STS-91 MISSION ARCHIVE (complete) Updated: 06/12/98 Shuttle Discovery: Final Mir Docking Mission By William Harwood CBS News/Kennedy Space Center The following copy originally was posted on the CBS News "Up To The Minute" Current Mission space page (http://uttm.com/space/missions/current.html). Comments and corrections welcome! TABLE OF CONTENTS -New external tank passes fueling test (05/19/98) -STS-91 mission preview (05/22/98) -Shuttle crew arrives; cosmonauts troubleshoot Mir glitch (05/30/98) -Mir computer replaced; problems continue (05/31/98) -Cosmonauts repair computer system (06/01/98) -Shuttle Discovery rockets into orbit on final Mir mission (06/02/98) -KU-band antenna failure eliminates shuttle television (06/03/98) -Discovery docks with Mir; KU-band problem hampers AMS checkout (06/04/98) -KU-band antenna repair fails; Ryumin comments on Mir (06/05/98) -Spektr leak eludes detection; Thomas eager for time off (06/06/98) -Shuttle-Mir crews hail Phase One program (06/07/98) -Shuttle Discovery undocks from Mir station (06/08/98) -Experimenters may seek second flight for AMS (06/09/98) -Light at end of tunnel for AMS? (06/10/98) -Shuttle systems tested for Friday landing (06/11/98) -Discovery returns to Earth; closes out phase one program (06/12/98) =================================================================== New external tank passes fueling test (05/19/98) Mission managers at the Kennedy Space Center today tentatively cleared the shuttle Discovery for blastoff June 2 on NASA's final flight to the Russian Mir space station. Liftoff from pad 39A at the Kennedy Space Center currently is targeted for 6:09:54 p.m. with landing on tap at 2:03 p.m. on June 12. The only technical issue under review is a slight leak in a water check valve used by one of the shuttle's three electricity producing fuel cells. The fuel cells combine oxygen and hydrogen to produce electricity and, as a by product, water. The water is either directed to on-board tanks for use by the crew or dumped overboard using check valves. Engineers are assessing the leak to determine if it poses any threat to the orbiter or to Mir's systems. If the valve in question has to be replaced, Discovery's launch could be delayed one to two weeks, engineers say. A final decision on whether Discovery can fly "as is" is expected in the next week or so. Today's flight readiness review came one day after a critical test of Discovery's new super lightweight external fuel tank, the first such tank to be assigned to a mission. The $43 million aluminum-lithium tank weighs 7,500 pounds less than NASA's original fuel tanks, allowing shuttles to carry heavier space station cargoes to orbit. The tanks are difficult to make and the fueling test Monday was designed to prove they can safely handle the stresses generated by their half-million-gallon load of supercold liquid oxygen and hydrogen rocket fuel. Here is NASA's status report describing the results of the test: ----- Today, Shuttle engineers successfully completed the tanking test of the new super lightweight external tank (SLWT) set to fly for the first time with Shuttle Discovery on mission STS-91. From Firing Room No. 1, the test team subjected the external tank and orbiter to a simulated launch countdown scenario. The simulated countdown clock started Saturday night at 9 p.m. with reactant loading of Discovery's power reactant storage and distribution system and culminated with a planned ground launch sequencer (GLS) cut-off at T-31 seconds today at 4:50 p.m. Cryogenic loading of the SLWT liquid hydrogen tank began at about 7:20 a.m. today and loading of the liquid oxygen tank began at about 10 a.m. A SLWT data evaluation team with members from KSC, Johnson Space Center and Marshall Space Flight Center were primarily interested in the tension loads that would be placed on the new tank during fuel loading. The extremely cold cryogenic fuels can cause the external tank to shrink up to 1-inch in diameter and several inches in length. This shrinkage places a tension or "pinch" load on the external tank/solid rocket booster strut attach points located near the tank's aft dome. The data evaluation team began gathering "pinch" load data at the 7 percent full mark during liquid hydrogen tanking. Throughout the entire liquid hydrogen tanking process, the tension loads were well within the acceptable limits. The SLWT data evaluation team completed their test objectives earlier than expected so the test team chose to move GLS cut-off up by about two hours. An orbiter data evaluation team also used the test scenario as an opportunity to check-out various orbiter systems. The KSC ice/debris inspection team conducted remote inspections of the external tank from firing room No. 1 throughout the test and performed an onsite inspection after the SLWT was 100 percent full and halfway through stable replenish. Though additional hands-on inspections will follow this week, preliminary reports show the external tank in excellent condition. ----- NASA and its prime contractor, Lockheed Martin, ran into problems with weld cracks during development of the super lightweight tank. Here's a bit more background from a story originally written for Space News in 1997: ----- The bullet-shaped shuttle fuel tanks, built by Lockheed Martin's Manned Space Systems division in Michoud, La., carry the supercold propellant burned by the shuttle's three liquid-fueled rocket engines. The tanks are 46.9 meters long and 8.4 meters in diameter. Each bright-orange tank, the only part of the shuttle system that is not reused, is made up of two subtanks: A 29.5-meter tank that carries 104,308 kilograms of liquid hydrogen and a smaller 16.6-meter tall tank at the top of the structure that carries 625,850 kilograms of denser liquid oxygen. The individual tanks are made up of cylindrical barrel sections that are welded together in a stack and capped by domes at each end. Viewing a tank vertically, the barrel sections are made up of eight panels that are joined together at the seams by vertical welds. Completed barrel sections then are welded together with horizontal circumferential welds. During development, Lockheed Martin had problems with cracks where these circumferential welds intersect the vertical welds in the barrel sections. When the vertical welds were re-heated during the process of joining two barrel sections, small cracks developed. "This material doesn't like to be re-heated," NASA program manager Parker Counts said. "You get small cracks and then you've got to go back and repair them." The cracks in the first tank, originally scheduled for delivery to NASA in September 1997, were discovered after a so-called proof test at the Michoud facility. The oxygen tank was pressurized with water to simulate internal conditions during flight while the hydrogen tank was pressurized with nitrogen. In addition, the tanks were subjected to external forces that simulate those associated with a shuttle launch. Out of 914 meters of welds in the subtanks that will make up the first super lightweight tank, engineers discovered 16 cracks in the hydrogen tank and 11 in the oxygen section. Counts said the cracks averaged about 0.25 centimeters long and invisible to the unaided eye. "We have done testing that shows these small cracks could, in fact, handle the flight loads," said Jerry Smelser, deputy manager of the external tank project. "They would not be catastrophic were we to fly with one. But from a conservative standpoint, we're going in and fixing them." To fix a crack, engineers first "grind it out to a point where we believe we've got the full crack out," Counts said. Re-welding may also be necessary. Then, additional inspections are carried out using X-rays and penetrating dyes to make sure the problem has been corrected. "We've learned a lot about aluminum-lithium," Counts said. "It's definitely the material of the future. But it's definitely not as easy to work with as the old stuff." =================================================================== STS-91 mission preview: Mir docking, astrophysics on tap (05/22/98) The shuttle Discovery is set for blastoff June 2 on NASA's ninth and final mission to dock with the Mir space station. While the primary goal of the flight is to bring astronaut Andrew Thomas back to Earth after 140 days in space, the shuttle Discovery's crew also plans to drop off needed supplies and equipment, bring experiment samples and hardware back to Earth and test an upgraded robot arm that will be used to help build the international space station. And in another attempt to help pinpoint leaks in Mir's punctured Spektr module, Discovery's crew also will deliver a special pressurized gas that will be injected into the abandoned lab during the mission. As the gas leaks out it should fluoresce in direct sunlight, allowing the astronauts and cosmonauts to see and photograph where the leaks are occurring. Veteran cosmonaut Valery Ryumin, a senior Russian manager who made two visits to the now defunct Salyut-6 space station, is joining Discovery's crew to carry out a detailed inspection of Mir to assess its overall health after more than 10 years in space. And in a scientific first for the space program, a six-ton magnetic spectrometer at the back of Discovery's cargo bay will run for 100 hours during the flight to look for atoms of antimatter in an experiment that could reshape current theories about the birth of the universe. "Most of the theoretical physicists believe there should be no antimatter and they have various scenarios [to explain it]," said Samuel Ting, Nobel Prize-winning principal investigator for the $33 million Alpha Magnetic Spectrometer. "So if you find antimatter, anticarbon, then all the predictions are wrong. ... It would provide us with a much deeper understanding of the origin of the universe." Making its second visit to Mir and its first docking, the shuttle Discovery is set for liftoff at 6:09:54 p.m. on June 2. The actual launch window opens at 6:04:59 p.m. and closes at 6:14:57 p.m. Earth's rotation will carry Discovery directly into the plane of Mir's orbit in the middle of that window, at 6:09:54 p.m., and that's when NASA hopes to launch the orbiter on its 24th flight, the 91st in shuttle history (the window and preferred launch time likely will change slightly based on updated Mir tracking). On the flight deck will be commander Charles Precourt, pilot Dominic Gorie, flight engineer Wendy Lawrence and Franklin Chang-Diaz, who will become only the fourth man to fly in space six times. Seated on Discovery's lower deck will be Ryumin and Janet Kavandi. Precourt and Ryumin are making their fourth space flight while Lawrence is making her third. Gorie and Kavandi are rookies. "I've never been a gambler in my life," Chang-Diaz said at a pre-flight news conference. "I have no concerns whatsoever. I find that the machine works, it works very reliably and I feel perfectly safe. That doesn't mean I'm not scared. I am scared just like any normal human being would be. But I am quite confident with the technology that has been developed and I'm looking forward to developing further this technology so we can go farther out." New fuel tank debuts Discovery's flight is the first featuring NASA's new $43 million aluminum-lithium super lightweight external tank, which weighs 7,500 pounds less than the shuttle's original fuel tanks. That weight savings translates directly into increased payload to orbit and it's critical for upcoming international space station flights. The tank was loaded with supercold liquid oxygen and hydrogen rocket fuel May 18 and engineers say it performed as expected. For his part, Precourt said he's confident the tank stand up to the rigors of launch. "They did a great job at coming up with 7,500 pounds to come off of that structure," he said. "It would be akin to taking your car as it sits today, removing all four doors and the engine and still have something that drives down the street. So they've done a great job pulling off a large percentage of that weight." Discovery's rendezvous with Mir begins with liftoff and ends two days later with docking. As with past Mir visits, Discovery will approach the Russian station from directly below along an imaginary line called the "r bar" that connects Mir and the center of the Earth. By approaching along the r bar, the shuttle can use Earth's gravity and orbital mechanics to provide a natural braking force, eliminating the need to fire upward facing rocket thrusters that could damage Mir's fragile solar arrays. Discovery will approach Mir from behind in a nose-forward orientation. For the final approach, however, the shuttle will yaw 180 degrees to put its tail in the direction of travel to improve line-of-sight communications between the shuttle and NASA's TDRS comsats. Precourt is an old hand at shuttle-Mir dockings, having flown as a pilot on one docking mission and commander of another. But this approach will be a bit different in that Discovery's airlock and the attached docking module are mounted in the extreme forward section of the shuttle's cargo bay as they will be during assembly of the international space station. Clearances between the shuttle and Mir will be tight with this configuration and "they should really have the Mir in their face when they dock," said lead flight director Paul Dye. "I don't want to say it's routine, but we have perfected the approaches to the Mir such that we're using roughly one third of the fuel we used when we began [shuttle-Mir docking mission]," Precourt said. "It'll probably never be old hat. This is a very intense process to get the shuttle up to docking with the space station and to make sure everything goes smoothly. We've perfected the mission and how to get there and we've been able to overcome a lot of failures. "But when you come down to it, each mission is extremely important and what puts us on edge is wanting to make sure we get through it without mistakes, without hold ups with problems that would delay certain parts of the mission. We're always on our toes." Thomas eager to join shuttle crew As soon as hatches are opened between the shuttle and Mir, Thomas will officially join Discovery's crew. He was launched at 9:48:15 p.m. on Jan. 22, becoming the seventh and final American to make a long-duration stay aboard the Russian station. Assuming an on-time landing June 12, Thomas will have logged 140.6 days in space, pushing the cumulative U.S. time aboard Mir to 977 days, or 2.7 years, since joint flights began in 1995. Gaining such experience with long-duration spaceflight was one of the major goals of the shuttle-Mir program, known as Phase One of the international space station program. The idea was for NASA and the Russian Space Agency to learn how to work together aboard Mir before beginning assembly of the much more complex international space station later this year. Despite some initial mistrust and the unavoidable cultural clashes that occurred, both on the ground and in space, astronauts, cosmonauts and managers on both sides now say the Phase One program was a major success. "It's very difficult to imagine beginning the assembly of the international space station, beginning operations, without doing what we've done during the shuttle-Mir program," said Frank Culbertson, manager of the Phase One program for NASA. "Getting to know how to operate in space, getting to know how to work with an international partner, getting to understand the Russian way of doing business and they getting to understand the way we do business has been critical." Dye agreed, saying "We've learned a tremendous amount that's going to help us on ISS, not only from a technology standpoint - how to dock with space stations, how to operate them, how to point them, how to schedule things - but how to work with our Russian colleagues. "I've worked with some of my Russian colleagues now longer than I've worked with some of the members of my flight control team," he said. "We're good friends, we understand how each other thinks and that's going to help us tremendously as we move into the ISS program." Assuming an on time launch, Discovery will dock with Mir around 1 p.m. on June 4. Over the next four days, the combined crews will move 2,298.5 pounds of supplies and equipment to Mir and transfer another 2,536.4 pounds of material to the shuttle for return to Earth. In addition, the shuttle crew will transfer 1,200 pounds of fresh water to Mir. Here's the complete breakdown: MATERIAL................UP........DOWN Water...................1,200.....N/A U.S. Science............1.5.......1,230.8 French/German Science...64........0 Russian Logistics.......2,151.6...726.6 Miscellaneous...........81.4......579 TOTALS..................3,498.5...2536.4 "Actually, this is a fairly routine transfer mission," said Lawrence. "We will continue to bring up water and food for the station. Certainly our top priority is to retrieve Andy Thomas. Next on the list I would think are all his scientific results and he has a full complement of experiments that he conducted during his stay. There is some Mir scientific hardware, items we would like to bring down on the shuttle and also, Russian hardware items, equipment that has been replaced." On June 6, the astronauts will test Discovery's robot arm, carrying out a photo survey while docked to the station. The arm has been upgraded electrically and mechanically for use during international space station assembly and NASA is using Discovery's flight to make sure the upgrades work as expected in the space environment. "It will be stowed for most of the flight," Dye said. "It has upgraded hardware, new electronics which will be used for the first time seriously on STS-88, the first ISS mission with the shuttle. In order to make sure we haven't introduced any problems into the arm we want to check out the new equipment. We're going to do an RMS checkout while we're docked. We have clearance from the Russians to operate the arm in a small zone to keep it well clear of the Mir, by about 10 feet." Spektr leak test on tap Later that same day, the cosmonauts will inject a pressurized gas into the abandoned Spektr module and then observe the lab's exterior from various station and shuttle windows to look for signs of the gas escaping into space. The module was punctured one year ago when the station was rammed by an out-of-control Progress resupply craft and engineers have not been able to pinpoint where the leakage is occurring. While it's doubtful the Russians will attempt to repair Spektr, having techniques for locating leaks could prove valuable in the international space station era. "No one knows what type of experience will be needed in the future," Ryumin said through an interpreter. "However, doing this experiment now will be helpful. I don't believe it will have much of an impact on the ultimate determination of the lifetime or future operations of Mir station." Ryumin plans personal Mir inspection Ryumin helped design Mir and actively lobbied for a Phase One flight to the outpost to carry out a detailed personal inspection. After losing quite a bit of weight and passing NASA's physicals, he was assigned to Discovery's crew. His wife, cosmonaut Elena Kondakova, flew on an earlier space shuttle with Precourt. Culbertson said he was initially skeptical at the value of Ryumin's proposed Mir inspection "but as we've gotten into it, I can see there are going to be big paybacks." "There actually is a great deal of benefit to having someone who's had experience on previous stations such as he has on Salyut," Culbertson said. "He's got extensive time on orbit as well as extensive testing experience with hardware. I believe, as both a manager and an experienced engineer, he'll be able to look at Mir and evaluate not only its viability for the short term but also what types of things need to be done differently on ISS that will make it easier for the crew, easier for the ground to control, better for the hardware, whatever he can determine. And so he will spend a certain amount of his time looking all over the Mir, in nooks and crannies, and trying to find areas that can be improved on." Speaking through an interpreter, Ryumin said he plans to address "a list of questions compiled by our station designers, questions that only a person who's experienced in this field can properly answer." "These questions include the condition of the hull, the condition of the cabling and the condition of various feed throughs between modules," Ryumin said. "In short, those items of the station that cannot be replaced on orbit. Approximately 90 percent of the equipment we bring up into space can be replaced. However, the remaining 10 percent cannot and it is these 10 percent that ultimately determine the lifetime of the station. And these will be the issues with which I will be occupied during the flight." If all goes well, Discovery will undock from Mir around noon on June 8. The shuttle will drop straight down about 250 feet and then fly up to a point directly in front of the station on the velocity vector, or v bar, for a second Spektr gas release just as the two spacecraft move into orbital sunlight. The gas "has a tendency to fluoresce," Dye said. "This is not going to be a bright glowing cloud. This is a dim glowing cloud. We have tried it in vacuum chambers and we see a green glow. There are a lot of unknowns about whether we'll really see it [in space]. If you take the black background of space, the white blankets on the surface of the Mir and you're back-lighting this whole thing from behind you with sunlight, the question is whether the fluorescence of the gas will be bright enough to [see]. There's some thought that this gas might actually glow a little bit at night and so we're going to see what we can see." Finally, Discovery will move to a point directly above the station where its maneuvering jets will be fired to move away "and we'll be saying goodbye to Mir for the last time in the shuttle Mir program," Dye said. Where is the antimatter? And where is the missing mass? The remainder of Discovery's flight will be devoted to operations with the Alpha Magnetic Spectrometer, or AMS, payload. The goal of the experiment for Discovery's flight is to test the hardware, data storage and command and control techniques needed for long-duration operations aboard the international space station. The instrument will be commanded from the ground, but the crew will back up its data on board the shuttle. The AMS is designed to detect antimatter left over from the big bang - assuming there is any - and particles resulting from collisions between other particles making up what is known as dark matter. It does this by using a six-ton magnet, which bends the trajectories of charged particles as they pass through. Analysis of the resulting trajectories allows scientists to determine the nature of the particles themselves. By studying the rotational velocity of stars in distant galaxies and the motion of huge galactic clusters, astronomers have determined there is much less observable mass in the universe than what is required to generate the observed velocities. The mass required to explain the high velocities is 10 times greater than what is actually observed. "And that means 90 percent of the universe is not observable," said Ting, who shared the Nobel Prize with Burton Richter in 1976 for discovery of a subatomic particle crucial to quark theory. "Because it is not observable, that's why it is called 'dark matter.' And so the collision of dark matter [particles] can produced positrons, anti protons and gamma rays, which can be detected by AMS." For those of you interested in particle physics, Ting's machine is looking for byproducts produced when supersymmetric WIMPS - weakly interacting massive particles - called photinos in the galactic halo annihilate. Such particles are a feature of supersymmetry theories that attempt to unify gravity with the other three fundamental forces of nature. Such particles presumably were created in the big bang and the lightest of them should remain today in large enough numbers to account for the missing mass. "In our low-energy universe today, the lightest supersymmetric particle should still survive," writes astronomer Joseph Silk in "A Short History of the Universe. "It is expected to be the partner, in the sense of having a complementary spin, of the photon, and is therefore known as the photino. Its mass is expected to be 10 to 100 times that of the proton. The photino is uncharged and interacts very weakly with matter." The AMS instrument also will look for signs of antimatter, an issue with equally profound implications. "If the universe came from a big bang, at the beginning there must have been an equal amount of matter and antimatter," Ting said. "The question is, after 15 billion years, where is the universe made out of antimatter?" Few physicists would expect the AMS to detect any antiatoms because of two problems, one observational and one theoretical. On the observational front, if antimatter existed in today's universe the interfaces between regions of normal matter and antimatter would be zones of annihilation, producing high-energy gamma rays. No such radiation from matter-antimatter annihilation is observed. On the theorectical front, most physicists believe the antimatter question was settled in the first ten-to-the-minus 35th second of the big bang when the pressure and temperature were extreme enough to generate X bosons, particles that can cause protons to decay. Here's a brief explanation from "The Left Hand of Creation" by John D. Barrow and Joseph Silk: When the universe was about 10-to-the-minus-35 seconds old, X particles along with their antiparticles would have been profusely produced in equal numbers, so high was the temperature of the universe. A few moments later, the X and anti-X particles began to decay into quarks and leptons by the same process that causes protons to decay. However, the decay rates of the X and the anti-X are different, and the result is that equal numbers of X and anti-X particles can decay into unequal numbers of quarks and antiquarks. Later, as the universe cooled, these quarks matched up in triplets to form protons and antiprotons. The excess of quarks over antiquarks eventually manifested itself as an excess of protons over antiprotons. Annihilation between protons and antiprotons followed. "There is plenty of theoretical speculation on the disappearance of antimatter," Ting said. "If you assume there is a strong time reversal violation and if you also assume something called baryon number violation - namely, proton decay - then both the grand unified theory and the electroweak theory can explain why the antimatter universe disappears. But the same theories also predict magnetic monopoles, neutrinos with mass and none of them has been seen. In addition, both a time reversal violation and proton decay have not been observed on Earth." The question for Ting, then, is "where is the universe made out of antimatter that emits antinuclei such as antihelium or anticarbon? If anti universe exists, we should be able to detect antihelium and anticarbon as they travel through the galaxy near Earth. They cannot be detected on Earth because matter and antimatter will annihilate in the atmosphere." Using a six-ton magnet and a super sensitive detector, the AMS is 1,000 to 10,000 times more sensitive than balloon-borne antimatter detectors, capable of detecting one antiatom in 10 billion normal atoms. And detecting just one antiatom would be enough to upset currently held theories about the birth of the universe. But Ting said the goal of Discovery's mission is much more limited: To test the experiment under flight conditions before it is installed aboard the international space station. Analysis of AMS data will take quite a bit of time and real-time observations are not expected. While one cannot rule out the possibility of major discovery during Discovery's flight, don't hold your breath. The data analysis will be difficult and Ting is a notoriously cautious experimenter. =================================================================== Shuttle crew arrives; cosmonauts troubleshoot Mir glitch (05/30/98) 4:00 p.m. Update: Mir loses attitude control; crew in dark As NASA engineers geared up to start the shuttle Discovery's countdown to launch Tuesday on a flight to the Mir space station, the crew aboard the Russian outpost today was forced to shut down critical systems after an apparent software glitch caused its attitude control system computer to crash. Unable to automatically aim the station's solar arrays at the sun, the crew was forced to shut down Mir's stabilizing gyrodynes, causing the outpost to slowly drift out of its normal orientation. The cosmonauts also turned off Mir's air conditioning system, shut down its primary oxygen generator and turned off most of its lights to conserve power. On-board batteries are keeping critical refrigerators running to preserve biological experiment samples and to keep Mir's primary carbon dioxide removal system operating. NASA spokesman Kyle Herring in Moscow told reporters via a teleconference late today that Russian flight controllers believe the problem was caused by a software glitch and not a hardware failure. The computer in question was put through a self test shortly after the failure occurred and one of its three channels showed signs of problems. It should operate normally after rebooting. To be on the safe side, the crew's Soyuz entry vehicle has been powered up as has a Progress resupply ship. If the station drifts too far out of alignment, the Soyuz's jets likely will be used to move Mir back into the proper orientation to ensure good battery charging. In addition, at least one crew member will be up throughout the night to monitor Mir's systems. This sort of problem happened several times last year because of computer hardware failures and it typically took the crew up to 48 hours to recover. The last such failure occurred in early January. In this case, Herring said, the cosmonauts plan to reboot the motion control system computer early Sunday and if all goes as expected, the station should be back in its normal operating configuration by around 5 p.m. EDT Sunday. If so, the glitch will have no impact on plans to launch Discovery. Finally, some readers might recall that a new motion control system computer was launched to Mir aboard a space shuttle last year because of earlier problems. That computer remains in stowage aboard Mir, ready for use if necessary. Again, flight controllers do not anticipate any problems restarting the computer that crashed today. 1 p.m. Update: Shuttle crew arrives for blastoff The shuttle Discovery's four-man two-woman crew flew from Houston to the Kennedy Space Center today for the start of their countdown to blastoff Tuesday on NASA's final flight to the Russian Mir space station. Arriving in T-38 jet trainers, the astronauts touched down on the shuttle runway just before 1 p.m. The countdown was scheduled to begin at 9 p.m. and if all goes well, Discovery will take off on the 91st shuttle mission at 6:10:03 p.m. Tuesday. "We're really happy to be here," commander Charles Precourt told reporters. "I'm here to tell you, I have a crew that's more than ready for this mission. We're very excited about it. We've been talking to the crew on Mir and they're ready for us to come see them. I think we got the bad weather out of the way for today and with any good luck, we'll be having some good weather on launch day." Forecasters are predicting a 60 percent chance of acceptable weather Tuesday with the main concern being the possibility of thunderstorms in the launch area. The primary objective of the 91st shuttle mission is to pick up astronaut Andrew Thomas, who is wrapping up a 140-day stay in space. "Andy is more than ready to come home," Precourt said. "We talked with him via video teleconference the day before yesterday and the three of them looked, very, very good, they're in great spirits and really excited to see us." =================================================================== Mir computer replaced; problems continue (05/31/98) 7:40 p.m. Update: Replacement computer fails to operate properly A replacement control computer installed aboard the Mir space station today after a malfunction Saturday either is not working properly or is the victim of a malfunction somewhere else in the system. The computer is needed to keep Mir properly oriented toward the sun and if the problem is not resolved - or at least understood - by midday Monday, NASA likely will be forced to delay the shuttle Discovery's planned launch Tuesday on the agency's final Mir docking mission. The motion control computer that had been controlling Mir's attitude, or orientation, malfunctioned Saturday. After a bit of troubleshooting, Mir-25 commander Talgat Musabayev and flight engineer Nikolai Budarin installed a brand new replacement computer early today. During subsequent passes over Russian ground stations, flight controllers uplinked the navigation software necessary to keep Mir in a stable, sun-pointing attitude. After the software was uplinked, however, neither the crew nor ground controllers saw an expected indication from the computer that it was ready to run. The software was uplinked a second time during two subsequent ground passes. But again, the computer indicated it was not ready to operate. "They cannot get the computer restarted," said NASA spokesman Rob Navias. "In the last two comm passes of the day, the flight controllers uplinked all the attitude data again and got the same 'check motion control system' and they did not get the 'ready to execute' light." It was not immediately clear what might be the problem. "They're scratching their heads," Navias said. "They do not have a real answer at this point. It was suggested the problem may not be with the computer but with another avionics box that routes commanding through the Kvant 2 module." Unlike earlier motion control system failures experienced by Mir last year and in January, the failure Saturday did not cause the station to drift very far away from its normal orientation. Navias said power margins remain positive, meaning Mir's solar arrays continue to generate enough electricity for critical systems even though the station is not under active attitude control. "The plan is they'll start over from scratch in the morning," Navias said. Musabayev, Budarin and U.S. astronaut Andrew Thomas have gone to bed. The first communications pass tomorrow morning is expected around 2 a.m. EDT. The first chance flight controllers will have to study additional telemetry from Mir will be around 4 a.m. While engineers at the Kennedy Space Center are continuing to press ahead with Discovery's countdown to blastoff Tuesday on NASA's final flight to the Mir, the problem with the motion control system must be resolved before the shuttle will be cleared for flight. NASA's mission management team is scheduled to meet at 10 a.m. Monday and if Russian flight controllers do not have a solution in hand by that point, Discovery's countdown likely will be put on hold until the issue is resolved. Discovery must be off the ground by June 7 or the flight will be delayed until June 11, after a commercial Delta rocket launch on June 9. In the meantime, Mir's crew is in no danger. The station has plenty of power for its major life support systems and a Soyuz entry vehicle is available if some other failure forced the crew to abandon ship. This status report will be updated Monday as more information becomes available. 3:30 p.m. Update: Mir computer checkout takes longer than expected Flight controllers have uplinked five required software updates to enable a replacement motion control computer aboard the Mir space station to resume automatic control of the lab's orientation using on-board jet thrusters. Neither ground controllers nor the crew saw an expected indication from the computer that it was ready to proceed, but NASA spokesman Kyle Herring says the cosmonauts have been ordered to press ahead with normal activation. "Unfortunately, the computer never showed a signal [the software] was ready to be executed," Herring said by telephone from the Russian control center. "But the ground believes everything is loaded on board so they're pressing on. They're going to keep the crew up for another couple of orbits to continue to watch it [during passes over Russian ground stations]. They're hoping they can get on the attitude jets before they put the crew to bed." If all goes well, Mir will be back under automatic jet control later this evening and on Monday, the cosmonauts will re-activate the station's electrically driven gyrodynes to complete the repair. U.S. astronaut Andrew Thomas, meanwhile, told U.S. officials in Moscow that he was "not concerned about the situation up here. I'm watching it more with spectator curiosity than any concern." "I've been keeping a low profile up here," he said in a statement released by NASA. "Talgat [Musabayev] and Nikolai [Budarin] have been in the base block taking care of it." U.S. officials said earlier Thomas was a bit nervous about the status of Discovery's planned launch Tuesday on a flight to bring him home [see below for details]. But Thomas said later he was "very optimistic the computer problem will be resolved soon and that the STS-91 launch will occur on schedule." "The reports I'm hearing of the media saying I'm nervous are totally untrue," he said. "I feel good and look forward to seeing my family again." NASA had planned to stage a news conference with Thomas on Monday morning, but that conference is expected to be cancelled to avoid conflicts with the computer repair work. 11:30 a.m. Update: Mir computer replaced; shuttle countdown on track Cosmonauts aboard the Mir space station have replaced a suspect motion control computer with one carried up aboard a shuttle earlier this year and are in the process of reloading navitation software during passes over Russian ground stations. If all goes well, the new computer will begin controlling Mir's attitude, or orientation relative to the sun, by this evening U.S. time using jet thrusters. Frank Culbertson, NASA directory of shuttle-Mir operations, said the new computer appears to be working properly and that the cosmonauts hope to reactivate stabilizing gyrodynes by tomorrow morning. That will put Mir back in its normal operating configuration, clearing the way for the shuttle Discovery to blast off Tuesday on NASA's final Mir docking mission. U.S. astronaut Andrew Thomas, who's wrapping up a 140-day stay in space, took Mir's latest failure in stride, officials said, but expressed a bit of concern about whether his ride home would show up on time. "He's a little nervous, but no more so than I think anybody would be when your ride looks like it could be impacted," said Scott Gahring, a NASA's flight controller in Moscow. "He's just been asking some questions about how we feel about the strategy and we've been explaining it to him. ... He just wants to make sure he understands it." Mir's motion control computer shut down Saturday morning, the first such failure since January. Whenever that happens, the station cannot automatically maintain an orientation that allows its solar arrays to track the sun for power generation. In past failures of this sort, Mir has not always had suffient battery reserves to enable an orderly gyrodyne spin down. In those cases, the spinning gyrodynes have stopped suddenly, putting a torque on the station that caused it to quickly lose lock on the sun. This time, however, Mir had good battery reserves and the gyrodynes were shut down slowly. As a result, the station never drifted too far out of its normal attitude and the cosmonauts have not had to use their Soyuz entry vehicle's jets to regain attitude. Even so, the crew shut down the station's primary oxygen generator and its air conditioner Saturday to conserve power until automatic control was restored. Flight controllers initially thought the problem was the result of an overloaded CPU and the crew was asked to reboot the computer early today. "Their plan was to repower the computer early this morning our time, go through a short test and then start rebuildling the nav base, reloading the software," Culbertson said. "About three minutes after they did the short test, which passed, they had a hardware alert again on it so they decided maybe they really did have a hardware problem. So they shut it down and told the crew to go ahead and put the spare in. The spare they installed was taken up on STS-89, it's a brand new one. They have another spare in addition to that on board, a refurbished one." The Russians can reload navigation software only when Mir passes over Russian ground stations. Culbertson said it would take to to three 90-minute orbits to load the initial update, which will enable the computer to use Mir's jets to maintain normal attitude control. "Once they complete that, they'll reset everything and get back on jet control, probably by tonight our time," he said. "Then tomorrow morning, early our time, they expect to get the gyrodynes spinning back up." At the Kennedy Space Center, meanwhile, engineers are pressing ahead with Discovery's countdown to blastoff Tuesday at 6:10:03 p.m. NASA test director Doug Lyons said there are no technical problems at pad 39A and forecasters are now predicting a zero percent chance of bad weather Tuesday or Wednesday. NASA's mission management team will meet at 10 a.m. Monday to assess the shuttle's readiness to launch and the status of Mir's computer system. Discovery will not be cleared for flight unless Mir is under active attitude control or engineers have reason to believe it will be under control by the time docking takes place. This status report will be updated later today as more information becomes available. 