state data recorder and an upgraded fine guidance sensor. In addition, four spacewalking astronauts will repair or replace much of the telescope's peeling thermal insulation. =================================================================== Next shuttle launch delayed to Nov. 19; NASA reconsiders flight sequence (09/17/99) While Hurricane Floyd caused only minor damage at the Kennedy Space Center, work to prepare for the storm has forced NASA to delay the next shuttle flight from Oct. 28 to Nov. 19, officials said today. But shuttle managers are reconsidering which of two missions to launch first. NASA had planned to launch the shuttle Discovery on a 10-day voyage to service the Hubble Space Telescope on Oct. 28, followed by launch of the Endeavour on Nov. 19 on an 11-day flight to map Earth with high-resolution radar. Sandwiched in between is the Russian launch of a critical space station component called the service module on Nov. 12. The NASA launch schedule was defined in part by a requirement to avoid having a manned shuttle in orbit during the potentially dangerous Leonids meteor shower, which peaks around Nov. 17-18. To protect against the possibility of a weather-related landing delays, Discovery had to get off the ground by Nov. 4 at the latest. The next launch opportunity after that was Nov. 19. But shuttle processing was interrupted by Hurricane Floyd and NASA managers said today Discovery could not be readied for launch before the end of the Oct. 28-Nov. 4 launch period. The delay, coupled with concern about the time needed to turn both shuttles around for upcoming space station flights, has prompted shuttle program manager Ron Dittemore to reconsider which mission to launch first. If Discovery and the Hubble mission get the Nov. 19 launch slot, Endeavour theoretically could be ready for takeoff on the radar mapping mission around Dec. 10, sources say. But that's an extremely optimistic schedule and it appears more likely the flight would slip to around Jan. 13. Under that scenario, one of several launch options under debate, a space station servicing mission known as STS-101/2A.2 would take off in February or March, followed by launch of the first full-time station crew on April 6. Discovery would return to space in May for station assembly mission STS-92/3A to carry a truss element into orbit. Endeavour would follow suit on station mission STS-97/41 in June. The current launch debate follows on the heels of a similar discussion earlier this month when NASA managers first decided to launch Discovery ahead of Endeavour (see the Sept. 9 status report immediately below for complete details). The original schedule called for launching Endeavour on Sept. 16 and Discovery on Oct. 14. But both flights were delayed to repair dozens of wiring defects discovered in the wake of a short circuit during the shuttle Columbia's launch July 23. In some quarters, the Hubble mission has priority because three of the space telescope's six gyroscopes have failed, leaving the observatory one failure away from scientific shutdown. But the radar mission has its own dedicated supporters and as of this writing, it's not clear which mission NASA will launch first. =================================================================== Radar mission re-targeted for December launch (09/24/99) After reviewing the progress of work to repair shuttle wiring defects, program manager Ron Dittemore decided today to stick with plans to launch the shuttle Discovery around Nov. 19 on a mission to service the Hubble Space Telescope. There had been some doubt about whether the Hubble mission, known as STS-99, or a radar mapping flight aboard Endeavour, known as STS-99, would go first. That question was resolved today and the shuttle team now plans to launch the Space Radar Topography Mission around Dec. 6 - three days after NASA's Mars Polar Lander is scheduled to touch down near the martian south pole - if wiring repairs can be completed in time. And that's a big if. The 12-day STS-99 flight cannot launch much later than the first week in December because of Christmas holiday downtime, the possibility of an end-of-mission diversion to Edwards Air Force Base, Calif., and other factors that would impact downstream processing. Reliable sources say a December launch for STS-99 is a long shot and that it's more likely the flight ultimately will slip into January. This status report will be updated as conditions warrant. The flight plan and other mission-specific details will be updated when a new launch time is set. In the meantime, the flight plan continues to reflect a Nov. 19 launch. =================================================================== Radar flight slips to Jan. 13 (10/07/99) NASA managers today decided to delay the shuttle Discovery's launch on a Hubble Space Telescope servicing mission from around Nov. 19 to Dec. 2. A radar mapping mission aboard the shuttle Endeavour, which had been targeted for early December, will slip to Jan. 13. If this schedule holds up, NASA will log just three shuttle flights in 1999, the lowest total in a decade. NASA originally planned to close out 1999 with three shuttle launches. Endeavour was to take off Sept. 16 on the Space Radar Topography Mission, or SRTM, followed by Discovery's launch on the Hubble repair flight Oct. 14. A flight by Atlantis to deliver supplies to the international space station originally was planned for Dec. 2. But wiring defects discovered in the wake of a July shuttle mission forced NASA to delay all three flights and to move Discovery ahead of Endeavour. Shuttle managers initially held out hope of launching Discovery around Nov. 19 with Endeavour following suit in early December. In the end, however, work to repair a corroded propellant valve in Discovery's right-side orbital maneuvering system rocket pod, coupled with on-going efforts to complete wiring repairs, forced planners to delay Discovery's launch to Dec. 2 and to push Endeavour's flight to Jan. 13. Atlantis currently is scheduled for takeoff Feb. 10, although that date appears optimistic. "Our number one priority for the space shuttle is to fly safely, and that is why we delayed our launch preparations and have performed comprehensive wiring inspections and repairs," shuttle program manager Ron Dittemore said in a NASA status report. "As a result of our inspections, we've made significant changes in how we protect electrical wiring. We believe those changes, along with changes to the work platforms and procedures we use in the shuttle's payload bay, will prevent similar wire damage from recurring." =================================================================== Endeavour launch slips to end of January (12/29/99) With the shuttle Discovery safely back on planet Earth, NASA is setting its sights on the first shuttle mission of the new millennium, a radar mapping mission scheduled for launch around the end of January. NASA managers have not yet set a launch target, although sources say the flight appears to be off until Jan. 31 at the earliest (the most recent previous target was Jan. 23). Because of conflicts with rocket launches already scheduled for the Eastern Range, however, Endeavour's flight could slip to around Feb. 9 when all is said and done. NASA managers will meet next week to assess launch dates and this page will be updated as soon as a decision is made. =================================================================== NASA managers target Jan. 31 launch date for Endeavour (01/03/00) NASA managers today agreed to target Jan. 31 for launch of the shuttle Endeavour on a radar mapping mission. Conflicts with other launches coordinated by the Air Force Eastern Range could push the flight into early February and the launch date will be revisited later this week. As such, Jan. 31 is strictly a target and subject to change. In the meantime, an updated STS-99 flight plan has been posted below based on a Jan. 31 liftoff at 12:47 p.m. (an incorrect launch time was given in an earlier update). SpaceCalc, a set of Excel 5.0 worksheets that track a variety of mission events, including the STS-99 flight plan and major mission milestones, has been updated. In addition, the Statistics page has been updated to reflect the recent completion of shuttle mission STS-99. =================================================================== No decision yet on launch dates (01/10/00) Shuttle managers and representatives of the Air Force's Eastern Range are continuing discussions this week about possible launch dates for the shuttle Endeavour. The only firm target date is Jan. 31. NASA is optimistic about getting an additional launch opportunity on Feb. 1, but no decision has been reached on the agency's desire for backup launch opportunities Feb. 10 and 11. The Eastern Range, which provides the radar, self-destruct and photo documentation services for all rockets launched from the East Coast, is scheduled to shut down for modernization upgrades after the planned Feb. 6 launch of a Boeing Delta 2 rocket. The shutdown is expected to last a little more than two weeks. NASA is lobbying the Air Force to delay the start of the modernization work until March, agency sources say. While the shuttle Atlantis remains officially targeted for blastoff March 16 on a space station assembly mission, work to fix orbiter wiring defects is expected to delay that flight to mid-April at the earliest. In short, an Eastern Range shutdown in early to mid March would have no impact on NASA. The only other flights currently on the Range in March - a Titan 4B on March 1 and an Atlas 2AS on March 20 - presumably would be unaffected. Whether the Eastern Range will go along with NASA's proposal remains to be seen. But a decision is expected soon. =================================================================== NASA, Air Force remain at loggerheads on launch date issue (01/12/00) Representatives of NASA and the Air Force Eastern Range, the government agency that orchestrates U.S. launches from the east coast, remain at loggerheads over when the shuttle Endeavour might be able to take off on a long-delayed radar mapping mission. Because of the heavy power requirements of the shuttle's radar mapping payload, Endeavour can make no more than two launch attempts in a row before standing down for 72 hours to reload fuel for its electrical generators. As a result, shuttle managers are lobbying for at least two sets of two-day launch windows with the first opening on Jan. 31 and the second on Feb. 10. But the Eastern Range, which also handles Atlas, Delta and Titan rocket launches, is booked through the first week in February, after which it is scheduled to shut down for nearly three weeks for work to upgrade aging systems. While the Air Force can support shuttle launch attempts on Jan. 31 and Feb. 1, it cannot provide C-band radar tracking for Endeavour's landing 11 days later (not to mention another launch attempt on Feb. 10). Shuttle managers can give up C-band tracking once a mission is off the ground if the shuttle's three inertial measurement units are fully operational. But flight rules prohibit launching without an Air Force commitment to provide such radar tracking in the event of an IMU failure in orbit. As of this writing, both sides appear to be at an impasse and the issue may have to get resolved in Washington after a senior-level NASA-Pentagon review. Stay tuned! =================================================================== NASA, Air Force agree on launch dates for shuttle Endeavour (01/13/00) NASA and the Air Force Eastern Range, the government agency that orchestrates rocket launches from Florida, have agreed on two launch dates for the shuttle Endeavour. Liftoff now is targeted for 12:47 p.m. on Jan. 31 with a back-up opportunity the next day. The Air Force agreed to delay the start of range modernization work to provide C-band radar tracking for Endeavour's landing on Feb. 11 (see the previous entry for additional details). As of this writing, it appears NASA will not get a third and fourth attempt until late February or early March. =================================================================== NASA managers order tile bonding review (01/19/00) NASA managers attending a flight readiness review have approved a Jan. 31 target launch date for the shuttle Endeavour, pending the results of a paperwork review to verify the integrity of critical heat shield tiles. A protective tile debonded and fell from the shuttle Discovery's left inboard elevon, or wing flap, before or during entry last month and NASA managers want to make sure Endeavour has no similar problems. As of this writing, a launch delay is not expected, but the issue remains open pending a detailed paperwork review and it likely will be revisited again next week. Until then, Jan. 31 remains a "no-earlier-than" target date. An updated flight plan has been posted, along with an updated edition of SpaceCalc. =================================================================== Radar mast to be retracted one day early; dataset reduced (01/20/00) NASA managers have decided to have the shuttle Endeavour's crew retract a large radar antenna one day early - reducing the amount of data that will be collected about Earth's topography - because of concern about the potential impact of an antenna jam the day before entry. The flight plan had called for the 200-foot telescoping boom to be retracted around 10:45 p.m. on Feb. 10, one day before Endeavour's planned return to the Kennedy Space Center. But if the antenna jammed and a spacewalk was required to fix it the next day, the astronauts would be left with just one contingency day in the event of bad weather or some other problem that might delay landing. All shuttle flights are launched with enough on-board fuel and other supplies to remain in orbit at least two days beyond the planned landing date. That margin frequently is extended using power conservation, but that is not an option for Endeavour and its power-hungry radar payload. The radar system will use some 900 kilowatt-hours of energy during the mission, enough to power an average home for two to three months. As a result, Endeavour's crew has just two days of margin for end-of-mission problems, one of which could be lost to support a spacewalk if the radar mast jammed the day before entry. While the mast could be jettisoned, NASA managers apparently want to preserve a repair option if worse comes to worse. Retraction now is scheduled to begin around 9:57 p.m. on Feb. 9. While retracting the mast one day early will reduce the amount of data collected during Endeavour's mission, it will not necessarily translate into a straight 10 percent loss. Engineers are evaluating a variety of options to maximize the data return, including repeat passes over high priority targets at a slightly higher altitude. More details will be posted here as they become available. The STS-99 flight plan has been updated to reflect the early radar mast retraction. =================================================================== NASA managers study ways to increase science return (01/24/00) Shuttle planners are studying the feasibility of a flight plan alteration that would allow the shuttle Endeavour's crew to regain a half-day of lost radar mapping activity after a decision last week to retract a 200-foot radar antenna mast one day early. The shuttle's crew originally intended to leave the mast deployed until the day before entry, allowing scientists to log a full 10 days of mapping observations. But given the possibility of a jam during boom retraction, senior managers decided late last week to cut one day off science observations to allow time for a repair spacewalk if needed. The decision meant mission scientists would lose about 10 percent of the data they originally hoped to receive. As it turns out, the loss might be less than that. Lead flight director Paul Dye is assessing the feasibility of having the crew perform routine pre-spacewalk preparations in the middle of the mission, which would reduce the time needed to stage a repair spacewalk - should one become necessary - at the end of the flight. If the preparations can, in fact, be shoe-horned into the flight plan, the radar mast could remain extended an additional six to 12 hours, allowing scientists to come closer to their pre-flight goal. A decision one way or the other is expected later this week. In the meantime, the STS-99 flight plan has been updated to reflect recent changes in crew sleep shifts toward the end of the flight. The changes also are incorporated in a SpaceCalc update. The pre-flight timeline also has been updated. A detailed mission overview will be posted here later this week, along with the STS-99 edition of the Space Reporter's Handbook. =================================================================== Science extension appears unlikely (01/25/00) Going into mission STS-99, NASA managers are keeping their options open for collecting additional radar mapping data during the shuttle Endeavour's upcoming mission. But it does not appear likely the crew will be able to operate Endeavour's radar-mapping equipment much beyond the current nine-day, nine-hour limit. The astronauts originally intended to leave the 180-foot-long radar mast extended for a full 10 days - until the day before landing - but shuttle managers decided last week to have the crew retract the mast one day early in case of a jam that might require a repair spacewalk. Lead flight director Paul Dye then explored the possibility of having the crew carry out spacewalk preparations early in the mission as "get-ahead" work in case the mast did, in fact, jam during retraction. The goal was to add a few hours of radar observing time back into the flight plan. But sources say it does not appear enough additional time can be saved to extend radar observations beyond the current nine-day nine-hour mark. Even so, spacewalk preparations likely will be carried out early in the mission to help keep the crew's options open. But as of this writing, additional radar observations appear unlikely. =================================================================== STS-99 Mission Preview (01/26/00) By WILLIAM HARWOOD CBS NEWS SPACE CONSULTANT KENNEDY SPACE CENTER, Fla. - Racing through space at five miles per second a scant 146 miles up, the shuttle Endeavour's crew will face a make-or-break milestone five hours and 20 minutes after liftoff on a long-delayed radar mapping mission. That's when a telescoping 20-story mast is scheduled to begin extending like a giant Tinkertoy from a compact canister in the shuttle's cargo bay. At the end of the mast are two radar antennas that will work in concert with a pair of much larger phased-array antennas mounted in Endeavour's cargo hold to make a high-resolution three-dimensional map covering 72 percent of Earth's land masses. If all goes well, an elevation data point will be recorded every 30 meters, a nine-fold increase in resolution, or sharpness, over currently available global topographic maps. In addition, the data are expected to be twice as accurate as those in current global maps, allowing scientists to create a detailed 3D topographic map of the land masses that are home to 95 percent of the world's population. But data from the Shuttle Radar Topography Mission, or SRTM, will not be available to everyone. While a 90-meter data set will be available to the public around the world, the higher resolution 30-meter data will be restricted by the mission's primary sponsor, the National Imagery and Mapping Agency - NIMA - for use by U.S. military and intelligence agencies. Thirty-meter data covering the United States will be freely available because most of America already is mapped to 30-meter or better precision. But if you are interested in 30-meter topographic maps of Taiwan, for example - the kind of data that would allow military planners to build graphic terrain models for ultra-realistic flight simulations, hydrologic studies and strategic planning - you are almost certainly out of luck. "Digital terrain elevation data has applications in a number of different systems that we support," said Thomas Hennig, SRTM program manager for NIMA. "The term 'guaranteeing the information edge in the 21st century' is relevant to the quality of the SRTM data and the fact that it's a near global data set." Even so, NASA scientists insist responsible researchers can petition NIMA for access to 30-meter data in the same way scientists currently can request data from a 100-meter digital terrain elevation data set known as DTED-1. "The 30-meter data available worldwide is available to me, too, as a NASA scientist," said Michael Kobrick, SRTM project scientist at NASA's Jet Propulsion Laboratory. "I just have to ask them for it. I'm assuming the agreement will come out this way - they haven't signed on the dotted line yet - but the assumption is it'll be handled the same way the DTED-1 100-meter data is now. I can use the data, perform scientific analyses, make conclusions, publish those conclusions and so on. The only [restriction is] they require that I don't just publish the raw data themselves. I probably wouldn't want to do that anyway. Speaking as a scientist who wants the data, who wants to publish, I'm perfectly happy with the arrangement we have." Except that it's not yet a formal agreement. "We've been focusing on getting ready for the flight, we've been focusing on training for the support we will provide," Hennig said. "In the natural progression of things, the topic of the data access has been one we've slid to the right a little bit." While NIMA's sincerity on this issue has yet to be tested, NASA is focusing on making sure the data gets collected in the first place. And for that to happen, the 197-foot-long 640-pound radar mast aboard Endeavour must fully deploy from its canister in the shuttle's payload bay. Twin motors in the canister will turn the mast elements so folded longerons move along corkscrew-like grooves. As individual members travel along the track, they will unwind and snap into place as they exit the canister, forming 87 open bays measuring 27 inches tall and 44 inches wide. Once the mast is fully deployed and locked in position, it should be remarkably rigid, capable of withstanding side loads in excess of 1,000 pounds. But for the SRTM payload to work its 3D magic, the mast must extend all the way. If the drive motors refuse to start or if the