8:00 a.m. Update: Mir computer restart fails; crew to install replacement The crew aboard the Mir space station restarted the lab's motion control computer this morning after a failure Saturday, but the computer shut down again about two minutes later, leading flight controllers to suspect a hardware problem of some sort. The crew received permission to install a replacement computer during a communications pass shortly before 8 a.m. EDT. The computer, which helps keep Mir's solar arrays oriented toward the sun for battery charging and normal power generation, shut down Saturday morning. The crew then had to shut down Mir's stabilizing gyrodynes, its primary oxygen generator, the air conditioning system and most of the statin's lights to conserve power. At the same time, they powered up their Soyuz entry vehicle and a Progress resupply ship. Engineers initially thought the trouble was caused by a software glitch and that everything should be back to normal after a restart today. They were wrong. "They attempted to restart the computer earlier this morning," said NASA spokesman Kyle Herring reached by telephone in Moscow. "It ran about two minutes and then shut down. So now they think they may have a hardware problem rather than software." Herring said engineers believe the problem involves either the computer itself or by a device called a mode control unit. The latter is difficult to reach, however, "and it would take some time to change out," Herring said. So the crew was ordered to begin by replacing the motion control computer. There is one brand new computer on board ferried up aboard an earlier shuttle mission and another unit that had problems last year. Herring said he assumed the crew would install the new machine, but details remain a bit sketchy. It's too soon to say whether this issue will have any impact on NASA's plans to launch the shuttle Discovery Tuesday on the agency's final flight to Mir. Assuming the computer swap-out fixes the problem aboard the station, Discovery should be able to take off on time. A shuttle status report is scheduled for 9 a.m. on NASA television. A Mir updated is expected around 10 a.m. This status report will be updated after both events. =================================================================== Cosmonauts repair computer system (06/01/98) 4 p.m. Update: Mir back under attitude control Mir-25 commander Talgat Musabayev and flight engineer Nikolai Budarin successfully re-activated the Mir station's attitude control system today, switching to a backup motion sensor that appears to be working properly. The station's attitude, or orientation, currently is being maintained by periodic jet firings but if all goes well, the cosmonauts will re-activate Mir's more precise, electrically driven gyrodynes Tuesday to complete the last-minute repair. Barring additional failures, NASA managers are expected to clear the shuttle Discovery for blastoff as planned Tuesday at 6:10:03 p.m. on the agency's final visit to the Russian outpost. "We're ready. It's readlly been an incredible journery, an incredible sequence of events that has exceeded our original wildest imagination," shuttle program manager said of the shuttle-Mir program. "I think it's been an unqualified success." U.S. astronaut Andrew Thomas, laughing and in good spirits as he wraps up a four-and-a-half-month stay aboard Mir, told NASA controllers today "everything's fine up here, no show stoppers. It's kind of quite, kind of dull." Boris Sotnikov, acting manager of the shuttle-Mir program for Rocket Space Corporation Energia, said problems with Mir's motion control system - MCS - were resolved today by switching to a backup rate sensor, a device that measures the station's movement in space. "We all know that unfortunately, off-nominal situations do occur and one of these situations happened just this Saturday when our MCS computer malfunctioned," Sotnikov said through an interpreter. "First, we thought that software was malfunctioning. Our people back at mission control-Moscow were working around the clock and they found out the problem was not associated with a software malfunction." Instead, the Mir crew was ordered to replace the MCS computer. They did that Sunday, but the system failed to indicate it was ready to proceed after receiving navigation data from the ground. "We managed to check every single system that participates in the process of motion control, we've isolated the issue and more than likely this issue has to do with the angular velocity determination system," Sotnikov said. "We made several attempts to recover the attitude control of the station with the main system and after that we decided to use the backup system. "As of now I'm pleased to report to you that the attitude control was recovered," he said. "At this point we may say we are prepared to dock. At the same time, we still have to continue working several minor technical issues. But the main issue has been resolved and that's the most important thing." Asked whether it might make more sense to wait another day just to make sure the system would continue operating normally, Sotnikov said "the situation is basically under control and there is no reason to delay." "We've been flying the station for a long time, over 12 years now, and quite frankly similar situations have occurred in the past," he said. "We know how to recover attitude control. We're very confident. The situation is under contral, that's the bottom line. Rest assured, if there was any risk at all we definitely would have decided to slip the launch and wait until the situation was stable." And with that, engineers at the Kennedy Space Center are pressing ahead with plans to launch the shuttle on time Tuesday evening. Forecasters continue to predict a zero percent chance of bad weather and there are no technical problems of any significance at pad 39A. NASA's mission management team will meet around 8 a.m. Tuesday for a final assessment of both the shuttle's readines and Mir's health. Will advise. 1 p.m. Update: Mir computer finally initializes The MIr-25 cosmonauts successfully initialized the space station's motion control computer today after an earlier attempt resulted in an error message (see the 11 a.m. update below for details). NASA spokesman Kyle Herring said the computer appeared to be working normally, using a different rate sensor, and that the cosmonauts planned to attempt re-establishing automatic attitude, or orientation, control later this afternoon. A news conference with Frank Culbertson, dirctor of shuttle-Mir operations, is scheduled for 1:30 p.m. A pre-launch news briefing for the shuttle Discovery's flight to Mir is planned for 2:30 p.m. This status report will be updated after the briefings or as conditions warrant. 11 a.m. Update: Mir computer system still acting up Ground controllers have completed uplinking five packets of navigational software to a replacement motion control computer aboard the Mir space station. Despite earlier optimism the motion control system - MCS - would work properly this time around using a different rate sensor (see below for details), the computer sent another error message indicating a problem of some sort still exists. "They tried to reinitialize [the computer] and got an MCS message," said NASA spokesman Kyle Herring at the Russian flight control center near Moscow. "The computer itself appears to be working just fine. They're off looking at why they got the latest signature." With a fresh set of navigation software loaded into the motion control system computer, the cosmonauts were gearing up to hook the computer into the MCS to re-establish automatic control of Mir's orientation, or attitude, using the station's jet thrusters. But during a routine check to make sure all MCS equipment was working properly, the computer sent an error message indicating a problem still exists somewhere in the system. Earlier today, Herring said engineers suspected problems with a rate sensor used by the MCS had caused the system to malfunction over the weekend. By using a different rate sensor, the thinking went, the MCS would be able to work normally. But Herring said that switch was to have been made later in the MCS activation process and is not clear at this point what generated the error message. The bottom line: It's not yet known what might be wrong, what might be needed to finally correct the problem or whether the shuttle Discovery can be cleared for launch Tuesday on NASA's final planned visit to Mir. "They're still troubleshooting," Herring said of the Russian flight control team. Stay tuned! 8:15 a.m. Update: Cosmonauts switch to backup rate sensor It now appears problems with a motion sensor in the Kristall module of the Mir space station might have prevented a replacement control computer installed Sunday from working properly. Early today, Mir-25 commander Talgat Musabayev and flight engineer Nikolai Budarin tied the computer system to a different rate sensor in another module while ground controllers began reloading navigation software. The software is uplinked in five segments while Mir is over Russian ground stations and the first three sets were loaded into the computer successfully. After all the software is on board, the cosmonauts will attempt to restart Mir's motion control computer system. Based on data from the rate sensor, which determines Mir's orientation in space, the MCS sends commands to jet thrusters or spinning gyrodynes to keep the station properly positioned. But the MCS computer appeared to malfunction Saturday, throwing Mir into "free drift." As it turned out, the station never drifted very far from its normal position and the station's solar arrays were able to generate more than enough electricity for critical systems. But a healthy MCS is required for shuttle dockings and the failure Saturday happened just before NASA started the shuttle Discovery's countdown to launch Tuesday on the agency's final flight to Mir. Figuring the main MCS computer was at fault, the cosmonauts were ordered to install a replacement Sunday that was carried up earlier this year aboard a space shuttle. Despite two attempts, the new computer never indicated it had received the necessary navigation software and the crew went to bed with Mir still in free drift. NASA spokesman Kyle Herring at the Russian mission control center near Moscow said early today engineers now believe a problem with the "omega" rate sensor in the Kristall module, the one tied into the MCS, might have prevented the replacement computer from accepting the uplinked navigation software. The cosmonauts switched to the "ort" rate sensor in the Kvant-1 module today in a bid to resolve the issue. While the ort sensor does not provide the level of precision the omega does, it's well within the limits needed for a space shuttle docking. If all goes well, Mir could be back under automatic control by this afternoon using the station's rocket thrusters to maintain attitude, or orientation. Mir's stabilizing gyrodynes then will be spun back up to complete the repair procedure. For the curious, the shuttle can dock with Mir with the station in jet control mode or gyro control mode. Once docked, the shuttle's jets provide most of the stabilization required by both vehicles. NASA engineers, meanwhile, are pressing ahead with the shuttle Discovery's countdown to blastoff Tuesday at 6:10:03 p.m. NASA's mission management team meets at 10 a.m. to assess Discovery's readiness and the health of the Mir station. This status report will be updated as information becomes available. =================================================================== Shuttle Discovery rockets into orbit on final Mir mission (06/02/98) 10:45 p.m. Update: Astronauts troubleshoot KU-band communications problem The Discovery astronauts ran into problems with the shuttle's high-speed KU-band communications system shortly after the antenna was deployed. The antenna relays high-speed data, television and voice communications to the ground through NASA's Tracking and Data Relay Satellite system. It also acts as a tracking radar during orbital rendezvous procedures. During activation this evening, the system appeared to work normally in radar mode, but it did not operate in normal communications mode. Commander Charles Precourt turned the system off and back on again in hopes of restoring normal operation. But that did not resolve the problem and flight controllers were forced to go back to the drawing board. It's not yet clear what impact the possible loss of KU-band communications might have on Discovery's mission to dock with the Mir space station Thursday beyond the obvious loss of normal television from the orbiter (television would still be possible during passes over U.S. ground stations). The antenna apparently will work in radar mode, which is used during the terminal phase of rendezvous and docking. Discovery's major payload, a high-energy particle physics instrument, was designed to use the KU-band system to relay 100 hours of data to the ground for realtime analysis. As a backup, that data also will be recorded on board the shuttle. If the KU-band system cannot be recovered, the only loss would be realtime analysis. The data would be preserved on board for post-flight analysis. NASA spokesman Ed Campion in mission control said engineers would continue troubleshooting the problem overnight. This status report will be updated as more information becomes available. 7:45 p.m. Update: Shuttle Discovery rockets into orbit It's main engines roaring with power, the shuttle Discovery's solid-fuel boosters ignited with a flash of fire and thunder at 6:06:24 p.m. today, kicking off NASA's ninth and final flight to the Russian Mir space station. The only anomalies in an otherwise picture-perfect ascent were a main engine sensor failure 20 seconds after liftoff and two steering jet failures shortly after reaching orbit. Neither problem is expected to have any impact on the mission. Liftoff of the 91st shuttle mission came at the opening of a short eight-minute launch window after a near-flawless countdown. "I'd like to say thanks to the team that put this flight together," commander Charles Precourt said two minutes before liftoff. "As we head uphill into space we aim to make you proud and bring our good friend Andy home." He was referring to Australian-born NASA astronaut Andrew Thomas, launched to the Mir station in January. Thomas is the seventh and final U.S. astronaut to visit Mir and with an on-time landing June 12, he will have logged 140 days in space, pushing the total for American fliers to 977 days. The previous American space duration mark was 84 days. Discovery's fiery ascent marked the sixth on-time Mir docking mission in a row for the shuttle program. Eight-and-a-half minutes after liftoff, the shuttle slipped into a preliminary elliptical orbit with a low point, or perigee, of just 40 miles. A rocket firing about 43 minutes after launch raised the perigee and put the spacecraft in an orbit measuring 204 by 149 statute miles as Discovery's crew set off after the Mir station. "We'd like to welcome the new folks, Janet [Kavandi] and Dom [Gorie], to orbit," astronaut Scott Horowitz radioed from Houston. "Thank you very much," Precourt replied. "Everybody's doing great and the vehicle's just doing outstanding." "Copy all, Discovery, and it was quite a show." This was the first flight of a new super lightweight external fuel tank made of aluminium-lithium alloy. The $43 million tank weighs 7,500 pounds less than earlier tanks, which will allow shuttles to carry additional cargo to orbit during space station assembly in the years ahead. Despite weld cracks and other problems encountered during early development, the new tank appeared to perform flawlessly during today's ascent. "The tank worked as we expected," said Don McMonagle, chairman of NASA's mission management team. "Anytime you're flying a new piece of equipment people will, of course, give it a little extra attention and all of us, I think, breathed a sigh of relief [after launch]. We all feel good about the performance of the tank." While the new tank cost about $8 million more per copy than the tank it replaces, McMonagle said the additional payload capability is worth the additional cost. "From a program perspective, the 7,500 pounds of performance [we gain] everytime we use this tank is money in the bank in terms of being able to satisfy our customer needs," he said. "And our biggest customer is the international space station and they're the ones who need it worst." Shortly after reaching orbit, the tank was jettisoned to burn up in the atmosphere, putting on a bit of a show for Discovery's crew as it tumbled back toward Earth. "The tank was spinning at a good rate, about a degree per second, about the speed of the second hand in a clock," astronaut Franklin Chang-Diaz told ground controllers after the tank separated and fell back toward Earth. "And there was a lot of venting from what appeared to be relief valves ... in the mid body of the tank. A very, very large plume at various moments, sometimes continuously." The goals of the flight are to bring Thomas back to Earth; to deliver 3,500 pounds of water, science gear and other equipment to Mir; and to bring home another 2,500 pounds of mostly American equipment and experiment samples. See the STS-91 Mission Archive for a detailed overview of Discovery's flight. 6 p.m. Update: Launch time adjusted NASA has decided to launch Discovery at the opening of its launch window, in part because of a possible hydraulic problem with the launch gantry's orbiter access arm. By moving the launch time up, a brief hold could be tolerated before the end of the window. The new launch time is 6:06:24 p.m. 4 p.m. Update: Revised launch window Based on radar tracking of the Mir space station, NASA engineers have revised the shuttle Discovery's launch window. The window opens at 6:06:24 p.m. and closes at 6:14:02 p.m. But the preferred launch time, that is, the one requiring the least amount of fuel for a Mir rendezvous, is 6:09:02 p.m., one minute and one second earlier than originally planned. There are no technical problems of any significance at pad 39A and while it's hotter than usual today - 95 degrees at the pad - the weather appears ideal. This status report will be updated after launch or as conditions warrant. 1:10 p.m. Update: Shuttle Discovery fueled for blastoff Engineers have loaded the shuttle Discovery's new lightweight tank with its full half-million-gallon load of rocket fuel, setting the stage for blastoff this evening at 6:10 p.m. on NASA's final flight to the Russian Mir space station. The start of fueling was delayed about 15 minutes after a circuit breaker tripped following activation of a heater used by one of the shuttle's on-board oxygen tanks. Troubleshooting indicates no short circuits or other major problems and while engineers continue to troubleshooting, no impact on launch is expected. Discovery's four-man two-woman crew sat down for a brief lunch/photo opportunity at 1:09 p.m. before donning their pressure suits and heading for pad 39A. Boarding is scheduled to begin at 2;50 p.m. In the meantime, there are no other technical problems of any significance and forecasters continue to predict ideal weather for this evening's launch attempt. 9:35 a.m. Update: Shuttle Discovery cleared for fueling Running a few minutes behind schedule, engineers were cleared to begin pumping a half-million gallons of rocket fuel into the shuttle Discovery's external tank around 9:30 a.m. after troubleshooting a possible electrical problem aboard the orbiter. While the issue is not fully resolved as of this writing, engineers were given the go ahead to begin fueling in order to preserve today's launch opportunity at 6:10 p.m. Additional details will be posted when they become available. 