boom jams part way out, astronaut Janet Kavandi and German flier Gerhard Thiele are prepared to stage a grueling spacewalk to manually drive the mast out of its canister using a space station power tool. "We've trained for several different options," she said. "One would be if the mast did not initially deploy for a failure of the motors. We have redundant motors so it's unlikely they would fail. But in case they did, we can go out and manually attach a space station tool and drive the motors out. Gerhard and I would take turns because it's a fatiguing thing on the hands. It would take quite a while to do this. "Similarly, if the mast did not retract properly all the way back in, we can apply the same tool in the opposite direction and drive the motors so the mast retracts all the way back in," Kavandi said. "If the mast goes back in on its own but the latches do not completely latch shut, we can go out and manually latch the latches." If the mast jams and repair efforts are unsuccessful, Endeavour's astronauts will continue their mission, recording radar data with the operational antennas in the cargo bay. Useful radar imagery will be available after the flight even if topographic data is lacking. Concern about the reliability of the mast, the largest such structure ever deployed in space, prompted NASA managers to cut a day out of the crew's radar mapping to protect against the possibility of a jam during retraction. The flight plan originally called for the mast to be hauled back in the day before landing, giving scientists a full 10 days of observations covering 80 percent of Earth's land surfaces. But if the boom jammed during retraction, Kavandi and Thiele would not have time to stage a repair spacewalk and the crew's only option would be to jettison the canister and boom. Even though NASA and NIMA have no plans to fly the equipment again, shuttle managers were uncomfortable with the prospect of throwing away such valuable hardware. So they decided to have the mast retracted on the ninth day of the mission to preserve the possibility of a repair spacewalk if the boom does, in fact, jam. "This is a device we've never deployed before, it's the longest space structure anybody's ever put out and we would like to be able to get it back," said lead flight director Paul Dye. "If we had a problem on the stow day, the way we had the mission put together, we'd have had no opportunity to try to fix that problem with an EVA [spacewalk] or other means. We had stretched the mission as long as we possibly could. "By bringing it in a day earlier, we're going to preserve the capability to look at our options and if we do have a problem with the mast we will be able to look at other ways to bring it in without having to jettison it," he said. "You can look at it as a glass that's 10 percent empty or 90 percent full. And I think a 90 percent full glass is a pretty good mission success criteria." Endeavour is scheduled to blast off at 12:47 p.m. on Jan. 31. Launch originally was targeted for September, but the flight was repeatedly delayed because of wiring problems discovered in all four of NASA's shuttles after a potentially catastrophic short circuit during a July launch. Endeavour was given a clean bill of health in early January. Last-minute concern about potential tile problems was resolved by the middle of the month. Joining Kavandi and Thiele for the 11-day voyage - the first manned space flight of the new millennium - will be commander Kevin Kregel, pilot Dominic Gorie, Janice Voss and Japanese astronaut Mamoru Mohri. Thiele, a European Space Agency astronaut, is the crew's only space rookie. The SRTM payload occupies Endeavour's entire cargo bay, with the mast canister mounted just behind the shuttle's external airlock. Behind that are the large C-band and X-band transmit/receive radar antennas. The mast and C-band radar cost some $142 million while the German Space Agency contributed $42 million for the X-band antenna system. Hardware built for earlier shuttle radar missions, valued at $180 million, is being reflown as part of the SRTM mission. To collect as much data as possible, the SRTM payload will operate around the clock once the mast is deployed and the crew will operate in two 12-hour shifts. The red shift, which will be up during normal daylight and evening hours in the United States, is made up of Kregel, Thiele and Kavandi. The overnight, or blue shift, is made up of Gorie, Voss and Mohri. The astronauts will load some 270 data tapes during the flight to record some 8.8-terabytes of radar data, enough to fill 13,500 compact discs. In addition, they will carry out rocket firings each day to re-boost Endeavour's altitude, which will constantly be degrading because of friction with the extreme upper atmosphere. While the extended radar boom should be relatively immune to such rocket firings, NASA is taking no chances, utilizing a special "flycast" maneuver to reduce stress on the mast as much as possible. "If you were to pulse the jets on the space shuttle with the mast extended, the mast would spring aft and then spring forward until it damped out," Gorie explained before launch. "What we do with the flycast maneuver is we put in a very small [rocket] pulse to get the mast moving aft. And then when it would normally start to spring back forward, right at that exact instant, is when we pulse again and hold a sustained pulse with the reaction control jets. "That keeps the mast in that slightly extended state for the duration of the burn," Gorie continued. "Once we've stopped the burn and we've achieved the change in velocity we need to raise our orbit, the mast starts to spring back forward and when it's at the neutral point we pulse one more time to essentially catch it right in the center. What we've done with this maneuver is reduce the mast loads by 50 percent and we've reduced the deflections by 50 percent also, greatly increasing the margin we have." Dye said the mast is "actually pretty stiff" once it is deployed. "It's a remarkable structure, it's an engineer's dream," he said. "The kind of loads that we put on it are way, way below the kind of loads that it would take to break a member of the mast. So we're really not concerned about it breaking during anything that we can conceive of doing. "If we were to be wrong and it were to break, nothing would happen very fast, the mast would not fold up on you quickly. We have procedures in place to be able to jettison it, the whole canister with the mast, and to fly away from it. Since we have those procedures, we've practiced them, we did extensive training with the crew and all our life support team to handle this kind of emergency and we're very confident we can fly the mast safely." The entire SRTM payload tips the scales at 29,000 pounds and will consume about 810 kilowatt hours of power, enough to power an average home for more than two months. The system is exceedingly complex, building on lessons learned from earlier radar flights to achieve the high resolution interferometricy mapping planned for Endeavour's mission. "Interferometry, simply stated, is combining radar images acquired from two slightly different locations in space to derive three-dimensional models of the surface," said Kobrick. "It's tempting to make an analogy with human binocular vision. If an object is close enough to you, your eyes see slightly different pictures and your brain, through some not very well understood method, combines those pictures to make a three-dimensional model of the object in your mind. So your brain is kind of triangulating. "Well, interferometry triangulates too, in a sense. But the two antennas are so close together compared to the distance to the target, that the images actually are identical. But since we're using synthetic aperture radar, which uses coherent radiation like a laser does, there is another property to the image called 'phase.' And it turns out that by combining the phase of those two images, we generate a series of fringes. "Just like if I take a laser beam and shine it through two slits in metal, I'll generate optical fringes, we make literally radar fringes that overlay the image on the ground," Kobrick said. "If the ground isn't smooth, those fringes get distorted. By measuring those distortions, we therefore measure the topography." On previous shuttle radar mapping missions, only one set of payload bay antennas could be used. To obtain interferometric measurements, the shuttle had to fly over targets twice, using a slightly different ground track to simulate the stereo vision described by Kobrick. Edward Caro, SRTM chief engineer at JPL, came up with the idea of mounting a second set of antennas on an extendable mast to acquire interferometric data in a single pass. After additional analysis, engineers discovered the phased array transmitting antennas in the cargo bay, working in concert with receive-only antennas on the end of the boom, could map a swath 225 kilometers wide as the shuttle sailed along. As it turned out, such a radar system orbiting at an altitude of 146 miles would need to cover a swath just 118 kilometers wide to map 72 percent of the planet's land mass during nine days of observations. Paraphrasing Apple Computer Co.'s CEO Steven Jobs, Kobrick called this "an insanely great" idea that NASA and NIMA had no choice but to pursue. "We'll be transmitting out of the payload bay in both C-band and X-band and receiving that information on both [sets of] antennas," said Earnest Paylor, SRTM program scientist at NASA headquarters. "The information we'll be acquiring includes the amplitude of that signal, or the strength of that return signal, as well as timing information of how long it took that signal to leave the shuttle bay and return back to the antennas. That timing information allows us to compare the phase information of the signal in a process called interferometry, which allows us to compare those signals and derive information about the topography of the Earth." But turning an idea into reality was not easy. Along with developing a rigid, extendable mast, engineers had to come up with a way of precisely monitoring the position and orientation of the two radar antennas on the end of the boom. Only by knowing the exact orientation and distance between the payload bay and mast-borne antennas can engineers accurately interpret the interferometric data. Global Positioning System satellite antennas will be used to help determine the actual position of the shuttle in space while LED targets on the end of the mast will be used by an avionics system in the cargo bay to precisely determine the orientation of the outboard antennas relative to those in the cargo bay. Another system will measure the length of the mast to within three millimeters. Much of the equipment is refurbished hardware that flew on previous missions in other capacities. "We asked them to do something different," Kobrick said. "We said we want you to take a bunch of old, used stuff which in some cases is 10, 15-year-old technology, fancy it up without spending very much money, make it satisfy requirements that are incredibly strict, and by the way, we want it to work perfectly right out of the box and then work perfectly for the length of the mission. You'd almost have to be nuts to accept requirements like that. But they did." Currently, about 70 percent of Earth's surface is covered with elevation data spaced about 100 meters apart. Less than 5 percent of the surface is covered by 30-meter data. "So if I'm standing here and walk north, I have to walk at least the length of a football field before I get to the next data point," Hennig said of the 100-meter data set. "If I walk east, I have to walk that same distance. SRTM will take that distance and reduce it down to 30 meters. So I'll have 30 meters between post spacing, or between data values, instead of 100 meters. It's going to give me nine times as much data per unit area on the surface of the Earth as compared to the most common data I have available today. "The other thing is the accuracy of the data is going to be improved by roughly a factor of two," he said. "So I'm going to have nine times as much data and it's going to be roughly twice as accurate as the most abundant data I have available today." Even the 90-meter SRTM data set that will be publically available will be an improvement over the best [digital terrain elevation] data set that NIMA has now, called DTED-1. "It's only 60 percent complete, it has a lot of artifacts because it was cobbled together from disparate data sources acquired with different kinds of sensors and so on," Kobrick said. "One of the most compelling aspects of this data set, SRTM, will be its uniform nature, it's going to be the same quality everywhere. The DTED-1 data they have now is restricted in the since that you have to ask their permission to use it. The 100-meter data that we're going to produce is going to be wide open. So there's a quantum leap there already." At a pre-flight news conference, Hennig addressed military uses of the 30-meter data set in general terms, saying imagery experts will be able to "merge an image and elevation data together and create a three-dimensional image." "I can take other information about man-made features and overlay that on top of the image and again, create this fused, or merged, data set. The National Imagery and Mapping Agency is working on a data concept where the elevation data is literally and figuratively the foundation that goes into those data sets, it's the thing at the bottom of the stack that we tie everything into, whether its imagery, whether it's information about man-made features." He said military planners are especially interested in environmental analysis such as predicting where floods might occur. "That's a prime example where improved elevation data gives you the capability to do more," Hennig said. "If you're a disaster planner and you're trying to figure out where to put a camp for the people who are being displaced by a flood, you certainly want to know that where you go isn't also prone to flooding. If there's been a hazardous materials spill, you want to be able to predict the direction [of dispersion]. "Another example ... is in the enhancement of existing technologies," he said. "One example that we all take advantage of every day is cell phones. The placement of cell phone towers is very dependent on knowledge of the terrain. The better I know that terrain, the better I can do that job. Other examples would be locating new airports or planning the routes for new pipelines, for example. The better you know the shape of the Earth, the better you know the elevation, the better you can do that type of planning." In addition, high resolution terrain data will improve the performance of flight simulators, allowing military users to "save countless hours of actual flight time on aircraft, [reducing] the risk to the aircraft by having simulators do that job," Hennig said. "You can do mission planning, you can go in and with the simulator, visualize where I'm going before I've ever been there. That reduces the risk of carrying out the mission." NASA will use the SRTM data as part of its Earth Science Enterprise for a variety of purposes, incorporating the radar data into existing data sets to improve atmospheric, hydrologic and other environmental models. "Our objective is to study the global environment and try to understand human and natural induced changes to the global environment," said Paylor. "Our objectives are to increase scientific understanding as well as to develop practical applications of our science, technology and data that have more societal benefits." =================================================================== Astronauts arrive for launch; engine issue discussed (01/27/00) The shuttle Endeavour's crew flew to the Kennedy Space Center today for final preparations before launch Monday on an 11-day radar mapping mission. The countdown is scheduled to begin at 5:30 p.m. Friday and forecasters are predicting a 70 percent chance of acceptable weather during the shuttle's two-hour launch window. "I'm just really happy to be here," commander Kevin Kregel said at the shuttle landing facility shortly after noon. "It's a beautiful day. We're looking forward to doing this mapping mission, and hopefully we'll have a beautiful day like today and the winds will die down on Monday. We're ready to go fly." Launch processing is going smoothly, although engineers are assessing the possible impact of a problem discovered in one of the shuttle Discovery's hydrogen-fueled main engines after it returned to Earth last month. Details are sketchy, but sources say engineers found a small area of delamination in one of Discovery's engine pumps that has not been seen before. This issue likely will be discussed during NASA's normal launch-minus-one day readiness review Saturday to make sure whatever happened aboard Discovery does not pose a threat to Endeavour. For their part, Endeavour's astronauts are ready to go. "The science on this flight is going to be spectacular," said Janice Voss. "The 3D map of 80-percent of the surface of the Earth is going to be great to bring back for everyone on this planet." =================================================================== Engine issue assessed; countdown set to begin (01/28/00) NASA is gearing up to start the shuttle Endeavour's countdown this afternoon for a launch attempt Monday on a long-delayed radar mapping mission, the 97th flight in shuttle history and the 72nd since the Challenger disaster 14 years ago today. At the same time, engineers are racing the clock to assess the potential impact of unusual damage discovered in a main engine that flew aboard the shuttle Discovery last month. The countdown is scheduled to begin at 5:30 p.m. and forecasters are predicting a 70 percent chance of acceptable weather during Endeavour's two-hour launch window Monday. But hurried work to resolve the engine issue could force a launch delay if the analysis is not completed before NASA's launch-minus-two-day management review Saturday. In that case, shuttle program managers could elect to skip the Monday launch opportunity to give engineers more time to develop a flight rationale. Endeavour only has two launch opportunities this week - Monday and Tuesday - and if the shuttle misses both, the flight will be delayed to around Feb. 9. Otherwise, there are no technical problems of any significance at the launch pad. The engine issue cropped up earlier this week when engineers were carrying out routine inspections of the three hydrogen-fueled main engines aboard Discovery. Using a boroscope, they noticed a small area of delamination and scoring on a tip seal inside the high pressure hydrogen turbopump on main engine No. 2 [serial number 2043]. Each pump contains two nickel-alloy tip seals that run around the interior of the housing in line with two turbine blade wheels. The seals ensure that all the hot gas entering the pump turbine actually hits the turbine blades used to drive the machinery. About the size of a car engine, the pump generates 69,040 horsepower at flight levels, or about 100 horsepower per pound of weight (readers are encouraged to think about that for a moment before continuing!). There is an 18-thousandths-of-an-inch gap between the six-segment seals and the tips of the turbine blades attached to the two wheels. It is not unusual for blades to come in slight contact with the seals during engine operation, but the gouging seen after Discovery's flight was more than usual. The pump in question has been flown to Boeing's Rocketdyne plant in Canoga Park, Calif., for teardown and a detailed analysis to determine exactly what happened. The powerful pump worked normally during Discovery's ascent and post-flight inspections revealed no damage, or nicking, to any turbine blades. But the tip seals are critical items. The turbine shaft spins at 37,000 rpm and if a piece of the seal did, in fact, break away - or if one or more blades broke after contact with the seal - major internal damage could occur. Whether it could trigger a catastrophic shutdown is not clear and that obviously did not happen aboard Discovery. While testing may show that isn't even a credible failure scenario, engineers need to make sure of that before NASA's mission management team can clear Endeavour for flight. "It certainly is a key component of the pump and that's why we're taking the extra precaution to go and do this thorough evaluation to make sure that while we don't think there's anything of significance there, we want to make sure we're not overlooking anything," said NASA test director Doug Lyons. This status report will be updated as more information becomes available. In the meantime, see Boeing's "Amazing Facts" page for more interesting details about main engine operation. =================================================================== Countdown begins (01/28/00) Engineers at the Kennedy Space Center started the shuttle Endeavour's countdown this evening for a launch attempt Monday afternoon. The countdown began on time at 5:30 p.m. and will end at the opening of a two-hour two-minute launch window starting at 12:47 p.m. Monday. Senior managers will meet Saturday to assess Endeavour's readiness for launch, including the results of work to resolve questions about the integrity of critical main engine fuel pump seals. If the issue cannot be resolved in time, the flight could face a delay. See the next entry for details. =================================================================== NASA managers await word on engine issue (01/29/00) The shuttle Endeavour's countdown continues to tick smoothly toward blastoff Monday, but the mission faces two threats that could prompt a delay. While forecasters are predicting a 70 percent chance of good weather at the Kennedy Space Center, higher-than-allowable crosswinds are expected Monday and Tuesday at emergency runways in California and New Mexico. At least one of those sites must be "go" before Endeavour's crew can be cleared for blastoff and both are currently predicted to be out of limits. While NASA can't do anything about the weather, engineers are mounting a major effort to resolve a technical issue involving the shuttle's three hydrogen-fueled main engines. During routine inspections of the engines that helped launch the shuttle Discovery last month, technicians noticed a small area of delamination and scoring on a tip seal inside the high pressure hydrogen turbopump on main engine No. 2 [serial number 2043]. Each pump contains two nickel-alloy tip seals that run around the interior of the housing in line with two turbine blade wheels. The seals ensure that all the hot gas entering the pump turbine actually hits the turbine blades used to drive the machinery. There is an 18-thousandths-of-an-inch gap between the six-segment seals and the tips of the turbine blades attached to the two wheels. It is not unusual for blades to come in slight contact with the seals during engine operation, but the gouging seen after Discovery's flight was more than normal. The fuel pumps generate 70,000 horsepower each at full throttle and debris from a broken turbine blade or the seal itself could cause a premature shutdown or, possibly, a catastrophic failure. Engineers have been working the past two days to determine what caused the damage seen in Discovery's pump and to gain confidence that whatever it was will not affect Endeavour's engines. The results of this around-the-clock work will be presented to shuttle program manager Ron Dittemore this afternoon during an otherwise routine launch-minus-two-day readiness review. Whether the engineering community can present a convincing rationale for pressing ahead with Endeavour's launch or whether more time will be needed for additional analysis is not yet known. A news conference is planned for 4 p.m. to discuss whatever decision the mission management team reaches. Otherwise, there are no technical problems of any significance at pad 39A and there is little else to report. A detailed update will be posted here after the afternoon news conference. =================================================================== NASA defers engine decision; countdown continues (01/29/00) A flawed component that should have been sent to the scrap heap somehow made it into a space shuttle main engine, NASA managers said today, flying six times before weakening sufficiently to partially debond during a launch last month. While the damage was minor and did not cause any problems with the engine's operation, NASA engineers are struggling to make sure no similar rejects are in place aboard the shuttle Endeavour, which is scheduled to blast off Monday on a radar mapping mission. Shuttle program manager Ron Dittemore chaired a launch-minus-two-day mission management review today and deferred making a decision on whether Endeavour is safe for flight as is, giving engineers another 24 hours to review data and make sure their analysis is correct. Another management meeting will be held Sunday afternoon. "The folks have done a great job in gathering the data that supports flight," Dittemore said. "However, we have decided to give the team 24 hours to have more time and get shelf life on the rationale they presented today. So we will convene an L-minus-one MMT meeting tomorrow afternoon at 2 p.m. ... We think they have the right supporting rationale that will allow us to fly. But with pulling all that data together in a short amount of time, we need to give them an opportunity to sit back, relax, to think about it and make sure their logic is sound." During routine inspections of the engines that helped launch Discovery last month, technicians noticed a small area of delamination on a tip seal inside the high pressure hydrogen turbopump on main engine No. 2 [serial number 2043]. Each pump contains two nickel-alloy tip seals that run around the interior of the housing in line with two turbine blade wheels. Each seal is made up of six sections. The seals ensure that all the hot gas entering the pump turbine actually hits the turbine blades used to drive the machinery. There is an 18-thousandths-of-an-inch gap between the seals and the tips of the turbine blades attached to the two wheels. While it's not unusual for turbine blades to come in slight contact with the seals, the amount of debonding seen in the Discovery segment was "out of family" and more pronounced than normal. "We did track down this particular part," Dittemore said. "We have discovered it was a quality escape. It was a non-flight part that had been installed in a flight engine." A review of manufacturing records shows 16 of the 18 tip seal sections aboard Endeavour are, in fact, certified flight hardware. Unfortunately, engineers have been unable to find records showing the pedigree of the other two sections, which are installed in two different engines. "We cannot conclusively show we do not have a similar [substandard] part at this point in the STS-99 [Endeavour] fuel pumps," Dittemore said. "Our analysis, flight history and experience all support this as being no impact to flight operation or engine operation and will not result in an engine failure. The design of the tip seal is purposely designed to account for potential rub between the tip seal and the turbine blade and it's biased to protect the turbine blade from failing." He said a debond like the one aboard Discovery does not "represent a risk of failing the turbine blades. This is not one of those cases where we believe this tip seal's going to fall apart, a turbine blade would fail and then you would have a catastrophic failure of the engine. That's not what we're talking about here at all." As for how the substandard component got into an engine in the first place, Dittemore said the vendor apparently marked the part as acceptable for flight by accident, making an "honest mistake." "They scan and test this particular material and we believe it was rejected at that time and essentially should have been targeted for the scrap bin," he said. "Due to an error in the way we serialize and mark the segments of this tip seal, that was done in such a way as to allow this particular part to get back into the flight hardware. That clearly is a very bad thing, a quality esacpe that we've got to fix." If paperwork on the two Endeavour seal segments in question cannot be located, engineers will have to rely on analysis. Dittemore said that will include historical data on debonds, statistical analysis of their severity and the potential impact of debonding on pump operation. At this point, engineers believe Endeavour is safe for launch as is, but Dittemore acknowledged that without documentation there's no way to know for sure whether one or both of the seal segments in question aboard Endeavour have areas of weakness that could result in debonding during flight. Even so, he appeared optimistic Endeavour can be cleared for flight as is. "We look at our flight database, we look at all the parts made by the vendors, we look at what has been the worst case debond that has been scrapped," he said. "Is that one out of a thousand in that scenario? We know the one on STS-103, that debond, was way out of family compared to what they normally scrap. ... Those are the types of conversations we'll have to have if we can't conclusively prove [the parts are certified] by paper. It may be this is a very unlikely case ... and we wouldn't ground ourselves or scrub for that." =================================================================== Weather forecast worsens; no word yet on engine issue (01/30/00) The countdown for the shuttle Endeavour's blastoff Monday is proceeding smoothly toward launch amid last-minute analysis to make sure two suspect main engine components are safe for flight as is. Meteorologists, meanwhile, have revised their forecast for Monday, switching from 70 percent "go" to a 60 percent chance of low clouds and rain that could force a 24-hour delay. The outlook for Tuesday calls for an 80 percent chance of acceptable weather. With no technical problems at pad 39A, NASA's mission management team plans to meet at 2 p.m. to review overnight work to confirm a preliminary analysis that indicated critical seals inside high pressure hydrogen turbopumps are safe for flight. Part of a tip seal in a pump aboard the shuttle Discovery debonded slightly during launch last month. As it turned out, the component in question was a factory reject that never should have been installed in an engine in the first place. Manufacturing records prove 16 of 18 seal segments aboard Endeavour are, in fact, certified flight hardware. But paperwork on the other two segments has not been found, forcing engineers to rely on indirect analysis. "We look at our flight database, we look at all the parts made by the vendors, we look at what has been the worst case debond that has been scrapped," said shuttle program manager Ron Dittemore. "Is that one out of a thousand in that scenario? We know the one on [Discovery], that debond, was way out of family compared to what they normally scrap. ... Those are the types of conversations we'll have to have if we can't conclusively prove [the parts are certified] by paper. It may be this is a very unlikely case ... and we wouldn't ground ourselves or scrub for that." See the Reporter's Notebook below for a detailed report on this issue. An update will be posted here this afternoon, after NASA announces the results of the mission management team meeting. Assuming Endeavour is cleared for flight, there will not be a news conference. Stay tuned! =================================================================== Endeavour cleared for launch (01/30/00) Senior NASA managers late today cleared the shuttle Endeavour for blastoff Monday on a long-delayed radar mapping mission, concluding that two suspect engine components of unknown pedigree pose no threat to flight safety. Shuttle program manager Ron Dittemore said he believes Endeavour's three hydrogen-fueled main engines are safe to fly as is and that engineers will begin fueling the shuttle on schedule early Monday for a launch attempt at 12:47 p.m. "The main engine team throughout the country continued to work for the last 24 hours to review the data and analysis to support the flight," Dittemore told reporters. "We just met in the capacity of the mission management team, reviewed the information they had collected and concluded the engines are safe to fly. We will be picking up the count on schedule." Each of the shuttle's three main engines features a high pressure hydrogen turbopump that uses special seals to ensure all the hot gas entering the turbine section actually hits two sets of turbine blades to maximize power. Each nickel-allow seal is made up of three six-inch sections. During inspections of the engines that boosted the shuttle Discovery into orbit last month, engineers discovered a two-inch section of tip seal material had debonded, or pulled loose from its backing. As it turned out, the segment in question was a factory reject that never should have been installed in the first place. Manufacturing records show 16 of the 18 tip seal segments aboard Endeavour are, in fact, certified flight hardware. But engineers have been unable to locate supporting paperwork for the other two segments, one of which was built in 1979 and the other in 1993. As a result, engineers had to rely on statistical analysis to convince themselves Endeavour's engines are healthy and ready to go. "What we learned was the likelihood of the part that we had on STS-103 [Discovery] to reoccur again was very, very, very low," Dittemore said. "When we looked at all our database of the tip seals that we have built and then compared that to the tip seals that had been rejected, we determined that the part on STS-103 was [far outside our experience], in the neighborhood of eight sigma, way out to the far right. When you look at that and combine that with the fact that you don't believe the rubbing of the tip seal with the turbine blade to be a significant event, then you can convince yourself ... it's OK to fly." The mission management team will meet again at 3;27 a.m. to evaluate the weather and Endeavour's readiness for launch. Forecasters are predicting a 60 percent chance of low clouds and rain that could delay the flight, but no problems are expected for fueling. Assuming no other trouble surfaces, engineers will begin pumping a half-million gallons of supercold liquid oxygen and liquid hydrogen rocket fuel into Endeavour's external tank at 4:27 a.m. Fueling should be complete by 7:30 a.m. and if all goes well, the shuttle's crew will begin strapping in for blastoff a few minutes past 10 a.m. Liftoff remains targeted for 12:47 p.m. =================================================================== Shuttle Endeavour grounded by weather, avionics problem (01/31/00) 07:30 a.m. Update: Shuttle Endeavour fueled for blastoff The shuttle Endeavour's external tank has been loaded with a half-million gallons of supercold liquid oxygen and liquid hydrogen rocket fuel, setting the stage for a launch attempt at 12:47 p.m. There are no technical problems of any significance at pad 39A, but low clouds and rain from a slow-moving frontal system could cause problems as the shuttle's two-hour two-minute launch window approaches. The launch window will close at 2:49 p.m. Endeavour's six-person crew - commander Kevin Kregel, pilot Dominic Gorie, flight engineer Janet Kavandi, Janice Voss, Japanese astronaut Mamoru Mohri and German flier Gerhard Thiele - will sit down for a traditional photo op at 8:22 a.m. before suiting up and heading for the pad at 10:02 a.m. Here's today's countdown timeline in detail: TIME.........EVENT 08:22 a.m....Astronaut photo/TV opportunity 08:52 a.m....Final weather briefings with crew 09:02 a.m....Astronauts suit up for launch 09:27 a.m....Countdown resumes at the T-3 hour mark 09:32 a.m....Astronauts depart crew quarters for pad 39A 10:02 a.m....Astronauts arrive at the launch pad 11:17 a.m....Endeavour's hatch is closed 12:07 p.m....Start a 10-minute hold at the T-20 minute mark 12:17 p.m....Countdown resumes 12:28 p.m....Start a final 10-minute hold at the T-9 minute mark 12:38 p.m....Countdown resumes 12:42 p.m....Hydraulic power system startup 12:47 p.m....Launch This status report will be updated as warranted throughout the day. 09:35 a.m. Update: Astronauts head for launch pad Under a threatening, overcast sky, the shuttle Endeavour's four-man two-woman crew suited up and headed for pad 39A this morning to strap in for blastoff at 12:47 p.m. A frontal system has moved through the launch area, but low clouds in its wake continue to pose a threat. Endeavour's launch window opens at 12:47 p.m. and closes at 2:49 p.m. NASA is hopeful conditions will improve enough during the window to permit a liftoff, but as of this writing the launch team is not optimistic about getting Endeavour off on time. 12:10 p.m. Update: Weather outlook bleak for on-time launch The shuttle Endeavour's countdown entered a planned 10-minute hold at 12:07 p.m. Launch remains targeted for 12:47 p.m., but low clouds behind a slow-moving frontal system have not dissipated as hoped and the outlook for an on-time liftoff is remote. If conditions do not dramatically improve - and they are not expected to - a final hold in the countdown at the T-minus nine-minute mark will be extended in hopes the weather will improve before the end of Endeavour's launch window at 2:49 p.m. As of this writing, that appears to be an unlikely prospect, but Florida's weather is notoriously difficult to predict and shuttle crews have been surprised before. If Endeavour fails to get off the ground today, however, launch will be reset for 12:44 p.m. Tuesday. Meteorologists currently are predicting more bad weather, but an official forecast has not yet been released. The next available launch opportunity after Tuesday is Sunday, Feb. 6. 12:26 p.m. Update: Shuttle launch on hold due to technical problems A 10-minute hold at the T-minus 20-minute mark in the shuttle Endeavour's countdown has been extended because of technical problems involving the shuttle's electricity producing fuel cells and a master events controller. Fuel cell No. 1 is brand new while another is nearing the end of its operational lifetime and producing slightly less power than expected. Engineers are evaluating whether the new fuel cell can make up the difference or whether this is anything to worry about in the first place. The other problem involves input/output errors in a master events controller (MEC-2), one of two on board that control critical functions like separation of the solid-fuel boosters. No corrective actions are being taken while engineers review the data. 01:30 p.m. Update: MEC troubleshooting continues Engineers are continuing to troubleshoot an apparent problem with one of two master events controllers on board the shuttle Endeavour. The MECs control booster and external tank separation and both must be healthy before a shuttle can be launched. Earlier concern about suspect readings from the shuttle's electricity producing fuel cells has been resolved. A power-cycle test of MEC-2 has been carried out but engineers are still discussing whether the avionics system can be cleared for flight as is. The weather, meanwhile, continues to pose a threat with solid overcast and rain in the Kennedy Space Center area. The countdown remains in an extended hold at the T-minus 20-minute mark. Today's launch window closes at 2:49 p.m. A MEC failure aboard the shuttle Columbia in October 1995 caused a one-week launch delay for mission STS-73. In that case, the device itself had to be replaced. But trouble with a MEC aboard the shuttle Discovery in August 1984 was repaired with a software patch, delaying mission STS-41D just one day. NASA shares use of military radar tracking, telemetry and self-destruct systems with other commercial and military users. Endeavour has until Tuesday to get off the ground, or the flight will be delayed to at least Feb. 6, after launch of an Atlas 2 rocket carrying a commercial communications satellite. 02:00 p.m. Update: Countdown resumes; weather continues to threaten Engineers are continuing to troubleshoot possible problems with one of two master events controllers aboard the shuttle Endeavour. But launch director Dave King has ordered the team to count down to the T-minus nine-minute mark where discussions will continue during a final 10-minute hold. That hold almost certainly will be extended. Regardless of the ultimate resolution of the MEC issue, low clouds and rain over the Kennedy Space Center show no signs of dissipating before Endeavour's launch window closes at 2:49 p.m. 02:15 p.m. Update: Launch delayed at least 24 hours; possibly longer NASA managers have called off the shuttle Endeavour's countdown to blastoff because of low clouds and rain over the Kennedy Space Center. At the same time, engineers are continuing work to troubleshoot possible problems with an avionics system that controls separation of the shuttle's twin solid-fuel boosters and external fuel tank. Whether that issue can be resolved in time to support a launch attempt Tuesday at 12:44 p.m. remains to be seen. Launch had been targeted for 12:47 p.m. today, but a planned 10-minute hold at the 20-minute mark was extended when engineers discovered an apparent problem with master events controller No. 2, one of two such devices on board Endeavour that relay computer commands for critical booster/external tank separation functions. The problem cropped up at T-minus 29 minutes and after studying the problem for nearly two hours, results were inconclusive. At the same time, low clouds and rain over the Kennedy Space Center failed to dissipate and finally, at 2:08 p.m., launch director Dave King told the team to stand down for the day. "It looks like the weather is going to continue to be a problem for us today so at this point, we'd like to scrub for the day, we'd like to initiate a 24-hour scrub/turnaround," he said. King then passed the news on to commander Kevin Kregel aboard Endeavour. "Kevin, it's not going to get there today. We'll look at our options here and hopefully we'll try again tomorrow," King radioed. "OK, sounds good," Kregel replied. "I appreciate all the hard work everybody's put in today and we'll just give it 24 hours and try it again." But that remains to be seen. Engineers are still debating the health of MEC-2. Based on initial troubleshooting, it is not yet clear whether MEC-2 is safe to fly as is, whether a software patch might be needed or whether the device itself might need to be replaced. As mentioned previously, a MEC failure aboard the shuttle Columbia in October 1995 caused a one-week launch delay for mission STS-73. In that case, the device itself had to be replaced. But trouble with a MEC aboard the shuttle Discovery in August 1984 was repaired with a software patch, delaying mission STS-41D just one day. NASA shares use of military radar tracking, telemetry and self-destruct systems with other commercial and military users. Endeavour has until Tuesday to get off the ground, or the flight will be delayed to at least Feb. 6, after launch of an Atlas 2 rocket carrying a commercial communications satellite. 