09:10 a.m. Update: Engineers troubleshoot shuttle electrical glitch; Mir back in normal operation With the Mir space station's control computer back in operation, engineers at the Kennedy Space Center are working their own problem this morning as they ready the shuttle Discovery for blastoff this evening on NASA's final flight to the Russian outpost. An electrical current sensor on one of Discovery's internal liquid oxygen tanks tripped off this morning when a heater system was activated, indicating a possible short circuit. Engineers had planned to begin pumping a half-million gallons of rocket fuel aboard Discovery's external tank at 9:14 a.m., setting up a launch attempt at 6:10 p.m. But fueling was put on hold this morning until the electrical issue is resolved. Because Discovery has a short, 10-minute launch window, the team only has about an hour to an hour and a half to begin fueling or the flight will have to be delayed. Will advise. Mir's three-man crew, meanwhile, is readying the space station for Discovery's arrival Thursday. U.S. astronaut Andrew Thomas, a Mir crew member since January, said today's he's packed and looking forward to his first Earth meal in 140 days, asking ground controllers for a serving of lasagna and Oreo ice cream. "He seems pretty happy, doing well," said a NASA spokesman at the Russian mission control center near Moscow. Thomas's Russian crewmates coaxed a balky motion control system - MCS - back into operation Monday, two days after a computer failure that left the space station slowly drifting in space. The cosmonauts re-established motion control Monday, using a replacement computer to control Mir's attitude control jets, and early today, they began activating more precise spinning gyrodynes to complete the repair. As of 7:30 a.m. EDT, six gyrodynes - three in the Kvant 1 module and three in Kvant 2 - were back in operation and another five were expected to be running by 11 a.m. or so. Russian engineers now believe the original problem may have been caused by a faulty electronics box associated with Mir's "omega" rate sensor, a device that updates the computer on Mir's orientation in space. The cosmonauts switched to a backup "ort" rate sensor Monday, but engineers say the omega sensor might work just fine using a secondary electronics package. Troubleshooting continues. At the Kennedy Space Center, meanwhile, forecasters continue to predict ideal weather for tonight's launch attempt at 6:10:03 p.m., assuming they can clear up the electrical glitch and begin fueling operations. Fueling is a routine procedure, but for Discovery's flight a new tank is being used for the first time, an aluminum-lithium structure that weighs 7,500 pounds less than earlier models. The lightweight tanks are needed for upcoming space station assembly flights carrying heavy components to orbit and today's launch marks the new tank's debut. NASA and its contractor, Lockheed Martin, ran into major problems with weld cracks in the lithium-alumininum material during development of the new design, but engineers say the new tank is crack free and ready for flight. The shuttle-Mir launch window opens each day just before Earth's rotation carries the launch pad into the plane of Mir's orbit. The preferred launch time, the one that requires the least amount of fuel to reach Mir, is five minutes after the actual opening of the window. Discovery's countdown is timed to the opening of the launch window, that is, the final 40-minute hold at the T-minus nine-minute mark, will be set up as if the shuttle was launching at 6:05 p.m. Assuming no problems develop, however, that final hold will be extended to permit a liftoff at the preferred launch time of 6:10:03 p.m. Here is a timeline of today's countdown activity: 09:15 a.m....Fueling begins 01:09 p.m....Crew lunch/photo opportunity on NASA television 02:20 p.m....The astronauts leave crew quarters 02:50 p.m....The crew begins strapping in aboard Discovery 04:55 p.m....T-20 hold begins (10 minutes) 05:05 p.m....Countdown resumes 05:16 p.m....T-9 hold begins (40 minutes) 06:01 p.m....Countdown resumes 06:10 p.m....Discovery blasts off The goals of the 91st shuttle flight are to bring Thomas back to Earth; deliver supplies, equipment and fresh water to the Mir; and to return U.S. science gear to Earth. The astronauts also plan to operate a high energy particle physics experiment for 100 hours during the mission to look for atoms of antimatter and particles created in the collisions of theorized massive particles that make up 90 percent of the mass in the universe. See the CBS News STS-91 mission preview for a detailed overview of Discovery's flight. This evening's launch is timed to set up a docking with Mir at 12:59 p.m. Thursday. Once hatches between the two vehicles are opened, Thomas will officially become a member of Discovery's crew. Undocking is scheduled for June 8 and if all goes well, Discovery will land at the Kennedy Space Center around 2:03 p.m. on June 12. =================================================================== KU-band antenna failure eliminates shuttle television (06/03/98) 5 p.m. Update: KU-band antenna fix debated NASA engineers are working on two approaches for hotwiring circuitry aboard the shuttle Discovery to restore high-speed data downlink - and television - capability in the wake of problems that have knocked the orbiter's KU-band antenna system out of action. Lee Briscoe, a mission operations representative at the Johnson Space Center in Houston, said the KU-band system works fine in radar mode and it's able to receive commands and data from the ground. But the system that sends high-speed data, voice and telemetry back to Earth is not working. The shuttle can dock with Mir on Thursday whether the KU-band system works or not. But the current problem is preventing the shuttle from downlinking television except during infrequent passes over U.S. ground stations. Briscoe said analysis of telemetry shows commands to turn on the KU-band downlink transmitter result in about a one-second burst of data. The transmitter then stops. Engineers are not sure what is wrong, but it might be possible for the astronauts to install jumper cables that would provide an independent power source to the circuit used to activate the transmitter. Briscoe said engineers are still troubleshooting and no repair attempt will be made until after Discovery docks with the Mir space station Thursday. That's because the astronauts want to use the KU-band antenna in radar mode during final approach to Mir and no one wants to do anything in the meantime that could cause additional problems. The Alpha Magnetic Spectrometer, a particle physics experiment in Discovery's cargo bay, was designed to downlink its engineering and science data through the KU-band system and to use on-board disk drives as a backup. While the backup system is working normally, scientists are not able to look at high-rate data from the $33 million experiment in real time to calibrate the system. Briscoe said engineers have devised a plan to route that data through the shuttle's FM downlink system for transmission to the ground during passes over U.S. ground stations. The only other problem of any significance is a leaky valve allowing water produced by one of the shuttle's electrical generators to be dumped overboard (see the 8 a.m. update below for details). Briscoe said the leak, which was known about before launch, amounted to about four pounds of water per hour at normal pressure levels. Today, the pressure in the system was dropped to just five pounds above crew cabin pressure and the leak rate was cut in half. The astronauts originally planned to deliver 12 to 13 100-pound bags of water to the Mir station. A four-pound-per-hour leak would have cut that total by 200 to 300 pounds. Because the leak rate has been reduced today, the actual shortfall will be less than that and it's not considered a major impact. 4 p.m. Update: Astronauts describe mission, merits of Mir visits Apollo astronaut Tom Stafford, who commanded the first U.S.-Russian space mission in 1975, called Discovery commander Charles Precourt today to congratulate the shuttle crew on their mission to dock with the Russian Mir space station tomorrow. Discovery's flight marks the ninth and final shuttle-Mir docking mission in what NASA calls phase one of the international space station program. Phase two is the assembly of the new station using lessons learned from the shuttle-Mir program. "You're doing a tremendous job up there," Stafford called during a Sci-Fi Channel interview. "General Stafford, great to hear from you," Precourt replied. "We appreciate your support in standing behind us. We're having a blast up here, we're ready to go tomorrow." Stafford said members of a commission he heads to evaluate NASA's space station plans are "upbeat about the progress you're making in closing out phase one and we're looking forward to resolving issues with phase two. Everybody is very upbeat about the flight you're flying." Russian cosmonaut Valery Ryumin, who last flew in space nearly 20 years ago, told Stafford "everything is going well" and that "I feel the same as I did so long ago. The view from here is magnificent, when I look out the windows I am impressed with the view of our Earth the same way I was 20 years ago." Ryumin, director of shuttle-Mir operations in Russia, is on board Discovery to conduct a personal inspection of the aging Mir space station to identify problems that might affect the international space station. Asked to describe his impressions of launch aboard the space shuttle, Ryumin said it was difficult to compare his flights in the 1970s with the current mission. "Of course I've forgotten all the details of how it feels, but it seems to me that at the end of the orbital insertion it appeared as if some of the feelings were a little different from the Soyuz. But then again, it's been a long time since I've flown on the Soyuz. ... It may very well be it's somewhat more difficult for me to withstand the stresses than it was 20 years ago." The goal of Discovery's mission is to bring U.S. astronaut Andrew Thomas back to Earth after 140 days in space. Given all the problems Mir has had over the past year or so, an interviewer asked Precourt if he viewed the current flight as a rescue mission of sorts. "I don't see it as a rescue mission," Precourt said. "We're really proud to be bringing Andy home and it's been a great program. Phase one through thick and thin has been extremely successful, probably moreso than anybody would have expected, even those of use who worked real closely in the program. Things are going really well for us. When things fail, we fix them and that's what we're learning the most out of this phase one program, that if you're going to live a long time in space you've got to be able to fix it as you go, you can't come home to fix it on the ground." In spaceflight, Lawrence said, "there are always situations we just can't anticipate so we need to be prepared to learn as we go. If we aren't learning lessons as we go, then I don't think we're going to be as successful as we could possibly be." Stafford agreed and compared the lessons learned from the phase one program to those in the Gemini program that paved the way to the Apollo moon landings. "A lot of people wanted to go from Mercury to Apollo and not have Gemini," he said. "But without Gemini, Apollo would have had major, major problems. The wonderful work that's being done here on phase one definitely leads us into phase two. We don't know all the answers, but what you've done sure puts us a long way down the road to help solve all the problems and work together to a successful ending." Precourt said Discovery's rendezvous and docking "will be nostalgic in that the Mir has been in space for 12 years and we were able to join them in the work that they do in space. And knowing our last docking is the beginning of the end for that space station is nostalgic because we won't be able to go back to it and we'll have to move on. "It's really a stepping stone for us into the next era," he added. "And there's always nostalgia when you leave one and go to the next and there certainly will be a lot of that when we close the hatch this time. It's been a great, great program. I've said it many times and I'll say it again, we've learned far more than we ever could have expected and it's been well worth the trials and tribulations. We're looking forward to bringing Andy home and jumping off into phase two of the international space station." 10:30 a.m. Update: Thomas elated with shuttle launch NASA astronaut Andrew Thomas, wrapping up a 180-day stay aboard Mir, told NASA flight controllers near Moscow he is elated with the news of Discovery's on-time launch. He was informed of the liftoff around 2 a.m. EDT today. Here's a transcript of a conversation between Thomas and operations lead Christine Chiodo: AT: Andy's up. What's new? CC: You have company in orbit! AT: Oh, excellent! CC: Yeah, launch went really well. We just got here and spoke with the shuttle team. They're working a couple of items, but nothing that would impact rendezvous. We'll get you more info. AT: Okay, so the super lightweight tank performed fine? And launch was nominal? CC: Yeah, it was really pretty. We watched it last night. All is well. AT: You're a saint to get on the comm and tell me that. That's definitely going to make the next few days interesting for me. CC: Yep. For us too. 10 a.m. Update: Space Reporter's Handbook posted The CBS News Space Reporter's Handbook, a compendium of mission-specific data, up-to-date statistics and shuttle program background, is now online in Adobe Acrobat format for downloading. This 2.2-megabyte file is available in Stuffit and WinZip archives for Macintosh and Windows 95 users. The SRH originally was intended to serve as a handy source of useful information for writers, correspondents and producers and as such, internet readers might find it useful. Comments, suggestions and corrections welcome! 8 a.m. Update: KU-band communications link down; crew awake The Discovery astronauts were awakened on schedule shortly after 7 a.m. this morning and told that flight controllers have not yet figured out what can be done to fix the shuttle's high-speed KU-band communications system. The KU-band system works in two modes, acting as a television/data relay antenna or as a radar for use during rendezvous procedures. The radar rendezvous system is working normally, but an on-off circuit in the KU-band electronics apparently is not sending the proper commands to the antenna to enable normal communications. The system can, however, receive commands and data from the ground. If the KU-band problem cannot be fixed, there will be virtually no television from Discovery for the duration of the flight. In addition, the shuttle will not be able to send down high-rate data from the shuttle and its major payload, a high-energy particle physics experiment called the Alpha Magnetic Spectrometer. The AMS payload, however, was designed to use on-board hard disks for data storage as a backup to the KU-band system so no loss of data is expected. The problem would, however, prevent any realtime data analysis by scientists on the ground during the flight. The primary impact of the KU-band problem for all practical purposes is the loss of television from the shuttle. Discovery's rendezvous and docking with the Russian Mir space station will take place as scheduled Thursday, but we won't be able to watch it happen. Engineers are still troubleshooting the KU-band system, however, and a solution may yet be found. Will advise. The only other technical problem of any significance involves a water leak in the system that generates the shuttle's electricity. The shuttle is equipped with three fuel cells that generate power by combining hydrogen and oxygen in a sort of reverse electrolysis. A byproduct of the reaction is water, which the crew drinks; the excess is dumped overboard. During Mir docking missions like Discovery's, the excess water is stored on board and transferred to the Russian space station. Discovery's crew planned to transfer at least 1,200 pounds of fresh water to Mir, but a leaky check valve associated with fuel cell No. 3 will reduce that amount somewhat. Engineers knew about this problem before launch and while precise numbers are not yet available - the leak rate is in the neighborhood of a few pounds per hour - the overall impact is not expected to be major. Otherwise, Discovery is in good shape and the astronauts are pressing ahead with pre-rendezvous activities. Commander Charles Precourt and pilot Dominic Gorie will carry out additional rocket firings to fine-tune Discovery's approach to Mir. Other activities on tap include water bag fills, rendezvous tools checkout, orbiter docking system checkout and secondary science activity. At 4:56 p.m., the crew will be interviewed by the Sci-Fi Channel and KNX radio. =================================================================== Discovery docks with Mir; KU-band problem hampers AMS checkout (06/04/98) 6 p.m. Update: Shuttle data relay problem hampers physics experiment Problems with the shuttle Discovery's high-speed KU-band data relay system not only have derailed television coverage of today's shuttle-Mir docking, they also are seriously hampering efforts to check out and calibrate a $33 million high-energy physics experiment. The Alpha Magnetic Spectrometer, designed to look for antimatter nuclei and other exotic particles from deep space, was designed to beam down science and engineering data through Discovery's KU-band system. While the data is being stored aboard the shuttle on removable hard disks as a backup, scientists need realtime communications to observe the instrument in action and then to optimize its performance. For Discovery's flight, the AMS was to collect science data for 100 hours. About six hours was thought to be needed for proper calibration. The instrument has operated about 50 hours so far during the flight but only one hour of data has made it to the ground. "We have not had time to tune the [instrument] to optimize it for science," said experiment manager Jim Bates. "It's kind of like a radio that you just turn on and you may be on the station or you may not be on the station." The AMS is aboard Discovery primarily for an engineering test flight. The instrument, built around a six-ton Chinese-built magnet, ultimately will be mounted on the international space station for a three-year run. It is the first high-energy physics experiment to be conducted in space and the potential scientific payoff is profound. If the instrument cannot be fully tested during Discovery's flight, scientists might lobby for a second flight. The stakes are that high. Most scientists believe antimatter was destroyed during the first instant of the big bang because of an asymmetry in the way certain particles decay to produce quarks and leptons. That asymmetry, it is believed, created more "normal" nucleons than antiparticles and that excess after annihilation is what makes up today's universe. That belief is rooted in theory. But there also is observational evidence supporting the lack of antimatter in the universe. No one has yet observed the high energy gamma rays one would expect from regions where matter and antimatter meet and annihilate. But no one has ever made a direct measurement and if the AMS detects a single antimatter nuclei of helium or carbon, for example, current theories about the birth of the universe and its subsequent evolution would be in jeopardy. Equally profound, the AMS may be able to detect particles produced when super symmetric dark matter particles collide. It is believed that 90 percent of the mass of the universe is undetected, possibly in the form of weakly interacting massive particles - WIMPs - left over from the big bang. If the AMS actually detects evidence of such particles, astronomers will gain insights into the nature of the dark matter thought to pervade the cosmos. Roberto Batiston, an Italian researcher with the international AMS project, said in an interview today the instrument needs to be fully calibrated and understood before it is mounted on the international space station. "The agreement with NASA was for 106 hours of time for this flight," he said. "We had about five or six hours of time devoted to the optimization and the calibration of the instrument to get the best results. It means that right now, with the limited data we have, this calibration is correspondingly reduced. We have about an hour right now. "It's quite difficult to put a threshold and say when we'll feel totally safe," he said. "But clearly, one hour is much less than five hours. So if by the end of the mission the time we have to optimize and calibrate the instrument is much less than five hours, the possibility of a second flight is a serious possibility." The reason is that the AMS cannot be modified once it is on the space station. "This is a fairly complicated instrument, almost 100,000 channels, and the signals we're looking for are small, meaning one or two particles in hundreds of millions in some cases," Batiston said. "You cannot just rely on rough data. You have to understand the fine details of the performance of the instrument to be sure it's optimized for finding very rare events. "One of the reasons for the shuttle flight was to test in space the performance of this complicated detector, meaning that you want also to test fine effects, details of the functioning. It means if we find some details are not perfectly designed we might want to redesign them and modify them for the space station. Unfortunately, once you are on the space station you have to be perfect, you cannot modify it any more." NASA managers are debating possible KU-band repair options but as of this writing, it's too early to say whether they might prove successful. 