06:30 p.m. Update: NASA defers decision on Tuesday launch; MEC troubleshooting continues NASA managers still do not understand why a critical avionics box failed a routine health check at T-minus 29 minutes today. Shuttle program manager Ron Dittemore said NASA's mission management team will meet at 2:30 a.m. to discuss the results of overnight troubleshooting before making a decision on whether to fuel Endeavour for a second launch try. Forecasters are predicting a 60 percent chance of acceptable weather during the shuttle's two-hour four-minute launch window. The window opens at 12:44 p.m. "Right now, the forecast still indicates about a 40 percent chance of no go," Dittemore said. "But we'll see how that improves over the night." NASA managers are more concerned about the status of one of Endeavour's two master events controllers, or MECs, mounted in two avionics bays in the shuttle's engine compartment. The MECs send the commands that ignite the orbiter's twin solid-fuel boosters and control the separation of the boosters and external fuel tank. The shuttle can safely fly with just one operational MEC, but NASA's flight rules require both to be up and running before a shuttle can be cleared for launch. "We have two of these MECs on board and they are redundant. But we require two of two for launch," Dittemore said. "It is absolutely critical that they work." During a routine health check at T-minus 29 minutes today, MEC-2 did not respond as engineers expected. A hold at the T-minus 20-minute mark was extended while technicians studied the problem and assessed the data. In a test, MEC-2's health-check circuits were powered down and restarted and this time, the device generated the proper response. But engineers have been unable to figure out what caused the original failure. "We don't yet fully understand why we had the erroneous response on the first health check," Dittemore said. "We have formed a team that will work during the late hours this evening to isolate the cause of the erroneous response and to confirm that we have a good MEC. We plan to meet again at 2:30 a.m. ... to confirm the findings of the team. At that point, we will decide whether we are ready to proceed with tanking." Dittemore said if overnight troubleshooting fails to isolate the problem - or prove that whatever it is will not affect the MECs performance in flight - launch will be scrubbed and the box will be replaced. Replacement, however, would take about one week: Three to four shifts to install a new unit and then several days to carry out an elaborate set of tests to make sure the new box is healthy and properly connected to numerous pyrotechnic devices used to separate the boosters and tank. "It's fairly simple to change out the box," Dittemore said. "However, because of the function of the box - it's involved with a number of the pyro functions - we would have to go safe our pyro charges, then remove and replace the box, then retest and the re-install our pyro functions again. So that would take some time." Replacing MEC-2 likely would delay launch until Feb. 8 or 9. But a Boeing Delta rocket currently has the Air Force Eastern Range booked for a launch attempt on Feb. 9. The Eastern Range provides the radar tracking, photo documentation and self-destruct support used by all rockets launched from the East Coast and each range customer gets at least two launch opportunities. If the Delta flight stays on track, the next attempt to launch Endeavour - assuming the MEC has to be replaced - would be more like Feb. 11 or 12. If MEC-2 is cleared for flight Tuesday and Endeavour is grounded again by bad weather or some other problem, NASA could make two more launch attempts Sunday and Monday, after a Lockheed Martin Atlas 2 takes off carrying a commercial communications satellite. At this point, there's no way to predict what Dittemore and company might decide. This status report will be updated as soon as a decision is made. In the meantime, the mission flight plan below has been updated to reflect a Tuesday launch. A revised NASA television schedule will not be available until after a decision is made on when to launch. =================================================================== MEC replacement ordered; launch postponed to at least Feb. 9 (02/01/00) 03:30 a.m. Update: Second launch try scrubbed; suspect avionics box blamed NASA managers decided early today to replace a suspect avionics box aboard the shuttle Endeavour, delaying launch to at least Feb. 9 and possibly longer. Shuttle program manager Ron Dittemore made the decision after engineers were unable to determine what caused one of Endevour's two master events controllers to fail an initial health check at the T-minus 29-minute mark in Monday's countdown. The MECs control booster ignition and fire the pyrotechnic devices that allow the boosters and external fuel tank to be jettisoned after use. While the shuttle can safely fly with just one operational MEC, NASA's flight rules require both to be healthy at launch for redundancy. Overnight, engineers studied data from MEC-2 and ran additional tests trying to determine if the device was safe to fly as is. But in the end, they were unable to duplicate the initial health check failure and Dittemore decided to play it safe and replace the suspect device. While the replacement itself is not terribly time consuming, the MECs are connected to myriad pyrotechnic devices that complicate the work. "It's fairly simple to change out the box," Dittemore said Monday evening. "However, because of the function of the box - it's involved with a number of the pyro functions - we would have to go safe our pyro charges, then remove and replace the box, then retest and the re-install our pyro functions again. So that would take some time." Replacing MEC-2 will delay launch until around Feb. 9. But it is not yet clear whether that date is available on the Eastern Range, the Air Force organization that orchestrates all East Coast launches. It is thought that Boeing has the range booked Feb. 9 for a Delta-Globalstar rocket launch. If so, Endeavour likely will be delayed until Feb. 11 or 12 depending on when the Delta actually takes off. If the Delta slips for some reason, however, NASA presumably could book Feb. 9 for the shuttle. But that remains to be seen. This status report will be updated as more information becomes available. In the meantime, see the next entry for additional details about the MEC issue. =================================================================== Shuttle Endeavour rescheduled for Feb. 11 launch (02/02/00) 12:30 p.m. Update: Shuttle launch tentatively reset for Feb. 12 Launch of the shuttle Endeavour on a radar mapping mission is expected to be rescheduled for 12:25 p.m. on Feb. 12. NASA has not officially given up on Feb. 11, but it appears unlikely the Air Force Eastern Range, the government agency that orchestrates all East Coast rocket launches, will be able to support. The shuttle launch initially was believed to be in conflict with a planned Boeing Delta 2 flight to boost a set of Globalstar telephone satellites into orbit. But the commercial Delta flight is now targeted for liftoff Feb. 8. It takes up to two days to reconfigure Eastern Range tracking, telemetry and self-destruct systems to support a different mission. And the Air Force is staging a major pre-launch test for a shuttle-class Titan 4 rocket on Feb. 10 that requires Eastern Range support. The Titan 4, carrying a missile early warning satellite, is scheduled for liftoff Feb. 21. If the Feb. 10 test stays on track, it's unlikely NASA will be able to move up Endeavour's launch to Feb. 11. An official decision is expected shortly. The shuttle's launch window will open at 12:25 p.m. on Feb. 12 and close at 2:39 p.m. for a duration of two hours and 14 minutes. The window would open at 12:22 p.m. on Feb. 13 and close at 2:38 p.m. for a duration of two hours and 16 minutes. The goal of Endeavour's flight is to map most of the world's land masses with high resolution radar using antennas in the shuttle's cargo bay and on the end of a 197-foot telescoping mast. The STS-99 launch window is based in large part on the angle of the shuttle's orbit with the sun, which affects the temperature of the mast and, possibly, its behavior during retraction. 10:40 p.m. Update: Titan launch delayed; shuttle launch expected to move up one day to Feb. 11 Launch of an Air Force Titan 4 rocket carrying a missile early warning satellite has been delayed because of unspecified problems, NASA sources say. As a result, the space agency has asked the Air Force Eastern Range to move up the shuttle Endeavour's launch on an oft-delayed radar mapping mission from Feb. 12 to Feb. 11. Earlier today, it appeared all but certain NASA would have to settle for Feb. 12 because of a Delta rocket launch on Feb. 8 and a Titan 4 test on Feb. 10 that required support from the Eastern Range, the government agency that orchestrates all rocket flights from the East Coast. But by the close of business this afternoon, the Titan launch, which had been scheduled for Feb. 21, had slipped into March, sources said, making the Feb. 10 fueling test a moot point. Assuming all of this holds up, the shuttle launch window on Feb. 11 would open around 12:28 p.m. - the exact time has not yet been computed - and closes at 2:40 p.m. for a duration of roughly two hours and 12 minutes. The goal of the flight is to map some 72 percent of the planet's land mass with a high-resolution radar system. The payload demands all the electrical power the shuttle can provide and as a result, only two launch attempts in a row can be attempted before engineers are forced to stand down to top off Endeavour's on-board fuel supplies. NASA managers initially believed refueling operations would take 72 hours to complete. But engineers have come up with a way to top off the on-board fuel supplies in just 48 hours, giving NASA additional opportunities to get Endeavour off the ground if additional delays are encountered downstream. =================================================================== NASA develops strategy to maximize odds of launching Endeavour (02/03/00) With the oft-delayed shuttle Endeavour now scheduled for launch Feb. 11 at 12:30 p.m., NASA managers have developed a strategy to maximize their chances for getting the shuttle into orbit by Feb. 16, the crew's last chance this month. NASA can attempt to launch Endeavour any time between Feb. 11 and Feb. 16. But because of the power demands of the orbiter's radar-mapping payload, NASA can only make two attempts in a row before standing down to top off on-board fuel supplies for Endeavour's three electrical generators. Shuttle planners initially believed it would take three days to top off internal supplies of liquid oxygen and hydrodgen and ready the orbiter for another launch attempt. But engineers have figured out a way to complete the work and have Endeavour ready to go again in just two days. If Endeavour fails to get off the ground Feb. 11 or 12, NASA managers will evaluate the weather forecast and then decide whether to make launch attempts Feb. 14 and 15 or Feb. 15 and 16 depending on which option appears more favorable. A launch on Feb. 16 would result in a landing Feb. 27, the day before the Air Force Eastern Range - the agency that orchestrates all East Coast launchings - shuts down for three weeks of upgrades. The Eastern Range provides photo documentation and C-band radar tracking for shuttle landings. For launches through Feb. 16, C-band radar tracking will be available for Endeavour's planned landing. But all shuttles are launched with enough supplies on board to permit two extra days in orbit if weather or some other problem causes a landing delay. For a launch on Feb. 15, Endeavour's crew would not have C-band radar support for the second contingency day. For a launch on Feb. 16, C-band radar would be unavailable for both extension days. But it would be available - as required by NASA flight rules - for on-time landings. =================================================================== Astronauts return for launch (02/07/00) The shuttle Endeavour's six-member international crew flew back to the Kennedy Space Center from Houston Monday to prepare for blastoff Friday at 12:30 p.m. on an oft-delayed radar-mapping mission. Flying in T-38 jet trainers, commander Kevin Kregel, pilot Dominic Gorie, flight engineer Janet Kavandi, Janice Voss, German astronaut Gerhard Thiele and Japanese flier Mamoru Mohri landed at Kennedy's 3-mile-long shuttle runway at noon. "It seems like we were only just here a week ago," Kregel joked with reporters. "We're really glad to be back. The weather looks like it's going to be favorable for our launch attempt on Friday. The vehicle's clean, they went ahead and replaced the master events controller, so we're getting ready to get back in the saddle and do the mapping mission." An attempt to launch Endeavour Jan. 31 was called off because of low clouds and rain. But, as Kregel said, even if the weather had cooperated the flight would have been delayed because of problems with one of two avionics boxes aboard Endeavour called master events controllers. The MECs control booster ignition and the separation of the boosters and the orbiter's external fuel tank. MEC-2 failed a health check at the T-minus 29-minute mark and after extensive troubleshooting, NASA managers ordered engineers to replace the suspect unit. That decision precluded a launch attempt on Feb. 1 and liftoff was delayed to at least Feb. 9. But conflicts with other rocket launches on the Air Force Eastern Range ultimately forced NASA to settle for Feb. 11. NASA has until Feb. 16 to get Endeavour off the ground or the flight will be delayed to late March. See the next entry for details about how NASA plans to maximize the odds for getting the shuttle into orbit this month. =================================================================== Weather 'go' for launch; booster issue assessed, resolved (02/08/00) 09:45 a.m. Update: Weather 'go' for launch With forecasters predicting an 80 percent chance of good weather Friday, engineers at the Kennedy Space Center are standing by today to restart the shuttle Endeavour's countdown to blastoff on a long-awaited radar mapping mission. The countdown is scheduled to begin at 5:30 p.m. and if all goes well, Endeavour and its six-person crew will blast off from pad 39A at 12:30 p.m. Friday at the opening of a two-hour 10-minute launch window. Endeavour was grounded last week by a faulty master events controller, one of two that control ignition of the shuttle's two solid-fuel boosters and the separation of the boosters and external fuel tank. NASA test director Doug Lyons said today a replacement MEC has been installed, retested and cleared for flight. The only technical issue of any significance involves slightly damaged protective tape over a critical wire harness in the shuttle's left-side booster. The wires in question carry signals telling launch controllers whether the booster's "safe-and-arm" device switched from safe to arm or vice versa. In the "safe" position, booster ignition commands cannot physically reach the rocket's ignitor. The boosters can only be fired when the device is in the "arm" position. The wire in question does not send ignition or safe-and-arm commands. It merely tells controllers whether the S-and-A worked properly. During routine booster closeouts last night, engineers noticed some scuffing on protective tape wrapped around the S-and-A indicator wires. The damage was not seen during closeouts prior to Endeavour's last launch attempt, implying it might have been caused by workers reconnecting equipment that had to be disconnected before the faulty master events controller could be replaced. But that remains to be seen. Engineers are carrying out additional inspections today to make sure the wire itself is not damaged. If that turns out to be the case, this issue likely will have no impact on Friday's launch. If the wire harness has to be replaced, however - and that does not appear likely as of this writing - launch would be delayed. Because of the power requirements of Endeavour's radar payload, NASA can only make two attempts in a row to launch Endeavour before standing down to top-off on-board fuel supplies. While forecasters are predicting an 80 percent chance of good weather Friday, the outlook for Saturday calls for a 70 percent chance of low clouds, rain and possible thundershowers that would delay launch. If Endeavour is not off the ground by Saturday, NASA managers will look at the forecast and then decide whether to make launch attempts Feb. 14 and 15 or Feb. 15 and 16. Feb. 16 is the last day this month the shuttle can be launched. See the Feb. 3 status report for a detailed look at NASA's launch strategy. 06:30 p.m. Update: Shuttle countdown begins; booster issue resolved Countdown clocks restarted today for the shuttle Endeavour's delayed blastoff Friday on a radar mapping mission. The countdown began on time at 5:30 p.m. and if all goes well, Endeavour will rocket away from pad 39A at 12:30 p.m. Friday. Forecasters continue to call for an 80 percent chance of acceptable weather. Earlier today, engineers completed inspections of scuffed tape on a critical wiring harness in the shuttle's left-side booster and concluded the damage was strictly superficial. No major repairs were needed and the booster was cleared for launch as is. There are no other technical problems of any significance. =================================================================== Endeavour set for blastoff (02/09/00) 10:15 a.m. Update: Shuttle launch on track; weather poses minor concern With no technical problems of any significance at launch pad 39A, the shuttle Endeavour's countdown continues to tick smoothly toward liftoff Friday on a radar mapping mission. A Global Positioning System - GPS - navigation receiver needed by the shuttle's radar payload failed a self test early today, but the unit can be replaced, if necessary, with no impact on the countdown. The only question mark at this point - and it's not much of one - is the weather, with forecasters calling for an 80 percent chance of acceptable conditions during Endeavour's two-hour 10-minute launch window Friday (the forecast calls for a 60 percent chance of "go" conditions Saturday). The issue is potentially high crosswinds at NASA's shuttle runway where Endeavour's crew would have to attempt an emergency landing in the event of an engine failure early in flight. While the forecast calls for only a 20 percent chance of a crosswinds violation, meteorologists concede this is little more than an educated guess. The weather database at the Kennedy Space Center is built on data collected in the morning and late afternoon. The 80 percent "go" forecast is based on interpolation, as are most launch forecasts. But the computer models used to make such predictions are a bit unreliable when it comes to predicting the kind of weather patterns currently in play. The crosswind limit for a daylight shuttle landing is 15 knots, or about 17 mph. In the end, NASA managers may end up relying on the recommendation of astronaut Charles Precourt, who will be flying approaches to the shuttle runway in a business jet rigged to handle like a space shuttle on final approach. If there is no turbulence, and if Precourt is comfortable with the winds, NASA managers could waive the 15-knot rule and permit a takeoff with winds as high as 17 knots or so. But that will be a realtime call. A pre-launch news conference with shuttle program manager Ron Dittemore, launch director David King and Capt. Clif Stargardt, staff meteorologist with the Air Force 45th Weather Squadron, is scheduled for 3 p.m. The briefing will be carried on NASA television and this status report will be updated after its conclusion. 05:15 p.m. Update: Shuttle managers say Endeavour in good shape, ready for launch The shuttle Endeavour is ready for blastoff Friday, shuttle program manager Ron Dittemore told reporters this afternoon. "The vehicle, crew and all support teams are ready to fly," he said. "We've changed the hardware that resulted in the scrub last week, we've completed our retest successfully, we're not working any issues and we're proceeding with launch countdown operations. I'm encouraged. The sun is shining, it looks like it's clear skies and hopefully if the weather is good to us, we'll have a good launch on Friday." A Global Positioning System - GPS - navigation receiver that failed a self test early today will be replaced with no impact on launch. There are two GPS systems on board Endeavour and NASA officials said earlier the receiver in question was part of the shuttle's radar-mapping payload. As it turns out, the suspect component is part of an experimental shuttle navigation system, not the radar. Again, the receiver's replacement poses no impact on launch. Endeavour was grounded Feb. 3 by bad weather and troubleshooting to resolve an apparent problem with one of the shuttle's two master events controllers, devices that control the separation of the orbiter's external tank and boosters. The suspect avionics box has been replaced and retested. The faulty unit is undergoing laboratory analysis, but engineers have not yet been able to duplicate the failure that cropped up at T-minus 29 minutes on Feb. 3. =================================================================== Weather outlook improves for shuttle launch (02/10/00) The shuttle Endeavour's countdown to blastoff continues to tick smoothly along, with forecasters now predicting a 90 percent chance of good weather during the shuttle's two-hour 10-minute launch window. The only concern is a slight chance for higher-than-allowable crosswinds at the shuttle's emergency runway. The forecast for Saturday calls for a 60 percent chance of acceptable weather. There are no technical issues of any significance at launch pad 39A. Engineers currently are turning on the orbiter's navigation equipment and gearing up to activate and test communications gear. A large protective gantry will be rolled away from Endeavour around 6:30 p.m., exposing the vehicle to view and setting the stage for fueling at 4:10 a.m. Friday. =================================================================== Shuttle Endeavour rockets into orbit (02/11/00) 07:20 a.m. Update: Shuttle Endeavour fueled for blastoff The shuttle Endeavour has been loaded with a half-million gallons of rocket fuel, setting the stage for blastoff at 12:30 p.m. on a long-delayed radar-mapping mission. The weather appears near perfect and forecasters continue to call for a 90 percent chance of acceptable conditions during Endeavour's two-hour 10-minute launch window. The goal of the 97th shuttle mission is to map more than 70 percent of the planet's land masses with high-resolution radar, allowing military planners and civilian researchers to build 3D topographic maps of unprecedented detail. Some of the more interesting radar targets are included in the mission flight plan below through the first day of the mission. It will be updated throughout the flight. Otherwise, there is little to report this morning. The countdown is holding at T-minus three hours for routine inspections and there are no technical problems of any significance at pad 39A. 10:15 a.m. Update: Crew straps in for launch The shuttle Endeavour's six-member crew has strapped in for blastoff at pad 39A. The launch window opens at 12:30 p.m. and at present, there are no technical problems of any significance and the weather continues to look favorable for an on-time liftoff. Here are the remaining milestones in today's countdown: TIME........EVENT 11:50 a.m....Countdown enters a 10-minute hold at the T-20 minute mark 12:00 p.m....Countdown resumes at the T-20 minute mark 12:11 p.m....Countdown enters a final 10-minute hold at the T-9 minute mark 12:21 p.m....Countdown resumes at the T-9 minute mark 12:30 p.m....Launch 12:39 p.m....Main engine cutoff; shuttle in orbit A detailted mission preview is available below. This status report will be updated as warranted throughout the day. 12:55 p.m. Update: Shuttle Endeavour rockets into orbit The space shuttle Endeavour thundered away through a clear blue sky today, rocketing up the East Coast and into orbit to begin a long-delayed radar mission that will help military planners build detailed 3D maps covering most of the world's land masses. With Endeaovur's main engines at full throttle, the shuttle's solid-fuel boosters roared to life at 12:43:40 p.m. - 14 minutes late because of a trio of minor last-minute problems - beginning the first manned space flight of the new millennium. Eight-and-a-half minutes later, Endeavour was in space. "Kevin, it looks like a great day to go fly, a great opportunity to send you on your Earth mapping mission," launch director David King radioed commander Kevin Kregel during an extended hold at the T-minus nine-minute mark. "If you guys are ready, we're going to pick up the count here momentarily." "The whole crew is ready, we appreciate all your hard work and we're ready to map the world," commander Kevin Kregel replied. Endeavour put on a spectacular show as it climbed away from pad 39A, visible for dozens of miles around as it wheeled about to line up on the proper trajectory. Joining Kregel aboard Endeavour were pilot Dominic Gorie, flight engineer Janet Kavandi, Janice Voss, Japanese astronaut Mamoru Mohri and German flier Gerhard Thiele. The astronauts originally expected to blast off in September, but the flight was repeatedly delayed, first by work to fix fleet-wide wiring problems and then, on Jan. 31, by bad wather and trouble with a critical avionics system that helps control separation of the shuttle's external tank and boosters. The suspect master events controller was replaced and today's countdown went off without a hitch. Kregel and company will face a make-or-break milestone five hours and 30 minutes after liftoff when a telescoping 20-story mast is scheduled to begin extending like a giant Tinkertoy from a compact canister in the shuttle's cargo bay. At the end of the mast are two radar antennas that will work in concert with a pair of much larger phased-array antennas mounted in Endeavour's cargo hold to make a high-resolution three-dimensional map covering 72 percent of Earth's land masses. Military planners hope to use the highest resolution 30-meter data to build detailed computerized 3D topographic maps for simulations, tactical planning and peace-keeping missions. Civilian planners will have access to less detailed 90-meter data and, on a case-by-case basis, selected portions of the 30-meter data set. But first, the 197-foot-long radar mast must fully deploy. It is the largest structure ever built for extension in the space environment and the success of Endeavour's mission depends on its successful operation. "There's certainly an element of mission risk. Not safety risk, mission risk," said shuttle program manager Ron Dittemore. "You just can't test that large a structure in a zero-G [gravity] environment until you're there. So we've done all we can think of as far as testing in a one-G environment and simulating the effects of our maneuvers on the mast and then designing in the right robustness. We've done all we can to protect mission success, but there is that element of risk that there may be something we didn't get that we don't quite understand." Space station engineers sincerely hope not. The station's solar arrays rely on a similar extension mechanism and a successful mast deploy later today will give them confidence the station design is sound. "Some of the station elements use the very same technology," Dittemore said. "If this works very well, that gives us a lot of confidence our design on space station is also going to work well. If this happens to have something we haven't thought of, then we're going to take a second look at what the design may be on station." Twin motors in the canister will turn the mast elements so folded longerons move along corkscrew-like grooves. As individual members travel along the track, they will unwind and snap into place as they exit the canister, forming 87 open bays measuring 27 inches tall and 44 inches wide. Once the mast is fully deployed and locked in position, it should be remarkably rigid, capable of withstanding side loads in excess of 1,000 pounds. Lead flight director Paul Dye called the radar mast "a remarkable structure, it's an engineer's dream." And even if the mast somehow failed, it would post no threat to the shuttle's crew. "If we were to be wrong and it were to break, nothing would happen very fast, the mast would not fold up on you quickly," Dye said. "We have procedures in place to be able to jettison it, the whole canister with the mast, and to fly away from it. Since we have those procedures, we've practiced them, we did extensive training with the crew and all our life support team to handle this kind of emergency and we're very confident we can fly the mast safely." But for the SRTM payload to work its 3D magic, the mast must extend all the way. If the drive motors refuse to start or if the boom jams part way out, Kavandi and Thiele are prepared to stage a grueling spacewalk Sunday to manually drive the mast out of its canister using a space station power tool. "We've trained for several different options," she said. "One would be if the mast did not initially deploy for a failure of the motors. We have redundant motors so it's unlikely they would fail. But in case they did, we can go out and manually attach a space station tool and drive the motors out. Gerhard and I would take turns because it's a fatiguing thing on the hands. It would take quite a while to do this. "Similarly, if the mast did not retract properly all the way back in, we can apply the same tool in the opposite direction and drive the motors so the mast retracts all the way back in," Kavandi said. "If the mast goes back in on its own but the latches do not completely latch shut, we can go out and manually latch the latches." Dittemore said he won't relax until NASA's mission management team meets Saturday morning to review the mast deployment. "We do have a lot of critical activities [today]," he said. "The mast deployment is one and then once we get it deployed and latched in that configuration we're doing a number of tests using vernier jets and primary jets to give us the confidence we've done all our math modeling correctly and we understand just how the mast is going to react to our maneuvers. That's going to take place late in the afternoon and into the evening and we'll have our folks working through the night to give us a good idea whether or not our analysis and our testing is accurate. "And so Saturday morning, when we come in and start talking as the mission mangement team, that's going to be first on the agenda, how well did we characterize the mast," he said. "If it was done well, we're off and running. If it's not done as well as we hoped, we might have to do some more tests." Assuming the mast successfully deploys, the astronauts will start collecting radar data early Saturday. An elevation data point will be recorded every 30 meters, a nine-fold increase in resolution, or sharpness, over currently available global topographic maps. In addition, the data are expected to be twice as accurate as those in current global maps, allowing scientists to create a detailed 3D topographic map of the land masses that are home to 95 percent of the world's population. See the STS-99 mission preview in the Reporter's Notebook below for additional details about this mission. The STS-99 Flight Plan will be updated as soon as possible to reflect the actual launch time and a revised NASA TV schedule will be posted here as soon as it's released. This status report will be updated as warranted throughout the day. 07:00 p.m. Update: 20-story radar mast successfully extended The Endeavour astronauts successfully deployed a telescoping 20-story radar mast this evening, a make-or-break milestone for their mission to map the planet with high-resolution radar. The collapsible mast began extending from its storage canister in Endeavour's cargo bay at 6:27 p.m. and 17 minutes later, at 6:44 p.m., the open framework structure was fully deployed. Commander Kevin Kregel, flight engineer Janet Kavandi and German flier Gerhard Thiele plan to spend the evening working through a long checklist activating and testing various radar systems and mast monitoring devices. A series of rocket firings will be carried out to test the rigidity of the structure before radar mapping begins around 3:30 a.m. Saturday. That work initially will be carried out by the overnight shift, made up of pilot Dom Gorie, Janice Voss and Japanese astronaut Mamoru Mohri. The 197-foot-long 640-pound radar mast was carried into orbit in a compact storage canister at the front end of Endeavour's cargo bay. It was driven out by twin motors that drove folded longerons along corkscrew-like grooves. As individual members moved along the track, they unwound and snapped into place as they exited the canister, forming 87 open bays measuring 27 inches tall and 44 inches wide. The boom was designed to withstand side loads in excess of 1,000 pounds, far more than it will experience from the shuttle's maneuvering jets. Concern about the reliability of the mast, the largest such rigid structure ever deployed in space, prompted NASA managers last month to cut a day out of the crew's radar mapping to protect against the possibility of a jam during retraction. The flight plan originally called for the mast to be hauled back in the day before landing, giving scientists a full 10 days of observations covering 80 percent of Earth's land surfaces. But if the boom jammed during retraction, the crew would not have time to stage a repair spacewalk. In that case, the boom would have to be jettisoned. Even though NASA and the mission's sponsor, the National Imagery and Mapping Agency, have no plans to fly the equipment again, shuttle managers were uncomfortable with the prospect of throwing away such valuable hardware. So they decided to have the mast retracted on the ninth day of the mission to preserve the possibility of a repair spacewalk if the boom does, in fact, jam during retraction. "This is a device we've never deployed before, it's the longest space structure anybody's ever put out and we would like to be able to get it back," said lead flight director Paul Dye. "If we had a problem on the stow day, the way we had the mission put together, we'd have had no opportunity to try to fix that problem with an EVA [spacewalk] or other means. We had stretched the mission as long as we possibly could. "By bringing it in a day earlier, we're going to preserve the capability to look at our options and if we do have a problem with the mast we will be able to look at other ways to bring it in without having to jettison it," he said. "You can look at it as a glass that's 10 percent empty or 90 percent full. And I think a 90 percent full glass is a pretty good mission success criteria." 08:00 p.m. Update: Possible external fuel tank anomaly Replays of video from long-range tracking cameras this evening showed what appeared to be an anomaly with the shuttle Endeavour's external fuel tank during launch earlier today. At least two camers showed an area on the back of the tank [the side farthest from the belly of the orbiter] in the intertank region where there was no orange foam insulation. The area was square in shape - presumably an intertank access door - and distinctly black against the protective orange foam. It rotated into view during the shuttle's roll program immediately after launch. It is unclear as of this writing if a piece of insulation actually fell off or whether the access panel was painted black for some reason. But it appeared unusual to veteran space reporters and an update on this issue will be posted here when more information is available. Otherwise, the astronauts are pressing ahead with work to check out and activate Endeavour's radar mapping equipment. A 197-foot-long radar antenna mast erected at 6:27 p.m. weathered the mild jolt from a shuttle rocket firing without a quiver, giving engineers increased confidence the boom is as rigid as they had hoped. An update to the NASA television schedule (revision A) has been posted below, along with an updated version of the STS-99 flight plan. This status report will be updated as warranted. =================================================================== Radar mapping operations commence; mission managers elated (02/12/00) 09:45 a.m. Update: Radar mapping underway; mission off to smooth start The Endeavour began around-the-clock radar mapping operations early today after successfully erecting and testing a towering 20-story antenna boom Friday. Other than minor problems with a damper system that, as it turned out, is not needed, the Shuttle Radar Topography Mission is off to a flying start. "So far, everything has gone about as perfect as we could have imagined," pilot Dominic Gorie told a reporter this morning. "We started mapping early and so far, everything's gone just very fine." To collect as much data as possible, Endeavour's astronauts are working around the clock in two 12-hour shifts. Commander Kevin Kregel, Janet Kavandi and German astronaut Gerhard Thiele are working what amounts to the day shift in the United states while Gorie, Janice Voss and Japanese astronaut Mamoru Mohri are working the overnight shift. Voss and her shiftmates were asleep when the radar boom was extended Friday evening. She said today she was amazed at the view when she woke up to begin mapping operations. "I was sound asleep and dreaming at the moment of what it would look like," she said. "But I have to say, it was pretty amazing. When I got up this morning, I climbed up in commander's seat and looked out his window and I saw the mast just gleaming in front of me. It was really gorgeous." Engineers devised elaborate systems and complex shuttle maneuvers to minimize any flexing of the mast and so far, the boom has proved to be more rigid than calculations predicted. "What Janice and I observed this morning with Mamoru was a pulse test [shuttle thruster firing]," Gorie said. "When we were looking out the window at it and on the monitors, we saw in essense no movement on the medium pulse test. Later on today, Kevin's going to be doing some higher energy pulse tests and we expect to see, based on what we saw earlier, less than the predicted movement." A complex set of rocket firings making up what is called the "flycast" maneuver will be used to raise Endeavour's orbit slightly each day to counteract the braking effects of atmospheric drag. The pulse tests described by Gorie are being carried out to fully characterize the rigidity of the radar boom prior to daily flycast operations. "If you were to pulse the jets on the space shuttle with the mast extended, the mast would spring aft and then spring forward until it damped out," Gorie explained before launch. "What we do with the flycast maneuver is we put in a very small [rocket] pulse to get the mast moving aft. And then when it would normally start to spring back forward, right at that exact instant, is when we pulse again and hold a sustained pulse with the reaction control jets. "That keeps the mast in that slightly extended state for the duration of the burn," Gorie continued. "Once we've stopped the burn and we've achieved the change in velocity we need to raise our orbit, the mast starts to spring back forward and when it's at the neutral point we pulse one more time to essentially catch it right in the center. What we've done with this maneuver is reduce the mast loads by 50 percent and we've reduced the deflections by 50 percent also, greatly increasing the margin we have." The STS-99 flight plan below includes high interest radar targets through the end of the day today. These targets also are included in the SpaceCalc flight planner worksheet. The flight planner has been revised so the ascent-entry clock macro will count down to each event. The flight plan will be updated later today to include Sunday's targets. 02:50 p.m. Update: Mission managers elated with initial success of radar mission NASA managers, scientists and engineers in the United States, Germany and Italy are elated today at the performance of the shuttle Endeavour's radar mapping payload. After successfully extending a 197-foot telescoping radar antenna mast Friday evening - the longest rigid structure ever deployed in space - the Endeavour astronauts began mapping operations ahead of schedule. The first images were released today at a news conference. "Can you all hear my heart beating? You ought to be able to," said Michael Kobrick, NASA's project manager for the Shuttle Radar Topography Mission. "This has been the best 25 hours and 19 minutes of my life so far. Launch was beautiful, of course, but I think the defining moment in a lot of our lives was the beginning of the deployment of that 200-foot mast. "I can tell you in the payload operations control center, in the customer support room, you could have cut the air with a knife," he told reporters at a 2 p.m. briefing. "And then when we saw that first motion, there was just an explosion of excitement, enjoyment, pride and, I'll admit, relief. ... The best thing I can compare it to is tearing down your car engine and having it all over the garage. And you put it all back together, you think you know what you're doing and you hope you did it right. But boy, when you put that key in and it starts right up perfectly, what a delightful surprise. And that's what happened to us. We started it up and it started on the first crank." A test image taken by the radar system as the shuttle passed over New Mexico Friday clearly showed the San Andres mountains and the White Sands area north of El Paso. The image was color coded for elevation, showing the White Sands area to be some 1,000 feet lower than a valley on the other side of the mountain range. And that is precisely what the radar system was designed to do: Collect elevation data over 75 percent of the planet's land masses between 57 degrees north latitude and about 56 degrees south latitude. "Everything is just great," Kobrick said. "Things have gone so well, it's almost a little spooky. I kept looking behind me trying to figure out what's going to go wrong. Basically, nothing has that's going to affect our mission in any extent. The checkout went so well we actually started mapping a little early. As of the end of our first planning sequence, which was about 18 hours 30 minutes [into the mission], we had finished 18 data takes [covering] four-and-a-half-million kilometers. That's about half the area of the United States. We're on track for completing our mapping mission as planned." Only two minor anomalies have been noticed to date. A damper system that works like a shock absorber to minimize the forces acting on the mast has not yet been activated because of temperature issues. As it turned out, the mast is behaving just fine without it. The mast also is equipped with a cold-gas thruster on the end to counteract gravitational effects that otherwise would torque the orbiter out of the proper orientation. The thruster only exerts one-third of an ounce of force, but that's enough to counteract the unwanted gravitational effects. Engineers have been mildly surprise that the thruster is using up its nitrogen propellant faster than expected and could run out in six days or so. Kobrick said that's a worst-case assessment and even if the thruster does, in fact, run out, the shuttle has enough maneuvering fuel on board to make up the different. Bottom line, he said: No impact. But he cautioned that surprises could still be in store. The 11-day mission is just getting underway and "some of this stuff is new," he said. "We have the largest structure ever erected in space and all that. So we're a little bit careful. I'm reminded of the philosopher Steven Wright when he said 'my plan is to live forever and so far, I'm right on track.' Well, so far, we're right on track." One final note: NASA engineers say what appeared to be an area of missing foam insulation on Endeavour's external fuel tank during launch Friday was, in reality, the normal appearance of a black access door in the intertank region. There was no problem with the tank. =================================================================== Radar mapping continues; boom thruster anomaly studied (02/13/00) 10:00 a.m. Update: Radar mapping continues; boom thruster anomaly studied The shuttle Endeavour's crew continues to sail through their radar mapping chores, covering nearly eight million square miles by early today. The astronauts also completed their first "flycast" maneuver early this morning, successfully raising Endeavour's orbit slightly without over stressing the 197-foot-long radar mast extended from the left side of the shuttle's cargo bay. The flycast rocket firing maneuver is required once each day to make up altitude that is constantly being lost because of the braking effects of the shuttle's passage through the extreme upper atmosphere. Engineers are continuing to troubleshoot problems with a cold gas thruster on the end of the radar boom that was designed to counteract weak but unavoidable gravitational effects that tend to torque the shuttle - and its radar antennas - out of the proper orientation for mapping. The thruster has been using up its nitrogen propellant faster than expected and not supplying the necessary propulsion. Engineers have checked for signs of leakage, but so far nothing obvious has turned up. The thruster currently is using propellant at normal rates, "but without the expected propulsive effect," flight controllers told the crew in a morning message. The shuttle's reaction control system - RCS - maneuvering jets can keep Endeavour properly oriented on their own and so far, mapping operations have not been affected. But if the nitrogen thruster turns out to be inoperable, engineers calculate Endeavour will run short of propellant for these corrective maneuvers about eight hours before the planned end of mapping. That does not, however, translate into eight hours of lost data because the gravitational effects in question are subtle, difficult to predict and take time to manifest themselves. Still, if the nitrogen thruster cannot be recovered, scientists could lose some small amount of data toward the end of the mission. But flight controllers are studying ways to conserve the shuttle's RCS propellant and at this point, it's premature to speculate about the possible outcome of this issue. "We are working to quantify our RCS prop usage for the remainder of the mission, as RCS compensates to keep Endeavour out of gravity-gradient attitude," the mission control message said. "Current prop estimates are a big extrapolation, but they show us coming up approximately eight hours short. We are reviewing prop conservation ideas." See the STS-99 flight plan below for a list of interesting radar targets over the next 24 hours. There is no mission status briefing today. 