3:15 p.m. Update: Shuttle crew welcomed aboard Mir "Andy! How're you doing, bud? Andy!" shuttle commander Charles Precourt yelled as he floated aboard the Mir space station today. "Welcome back to Mir," Thomas quietly replied, embracing his new commander, officially joining Discovery's crew and ending 130 days as a Mir crew member. Precourt opened a final hatch between Discovery and Mir's shuttle docking module at 2:34 p.m. after a picture-perfect docking. Mir-25 commander Talgat Musabayev enthusiastically welcomed the shuttle crew aboard. "Good to see you in space!" he said to Precourt and company as they floated aboard one by one. Former cosmonaut Valery Ryumin, making his first space flight in 18 years, was all smiles as he came on board, getting his first glimpse of a space station he helped design and manage as director of shuttle-Mir operations. A few moments later, the combined crews gathered in Mir's core module for a traditional welcoming ceremony. There was no television from the shuttle because of Discovery's KU-band antenna problem, but the astronauts and cosmonauts could be seen briefly on Russian television. "Welcome to space station Mir!" Musabayev said in fairly good English. "Glad to see you again in space, glad to hear you in space. You look good. Welcome to space station Mir!" "Thank you, Talgat, thank you very, very much," Precourt replied. "We're feeling great and glad to be here." Precourt then passed the microphone to Thomas "because he has the most to say, we think, right now. Talgat says for four months he's been pretty quiet, but I think he's bubbling over with something to say." He was. "You can't imagine how wonderful it was to look out the window at about two this afternoon [Decreed Moscow Time] and see a bright point of light on the horizon, which I knew to be the shuttle," Thomas said. "I spent the afternoon watching it slowly grow in size as it loomed up close to us. It was really an absolutely magnificent sight. We just a few moments ago opened the hatch and I had the great pleasure of seeing my friends and colleagues float on through and join us. It's really a wonderful moment for me to complete my stay on Mir with this good company I have right now." Precourt then passed the microphone to his crewmates for their first impressions of Mir. Franklin Chang-Diaz, only the third man to fly in space six times, said he was thrilled to finally be aboard the Russian station "and I look forward to a few days of getting to know this space station and learn from it." Janet Kavandi, making her first flight, said "this is just my second day in space, period, so this is like overwhelming. It's a magnificent sight to come up to something that looks like this from far away, like Andy said, like a point of light, and watch it grow until it becomes an incredible space station in front of you and then to dock and actually go across and see other human beings in space. Unbelievable." Russians always exchange gifts when visiting and Precourt took obvious pleasure presenting fresh onions to Musabayev and flight engineer Nikolai Budarin. "We've got a little gift for Talgat," he said, triggering a round of laughter. "I've got a little onions here for Talgat that he ordered last week, asked us to bring them aboard, and we're always happy to bring fresh food aboard for a crew that's been in space so long. They really deserve it. We're glad to be here helping them with their workload." "I like onions very good!" Musabayev said in English. The crews then got back to work, beginning four days of logistics transfer activity, moving hardware and experiment samples from Mir to the shuttle for return to Earth and fresh supplies from the shuttle to Mir. The crews plan to enjoy a meal together later in the day when NASA hopes to relay additional television from Mir. 1:20 p.m. Update: Shuttle Discovery docks with Mir space station The shuttle Discovery, skillfully guided by veteran commander Charles Precourt, gently docked with the Mir space station today as the two spacecraft sailed through orbital sunset 230 miles above central Asia at five miles per second. "Contact and capture, Houston," Precourt radioed as the docking systems engaged at 12:58 p.m. "It looked beautiful, Houston, just beautiful!" "It looked beautiful from here," astronaut Marc Garneau radioed from mission control in Houston. "Masterful flying." It was the ninth and final shuttle-Mir docking in a successful program to use the Russian station as a training ground for assembly and operation of the international space station starting later this year. The primary objectives of this last Mir visit are to pick up NASA astronaut Andrew Thomas after four months aboard the station and to deliver needed supplies and water to the aging outpost. If all goes well, Discovery will remain docked until Monday, returning to the Kennedy Space Center on June 12. Despite minor problems with shuttle equipment used to provide tracking and closure rate data for docking, Precourt completed the linkup right on time at 12:58 p.m. over a Russian ground station. The final moments of the rendezvous were seen live in the United States via television from the Mir station. The shuttle's KU-band television system is not working propery, forcing NASA to rely on Mir's periodic television downlink. After pressure checks to make sure the two docking systems are properly engaged, the crews will open hatches between Discovery and the Mir around 2:41 p.m. NASA hopes to provide Russian television of hatch opening, but that might not be possible. In any case, Thomas will officially join Discovery's crew as soon as the hatches are open. Additional television is expected between 5:09 p.m. and 6:06 p.m. as the combined crews enjoy a joint meal in the Mir core module. "Once again, congratulations on an outstanding rendezvous and a historical ninth docking with Mir," Garneau called. "It was beautiful to watch from down here, you have a very light touch. We really enjoyed the whole thing. Congratulations." "Thanks, Mark. We enjoyed it tremendously and we're really happy to be here," Precourt replied. "In a few minutes, hopefully we'll be inside sharing some celebrations of this great docking, this great program, with the Mir crew." 9:40 a.m. Update: Discovery begins final phase of Mir rendezvous Trailing the Mir space station by eight nautical miles, commander Charles Precourt fired the shuttle Discovery's steering jets over western Africa to begin the terminal phase of today's long-awaited rendezvous. If all goes well - and there are no technical problems of any significance at present - Discovery will dock with Mir at 12:58 p.m. Hatch opening is expected around 2:41 p.m. "Houston, we've got the Mir out the front window and at this range, we can discern the individual modules," Precourt radioed shortly before the terminal initiation - TI - rocket firing. "We wish we were up there with you," Canadian astronaut Marc Garneau replied from Houston. "We wish everybody could come see this," Precourt said. Because of problems with Discovery's KU-band communications system, the astronauts are unable to downlink any live television. NASA managers have asked their Russian counterparts to provide whatever video might be possible from cameras aboard the Mir station. Here are the windows when TV from Mir is expected (all times EDT): WINDOW OPEN...WINDOW CLOSE...EVENT 12:29 p.m.....01:06 p.m......Video of the shuttle's approach and docking 01:59 p.m.....02:44 p.m......Mir preparations for hatch opening 05:09 p.m.....06:06 p.m......Joint meal aboard Mir 5:45 a.m. Update: Astronauts gear up for Mir rendezvous The Discovery astronauts were awakened at 5:06 a.m. to prepare for today's rendezvous and docking with the Russian Mir space station. If all goes well, commander Charles Precourt will guide Discovery to a gentle docking with the Russian outpost around 12:58 p.m. After pressure checks, hatches between the two vehicles should be opened around 2:41 p.m. At that point, astronaut Andrew Thomas, launched to Mir in January, will officially become a member of Discovery's crew, living and sleeping aboard the shuttle until his return to Earth June 12. "For all of the most recent shuttle flights to Mir when we've been bringing up a NASA astronaut to leave and bringing back another one, the handover of the crew member occurred when the up-going crew member had checked out their suit, installed their seat in the Soyuz [entry vehicle] and received their Mir safety briefing," said lead flight director Paul Dye. "At that point, they became a Mir crew member and the down-going person became a shuttle crew member. Since we're not bringing anybody up this time, Andy becomes a shuttle crew member as soon as we open the hatch." Discovery's KU-band antenna system is still on the blink, preventing the crew from transmitting television to the ground (the antenna works fine in radar mode). But NASA hopes to get views of final approach and docking from Russia's Altair satellite. While hatch opening will not be televised live, scenes from the traditional welcoming ceremony and joint meal are expected\. As with past shuttle-Mir dockings, Discovery will approach from directly below, along an imaginary line called the r-bar connecting Mir and the center of the Earth. By approaching from below, commander Charles Precourt can use Earth's gravity and orbital mechanics to provide natural braking, eliminating the need to fire upward-facing jets that might damage Mir's solar arrays or optical systems. "We'll wake up and immediately start doing some correction burns," Precourt said Wednesday. "We're in an orbit of about 170 [nautical] miles and the Mir station is approximately 200 miles altitude above the Earth. And in that lower orbit, we're gradually catching them and as we do, we'll raise our orbit to meet them. And that whole process will take the better part of the day. "What we'll do is use our jets on board to correct our orbit to match the Mir's and at some place around 1,000 to 2,000 feet below the Mir, we'll take over manual control and steer in from underneath the Mir to nestle into its docking mechanism." After intercepting the r-bar, Discovery will yaw 180 degrees "so that we set ourselves up for what we call our tail-forward approach to the Mir," Dye said. "This is for good communications coverage from our antennas. There's nothing surprising or really new about the docking approach. Charlie, of course, has done this a couple of times." One change from past dockings is that Discovery's airlock and docking module are mounted as far forward in the cargo bay as possible, the configuration that will be used for assembly of the international space station. This will make for some fairly tight clearances between Discovery and an antenna aboard Mir and while no problems are expected, "they should really have the Mir in their face when they dock," Dye said. For readers interested in more detail about today's rendezvous, here is a description from NASA's press kit: About two hours before the scheduled docking time on Flight Day three of the mission, Discovery will reach a point about eight nautical miles behind the Mir Space Station at which time the astronauts conduct a Terminal Phase Initiation (TI) burn, beginning the final phase of the rendezvous. Discovery will close the final eight nautical miles to Mir during the next orbit. As Discovery approaches, the shuttle's rendezvous radar system will begin tracking Mir, providing range and closing rate information to Discovery's astronauts. The crew members will also begin air-to-air communications with the Mir crew using a VHF radio. As Discovery reaches close proximity to Mir, the Trajectory Control Sensor, a laser ranging device mounted in the payload bay, will supplement the shuttle's onboard navigation information by supplying additional data on the range and closing rate. As Discovery closes in on the Mir, the shuttle will have the opportunity for four small successive engine firings to fine-tune its approach using its onboard navigation information. Flying a slightly modified rendezvous profile for improved efficiency identical to prior Mir dockings, Discovery will aim for a point directly below Mir, along the Earth radius vector (R-Bar), an imaginary line drawn between the Mir center of gravity and the center of Earth. Approaching along the R-Bar, from underneath the Mir, allows natural forces of Earth's gravity to assist in braking Discovery's approach. During this time, the crew will begin using a hand-held laser ranging device to supplement distance and closing rate measurements made by other shuttle navigational equipment. The manual phase of the rendezvous will begin just as Atlantis reaches a point about a half-mile below Mir. Commander Charlie Precourt will fly the shuttle from the aft flight deck controls as Discovery begins moving up toward Mir. Because of the approach from underneath Mir, Precourt will have to perform very few braking firings. However, if such firings are required, the shuttle's jets will be used in a mode called "Low-Z," a technique that uses slightly offset jets on Discovery's nose and tail to slow the spacecraft rather than firing jets pointed directly at Mir. This technique avoids contamination of the space station and its solar arrays by exhaust from the shuttle steering jets. Using the centerline camera fixed in the center of Discovery' docking mechanism, Precourt will align Discovery's docking mechanism with the Docking Module mechanism on Mir, continually refining this alignment as he approaches within 300 feet of the station. When Discovery is 170 feet from the station, the Shuttle will briefly stop and perform a stationkeeping maneuver to maintain its distance from Mir. At that time, a final go or no- go decision to proceed with the docking will be made by flight control teams in both Houston and the Russian Mission Control Center in Korolev, outside Moscow. At a distance of about 30 feet from docking, Precourt Precourt will again stop Discovery briefly to adjust the docking mechanism alignment, if necessary. When Discovery proceeds with docking, the shuttle crew will use ship-to-ship communications with Mir to inform the Mir crew of the shuttle's status and to keep them informed of major events, including confirmation of contact, capture and the conclusion of damping. Damping, the halt of any relative motion between the two spacecraft after docking, is performed by shock absorber-type springs within the docking device. Mission Specialist Wendy Lawrence will oversee the operation of the Orbiter Docking System from onboard Discovery. "I don't want to say it's routine, but we have perfected the approaches to the Mir such that we're using roughly one third of the fuel we used when we began to go from the beginning of the manual phase to the end because we've perfected the techniques so well," Precourt said. "It'll probably never be old hat," he added. "This is a very intense process to get the shuttle up to docking with the space station and to make sure everything goes smoothly. We've perfected the mission and how to get there and we've been able to overcome a lot of failures. But when you come down to it, each mission is extremely important and what puts us on edge is wanting to make sure we get through it without mistakes, without holdups with problems that would delay certain parts of the mission. We're always on our toes." See the STS-91 mission preview for a detailed overview of the mission's objectives. =================================================================== KU-band antenna repair fails; Ryumin comments on Mir (06/05/98) 8:45 p.m. Update: Ryumin assesses Mir station Valery Ryumin, a former cosmonaut and now director of shuttle-Mir operations in Russia, is on board the shuttle Discovery to make a personal assessment of Mir's health and to identify changes that might be required for the international space station (ISS). Ryumin last flew in space 18 years ago as a crew member of the old Salyut-6 space station. During a conversation with ground controllers today, he painted a surprisingly candid picture of how cramped and crowded the aging Russian outpost has become (transcript provided by NASA): "Station looks good, but very busy (stuffed with a lot of hardware). ... There are a lot of cables and wires, which will be very difficult to disconnect in case we need it. It was possible to isolate Spektr, since it was a new module and wasn't stuffed with all the hardware. "I think people at MCC (mission control center) don't realize how stuffed the station is, it is not simple to work here. Salyut was busy as well, but not to such an extent, we have to think how to prevent ISS from such clogging. I understand that we want to stow a lot of hardware, but we need to make a special storage place for this, maybe lockers as on the shuttle, because now everything is hanging on the walls, cameras, lenses, and so on. "It is difficult to tell you everything, I think I have to shoot video and show it to our leaders. The cabin is overstuffed. I can tell you many things, but you may no believe me, everything is very, very tight here, it is very difficult to reach necessary panels which we need. ... It is very difficult to work here for a new cosmonaut." Before launch, Ryumin described his role on the current mission, saying "I will be involved in addressing a list of questions compiled by our station designers, questions that only a person who's experienced in this field can properly answer." "These questions include the condition of the hull, the condition of the cabling and the condition of various feed throughs between modules," he said. "In short, those items of the station that cannot be replaced on orbit. Approximately 90 percent of the equipment we bring up into space can be replaced. However, the remaining 10 percent cannot and it is these 10 percent that ultimately determine the lifetime of the station. And these will be the issues with which I will be occupied during the flight." 5 p.m. Update: Thomas has mixed feelings about trip home Astronaut Andrew Thomas, winding up a 140-day stay in space, said today he was elated at the sight of the shuttle Discovery approaching the Mir space station to finally bring him back to Earth. "Actually I have to say there was an element of disbelief in it because I've been up here for four-and-a-half-odd months, waiting for this arrival with some element of uncertainty as to when it was actually going to happen," he told an interviewer. "I knew it would, but the exact date was a bit of a moving target for a while. So I couldn't really believe it was actually happening. "It was a wonderful sight to see the shuttle coming up over the horizon, first as a point of light and then growing ever larger and ever larger and finally feeling the station shudder momentarily as we docked," he added. "It was a splendid sight and I'm really thrilled to see these guys here. We're having a great time." Thomas said he never felt culturally isolated aboard Mir because of books, movies, CDs, computers and other diversions "which helped me relax and unwind. So I wouldn't say I felt a strong sense of cultural isolation in that way." He also said he was looking forward to the process of re-adapting to gravity. "Actually, I think the whole idea of going back to one G and re-adapting is going to be one of the interesting facets of doing a long-duration mission," he said. "I think it's going to be a personal experience, I think it's different for different people. I'm keenly interested to see just how my metabolism will react to that sudden load up of gravity. I think it's going to be a very interesting experience." While he's clearly eager to get home, Thomas said he had mixed feelings about leaving Mir-25 commander Talgat Musabayev and flight engineer Nikolai Budarin behind. "You know, I've spent four-and-a-half months up here and this environment was my world, completely, everything here was the total world for me," he said. "I've become very adapted to that environment, very accepting and very comfortable with that environment, and now it's all going to change. I'm going to go back to a one-G environment, back to my own home and friends, which will be good, but it is a big change. So there's kind of a mixed feeling with that." Two of Discovery's crew members are first time shuttle fliers and one of them, Janet Kavandi, said the launch experience was more than she bargained for. "Until I felt the SRBs (solid rocket boosters) go off I didn't really fully anticipate what was going to happen," she said. "But when I did feel the SRBs - and you really can feel them - I suddenly realized it was finally going to happen. It brought tears to my eyes, I was actually crying on the way up. Not because I was scared, but because it was just a flood of emotion as I felt all the power and everything thrusting us into space." 