10:00 p.m. Update: NASA managers discuss ineffective gas thruster NASA managers now say the shuttle Endeavour's radar mapping work could be cut short by up to a day, in a worst-case scenario, because of problems with a small nitrogen gas thruster that is causing the orbiter to use more rocket fuel than expected. But in an informal teleconference Sunday evening, flight director Leroy Cain said engineers are studying ways to save propellant and that he's optimistic any shortfall can be made up. In that case, no data would be lost. But engineers won't know for sure until they complete a detailed analysis over the next few days. "We are anywhere from nominal end of mission [no loss of data] to slightly reduced and I think at this point, not more than a day based on what I have seen," Cain said. "I think there's a great potential we'll make the end of mission based on our ability to find some efficiencies in [propellant usage]. Again, I would stress that we need to go and look hard at some of the major items in that timeline to make sure we understand what the [propellant requirements] might be before we can really characterize it accurately." Endeavour's radar mapping system includes two antennas on the end of a telescoping 197-foot-long mast extending out of the orbiter's pay load bay roughly parallel to the shuttle's left wing. During mapping operations, the shuttle flies tail first with its payload bay facing Earth. Given that configuration, subtle but unavoidable gravitational effects act to torque the shuttle about its roll axis. If not counteracted, the shuttle would end up oriented with the antenna boom pointed straight up toward deep space. As a result, the mast is equipped with a small pressurized nitrogen gas thruster aimed in the opposite direction. While the shuttle's maneuvering jets could easily keep the shuttle properly oriented, it would require too much rocket fuel. The nitrogen thruster worked properly when the mast was first deployed Friday. But for some reason, it suddenly started using more nitrogen gas propellant than expected. "The first indication we saw was a flow rate of nitrogen that was about three times greater than what we expected," said chief engineer Edward Caro. "We ... decided the smart thing to do was just to turn it off and understand what was going on. Then we opened the valve again and let the nitrogen flow. On that cycle, what we saw was that the gas flow returned to the normal rate, which was about 15 pounds of pressure per hour. From that indication, it would almost appear that had fixed the problem. "But when we looked at the thruster firing it didn't seem to have the benefit that we had earlier in the mission," he said. "So we're now in a troubleshooting mode. The gas is flowing, but we're not getting any benefit from it. Where is it going? And that's a question we haven't answered yet." The main nitrogen propellant valve was closed again Sunday evening to give flight controllers time to fully assess how much rocket fuel the shuttle's autopilot expends on its own keeping the spacecraft properly oriented. The astronauts planned to reopen the valve overnight to let engineers determine what effect, if any, the thruster has on that known propellant usage. After that, engineers will have a better idea about what impact an inoperable thruster might have on mapping duration. =================================================================== NASA managers downplay impact of ineffective thruster (02/14/00) NASA managers today downplayed the potential impact of a malfunctioning nitrogen gas thruster on the end of the shuttle Endeavour's 197-foot-long radar antenna boom. The thruster is in place to counteract subtle gravitational effects that tend to torque the shuttle and its antennas out of position for radar mapping. With the small jet out of action, Endeavour's computer autopilot is firing the shuttle's small maneuvering jets to keep the orbiter properly oriented, burning up nearly twice the propellant that would be used if the nitrogen thruster was working normally. In a news briefing Sunday evening, flight director Leroy Cain said the excess fuel usage, in a worst-case scenario, could force the astronauts to cut short their mapping operations by some amount, possibly up to a day. He stressed, however, that the jet problem might turn out to have little or no impact at all. Reporters promptly filed stories saying the mission was in jeopardy of losing up to a day of science. In a news briefing this afternoon, NASA managers went out of their way to backtrack, refusing to provide any details about how much fuel the radar mapping operation is consuming or to speculate on how much mapping might ultimately be lost. Mission operations representative Milt Heflin said it will take another few days to figure out what can be done to maximize the time available for radar mapping. "This is going to evolve over time," said Heflin, a former shuttle flight director. "That's why we're not ready to state that science mission duration is [some] number because this is going to occur over the next two or three days. And I also would like to emphasize again - because I've been here before - we are now dealing with reality. And that's great, because after two or three days of reality we might see something that's even better than expected. So we've got to let all that play out." Heflin said engineers are evaluating a variety of options to improve efficiency and reduce fuel usage. In the meantime, "I can't tell you today what mission impact we might have," he said. "Right now, we are full duration as far as our mapping is concerned until we know otherwise." "What we're dealing with here is an experiment," Heflin said. "I would take the results of this experiment to date and I would put that up against any laboratory with any apparatus in the world. Because I think what these folks have done with that first-time apparatus is remarkable, absolutely remarkable. I think that's what we need to focus on. I will get accused of lecturing and I apologize for that. But you know, we have a tendency every now and then to kind of focus on the negative. Well, our glass is more than half full here, folks, and we ought to really focus on some of the great science these folks are doing." While virtually every question focused on the thruster problem, mission scientists unveiled fresh radar images at today's briefing, including spectacular 3D shots of the White Sands, N.M., area and another showing previously hidden river channels and gulleys in the Amazon rain forest. =================================================================== NASA managers optimistic thruster issue can be resolved (02/15/00) 10:15 a.m. Update: Astronaut says thruster problem may be due to ice blockage Astronaut Janice Voss, taking a break from her radar mapping chores, said today it's too early to tell if the shuttle Endeavour's mapping mission might have to be shortened because of trouble with a small nitrogen gas thruster. "We're looking at power, we're looking at propellant usage and I don't think the decision has been made exactly as to how this flight is going to finish yet," she said. "We're still working real hard to get as much data as we possibly can." The thruster in question, mounted on the end of a 197-foot-long radar mast, was designed to counteract subtle gravitational effects that otherwise would torque the shuttle out of the optimum orientation for mapping. The tiny jet uses pressurized nitrogen gas and puts out one-third of an ounce of force. "It just goes to show you in the microgravity environment we have how big an effect a very tiny force can have," Voss said. "That small force over 10 days makes a big difference to the flight." The jet has not been working properly since the first day of Endeavour's mission, forcing the shuttle's autopilot to fire small maneuvering jets to compensate. While that's not a problem in and of itself, the additional rocket firings are using up precious fuel. Engineers are studying ways to fix the nitrogen thruster and looking at techniques to save rocket fuel by changing the way the shuttle's autopilot fires the maneuvering jets. In a worst-case scenario, the crew might be forced to end radar mapping operations a few hours early, possibly up to a day, according to weekend estimates. Those estimates likely have changed by now, but NASA has not yet provided an update. "We have a very tiny thruster that's on the end of this long 200-foot mast," Voss explained. "It puts out a very small amount of force, it's about the weight of a penny if you had the thruster in your hand. And it's just to help keep this thing lined up properly. It's such a small force that our shuttle jets can compensate, but it takes extra fuel. "They think maybe there's some ice blocking that port, they're trying to work on that problem, to clear the thruster problem," she said. "In the meantime, they're trying to adjust the way we use our propellant on board so that we'll use less of it to make up for that small extra amount we're using to compensate for the thruster that's blocked." Even if mapping operations are shortened, Voss said the crew will still come home with a complete map covering some 75 percent of Earth's land masses. "They're still working that problem and they may completely solve it and allow us to finish the mission without any impact from that thruster," she said. "Even if they can't do that and we end up not having the propellant to finish completely, we still get a map all the way around. In order to get the maximum accuracy, you have to cover every point twice. So if we don't get the second round, it just means it'll be about 1.7 times less accurate than it would have been at that area of the map. We'll still get a complete map." Asked how the crew is holding up during the somewhat repetitive around-the-clock flight, Voss said "we're doing great. We're very pleased with the success of this flight so far and we're looking forward to a lot more great days like we've been having." 05:00 p.m. Update: NASA managers optimistic about overcoming thruster problem Flight controllers have implemented five measures to help the shuttle Endeavour's crew conserve rocket fuel and are studying additional techniques to ensure radar mapping operations can run for a full nine days and nine hours as originally planned. Milt Heflin, a mission operations representative at the Johnson Space Center, said today he's hopeful no data will be lost when all is said and done. "I'm optimistic we're not going to fold our tent early," he said. "But I've got to tell you also, I'm probably a couple of days away from coming here and telling you we're there. But we're well on our way." The problem is a malfunctioning nitrogen thruster needed to help keep the shuttle and its 197-foot-long radar mast properly oriented for mapping. Without the thruster, the shuttle's autopilot must fire rockets to keep the shuttle "in attitude." And that uses up precious fuel, raising the concern that NASA might be forced to end radar mapping operations a few hours early. Flight controllers are leaving no stone unturned to find ways of conserving fuel. Early today, they even noticed the subtle effects of German astronaut Gerhard Thiele exercising on a stationary bike. In the microgravity of space, Thiele's workout actually affected the shuttle's orientation in space by a very slight amount, prompting jokes about adding additional exercise sessions. The five conservation measures implemented to date mostly involve relaxing the limits used by the shuttle's automatic pilot to determine when a rocket firing is needed. Flight controllers also have made adjustments to slow down how fast the shuttle moves from one orientation to another. Finally, engineers noticed that less fuel was used when excess water, generated continuously during flight, was dumped overboard through a side-pointing nozzle instead of the shuttle's flash evaporator. Still under consideration, but not yet implemented, are proposals to eliminate one or more orbit-raising trim burns, using different maneuvering thrusters for routine changes in orientation and shifting to another set of autopilot routines that might prove slightly more efficient. In the meantime, radar mapping has proceeded in fine fashion with no problems of any significance. Deputy project scientist Thomas Farr said that as of this afternoon, the shuttle's radar system had mapped 33 million square kilometers twice and 73 million square kilometers at least once, an area equal to Africa and North and South America combined. To achieve the highest accuracy, the shuttle must map every area twice, once while moving from southwest to northeast and once while moving northwest to southeast. That insures that every given point is illuminated from two sides, eliminating possible radar shadows. =================================================================== Radar mast thruster issue appears resolved (02/16/00) Flight controllers believe they have identified enough fuel saving measures to ensure the shuttle Endeavour's crew can complete their radar mapping mission despite a malfunctioning nitrogen thruster. While propellant margins at present are slim, it appears all but certain the astronauts will be able to carry out a full nine days and nine hours of mapping, collecting 3D elevation data over about 72 percent of the planet's land masses. As of this afternoon, the crew had mapped more than 73 percent of that target area, or 35 million square miles, at least once. More than 38 percent of the area, or about 18 million square miles, has been mapped twice, which is required for the highest possible resolution. That number will increase rapidly toward the end of the mission. The only problem of any significance so far during Endeavour's flight has been a balky nitrogen gas thruster on the end of the shuttle's 197-foot-long radar mast. The thruster was designed to counteract subtle gravitational effects that, over time, would torque the shuttle and its radar antennas out of the proper mapping orientation. Because the thruster is malfunctioning, the shuttle's autopilot is using rocket power to maintain the proper orientation, burning up precious fuel. Flight controllers have implemented a variety of fuel savings techniques in recent days and Milt Heflin, a flight control representative, said today he's confident those measures will enable the crew to complete their mapping chores. Engineers may even figure out a way to return the nitrogen thruster to service. Earlier today, astronaut Janice Voss reported seeing a pebble-sized chunk of debris come flying out of Endeavour's cargo bay just after pilot Dominic Gorie opened a nitrogen line valve to help engineers continue their troubleshooting efforts. It's possible the white debris was a chunk of ice that may or may not have been affecting the system's performance. The valve was reopened just before 10 p.m. for additional tests and troubleshooting. =================================================================== Scientists elated with initial mapping results (02/17/00) The Endeavour astronauts pressed ahead with their radar mapping work today, beaming down a steady stream of data while engineers put the finishing touches on plans to conserve rocket fuel to permit a full-duration science mission. As of this afternoon 52.9 million square kilometers had been mapped with Endeavour's cloud-penetrating radar system, or 44.4 percent of the crew's goal for a nine-day nine-hour mission. Some 93.6 million square kilometers have been mapped at least once. Two passes over each target zone are required to eliminate possible radar shadows and to achieve the highest possible accuracy. By the end of the mission, the crew will have mapped some 72 percent of the world's land masses. Among the radar images released today were shots showing the Los Angeles basin and areas around the San Andreas Fault near Lancaster, Calif. Los Angeles International Airport could be seen, along with the Rose Bowl and the Jet Propulsion Laboratory. While the images in and of themselves did not reveal any insights to the casual viewer, scientists said high-resolution 3D maps based on these data will be a boon to geophysicists trying to understand the mechanics of earthquakes. And if a radar mapping satellite capable of Endeavour's high resolution is ever launched, scientists might even be able to "see" an earthquake in progress. "You can clearly map the faults and from some of those maps you can start seeing displacement of some very recent features that will help us determine how often these faults break and cause earthquakes and how large those resulting earthquakes might be," said JPL researcher Diane Evans "So right away, these digital topographic maps and the perspective they give geophysicists are invaluable to understanding earthquakes. And then when we start doing more routine mapping with interferometry we'll start actually seeing the motion as it's happening." Milt Heflin, a flight operations representative at the Johnson Space Center, said engineers have identified enough fuel conservation measures to permit Endeavour's crew to complete all of its planned mapping work. Problems with a small pressurized nitrogen gas thruster on the end of a 197-foot-long radar mast have caused the shuttle to burn up more fuel than expected, raising questions earlier in the flight about whether enough fuel was available to complete the research. "My optimism has changed to reality," Heflin said today. "We have crossed this bridge. We are now at the point we wanted to be as far as saving propellant to be able to do the nine-days, nine-hour mapping mission. We're there. We're not taking any days off of the mission." Late this afternoon, the astronauts ran into problems with one of their high-speed data recorders. The crew spent a fair amount of time troubleshooting the machine but it was not immediately clear what inmpact, if any, the problem might have. Spare recorders are on board if worse comes to worse. =================================================================== Radar mapping extension approved (02/18/00) 04:00 p.m. Update: NASA managers consider extending radar mapping work NASA managers say the shuttle Endeavour's radar mapping mission is proceeding so smoothly - including the performance of its unique 197-foot-long antenna boom - that they're considering extending mapping operations about nine hours or so to collect additional data. This will not affect the duration of the mission and landing will remain targeted for 4:52 p.m. Tuesday. But if mapping operations are, in fact, extended, the crew will lose any chance to stage an emergency spacewalk to make repairs if the mast jams or otherwise refuses to retract properly early Monday. In that case, the crew's only recourse would be to jettison the mast and its storage canister to burn up in the atmosphere. "We're looking into seeing what we might be able to do to squeeze out a little more science time," said Milt Heflin, a mission operations representative at the Johnson Space Center. "We've just started that activity, we're not sure where it's going to lead us to." NASA originally planned to carry out mapping operations for 10 days and 10 hours, allowing the crew to map a full 80 percent of the planet's land masses with high-resolution radar. But in late January, mission managers decided to cut a day out of the mapping timeline to preserve a chance to stage a contingency spacewalk to manually crank the mast in should its motors fail. Because the radar payload uses so much electrical power, a spacewalk would not have been possible after a full-duration 10-day 10-hour mapping operation without eating up one of the crew's contingency landing days. Prior to launch, managers were adamant about preserving the option of a repair spacewalk, saying there were no plans to collect more than nine days nine hours of data. Even that goal seemed at risk earlier in the flight because of problems with a small nitrogen gas thruster needed to counteract subtle gravitational forces that otherwise would torque the shuttle and its radar mast out of the proper mapping orientation. As a result, the shuttle's normal maneuvering jets had to fire more than expected to compensate, burning up precious rocket fuel. Flight controllers then implemented a number of fuel conservation techniques to enable the crew to continue mapping for the full nine days nine hours. In the end, enough fuel is expected to be conserved to enable a few additional hours of mapping. "We spent a lot of time working to save propellant and we've done a very good job with that," Heflin said. "Part of this has to do with the propellant savings that we've had. A lot of it has to do with the performance of the radar system and what we're doing. We don't want to just rest on our laurels right now, we'd like to see if there's anything we can possibly do to squeeze out a little more time. So we've kicked off that effort." While enough fuel appears to be available for a few hours of additional mapping, there would not be enough for a contingency spacewalk as well. But based on the performance of the mast so far, engineers are confident it will retract properly when the time comes. So confident, they're willing to accept the slight risk of a malfunction that could force the crew to dump the mast overboard. "Our evaluation of that risk is it's extremely small," said project scientist Michael Kobrick of NASA's Jet Propulsion Laboratory. "We're greatly buoyed by the fact that this thing deployed perfectly, it's operated perfectly, it's matching our predicts spot on. We have no indication that there's going to be any problem. The motors look like they're going to start right up. I feel like Joe Namath in that second Superbowl. It's going to stow. We're going to win." Overall, Kobrick said the complex four-antenna radar system has worked flawlessly, better than his wildest dreams. "My dreams are pretty wild, but this is exceeding even those," he said. The goal of the mission is to collect elevation readings every 30 meters over 80 percent of the world's land masses. That will enable cartographers to build a 3D topographic map of the world that is nine times better than anything currently available. Each elevation reading was to be accurate to within 16 meters when measured from the center of the Earth and to within 10 meters relative to adjacent measurements. As it turns out, Kobrick said, the radar system has performed far better than engineers expected and the anticipated errors will not be as great as initially believed. The result will be an even more accurate map than researchers expected. "We're besting it by a substantial margin," Kobrick said. "The bottom line of all those geeky numbers are they're all better than we expected by a factor of two or three." It is in large part because of the exceptional performance of the radar system that NASA managers agreed to consider a mapping extension at the possible risk of losing the mast should it fail to retract properly. In the end, the value of the additional data likely will outweigh the value of the mast, especially since NASA has no current plans to refly the hardware. "Every hour we get toward our original objective is getting us closer to our uniform data set that we envisioned," said program scientist Earnest Paylor. "So we're happy to be part of this and any additional hour we can get is more science data for us. So that's just tremendous. ... To put this in perspective, we have been trying to acquire a data set of this quality and this resolution for decades. To try to do this in a 10- or 11-day mission is absolutely astounding." 08:30 p.m. Update: Radar mapping extension approved Based on the near-perfect performance of the shuttle Endeavour's radar mapping equipment, NASA managers late today agreed to extend crew's radar mapping work by nine hours. The flight plan originally called for the astronauts to stop mapping operations Sunday evening and to retract a telescoping 197-foot-long antenna mast around 9:44 p.m. Sunday. Under the new plan, the mast will remain extended until around 6:44 a.m. Monday morning, allowing the crew to collect valuable mapping data that otherwise would be lost. Landing at the Kennedy Space Center remains targeted for Tuesday afternoon at 4:52 p.m. NASA is in the process of updating the STS-99 television schedule to reflect the radar mapping extension. Revision J of the TV schedule was released with several errors and is being corrected. Revision K is expected by 10 p.m. or so. The only major changes are the deletion of work to prepare for a possible repair spacewalk in the event the radar mast fails to retract properly. The crew does not have the propellant necessary to accommodate a radar mapping extension as well as a spacewalk. See the 4 p.m. CBS News status report for complete details. Revision K of the NASA television schedule will be posted as soon as possible. In the meantime, see the STS-99 flight plan on the Current Mission page for a complete list of radar targets through Monday morning. =================================================================== Extra nine hours means big boost for science (02/19/00) NASA's decision to extend the shuttle Endeavour's radar mapping work by nine hours will translate into a "significant improvement" for science, researchers said today, allowing the astronauts to come within a few percentage points of their original mapping goals. The astronauts originally planned to map some 46 million square miles [119 million square kilometers] of land between 60 degrees north latitude and about 56 degrees south latitude over the course of 10 days and 10 hours. That translates into about 80 percent of the planet's land area. Before Endeavour's Feb. 11 launch, however, mission managers cut one day out of the radar mapping timeline to allow time for a possible emergency spacewalk should the shuttle's 197-foot radar antenna mast fail to retract properly. But for the most part, the Shuttle Radar Topography Mission - SRTM - equipment has worked flawlessly throughout the flight, prompting a decision Friday to extend mapping operations by nine hours to collect additional data. Not enough fuel was available to restore the entire lost day and as it is, the additional mapping work will eliminate any chance for a repair spacewalk. Should the antenna boom jam or malfunction, the crew will have no recourse but to dump it overboard. But engineers are confident the mast will work properly. And so, instead of retracting the radar mast nine days nine hours after launch, the astronauts will leave it fully extended until a mission elapsed time of nine days 18 hours, or until around 6:44 a.m. Monday. As of noon today, the astronauts had mapped 42.5 million square miles [110 million square kilometers] of real estate at least once and about 30 million square miles [77 million square kilometers] twice. To achieve the highest possible accuracy, the radar needs to map each target two times from different directions to eliminate possible radar shadows caused by topography or man-made structures. Before the additional nine hours was put back into the mapping timeline, SRTM managers expected to fully map about 72 to 75 percent of the target land areas during nine days and nine hours of mapping, losing coverage of some 386,000 square miles [1 million square kilometers]. Some 4.2 million square miles [11 million square kilometers] would have been mapped just once, not twice as originally planned. Given the additional nine hours, however, only 77,220 square miles [200,000 square kilometers] of the original target area will be left unmapped - mostly in North America where high-resolution maps already are available - and all but 2.4 million square miles [6.3 million square kilometers] will be mapped twice as desired. To put it another way, researchers originally planned to map 46 million square miles of land at least once. They now expect to get 43.5 million square miles. =================================================================== NASA says radar data exceeded expectations (02/20/00) 09:30 a.m. Update: NASA revises radar shutdown time NASA managers decided overnight to terminate radar mapping operations aboard the shuttle Endeavour at 6:54 a.m. Monday (mission elapsed time: nine days 18 hours 10 minutes). This is 10 minutes later than originally targeted to permit the crew to make a final mapping pass across Australia. Endeavour's 197-foot radar antenna mast will be retracted starting at 8:14 a.m. Monday. Landing remains on track for 4:52 p.m. Tuesday. Revision M of the NASA TV schedule has been posted below, along with updated 2-line elements for satellite tracking programs. The STS-99 flight plan also has been updated to include final radar targets. This status report will be updated after today's 2 p.m. mission status briefing. In the meantime, the shuttle's radar mapping work is continuing smoothly with no technical problems of any significance. 07:15 p.m. Update: Radar numbers add up to 94.6 percent of pre-launch goal The shuttle Endeavour's radar-mapping astronauts are expected to accomplish 94.6 percent of their prelaunch goal, collecting dual elevation measurements over 43.5 million square miles for a near global 3D topographic map. The actual end result may be even better. The astronauts mapped 45.9 million square miles at least once, achieving 99.96 percent of the pre-flight target. Because of the better-than-expected performance of the shuttle's radar system, some of that one-pass data may provide information comparable to the more accurate dual-pass results. "It's really difficult to comprehend the magnitude of what we're about to accomplish," said Earnest Paylor, Shuttle Radar Topography Mission - SRTM - program manager for NASA. "This truly is a magnificent accomplishment. ... I'm quite certain that SRTM data will probably be one of the most universally useful data sets we've ever acquired. It will become the foundation of our geospatial data analysis activities and probably stand the test of time. I venture to say the more mature the SRTM data set becomes, the more people, the more scientists and engineers will begin using it and we'll find even more uses for this data set." Radar mapping operations are scheduled to end at 6:54 a.m. Monday after nine days 18 hours nine minutes and 13 seconds of around-the-clock measurements. The astronauts plan to begin retracting a telescoping 197-foot radar antenna mast at 8:14 a.m. Monday to set the stage for landing Tuesday at 4:52 p.m. Technicians will be standing by at the Kennedy Space Center to cart away some 326 high-capacity radar data tapes containing enough digital information to fill 20,600 compact discs. Lead flight director Paul Dye said engineers spent the weekend reviewing procedures for retracting the radar mast - the largest rigid structure ever erected in space - and "frankly, we haven't found anything to change. We're still confident we don't have anything unexpected." Concern about problems during mast retraction prompted NASA managers to cut one day out of the mapping timeline before Endeavour even took off to provide time for an emergency spacewalk if needed. While the crew had problems last week with a small nitrogen gas thruster on the mast, flight controllers devised fuel-saving workarounds and otherwise, the radar equipment worked flawlessly. So flawlessly, in fact, that NASA managers decided Friday to add nine hours back into the radar mapping timeline, judging the value of the additional data outweighed the presumably small risk of a problem with the mast. "We've had everybody look at the mast, the mast deployment, we've looked at data, we've looked pictures, it's in exactly the shape we expected it to be," Dye said. "We saw no anomalies during deploy so we expect no anomalies during retraction." But if the mast does, in fact, fail to retract, the crew will have no choice but to dump it overboard. The decision to extend mapping operations by nine hours, coupled with lost propellant due to the malfunctioning nitrogen thruster, eliminated any chance for staging a repair spacewalk. If the mast fails to retract, the astronauts can simply turn a switch to fire small pyrotechnic charges that will release the mast and its storage canister from the shuttle's cargo bay. "The jettison is actually extremely simple," Dye said. "There's a rotary switch that selects about four different sequences of pyros that sever the connections to the mast. If we have to jettison it, we basically let the whole canister go. The procedure doesn't take very long. ... The mission specialist will throw the switch to sever the mast, it's a simple activity with essentially no relative motion. Once it's separated, the commander takes a look at it, he thrusts downward with the shuttle, backs away from it and in a matter of about eight to 10 feet of motion we're completely clear of the mast. We pulse away a little bit more then we ... do a series of three burns that gets us away from the mast. At that point, it's gone. It's a very simple jettison, it's almost an undocking." While the crew collected a bit less radar data than originally anticipated, the astronauts will have mapped every point on the globe between 60 degrees north latitude and 56 degrees south latitude except a region the size of West Virginia in six diamond-shaped areas spread out across North America. Those voids will have little or no impact, however, because virtually all of North America already has been mapped to the same level of resolution, or clarity. The radar data is stored on tape aboard Endeavour. Only a few percent were downlinked to Earth during the mission to verify the performance of the equipment. That "quick-look" data was the foundation for several photographs released during the flight to demonstrate the quality of the SRTM product. But mission managers said the final, fully processed data will provide even better views. "We have terabytes of data on board," said Thomas Hennig, SRTM program manager for the National Imagery and Mapping Agency. "What we've been able to see during the mission is just a very small percent of that data that we've been downlinking for quality control purposes." Once Endeavour returns to Earth, the data tapes will be sent to the Jet Propulsion Laboratory in Pasadena, Calif. After fine-tuning complex processing software, researchers will begin "cranking through the massive quantities, the terabytes of information we have to get processed," Hennig said. "Out of that, comes the digital terrain elevation data," he said. "Where today we can walk out and buy a data set where it's a thousand kilometers between each data point, we'll be coming out of this with a data set that has those data points 100 meters apart. So that's 100 times more data in a given unit of area. And the quality of the data is at least twice as good as that near global set that's available today." Dye said the quality of even the quick-look images was enough to distract his flight control team. "The images these guys are getting are just absolutely stunning," Dye said. "We've got them posted all over the control center and the only problem we have is people just standing there and freezing in front of the pictures because they're so pretty they don't want to go back to work. It's just amazing stuff. What's even more amazing, these pictures are just whetting our appetites for most of the data that's yet to come. We're just seeing a very, very small tip of the iceberg here." =================================================================== Astronauts complete radar mapping; retract mast on fourth try (02/21/00) 07:30 a.m. Update: Astronauts wrap up radar mapping The Endeavour astronauts concluded their radar mapping work this morning after a final data take across Australia, logging 222 hours and 23 minutes of near continuous observations since the project began. That's enough raw data to fill some 20,600 compact discs. Radar mapping started at 12:31 a.m. on Feb. 12 and ended this morning at 6:54 a.m. at a mission elapsed time of nine days 18 hours and 10 minutes. During that period, the crew mapped more than 75 percent of the planet's surface and virtually all of the land masses between 60 degrees north latitude and 56 degrees south latitude. The crew currently is gearing up to retract Endeavour's 197-foot-long radar antenna mast starting around 8:15 a.m. The telescoping boom extended normally five-and-a-half-hours after blastoff Feb. 11 and based on its performance to date, engineers don't anticipate any problems. But there is little the creew can do if the mast does, in fact, jam. A decision over the weekend to extend radar mapping by nine hours eliminated any chance for a repair spacewalk. This status report will be updated after retraction is complete or as conditions warrant (see the 7:15 p.m., 02/20, update below for complete details). Once the mast is retracted, the astronauts will spend the rest of the day packing up and preparing the shuttle for landing Tuesday afternoon at the Kennedy Space Center. The crew has two opportunities to land in Florida Tuesday and one to land at Edwards Air Force Base, Calif. Here are the latest numbers: TIME............EVENT...............SITE 03:52:00 p.m....Deorbit ignition 04:50:27 p.m....Landing.............Kennedy Space Center 05:23:40 p.m....Deorbit ignition 06:22:26 p.m....Landing.............Kennedy Space Center 06:50:40 p.m....Deorbit ignition 07:48:08 p.m....Landing.............Edwards Air Force Base Additional landing details, along with the latest weather forecast, will be posted here later today, along with notes from a 4 p.m. mission status briefing with entry flight director John Shannon. 08:45 a.m. Update: Radar mast retraction comes up short In the only moment of real drama since radar mapping operations began Feb. 12, the Endeavour astronauts ran into problems retracting and latching down a telescoping 197-foot long antenna mast today in the last major milestone before landing Tuesday. Twin motors began turning at 8:19 a.m. to pull the mast - the largest rigid structure ever deployed in space - into a compact canister in Endeavour's cargo bay. As each open bay of the boom entered the canister, the longerons making up the bay collapsed as they were directed around a rifling-like groove in the canister's interior. Each of the 86 external bays making up the mast appeared to collapse normally, but retraction stopped about an inch short at 8:37 a.m. Two of three latches are required to lock the canister closed but engineers saw no indication that latching occurred. It is not yet known whether Endeavour's crew can correct the problem, whether the shuttle can safely land with an unlatched mast or whether the mast and its storage canister might have to be jettisoned. There are no plans to fly the radar mast again, but NASA wants to preserve the hardware if at all possible. A similar design will be used to deploy solar arrays on the international space station. Before Endeavour's launch Feb. 11, NASA managers cut one day from the crew's radar mapping work out of concern the mast might jam or malfunction during retraction. Under the original 10-day 10-hour mapping timeline, the astronauts would not have had time to stage a repair spacewalk if the mast failed to fully retract. By cutting a day from the timeline, NASA preserved an option to attempt repairs. But the mast deployed flawlessly on the first day of the mission and telemetry showed it to be remarkably stable throughout the flight, despite constantly changing temperatures as the shuttle moved from sunlight into Earth's shadow and back again. NASA managers ultimately put nine hours of the lost mapping day back into the timeline, deciding the value of the additional data outweighed the minimal risk of a jam. This status report will be updated as warranted. 09:20 a.m. Update: Spacewalk ruled out; mast evaluation continues Engineers are continuing to assess a problem getting a telescoping 197-foot-long radar antenna lached down in the shuttle Endeavour's cargo bay. The $35 million mast retracted into its storage canister normally, but stopped about an inch short. Two of three latches are required to lock the top of the canister down, but no such indications have been seen. While flight controllers studied the situation, commander Kevin Kregel radioed that even though the mast was not fully retracted, he did not think there would be any problem closing the shuttle's cargo bay doors. Then he asked if there was any possibility astronauts Janet Kavandi and Gerhard Thiele might be asked to carry out an emergency spacewalk to manually latch the canister shut. Mission managers said over the weekend a decision to extend radar mapping by nine hours had eliminated any chance for such an excursion. And that still appears to be the case. "From our standpoint, looking how far the antenna is in, it doesn't look like closing the payload bay doors is an issue," Kregel said. "I guess the number one question is, I've got Janet and Gerhard still sleeping. If it needs to be an option to step outside, we're prepared to do that. But I'd like to keep them in crew rest if that's the case. So keep me advised." "Appreciate your concerns for your crew members," astronaut Stephen Robinson replied from Houston. "Our current plans do not include them heading out the door. So I think you can leave them as is." 09:50 a.m. Update: Initial mast repair attempt fails A second attempt to latch down a telescoping radar mast in the shuttle Endeavour's cargo bay has failed. Flight controllers had hoped that higher temperatures might warm up stiff components inside the boom's storage canister. The astronauts were told to drive open three latches and then to turn on the boom retraction motors. The hope was the mast would retract a final inch and that at least two of the three latches on the storage canister would engage. They didn't. "We saw perhaps just a tiny movement at initial power up but then nothing else," commander Kevin Kregel radioed. "And of course, you saw the currents in the (mast retraction motors) were pretty high, around 3.0." "We copy and concur," astronaut Stephen Robinson replied from mission control. "Stand by, we'll have more words for you." 10:20 a.m. Update: Third attempt to latch mast fails The Endeavour astronauts switched two radar mast retraction motors to maximum torque and made another attempt to drive the boom a final inch into its storage canister. The mast moved about a quarter of an inch toward the closed position, but quickly stalled out. When the motors were turned off, the canister lid moved back out slightly. The lid remained about an inch shy of fully closed. "And Houston, if you had good downlink you saw we had initial good movement, maybe about a quarter of an inch or so, and then it just stalled out right there," commander Kevin Kregel radioed. "When the power came off, it came back about half that distance I'd estimate. It's a little bit closer, not much, than where we started off." "Good report, Kevin," astronaut Stephen Robinson radioed from Houston. "We're back to our thinking caps here." While astronauts Janet Kavandi and German flier Gerhard Thiele are trained to carry out an emergency spacewalk to manually drive the latches closed, flight controllers have pretty much ruled out that option. A decision over the weekend to extend radar mapping operations by nine hours eliminated any chance for a spacewalk because of tight propellant margins. On top of that, the landing weather forecast is not favorable for Wednesday and Thursday. It appears the crew's best chance to get down in either Florida or California will be Tuesday, as planned. A spacewalk would delay Endeavour's return to Earth by at least one day. If engineers cannot figure out some other way to get the mast fully retracted, the astronauts may be forced to dump the boom and its storage canister overboard. There are no plans to fly the $35 million mast again, but a similar design will be used to deploy solar arrays on the international space station and engineers would like to get the radar boom back for analysis if at all possible. "It's going to be a few more minutes, a little longer, before we have some words for you," Robinson radioed around 10:15 a.m. "It might be a good time to take a break, get some lunch. ... We'll let you know as soon as we know more." Lead flight director Paul Dye said Sunday the jettison procedure, if it comes to that, is straightforward. The astronauts would turn a switch and small pyrotechnic charges would fire, severing connections between the storage canister and the payload bay. This would not "blow" the canister out of the payload bay. In fact, it would cause little or no motion at all. Instead, Kregel would fire thrusters on the shuttle to drop the orbiter away. "The jettison is actually extremely simple," Dye said. "There's a rotary switch that selects about four different sequences of pyros that sever the connections to the mast. If we have to jettison it, we basically let the whole canister go. The procedure doesn't take very long. ... The mission specialist will throw the switch to sever the mast, it's a simple activity with essentially no relative motion. Once it's separated, the commander takes a look at it, he thrusts downward with the shuttle, backs away from it and in a matter of about eight to 10 feet of motion we're completely clear of the mast. We pulse away a little bit more then we ... do a series of three burns that gets us away from the mast. At that point, it's gone. It's a very simple jettison, it's almost an undocking." Flight controllers have until about 1:15 p.m. to resolve the issue one way or the other without impacting landing preparations. Given the weather forecast, it appears doubtful at this point that NASA managers would consider a mission extension. Whether they would consider letting Endeavour's crew return to Earth with the mast in its current unlatched configuration is not yet known. 