2:50 p.m. Update: KU-band repair effort fails The Discovery astronauts attempted to fix the shuttle's balky KU-band antenna system today, stripping insulation off a critical wire bundle and hooking up a voltmeter to isolate which of two electronics boxes was preventing the system from relaying data to the ground. The problem prevents the crew from transmitting any television or science data to the ground via satellite. "Basically, we had narrowed it down to one of two electronic boxes in the KU-band system," said Bob Castle, a NASA flight director and an expert on the shuttle's communications systems. "One is called the signal processing assembly, which is inside the orbiter in the avionics bay, and the other is the deployed electronics assembly, which is out in the payload bay. It's the large box the antenna is physically mounted right on. It was in one of those two boxes." The crew was asked to carry out an in-flight maintenance procedure, or IFM, to measure the voltage in a wire that runs between the two boxes. A voltage between 24 and 28 volts would have indicated the problem was in the deployed electronics assembly. In that case, there was nothing that could be done. But zero voltage would have indicated a problem in the signal processing assembly. In that case, it might have been possible to hot-wire the system, bypassing the SPA with voltage from another source. Unfortunately, commander Charles Precourt reported a nice, steady voltage on the circuit in question, ending any realistic hopes of a repair. "That says the problem is almost certainly in the deployed electronics assembly outside in the payload bay," Castle said. "There is not a whole lot we're going to be able to do about that. We haven't given up yet, but I don't want to mislead anybody. The chances of recovery, I think, are fairly low." As a result, no television is expected from Discovery for the remainder of the mission except what NASA can arrange using the Mir space station's cameras and a Russian communications satellite. "We just wanted to say a big thank you for responding so quickly to that IFM and for doing a great job," astronaut Marc Garneau radioed the shuttle crew from Houston. "Unfortunately it didn't work. We believe it was worth a try, it might have been the solution. Just to let you know, we're going to be trying to pull down AMS data at every possible opportunity throughout the rest of the mission. And of course, Franklin, keep changing out those hard disks." "Yes, Marc, no problem, we'll keep on gathering all the data here," Chang-Diaz said. "It was definitely worth a try. Very interesting to see what these boxes look like behind the panel. Don't give up hope yet!" "Absolutely not. We're in the business to make things work," Garneau said. "Yeah, that's what space flight is all about." Along with losing television, the KU-band problem has prevented scientists from receiving near continuous realtime data from a $33 million high-energy physics experiment in the shuttle's cargo bay. Instead, the data are being downlinked in short bursts during passes over specific ground stations, complicating efforts to calibrate and fine tune the instrument. "All the data is recorded on board," Castle said. "What they need to be able to do is see it while they make some adjustments, to be able to make an adjustment in the experiment, see how the data changed, make another adjustment. So rapid response is what's important." The "adjustments" can be made at anytime, using the shuttle's normal S-band communications system and its KU-band radio, which is able to receive commands normally. But the science data from the Alpha Magnetic Spectrometer can only be downlinked over three NASA ground stations and a handful of military sites. "It's like tuning a radio where you can adjust the knob, you can turn it left or right, and you have status come down saying the radio is turned on and the knob did or did not move," Castle said. "But you can't hear the radio. So it's real tough to tune it." 6:30 a.m. Update: Astronauts continue Mir logistics transfers American astronaut Andrew Thomas, wrapping up a 140-day stay in space, moved aboard the shuttle Discovery Thursday and spent his first night on U.S. soil, so to speak, since being launched to the Russian Mir space station in January. Thomas logged 130 days aboard Mir and pushed the U.S. total to 907 days, the last 802 of them in a row. Assuming an on-time landing June 12, NASA astronauts will have logged 977 days in space since the joint program began in March 1995. The Discovery astronauts were awakened at 4:06 a.m. today for their first full day of docked activity. Over the next three days, the combined crews will transfer supplies and equipment from the shuttle to Mir and move mostly U.S. science gear and experiment samples from the station to Discovery for return to Earth. The shuttle's KU-band high-speed data relay system remains out of action and no television from the shuttle is expected beyond what NASA arranges to provide using Mir's camera system and a Russian communications satellite. The only other technical problem of any significance is an overboard water leak in the shuttle's electrical generation system. The shuttle's three fuel cells combine oxygen and hydrogen to produce electricity and drinking water. Excess water normally is dumped overboard, but for Mir docking missions it is transferred to the space station in large rubber bags. NASA originally intended to transfer about 14 bags of water but the leak in a check valve used by fuel cell No. 3 will force the Russians to settle for 12 to 13 bags, or about 1,100 pounds. This is a minor impact that the Russians knew about before launch. A mission status briefing is scheduled for 2 p.m. and the joint shuttle-Mir crew will be interviewed at 4:20 p.m. by the Cable News Network and the Voice of America. Both interviews will be carried on NASA television through the Russian Altair communications satellite. This status report will be updated after the mission status briefing or as conditions warrant. =================================================================== Spektr leak eludes detection; Thomas eager for time off (06/06/98) 2:30 p.m. Update: Gas release fails to pinpoint Spektr leak Mir-25 flight engineer Nikolai Budarin injected a fluorescent gas into the airless Spektr module today in a bid to pinpoint punctures in the lab's hull caused by a catastrophic space collision last summer. Engineers were hopeful the gas would fluoresce when hit by sunlight after leaking out into space, leaving a glowing trail of sorts back to as-yet-unseen punctures in Spektr's hull. But they were not sure if the softly-glowing cloud would actually be visible to the astronauts and cosmonauts aboard Mir. As it turned out, it wasn't. "Dom [Gorie] and I are on the flight deck, we saw a couple of crystals of ice come from the area of the solar arrays, nothing from the base where the module attaches, and some debris from the area of the solar arrays," shuttle commander Charles Precourt radioed. "There has not been any sign of the gas fluorescing." Spektr was damaged last June when an out-of-control Progress resupply vehicle slammed into one of the module's four solar arrays and then the lab itself. The solar array was virtually destroyed and the module was punctured, forcing the crew to seal it off from the rest of the space station. Engineers suspect the hull was breached near the base of the damaged solar array, but they're not positive. A much more extensive test will be carried out Monday, after Discovery undocks from the Mir station. Engineers say the crew should have a better chance to spot the gas at that time, based on lighting conditions and other factors. "We were just talking it over and we all agree that from our vantage points from different windows, none of those windows have a view directly at the base of the solar array that was damaged," Precourt radioed after today's test. "And that might be why we're not seeing anything. For the fly around [Monday], we should get a direct view at the base of the solar array at some point. Perhaps the gas is dissipating as it moves away from its leak spot to a point where it doesn't fluoresce bright enough any more by the time it's in the field of view we have ... in the docked phase." Mir will be deorbited next year and it's doubtful the Russians will actually attempt to repair and repressurize Spektr regardless of whether the tests carried out during Discovery's mission ultimately pinpoint the leaks. But such tests could prove useful during international space station operations if any leaks develop in that spacecraft. "Our mission, one of its goals, is to restore the functionality of the Spektr," Mir-25 commander Talgat Musabayev told CBS Radio earlier today. "But this is not an end in itself. It's more of a scientific experiment in order to, in the future, be able to have the experience of determining if necessary, God forbid, such information from the international space station. This experience will come in handy." See the 4:50 a.m. update below for complete details of the test. 1 p.m. Update: Cosmonaut concerned about Mir clutter; Thomas eager for home Astronaut Andrew Thomas, a wind surfer, mountain biker and expert horse rider, says the one thing he wants most after four-and-a-half months cooped up aboard the Russian Mir space station is a bit of time off and a good cup of coffee. Without the straw. "Every moment up here is sort of committed and planned out ahead of time because time is a very valuable resource up here," he told CBS Radio today in a brief interview. "So I'm looking forward to not having anything to do for a while. That's going to be a great pleasure for me. "Another thing I'm looking forward to is not having to eat my meals out of packets, not having to drink my drinks out of bags with a straw," he added. "I'll be able to eat meals off a plate and drink coffee out of a cup. I think that's going to be kind of a fun feeling, too." Thomas is the seventh and final American to make a long-duration stay aboard Mir. With his return to Earth June 12, American astronauts will have logged 970 days in space during the shuttle-Mir program, the last 812 days in a row. Thomas said his toughest moment, "curiously enough, was right at the beginning of the flight when we had a lot of people on board and it was very crowded." "Once we settled down into a routine with just the three of us, it then became a lot easier and I soon developed a very pleasant sort of work routine and recreation routine and felt very comfortable living on the station," he said. "At no point did I feel like I needed to leave suddenly. It was a very sort of comfortable and easy lifestyle in some ways." Asked what he viewed as the most important "lesson learned" from the joint shuttle-Mir program, Thomas cited the human element, saying "I think the training program that you're put through ahead of the flight is extremely important. You have to spend a lot of time working with the crew you're going to fly with before the flight so that you can get to know them and you can start to build a relationship before you fly. I think that's really critical when we've got members of the crews that are coming from such diverse backgrounds." Veteran cosmonaut Valery Ryumin, manager of the shuttle-Mir docking program in Russia, says he's concerned about how cluttered the Mir space station has become during its 12 years in space. Carrying out a personal inspection as a member of Discovery's crew, Ryumin said planners need to give this issue more attention before building the new international space station to avoid similar problems in the future. "Yes, this is a serious problem," Ryumin told CBS Radio. "I've been on the station and I've seen just how serious this problem is. The question of items on the station is important and is going to be an important one for the international station. I'd like to know why this happened, we didn't plan for this to happen in the course of so many years. We brought so many things here over the first five years that it became impossible to store all of it. "I think if we manage this work for the international space station from the very beginning that we will be able to solve this and address this issue," Ryumin said. "We'll be able to understand what we bring and where we're going to put it and how we're going to dispose of it. This needs to be managed. It's a serious question because otherwise the international space station is also going to be full of extra articles." Ryumin told ground controllers in Moscow Friday "the cabin is overstuffed. I can tell you many things, but you may not believe me, everything is very, very tight here, it is very difficult to reach necessary panels which we need. ... It is very difficult to work here for a new cosmonaut." 4:50 a.m. Update: Spektr gas release, robot arm test on tap The Mir-25 crew plans to inject a fluorescent gas into the punctured Spektr module today in yet another bid to pinpoint leaks in the abandoned lab. As the gas escapes into space, sunlight may make it glow, allowing the crew to locate leaks caused during a collision last summer with a Progress resupply vehicle. "This is not going to be a bright glowing cloud," said lead flight director Paul Dye. "This is a dim glowing cloud. We have tried it in vacuum chambers and we see a green glow. There are a lot of unknowns about whether we'll really see it [in space]. If you take the black background of space, the white blankets on the surface of the Mir and you're back-lighting this whole thing from behind you with sunlight, the question is whether the fluorescence of the gas will be bright enough to [see]. There's some thought that this gas might actually glow a little bit at night and so we're going to see what we can see." Even if the crew manages to spot where the Spektr module is leaking, it is doubtful any attempt will be made to actually repair the abandoned lab. Rather, the exercise is aimed at perfecting techniques for spotting leaks on the international space station. "I would not say there is definitely no chance of resurrecting Spektr," cosmonaut Valery Ryumin said before launch. "However, the question really that must be addressed is, is it reasonable to expend resources to do so? The experiment we're going to do jointly ... is intended really more for the international space station. "No one knows what type of experience will be needed in the future," he said. "However, doing this experiment now will be helpful. It's better to do this experiment now rather than do it later. I don't believe it will have much of an impact on the ultimate determination of the lifetime or future operations of Mir station." Another gas release is planned just after Discovery undocks from Mir. With the shuttle directly ahead of the station, the gas will be injected into Spektr just as the station moves into orbital sunlight. "We're going to separate straight down ... to about 200 to 250 feet with the nose forward into the direction we're traveling," Dye said. "When we reach that point and are stable, the Mir will begin its maneuver from its undocking attitude to an attitude that will give us the best view of the Spektr. At the same time, we'll begin a fly around to the v-bar, which is forward of the Mir. We'll stay at that range of about 200 to 250 feet. This will be mostly in the dark. "We'll sit there on the v-bar until sunrise, at which point the Spektr will start venting some gas which should fluoresce," he said. "Then the space station will pirouette in front of us so we can inspect all sides of the Spektr. This is to determine if we can come up with techniques for finding leaks from leaking modules." Along with the Spektr test today, the shuttle astronauts also plan to test an upgraded robot arm, or RMS, designed for use during assembly of the international space station. "It has upgraded hardware, new electronics which will be used for the first time seriously on STS-88, the first ISS mission with the shuttle," Dye said. "In order to make sure we haven't introduced any problems into the arm we want to check out the new equipment. We're going to do an RMS checkout while we're docked. We have clearance from the Russians to operate the arm in a small zone to keep it well clear of the Mir, by about 10 feet." Finally, astronaut Andrew Thomas will be interviewed by CBS Radio today at 11:55 a.m. This status report will be updated as soon as possible thereafter. =================================================================== Shuttle-Mir crews hail Phase One program (06/07/98) 2:20 p.m. Update: Final shuttle-Mir news conference With undocking on tap Monday, the combined crews of the shuttle Discovery and the Mir space station gathered today for one final news conference and farewell ceremony to close out the shuttle-Mir docking program. Discovery commander Charles Precourt and Mir-25 skipper Talgat Musabayev thanked the hundreds of managers, engineers and technicians in the United States and Russia who participated in the nine shuttle-Mir docking missions over the past four years. "It's a little bit sad for us to think about closing out such a great, enjoyable and successful program," Precourt said. "But it's also the beginning of a new era that we're all very, very happy to be undertaking. I think we're going to see even bigger and better things to come as we move into phase two." He was referring, of course, to the international space station both nations plan to begin building later this year. The shuttle-Mir program was known as phase one of the international project. Actual construction of the new station is known as phase two. "It's time for us to complete the first phase of the Russian-American program of space cooperation," Musabayev said through an interpreter. "I would like these relations between Russia and America, as the two greatest countries on the globe, not to be completed [and] have more exchanges. We've been working very well with these crews and there's a great deal of mutual respect and hopes for future work." Discovery is scheduled to undock from Mir at 12:01:24 p.m. Monday. In one final test, the shuttle crew will observe and photograph Mir's punctured Spektr module while a fluorescent gas is pumped in by the station crew. As the gas leaks out, Precourt and company hope to see it's glow as sunlight makes it fluoresce in the blackness of space. The gas release is scheduled to begin at 12:43 p.m., three minutes before orbital sunrise. The shuttle will move away for good with a rocket firing at 1:26 p.m. Precourt said both crews were a bit nostalgic about Mir, "just thinking how great it would be if we could bring back one of the modules. For instance, put Kristall in the payload bay and bring it back for all the world to share and see in a museum somewhere. ... Short of that, we are bringing back some small pieces, mementos, that we hope everyone can see." U.S. astronaut Andrew Thomas spent 130 days aboard Mir as the seventh and final NASA flier to make a long-duration stay aboard the Russian outpost. When he lands next week, he will have logged 140.6 days in space since launch last January. Despite his obvious eagerness to get home, Thomas said he'll miss the relatively simple lifestyle aboard Mir and the joy of being weightless. "The tasks we have to do up here, of course, are very complex," he said. "But the lifestyle itself is very defined, so you know what you have to do. So in that sense, it's an uncomplicated life style: You know what you have to do and you just go about it. And that's quite an easy part of the life. So having an uncomplicated life in that sense will be something I'll miss. "I'm going to miss the aspect of being weightless continuously," he continued. "It's really a great feeling and I enjoy it immensely. So I'm going to be kind of sorry that I'm not going to have that freedom of movement. Of course, I've enjoyed the view, I've enjoyed the sights, looking at the world as we go around, and that's something that's always been there and will now not be there and I'm certainly going to miss that. "And I'm going to miss the camaraderie my colleagues, Talgat and Nikolai, have offered me. They basically have opened up the station to me and allowed me to establish a home here and they've been the basis of all my social interactions for four-and-a-half months. We've had some great times together and that's something I'm also going to miss." While the prospect of re-adapting to Earth's gravity after four-and-a-half months in space might be daunting to some, Thomas said he's looking forward to the experience as just one more aspect of long-duration space flight. "Re-adaptation is going to be part of one of the interesting aspects of this whole process, which is by no means over for me," he said. "I think re-adaptation is a very personal thing, it depends on your own vestibular system and you're own neurology. So I don't really know how I'm going to react. I'm expecting that there will be perhaps some vestibular uncertainty, shall we say, and that's going to be a very interesting experience in itself. But in detail, of course, I don't know and I won't know until I do it. But I'm looking forward to doing it, I think it's going to be one of the really interesting aspects of long-duration flight." Musabayev said he and flight engineer Nikolai Budarin will miss Thomas as they continue their mission alone for the next two months. They are scheduled to be replaced by a fresh crew in August. "I must say that not everything went well in the beginning because we had differences of a cultural nature, we had differences in our technical approaches to things," Musabayev said. "But regardless of that, in the course of several weeks we found a common language, our American colleague, Andrew Thomas, became just an integral part of the crew here at Mir. We will be flying another two months without him until August and we have become very used to having him around. We are thankful to him for his fine work, we thank him and we wish him a good flight home." Russian cosmonaut Valery Ryumin, making his fourth space flight after an 18-year hiatus, won a seat on Discovery to carry out an engineering inspection of Mir. Ryumin participated in the design and management of every Russian space station and his goal here was to assess how Mir's systems have aged and to apply any lessons learned to the international space station program. Earlier in the flight, Ryumin said he was concerned by how cluttered the station had become in 12 years of flight. But today he said he'd seen nothing to indicate any problems serious enough to warrant an immediate end to the program. "We have over the past few days seen what we can," he said. "We have not determined or identified any systems that are in any sort of critical state and that would require an interruption of flight. The actual state of the hull, we cannot assess the current state of connectors between modules. Such things cannot be observed. But the things we have observed have led us to conclude there are no critical points and no worrisome items." At the end of the U.S. portion of today's news conference Precourt summed up the feelings of his crew by saying "I'll be a little sad that we're not coming back because each of my three flights here have been an adventure that I'll remember forever, an adventure I wish all astronauts and essentially any human on the planet could experience." "Seeing the history of this program close is somewhat sad, of course," he said. "And that, I'm sure will be going through our minds when we close the hatch [Monday], knowing we're not going to be coming back to this particular station." 