11:00 a.m. Update: Fourth attempt to retract mast succeeds The astronauts successfully retracted and latched a telescoping 197-foot-long radar antenna mast today after three unsuccessful attempts, driving the lid of a storage canister closed as required for landing Tuesday. The successful retraction ended at 10:50 a.m. - some two-and-a-half hours behind schedule - prompting cheers and applause in mission control. "Houston on my mark, three... two... one... mark," commander Kevin Kregel called as he turned on the boom's twin retraction motors, which were set at maximum torque. A similar attempt earlier failed, but this time around the mast moved outward slightly and then smoothly in, all the way to the full latch position. "It came out a little bit, then came shut," Kregel said. "We've got the power off and visually, it looks like it's closed." Counting the initial mast retraction as the crew's first attempt to stow the boom, the success came on the crew's fourth try. "Well, from the orbit three team, thanks for the exciting finish to an exciting mapping portion of the mission. Again, congratulations on a spectacular data set. Looking forward to seeing you and the data back home," astronaut Stephen Robinson called from mission control in Houston. "Steve, we feel the same," pilot Dominic Gorie replied. "We concur with the fantastic finish. We'll see you guys when we get home." 05:00 p.m. Update: NASA monitors weather; White Sands an option if Tuesday landing delayed The Endeavour astronauts tested the shuttle's re-entry systems today and packed up for landing Tuesday afternoon at the Kennedy Space Center. Touchdown on runway 33 is targeted for 4:50 p.m., weather permitting, to close out a remarkably successful 11-day radar mapping mission. But forecasters are predicting high winds and the possibility of a low deck of broken clouds, which could prevent a Florida landing on either of two opportunities. Conditions at Edwards Air Force Base, Calif., where Endeavour has a single landing opportunity Tuesday, are only marginally acceptable and both sites are expected to be unavailable Wednesday because of deteriorating conditions. If Endeavour can't get down Tuesday - and both landing sites will be staffed - entry flight director John Shannon will evaluate the forecast for Wednesday and, if conditions have not improved, decide whether to call up a third landing site at White Sands, N.M. White Sands is a backup landing site that has only been used once in shuttle program history: March 30, 1982, when the Columbia ended the third shuttle mission on the white gypsum runway. It has not been used since, and should Endeavour end up going to New Mexico Wednesday, NASA will be unable to provide live landing coverage on NASA television. "The orbital dynamics tomorrow give us two chances to land at Kennedy Space Center in Florida," Shannon said. "Then we have one opportunity to Edwards Air Force Base. We have activated Edwards Air Force Base for this flight starting tomorrow because of weather concerns Wednesday and Thursday. Right now, the weather is somewhat questionable at Kennedy Space Center for all three days - tomorrow, Wednesday and Thursday. "We're going to watch it real closely," Shannon said. "We'll take a good look at Kennedy for the first two revs. By that time, we should have a better feel for what the weather will be like Wednesday at Kennedy Space Center. If the forecast is that it is not going to get better, that we're not optimistic the weather would be better there on Wednesday then we'll go ahead and commit and if the weather at Edwards is acceptable tomorrow we would land there." White Sands - also known as Northrup Strip or the White Sands Space Harbor - will not be staffed Tuesday. But it likely will be activated Wednesday if Endeavour's crew is forced to stay in orbit an extra day. "That option has not been entirely ruled out for Wednesday or Thursday," Shannon said. "Right now, it's a little premature. We're not doing anything with White Sands tomorrow. But if the weather degrades and the forecast is for it to continue to degrade, if that happens we'll consider Northrup. But that is still a decision we would not make before going through all three opportunities tomorrow." The astronauts wrapped up their radar mapping chores at 6:54 a.m. today and retracted a 197-foot-long antenna mast. The telescoping boom failed to fully retract initially, stopping about one inch short. After two more attempts to drive the mast all the way in failed, a third try was successful at 10:50 a.m. Engineers suspect the boom's components loosened up a bit after they had time to warm up in a storage canister. Shuttle Radar Topography Mission managers released spectacular new radar images today showing the topography of an island in the Fiji chain, the San Francisco bay area and the San Gabriel Mountains north of Pasadena, Calif. The latter was part of a fly-through simulation providing viewers with a bird's eye view of the region. Project manager Michael Kobrick said all of the images shown during Endeavour's mission amounted to less than one-tenth of one percent of the 12 terabytes of data recorded by Endeavour's astronauts. "What do you say after you hit a home run?" joked Kobrick. "I feel like I have to almost apologize for the almost boring nature of this flight. We didn't rendezvous with anything, there were no spacewalks. But it shows you what a real science measurement experiment is like. It's tedious, time consuming, you have to work very carefully. Watson and Crick didn't just wake up one day and discover the structure of DNA. ... As we start to process this 12 terabytes of radar data, you're going to see things just about as exciting (as pictures from the Hubble Space Telescope)." =================================================================== Shuttle Endeavour glides to smooth sunset landing (02/22/00) 07:45 a.m. Update: Endeavour astronauts prepare for landing The Endeavour astronauts are packing away a few final items and gearing up for landing today at either the Kennedy Space Center in Florida or Edwards Air Force Base in Californ's Mojave Desert. The Spaceflight Meteorology Group at the Johnson Space Center in Houston is predicting higher-than-allowable crosswinds in Florida and a chance for a broken deck of clouds around 4,000 feet, either of which would prevent a landing. The first of two Florida landing opportunities comes at 4:50:27 p.m. Conditions at Edwards are expected to be within NASA's safety limits for touchdown during a single landing opportunity at 7:48:08 p.m., although meteorologists are keeping close tabs on gusty winds (see the SMG forecast below for complete details). Both landing sites are fully staffed and while NASA's preference is to land in Florida if at all possible - it costs about $1 million to bring a shuttle back from California - Endeavour's crew will head for California today if conditions at Kennedy are not within limits. "We're going to watch it real closely," entry flight director John Shannon said Monday. "We'll take a good look at Kennedy for the first two revs (orbits). By that time, we should have a better feel for what the weather will be like Wednesday at Kennedy Space Center. If the forecast is that it is not going to get better, that we're not optimistic the weather would be better there on Wednesday, then we'll go ahead and commit and if the weather at Edwards is acceptable we would land there." NASA normally would keep a crew in orbit an extra day in hopes of getting a shuttle back to Florida. But the forecast for Wednesday is "no-go" at both Edwards and Kennedy. If Endeavour can't land in either Florida or California today, the crew could be faced with a diversion to a backup landing strip at White Sands, N.M., Wednesday. Only one shuttle flight - STS-3 on March 30, 1982 - has ever landed at White Sands. Hoping for the best, the astronauts are following a timeline that sets up a landing at the Kennedy Space Center at 4:50:27 p.m. Here is the flight plan: TIME............EVENT 11:55:00 a.m....Deorbit timeline begins 01:13:00 p.m....The shuttle's payload bay doors are closed 01:25:00 p.m....OPS-3 entry software is loaded 02:29:00 p.m....The astronauts don their pressure suits 02:53:00 p.m....The astronauts begin strapping into their seats 03:15:00 p.m....The shuttle's rocket steering system is checked 03:19:00 p.m....Endeavour's hydraulic power system is configured 03:38:00 p.m....Mission control gives a "go" for deorbit ignition 03:40:00 p.m....The shuttle maneuvers to the deorbit attitude 03:53:00 p.m....Deorbit ignition 04:50:27 p.m....Landing on runway 33 at the Kennedy Space Center If the weather is clearly unacceptable for the initial landing try, the crew likely would delay closing Endeavour's cargo bay doors and shoot for a landing on the next orbit. Here are all the landing opportunities for Tuesday and Wednesday: TIME............ORBIT...EVENT...............SITE TUESDAY 03:52:40 p.m....180.....Deorbit ignition 04:50:27 p.m....181.....Landing.............Kennedy Space Center 05:23:40 p.m....181.....Deorbit ignition 06:22:26 p.m....182.....Landing.............Kennedy Space Center 06:50:40 p.m....182.....Deorbit ignition 07:48:08 p.m....183.....Landing.............Edwards Air Force Base WEDNESDAY* 03:41:00 p.m....196.....Deorbit ignition 04:33:00 p.m....197.....Landing.............Kennedy Space Center 05:04:00 p.m....197.....Deorbit ignition 05:58:00 p.m....198.....Landing.............Edwards Air Force Base 05:10:00 p.m....197.....Deorbit ignition 06:04:00 p.m....198.....Landing.............Kennedy Space Center 06:37:00 p.m....198.....Deorbit ignition 07:30:00 p.m....199.....Landing.............Edwards Air Force Base * Exact times (with seconds) TBD This status report will be updated throughout the day. 01:40 p.m. Update: Florida weather improves slightly; second opportunity appears more favorable The shuttle Endeavour's cargo bay doors have been closed and the orbiter's flight computers have been loaded with OPS-3 entry software, setting the stage for a landing later today in either Florida or California. The astronauts have two opportunities on successive orbits - at 4:50:27 p.m. and at 6:22:26 p.m. - to land at the Kennedy Space Center and one opportunity, at 7:48:08 p.m., to land at Edwards Air Force Base, Calif. Forecasters say conditions appear to be improving somewhat at the Kennedy Space Center. While crosswinds may be too high for the first opportunity, meteorologists say the winds may die down enough by the second to permit a safe landing at 6:22 p.m. "The weather at KSC is improving," astronaut Rick Sturckow radioed the crew from mission control. "We're still monitoring a potential crosswind violation for the first rev. However, it is looking better for the second opportunity." For a 4:50 p.m. landing, commander Kevin Kregel must fire Endeavour's braking rockets at 3:53 p.m. For a landing at 6:22 p.m., the braking rockets must be fired at 5:24 p.m. Otherwise, the crew likely will be heading for California. NASA wants to get Endeavour back on the ground in Florida if at all possible because it costs about $1 million to ferry a shuttle back to the Kennedy Space Center from California. An Edwards landing also adds a week or more to the turnaround time needed to ready a shuttle for its next launch. But given that both landing sites are expected to be "no-go" Wednesday, flight director John Shannon will not hesitate to send Endeavour's crew to Edwards later today if the weather does not permit a Florida touchdown. 03:30 p.m. Update: NASA rules out 4:50 p.m. landing The shuttle Endeavour's crew has been ordered to delay re-entry at least one 89-minute orbit because of high crosswinds at the Kennedy Space Center. If the winds die down later as forecasters hope, commander Kevin Kregel and his five crewmates will be cleared for a 6:22 p.m. touchdown at the Florida spaceport to close out an 11-day radar mapping mission. "Endeavour, you are no go for the deorbit burn," astronaut Rick Sturckow radioed from mission control at 3:30 p.m. "The winds at KSC, we saw a crosswind of 13 knots, peak 19. However, we expect them to decrease for the second opportunity. Additionally, the STA (shuttle training aircraft) reported significant turbulence below 500 feet with high workload in the pitch axis." If the second landing opportunity doesn't pan out, Endeavour's crew will be diverted to California for a touchdown at 7:48 p.m. at Edwards Air Force Base, Calif. 05:01 p.m. Update: Shuttle crew cleared for Florida landing The Endeavour astronauts have been cleared to fire the space shuttle's twin braking rockets at 5:25:10 p.m. to set up a landing on runway 33 at the Kennedy Space Center at 6:22 p.m. High crosswinds at the shuttle's 3-mile-long runway forced the crew to pass up their first landing opportunity at 4:50 p.m. and while the winds remain a bit blustery, flight director John Shannon cleared commander Kevin Kregel to deorbit and head for home. "Endeavour, Houston. Go for the deorbit burn," astronaut Rick Sturckow radioed from mission control. "OK, thank you, good news. Go for the burn," Kregel replied. The forecast calls for crosswinds of 10 knots with peaks up to 15 knots. Clouds are not an issue and the crosswinds appear to be decreasing as the afternoon wears on. 05:28 p.m. Update: Shuttle Endeavour fires braking rockets Flying upside down and backward over the southern Indian Ocean west of Australia, commander Kevin Kregel fired the shuttle Endeavour's twin orbital maneuvering system braking rockets at 5:25 p.m., slowing the spacecraft by 169 mph, just enough to set up a 6:22 p.m. landing on runway 33 at the Kennedy Space Center. The two-minute 19-second rocket firing went smoothly and there are no technical problems of any significance with the space shuttle. Crosswinds at the shuttle's 3-mile-long runway are expected to be within NASA's 15-knot safety limit by the time Endeavour arrives an hour from now. This status report will be updated after Endeavour lands or as conditions warrant. 06:40 p.m. Update: Shuttle Endeavour glides to Earth (updated at 07:45 p.m.) The shuttle Endeavour glided to a picture-perfect sundown landing today at the Kennedy Space Center, bringing home enough radar mapping data to fill more than 20,000 compact discs. The black-and-white spaceplane settled down to a smooth landing on runway 33 at 6:22:23 p.m. to wrap up an 11-day flight spanning 4.7 million miles and 181 complete orbits since blastoff Feb. 11. "Wheels stopped, Houston," commander Kevin Kregel called as Endeavour rolled to a stop. "Roger, wheels stopped, Endeavour. Kevin, congratulations to you and the crew on a highly successful mission of mapping the world," replied astronaut Rick Sturckow from mission control in Houston. Kregel, pilot Dominic Gorie, flight engineer Janet Kavandi, Janice Voss, Japanese astronaut Mamoru Mohri and German flier Gerhard Thiele were expected to climb off the orbiter about an hour after touchdown. All six will participate in a crew news conference around 9:30 a.m. Wednesday before flying back to the Johnson Space Center for reunions with friends and family members. "I want to thank everybody for coming out and seeing us land," Kregel said from the runway. "I guess we put on a fairly nice show where folks could see us from pretty far out. It was even better from inside. We're really proud to be part of this mission. I think the radar images that we bring back, taken around the world, are going to help out mankind, humankind from all countries for many years to come." Landing came one 89-minute orbit behind schedule because of high crosswinds at the shuttle landing facility. Despite initial concern the flight might be diverted to Edwards Air Force Base, Calif., the winds in Florida died down as the day wore on and entry flight director John Shannon cleared the crew to head for home. This was the 21st shuttle landing in a row at the Florida spaceport. Here are the latest numbers: ................KSC........EAFB........WS........Total Night landings..08.........05..........00........13 Day landings....42.........40..........01........83 TOTAL...........50.........45..........01........96 Most recent.....02/22/00...03/31/96....03/30/82 Technicians were standing by to retrieve more than 320 high c> Transfer interrupted! more than 20,000 compact disc's worth of mapping information. After copying the tapes to protect the data, a set will be flown to the Jet Propulsion Laboratory in Pasadena, Calif., for months of computer processing. The result will be a digital topographic map showing 80 percent of the world's land area in three dimensions. Over the course of Endeavour's mission, elevation readings were taken every 98 feet over virtually all the land between 60 degrees north latitude and 56 degrees south latitude. The resulting map is expected to be at least nine times better than anything currently available. =================================================================== Astronauts pleased with mission success (02/23/00) Looking relaxed and fit, commander Kevin Kregel and his crewmates said today they never had any doubt they would pull off the shuttle Endeavour's complex radar mapping mission, even when they ran into a thruster problem that could have forced them to cut their observations short. The astronauts landed Tuesday evening after a one-orbit waveoff due to high crosswinds at the Kennedy Space Center. "It's great to be back in Florida," Kregel said at a post-landing news conference early today. "I'm glad we got back in on the second rev because if you look at today's weather, I don't know if we would have made it back into Florida Today or not. And it certainly was a pretty darn good mission. I think 99 percent for first (radar mapping) pass and 96 percent for second pass, that's an A plus on anybody's report card. So we're really pleased with the outcome of this mission." Using a sophisticated C-band and X-band radar system, the astronauts actually accomplished 94.6 percent of their prelaunch goal, collecting dual elevation measurements over 43.5 million square miles for a near global 3D topographic map. The actual end result may be even better. The astronauts mapped 45.9 million square miles at least once, achieving 99.96 percent of the pre-flight target. Because of the better-than-expected performance of the shuttle's radar system, some of that one-pass data may provide information comparable to the more accurate dual-pass results. The data were collected with four antennas, two mounted in Endeavour's cargo bay and two on the end of a 197-foot-long telescoping mast. Early in the mission, a small nitrogen gas thruster on the tip of the mast malfunctioned, causing concern on the ground that mapping operations might have to be shortened. The thruster was in place to counteract subtle gravitational effects that acted to torque the shuttle out of the proper orientation for mapping. While Endeavour's small maneuvering jets could handle the task, it was not immediately clear whether enough fuel would be available. But flight controllers implemented a variety of fuel conservation measures and in the end, mapping operations were extended nine hours and 10 minutes to collect additional data. The only other problem of any significance came at the end of the flight when the 20-story radar mast failed to fully retract into its storage canister, stopping an inch or so short. On the theory that cables and other components might have stiffened in the cold of space, heaters were turned on inside the canister to warm the equipment up. On the third additional attempt to complete retraction, the mast finally seated normally. "As soon as it stopped a couple of inches short of fully closed, we all looked at each other and although we were a little bit surprised, it certainly wasn't something that had never been seen with that mast before," pilot Dominic Gorie said today. "They had added some canister heaters to fix that problem. Janice (Voss), it seems, was quite relaxed with the fix they were proposing. She was confident, and so I was as well, that heaters were going to solve the problem, it was just going to take some time. So during the interim, we actually grabbed some cameras and were taking some pictures of the view of Earth going by, fully confident that it was going to happen. ... We were just very confident because the mission had gone so well, there was no reason to think it was going to stop." ===================================================================