5:45 a.m. Update: Astronauts work to complete Mir transfers The Discovery astronauts are working through their last full day of docked operations with the Mir space station, transferring U.S. science gear, experiment samples and other equipment from the station to the orbiter for return to Earth. A crew news conference and farewell ceremony is scheduled for 12:30 p.m. with a mission status briefing on tap at 3 p.m. There are no new technical problems of any significance with the shuttle or its payloads. This status report will be updated after today's news conference or earlier if conditions warrant. =================================================================== Shuttle Discovery undocks from Mir station (06/08/98) 5:30 p.m. Update: Culbertson reflects on end of Phase One program NASA managers today hailed the conclusion of the shuttle-Mir docking program, also known as phase one of the international space station project, saying "it's been a wonderful experience." "Congratulations to the team, congratulations to the crews of both vehicles, congratulations to Andy Thomas for completing a wonderful stay on board the Mir and perservering through it all," said Frank Culbertson, manager of shuttle-Mir operations for NASA. "And congratulations to all the people who planned and built phase one and the people who executed it. It's been a wonderful experience." But even though joint flight operations have concluded, Culbertson said "it's a little too early to say goodbye to the Mir." "The Mir will be in orbit for at least another year or slightly more. It's a little too early to say goodby to phase one because we still need to land Andy safely and we need to continue his debriefing and rehabilitation after landing," Culbertson said. "So it's kind of hard to know what to say at this point. It's a mixture of feelings on both sides." Waxing a bit poetic, Culbertson told reporters that while the Russian word "Mir" means "peace" in English, it also can be translated as "village." "I think as a symbol of peace it has certainly done its job because we are concentrating on cooperative activities in space rather than conflict oriented activities," he said. "And I think the example we set sets the tone for the rest of the world. "I think the meaning 'village' is actually more applicable for the Mir, because I believe the term 'village' in Russian, as I understand it, is a group of people who live together for their mutual benefit and who support each other and take care of each other. If you weren't a good, productive member of the mir then you probably were cast out. "The positive side of that, however, is you did take care of each other and you did learn how to work together in close quarters and to use your resources for the entire group," Culbertson continued. "I think the Mir has done that. I think the Mir has made a community and village out of our space programs, not just in orbit but also on Earth because it's forced us to work together on things. It's forced us to solve problems, it's forced us to look at each other honestly and openly and to deal with our problems honestly and openly. And I think that's the best thing about working closely with a partner. "The Mir has done its job," he concluded. "It has made a village, a community, out of what we are trying to build and I think it'll be the foundation for what we do in the future. The other really good thing about the Mir is that for the first time in the shuttle program it gave us a place to go where there were people. It gave us a place to go where people were working and living, where we could take people and leave them and pick up people and take them back to Earth. ... For the first time we had a real good use of the shuttle as a vehicle for carrying people and cargo." 1:30 p.m. Update: Shuttle undocks from Mir station Ending an era, the shuttle Discovery undocked from the Mir space station today, closing out NASA's ninth and final mission to the Russian outpost as the agency gears up to begin building the international space station later this year. "All good things end sometime," Mir-25 commander Talgat Musabayev told shuttle commander Charles Precourt during a farewell ceremony earlier today. "And unfortunately we have, according to the program, of course, to part with our friends, American friends with the shuttle crew headed by its commander Charlie Precourt. He is our old friend. But I believe it's not our last joint mission. We hope for future cooperation and now we'd like to express our deep thanks to MCC [mission control] Moscow, MCC Houston to the shuttle crew for good joint work. Happy voyage, Charlie." Andrew Thomas, returning to Earth after more than four months aboard Mir, thanked Russian ground controllers for making his voyage a success. "Thanks for your assistance during the mission," he said in Russian. "I think it was a great time. We did a good job. And thank you for your efforts to make it a successful mission. Thank you very much and see you later." Before leaving Mir behind for good, the shuttle astronauts made one more attempt to help their Russian colleagues pinpoint a leak in the punctured Spektr module. With Discovery poised 240 feet directly in front of Mir, and with Spektr silhouetted against the black backdrop of space, a fluorescent gas was pumped into the airless module by Mir-25 flight engineer Nikolai Budarin. By looking for signs of the gas as it escaped into space, the astronauts hoped to see where the leaks were located on Spektr's hull. But as with a similar test Saturday, the gas did not fluoresce brightly enough to be seen by either Discovery's crew or Mir's. "Houston, so far nothing visible to the naked eye of discernible gas," shuttle commander Charles Precourt radioed mission control. "Once in a while we think we might be seeing something. Franklin's got the intensified image on the camcorder, but with the small viewfinder it's very hard to tell if anything discernible's there. We'll have to review that film." "Thanks, Charlie," astronaut Marc Garneau replied from Houston. "It sure is a pretty view of the station, though, from here, with the sun coming," Precourt said. "We're just sitting here in position and they're tracking the sun and it's just glowing. It's really something." "We can appreciate that," said Garneau. "Enjoy the view, because you're probably the last crew to have a good look at Mir." "Roger that." Interestingly enough, a bit of debris apparently plugged up a leak site on Spektr momentarily, allowing pressure to actually build up in the module as the gas was pumped in. "The gas doesn't seem to be escaping at the moment," Precourt said. "Marc, the Mir crew tells us they've got 53 millimeters (of mercury) and holding and the gas is not escaping according to that reading." A few moments later, however, the pressure began dropping again as one would expect. No one on either vehicle saw any sign of the fluorescent gas. Discovery undocked from Mir on time at 12:01 p.m., dropping straight away from the aging space station as the Mir crew looked on. The undocking was carried live on NASA television via television from a Russian ground station. "Houston, Discovery, we have physical separation," pilot Dominic Gorie called as the shuttle dropped away. Gorie then guided the orbiter into position for the gas release before leaving the area for good just before 1:30 p.m. "We've got the Mir crew waving at us through the windows, Houston," Precourt called. "You could almost reach across the vacuum of space and touch the Mir, it seems so close. And the view is incredible." "We understand. I guess 240 feet is pretty close, a couple of orbiter lengths," Garneau said. "Yeah, with the Mir as big as it is and you're 240 feet away, it's an up-close, personal view. It fills the overhead window." "We envy you." 9:30 a.m. Update: Hatches closed between Mir station and shuttle Discovery After hugs and handshakes and perhaps a tear or two, the crews of the shuttle Discovery and the Mir space station closed and dogged the hatches between the two vehicles today at 9:07 a.m., setting the stage for undocking at 12:01:24 p.m. Just before hatch closure, the astronauts and cosmonauts gathered in Mir's shuttle docking module for a final farewell marking the end of an era in U.S.-Russian cooperation. "It's going to be a pretty quiet moment for all of us, I'm afraid," commander Charles Precourt radioed before the farewell ceremony began. "The whole crew is here to say goodbye to a wonderful program, for what it's been to all of us and what we hope it will mean to all of us in the future." "And we agree, Charlie, this is a very historic moment," astronaut Marc Garneau said from Houston. Mir-25 commander Talgat Musabayev then spoke in Russian about the end of the shuttle-Mir program and the beginning of work to build the international space station later this year. The former is known as phase one of the international station program while phase two will commence with the start of construction later this year. "Houston, I don't think we could do any better than what Talgat has just said," radioed Precourt, who speaks fluent Russian. "No way can we stop the cooperation that started with this program. We've got to keep going together in the future and we're really happy to be leaping off in that direction with phase two." Speaking in English, Musabayev said, "Houston, thank you very much from all of us. ... Good luck, good luck," he said to Discovery's crew members as they floated through the hatch and into the shuttle. ... See you later, goodbye!" "And Houston, it's official, Valery has decided to come with us," Precourt joked as crewmate Valery Ryumin, a former Russian cosmonaut making his first flight in 18 years, left Mir and returned to Discovery. Just before Precourt left Mir for the last time, Musabayev gave the shuttle skipper a large spanner-type wrench to symbolize the transition from the shuttle-Mir program to the start of construction of the international space station later this year. "Houston, I can't think of a better gift to pass from phase one to phase two knowing the kind of work we're going to need to do to construct the international space station," Precourt said. "We're going to need this for all the work we've got ahead of us, Talgat. This is great. The whole flight has been fantastic, the whole phase one has been fantastic and we're looking forward to working with you again. Thank you very much." Then, after a final round of hugs, handshakes and photographs, the hatches were closed to set the stage for undocking. "Thanks to everybody," Precourt told Houston. "We'll see you soon." 5:15 a.m. Update: Shuttle crew gears up for undocking The Discovery astronauts are gearing up to undock from the Mir space station today, ending NASA's ninth and final visit to the Russian outpost and closing a remarkable chapter in U.S.-Russian cooperation. Leaving with one more person than they came with, commander Charles Precourt, on his third trip to Mir, and pilot Dominic Gorie planned to undock from the station at 12:01:24 p.m. "I'll be a little sad that we're not coming back because each of my three flights here have been an adventure that I'll remember forever, an adventure I wish all astronauts and essentially any human on the planet could experience," Precourt said Sunday. "Seeing the history of this program close is somewhat sad, of course. And that, I'm sure will be going through our minds when we close the hatch, knowing we're not going to be coming back to this particular station." Joining Discovery's crew for the flight back to Earth will be Andrew Thomas, who spent 130 days aboard Mir, the seventh and final U.S. astronaut to make a long-duration stay on the Russian station. With landing Friday, Thomas will have logged 140 days, pushing NASA's total to 977 days in orbit since the joint program began in 1995. The shuttle-Mir missions were known as phase one of the international space station program. The idea was to use Mir as a training ground before NASA and the Russian Space Agency began building the more ambitious international space station later this year. Whether one approves of ISS or not, the phase one Mir missions clearly accomplished the major goals of the program and resolved dozens of political, cultural and technical problems that had to be faced sooner or later in any joint endevour. In any case, today's undocking includes a final test to help the Russians pinpoint a leak in the punctured Spektr module. The shuttle will drop straight away from Mir to a distance of about 240 feet below the station. Gorie then will guide the shuttle to a point directly in front of the station. Three minutes before orbital sunrise, at 12:43:24 p.m., the Russians will begin pumping a fluorescent gas into Spektr. As the station moves into sunlight, the gas should begin glowing, providing a visible trail of sorts to the leak points on Spektr. In theory, anyway. A shorter test was carried out Saturday and the astronauts were unable to see the gas. Engineers hope the lighting and viewing conditions will be better today. "We'll slide on down, straight down to the 250-foot mark and when we reach that point and are stable, the Mir will begin its maneuver from its undocking attitude to an attitude that will give us the best view of the Spektr," said lead flight director Paul Dye. "At the same time, we'll begin a fly around to the v-bar (velocity vector), which is forward of the Mir. We'll stay at that range of about 200 to 250 feet. This will be mostly in the dark. "We'll sit there on the v-bar until sunrise at which point the Spektr will start venting some gas which should fluoresce," Dye said. "Then the space station will pirouette in front of us so we can inspect all sides of the Spektr." The idea is not so much to eventually repair and repressurize Spektr - the Russians don't appear to have the resources to operate Mir long enough to warrant a risky repair job - as it is to learn more about spotting leaks in space. Here is the timeline for today's undocking and fly around. TIME.................EVENT 11:14:08 a.m.........Sunrise 11:58:31 a.m.........Russian ground stations in contact with Mir 12:01:24 p.m.........Discovery undocks from Mir station 12:04:24 p.m.........Shuttle 50 feet from Mir 12:10:14 p.m.........Last Russian ground station loses contact 12:10:24 p.m.........Discovery 240 feet below Mir; begins fly around 12:11:00 p.m.........Sunset 12:12:24 p.m.........Mir maneuvers to gas release attitude 12:22:24 p.m.........Shuttle directly in front of Mir 12:43:24 p.m.........Spektr gas release begins 12:46:08 p.m.........Sunrise 12:46:24 p.m.........Gas release photography begins 01:03:24 p.m.........Gas release halted 01:05:00 p.m.........Russian television coverage begins 01:14:34 p.m.........Gas release photography ends 01:26:04 p.m.........The shuttle departs from Mir station 01:35:00 p.m.........Russian television coverage ends After the leak test, Gorie will guide Discovery to a point directly above Mir. A small rocket firing then will move the shuttle away from the station for good and the operational portion of the phase one program will be over. =================================================================== Experimenters may seek second flight for AMS (06/09/98) 3:30 p.m. Update: Scientists unable to calibrate AMS While the shuttle Discovery's docking with the Russian Mir space station has garnered all the headlines, an international team of scientists has been struggling throughout the mission to assess the performance of a $33 million cosmic ray detector called the Alpha Magnetic Spectrometer, or AMS. Because of problems with the shuttle's KU-band data relay antenna, AMS researchers have been unable to properly calibrate the otherwise smooth-working instrument, raising the possibility of a reflight. Built around a Chinese-built six-ton magnet, the AMS was designed to look for antimatter and subatomic particles produced by dark matter collisions. To do so, the instrument needs to be fine tuned, or calibrated, to maximize its sensitivity (see the STS-91 Mission Archive for an experiment overview). The idea was to use Discovery's mission to calibrate the AMS and then to attach it to the international space station for a three-year observing run. The AMS was designed to beam down its data using the shuttle's high-speed KU-band antenna system. As a backup, the experiment was equipped with removable hard drives on board the shuttle to archive all raw data. But Discovery's KU-band antenna system has failed to work properly throughout the flight and AMS researchers have been limited to receiving data during short passes over specific ground stations. In addition, telemetry from the experiment shows that the best orientation from a science perspective causes the device to overheat. As a result, the shuttle has been reoriented to a slightly less optimal orientation to properly manage temperature. The AMS was designed to be sensitive enough to detect one antimatter atom out of one billion normal atoms. Because of the KU-band communications problem, however, researchers do not know just how sensitive the instrument actually is. But Roberto Battiston of the Italian National Institute of Nuclear Physics says the detector is at least sensitive enough to detect antiprotons, which are difficult to detect on Earth. Based on looking at a few percent of the data collected by AMS, "we are able to see the experiment performs as designed, performs very well as designed," said Battiston. "We were able to detect many nuclei from helium, carbon and above and we have even detected many antiparticles in the form of antiprotons. ... The ratio of antiprotons versus protons is on the order of ten to the fourth, ten to the fifth, so they are very rare. The fact that we can detect them is a good indication the experiment is working as expected." Antiprotons, positrons - positively charged electrons - and antineutrons are produced naturally when normal subatomic particles collide at high energies. AMS is looking for whole atoms of antimatter, which, if they exist, can only be produced by antistars somewhere in the universe. But to improve the odds of success, the AMS must be properly calibrated and that can only be done in the space environment. "In order to calibrate the instrument, we were assuming five or six hours of continuous updating in order to sample data from ... all latitudes and longitudes," Battiston said. "The way we're receiving the data so far is a few minutes of data every hour or so at almost the same latitude. So we cannot understand in detail the performance of the instrument over the full set of latitudes and longitudes. Obviously, this will limit us to a certain extent in the calibration of the instrument. This instrument is designed to reach a high accuracy in detecting antimatter from matter on the order of one part in a billion. This is very difficult to achieve unless the detector is perfectly calibrated." Because of the role of Earth's magnetic field, what the instrument detects varies with latitude. But without being able to continuously monitor performance, scientists cannot fine-tune the instrument to maximize what it's able to detect. "This is why we were requesting continuous calibration for the first five or six hours and this was not possible to obtain," Battiston said. "So we are still evaluating how much this will limit our understanding of the instrument. Clearly, this was not the optimum condition we were assuming for this flight. ... In order to understand the instrument, a second pre [space station] flight might be needed." No formal request for a reflight, however, has been made, according to mission manager Jim Bates. The AMS is a Department of Energy payload and any such request would have to come from the DOE. "It's probably never reached its ultimate tuning to get the accuracy needed," Bates said. "We will probably not be able to accomplish our objectives we wanted and it's up to the managers to think about the possibility of reflights or whatever." 6:45 a.m. Update: Shuttle crew takes time off The Discovery astronauts are working through a relatively light day in orbit today, operating on-board experiments and helping flight controllers collect engineering data on the orbiter's broken KU-band antenna system. In addition, astronauts Janet Kavandi and Wendy Lawrence will use the shuttle's robot arm to gather data on the Canadian space vision system, a high-tech system that will be used during space station assembly to automatically position the arm. This afternoon, the crew will take a half-day off to enjoy the view, relax and generally catch their collective breath after a busy four days docked with the Mir. The official tally shows the astronauts and cosmonauts transferred 2,280 pounds of equipment and supplies to the Russian station along with 1,242 pounds of fresh water. Anoether 688 pounds of Russian equipment was moved from Mir to Discovery for return to Earth, along with 1,824 pounds of U.S. equipment and experiment samples. There are three in-flight public affairs events on tap today, an educational event involving Portuguese students at 7:26 a.m. and interviews with Mutual Radio, KMOX Radio and King TV starting at 10:31 a.m. This afternoon, Costa Rican-born astronaut Franklin Chang-Diaz, making his sixth space flight, will participate in a VIP call from Costa Rican President Miguel Angel Rodriquez. A mission status briefing is planned for 2 p.m. The only new technical issue this morning involves an experimental system that uses data from Global Positioning System satellites to update the shuttle's flight computers on where the orbiter is located. At some point, NASA would like to replace the shuttle's older inertial measurement units to improve accuracy. Early today, the GPS experiment hardware somehow sent corrupted data to the shuttle's data processing system. There was no mission impact and the suspect data was erased. But engineers want to know why it happened in the first place. =================================================================== Light at end of tunnel for AMS? (06/10/98) 4:45 p.m. Update: Ting: AMS can be calibrated on Earth There may be light at the end of the tunnel for the Alpha Magnetic Spectrometer aboard shuttle Discovery, a $33 million high energy physics experiment that has been hampered by problems with the orbiter's KU-band data relay system. While the AMS has been working throughout the mission, the communications glitch has prevented researchers from properly calibrating the instrument to maximize its ability to search for antimatter and other exotic particles from deep space. But Nobel laureate Samuel Ting, principal investigator with the AMS project, says researchers should be able to fine tune the six-ton detector in a particle accelerator on the ground after Discovery returns to Earth. By comparing data collected in space with particles detected in the accelerator, scientists should be able to interpolate to optimize performance. If all goes well, the AMS ultimately will be mounted on the international space station for a planned three-year run. "At the beginning, we requested six hours [of KU-band interaction] to optimize the detector," Ting said. "Because of the loss of KU-band, we were not able to do that. That means to understand the detector perfectly we're going to have to move the detector to an accelerator to do a calibration. But all in all, at least for the scientists in our group, we are truly happy with what we have seen so far and I don't anticipate any problems." Using an accelerator, Ting said, "you have different energies, different particles, and you can try to interpolate the results you're going to get in space. You pretty much understand from the response what you will get in space. Remember, we have many, many data points. So we're pretty confident we can do that. It will take a little longer, that's all." Ting is confident about success because data from the AMS shows the device is working at near maximum potential. Six built-in lasers show the detector's silicon components did not move more than a micron during Discovery's ground-shaking blastoff and "we see an abundant amount of protons and helium nuclei, indicating everything's functioning perfectly." "In addition, we also see negative charged particles and this is the track of an antiproton," Ting said, holding up a graph. "When we finish the experiment, we should be able to analyze the tapes I hope in a very short time and we'll let the world know what's the result of this experiment. But all in all, everything's been functioning exactly like what we designed. When we checked the detector on the launch pad at the Kennedy Space Center, we had [certain] responses and we checked the same quantities in space and they're exactly the same. The shuttle launch did not affect anything. And so I think we're going to have very interesting results from this experiment." The shuttle program reached a milestone today when data from Global Positioning System satellites was received aboard Discovery, processed and used to update the shuttle's navigation system. NASA is working to integrate GPS into the shuttle and to do away with costly ground-based TACAN landing aids. But the project is complex and engineers have had to work a variety of problems. Earlier this week, for example, the GPS hardware and the shuttle's flight computers had problems that resulted in erroneous data. Engineers think they know what happened and the computer in question [GPC-1] is now working normally again. But it's not yet clear if the GPS system will be active during Friday's re-entry. Lee Briscoe, director of mission operations at the Johnson Space Center, said engineers need to make sure no similar problems crop up during the computer-controlled entry. Otherwise, there are no new technical problems of any significance with the shuttle or its payloads. Earlier today, the astronauts used a camera on the shuttle's robot arm to look at a water dump nozzle on the side of Discovery's fuselage. One of the shuttle's three electricity producing fuel cells has been leaking water throughout the flight, but the crew reported today no ice had built up on the nozzle. "The orbiter's basically still in great shape," Briscoe said. The astronauts plan to spend Thursday packing up loose gear and checking out the shuttle's flight systems to make sure they'll be ready for Friday's landing. Touchdown at the Kennedy Space Center is scheduled for just after 2 p.m. "Right now, the weather looks real good at the Cape both Friday and Saturday, so we're looking forward to wrapping up the mission tomorrow and coming on back to KSC on Friday," Briscoe said. 6:30 a.m. Update: Shuttle crew in home stretch of historic mission The Discovery astronauts are in the home stretch of their historic mission, carrying out a battery of on-board experiments and engineering tests while gearing up for landing Friday at the Kennedy Space Center. In an impromptu inspection, astronauts Wendy Lawrence and Janet Kavandi plan to unberth the shuttle's robot arm this morning to take a close look at a nozzle on the orbiter's fuselage used to dump water overboard. One of the ship's three electricity producing fuel cells has been leaking water overboard throughout the flight and ground controllers want to make sure no ice has built up on the dump nozzle. Shortly after 6 a.m., commander Charles Precourt said water leaking from that nozzle had created a shower of ice crystals that made it look as if Discovery was flying through a snowstorm. This was quite normal, but unfortunately there was no video of what must have been a spectacular show. In other on-board activity today, additional tests are planned with the Spacehab Universal Communications System, an experimental system intended to provide an alternative method of sending voice, faxes and video from the shuttle to and from the ground using INMARSAT satellites. The astronauts have encountered a variety of technical problems with SHUCS and flight controllers say they are just now about halfway to the point where calls can be made. Shuttle pilot Dominic Gorie will carry out two runs with the solid surface combustion experiment, an ongoing project to learn more about how materials burn in weightlessness, and Lawrence will fill a plastic bag with about 100 pounds of water for use by the shuttle if landing is delayed for any reason. At 1:26 p.m., astronaut Franklin Chang-Diaz will participate in a Spanish-language interview with CBS Telenoticias and CNN en Espanol. Costa Rican-born hang-Diaz, the third man to fly in space six times, broke the shuttle record for cumulative time in space early today, exceeding the old record of 1,211 hours (50.5 days) set by astronaut Jeffrey Hoffman. =================================================================== Shuttle systems tested for Friday landing (06/11/98) 5 p.m. Update: Discovery set for landing The Discovery astronauts tested the shuttle's re-entry systems today and despite a bit more vibration than normal during hydraulic system checkout, flight director Wayne Hale said the veteran orbiter is in good shape for landing Friday at the Kennedy Space Center. Commander Charles Precourt and pilot Dominic Gorie plan to fire Discovery's twin braking rockets at 12:52:11 p.m., setting up a touchdown on runway 22 at 2:00:05 p.m. to close out NASA's ninth and final Mir docking mission. "All systems checked out normally," Hale said. "The crew did report some vibration and shuddering as they went through that. That's not the first time we've heard that from a crew. We are going to look at some of the data and make sure nothing untoward is going on. We think a lot of those vibrations are caused by the payload arrangement in the cargo bay and the natural frequency of the structure of the vehicle as we ... check out the hydraulic system aboard the shuttle." The astronauts also fired the shuttle's braking rockets during a pass over an ustralian radio telescope as part of a test to measure the effects of such plumes on the ionosphere. "At the end of that test, we did have one interesting note," Hale said. "On one of the engines, the left engine, one of the valves that controls the propellant flow to the engine is indicating 'open.' We don't believe that's a problem. Whether it's an indication problem or a real valve stuck in the open position, it's still usable, we have plenty of redundancy." The only other technical note of interest for readers who follow such things involves problems with an experimental navigation system being tested during Discovery's flight. Earlier in the mission, the system caused one of the shuttle's four primary flight computers to generate incorrect data. While engineers believe they know what caused the glitch, Hale said the experimental hardware will be deactivated for re-entry and landing just to be on the safe side. Forecasters are predicting excellent weather Friday and Saturday. The only issue, and it's not much of one, is smoke from wildfires in the central Florida area. "We have also been watching very carefully the smoke that's been generated from some wildfires in the area around central Florida," Hale said. "Someone has compared that to a normal day in the Los Angeles basin. We don't think that's going to be a problem, but of course we're going to watch that." Here are the latest landing numbers: ORBIT...TIME.........EVENT Friday 154.....12:52:11 p.m....Deorbit ignition 155.....02:00:05 p.m....Landing at KSC, runway 33 155.....02:28:55 p.m....Deorbit ignition 156.....03:35:55 p.m....Landing at KSC, runway 15 Saturday 169.....11:50 a.m.......Deorbit ignition 170.....12:54 p.m.......Landing at KSC 170.....01:25 p.m.......Deorbit ignition 171.....02:29 p.m.......Landing at KSC NASA is not expected to activate Edwards Air Force Base, Calif., for Friday's landing attempt. If entry is delayed to Saturday, however, the crew will have two California landing opportunities at 4:00 p.m. and 5:36 p.m. Assuming an on-time entry Friday, however, here's the crew's timeline: 08:51 a.m....Deorbit Prep begins 10:16 a.m....Cargo bay door closing 10:25 a.m....Flight computers loaded with OPS-3 entry software 11:29 a.m....The astronauts don their pressure suits 12:35 p.m....Mission control gives a "go" for deorbit 12:37 p.m....Discovery maneuvered to deorbit orientation 12:56 p.m....Deorbit ignition 02:00 p.m....Landing at the Kennedy Space Center A team of doctors and physical therapists will be standing by to assist astronaut Andrew Thomas as he begins re-adapting to gravity after 140 days in space. "Right away, we'll bring Andy to family and friends, he'll have a few minutes with them," said Tom Marshburn, a NASA flight surgeon. "Soon after that, he needs to fulfill the life sciences requirements. Usually, an hour and a half to two hours - potentially three hours - are required to fulfill that. After that, Andy has two hours that he can start doing some rehabilitation workouts. ... That'll be tailored purely to what Andy feels at the time." The rehabilitation period will last 45 days. A doctor will be available at all times. "Most of the time will be spent concentrating on Andy's physical rehabilitation, just making sure that he has a slow, progressive and safe return to normal functioning," Marshburn said. "He will have some life sciences requirements to fulfill during this 45 days. The first week will be fairly intense but after that, that will slack off. But typically his schedule will not take more than six hours per day. We like to give our long-duration crew members enough time to relax and to rest, to get back to their normal life and friends and families as much as possible." 2 p.m. Update: Thomas faces tough first days on Earth Two astronauts who spent more than eight months aboard the Mir space station have a simple message for returning Mir flyer Andrew Thomas: Take it easy. And go easy on the lasagna. "I would just tell Andy to be careful that first night, it's a dangerous time," said astronaut Michael Foale, who was aboard Mir last summer during a catastrophic collision. "Especially going to the bathroom!" "And that hot shower, don't make it a long one, it's a little hard to stand up, especially when you're washing your hair and your head has to move," added David Wolf, who replaced Foale aboard Mir. "That can get you twirling around pretty good that first night." Thomas has asked for lasagna and Oreo ice cream when he returns to Earth, but Wolf advised him to settle for simpler fare, saying "Don't eat the lasagna the night you land!" Both astronauts agreed Thomas can expect a variety of aches and pains as his body re-adapts to gravity after 140 days in space. "Muscular agony. That's exactly how it feels," said Foale. "It's like you've had the flu and every muscle aches. It's extraordinary. I had no idea how many muscles I had in my back and that they could all knot up at once. But they do. You feel very sore climbing up and down stairs or carrying your children, in my case. But that passes. In fact, the glow of just being back at home with your friends and family was just tremendous. So it's like getting over the flu but without the runny nose." Wolf joked that even his earlobes hurt the first few days back on Earth, "everything from there down my legs hurt. I'm still just getting back, four months out, to doing things nearly as well as I used to in terms of sports and such. Three or four days of extreme balance problems when he first gets back, likely some nausea in those first days along with some vestibular problems." But Wolf said Thomas' return to Earth will be a "glowing time in his life, it's really neat to come back to the spaceship Earth." Thomas said during an interview today he actually looks forward to the re-adaptation process. "I've been in an environment that's fundamentally unnatural for us and one of my great surprises was I started to feel very natural and very comfortable in that weightless environment after a short time. I've been that way for four-and-a-half months. Now I'm going to go back to what is the natural environment to be in and it's going to be a very interesting experience, I think, to see how my physiology, my neurovestibular system reacts to that change. "I think it's a personal transition, I think the response is different for different people," he said. "I suspect there will be moments of unpleasantness to it. But I think nonetheless it's going to be a very interesting thing to go through. I'm certainly looking forward to seeing how I feel and that whole experience. It's hard to imagine that something like gravity, which we take for granted, is for me, for some time at least, going to be totally alien and totally unnatural." Interestingly enough, more Americans have now spent time aboard Mir than Russians. Since the station's launch in 1986, 38 Russians have worked aboard Mir while 43 Americans have paid visits. Another 17 fliers from other nations also have visited the station. During nine docking missions, space shuttles delivered 28,086 pounds of equipment and supplies to Mir, along with nearly 15,000 pounds of water and a 9,000-pound shuttle docking module. Another 17,486 pounds of gear was returned to Earth. "It's been a great journey for everybody to this point, to execute and practice the things we're going to have to do over and over again in the future," said Frank Culbertson, manager of shuttle-Mir operations at the Johnson Space Center. "It's going to be quite a ride from here on. It's been quite a ride to date." Asked what he will remember most about his time aboard Mir, Foale described looking out into deep space during a power outage and realizing how big the universe is. "I had the luck to look at the universe and the galaxy from a totally quiet station, with nothing running, through a large window with the southern lights below us flickering and meteorites going into the Earth's atmosphere. And it was a tremendously vivid impression for me, something that Hollywood can never manage to equal, I think. It struck me just how small humankind is trying to do what it's doing but how great we are in attempting it." For Wolf, it was the memory of Mir itself. "I have a memory, I even dream of it now, of these red leather seats in the Mir and ivory looking buttons and a very classical, almost Jules Verne-type of spacecraft," said. "We will probably never have a spacecraft with this classic character. Even the musty areas that exist, the carpet that's worn, the picture of Yuri Gagarin over the table, there's over a decade of character built into this spacecraft. You get this Jules Verne feeling." Lessons learned working with the Russians aboard Mir will pay off during assembly of the international space station, all three agreed. And Foale provided an interesting example. "Probably the most visible problem we had to deal with on the Mir was the amount of water that condenses on the walls of a cold spacecraft in the event of a power failure or a bad attitude," he said. "In space, a space station has hot bits and cold bits and a big problem for a spacecraft designer is to make sure heat is spread uniformly around the station so you don't get water condensing in the cold areas. "That did happen on the Mir. At one point, seven tons of free water were condensed on the walls. Now this could happen to the international space station. ... We can't do major changes to the design. What we can do is change the way we think we're going to operate the station so we can minimize the effects of something like what happened on the Mir with the buildup of water on the walls." 6:30 a.m. Update: Crew awake; updating daily flight plan The Discovery astronauts are working through their final full day in orbit, wrapping up experiments, stowing loose gear and testing the shuttle's flight control system for re-entry and landing Friday. Touchdown at the Kennedy Space Center is scheduled for around 2:03 p.m. and forecasters say good weather is expected. "Right now, the weather looks real good at the Cape both Friday and Saturday, so we're looking forward to wrapping up the mission and coming on back to KSC on Friday," said Lee Briscoe, director of mission operations at the Johnson Space Center. At 8:56 a.m. today, commander Charles Precourt, pilot Dominic Gorie and flight engineer Wendy Lawrence were scheduled to begin a series of tests to make sure Discovery's flight control system and steering jets will be ready for entry. A news conference with Frank Culbertson, manager of shuttle-Mir operations for NASA, and Mir astronauts David Wolf and Michael Foale was set for 10 a.m. and at 12:51 p.m., the crew will participate in two final media interviews from orbit. Finally, entry flight director Wayne Hale will hold a traditional pre-landing news conference at 2 p.m. to provide the latest weather and technical data about Friday's entry. This status report will be updated after each of today's major events. =================================================================== Shuttle Discovery glides to windy touchdown (06/12/98) 10:10 p.m. Update: Thomas glad to be home; feels 'heavy' in gravity Australian-born astronaut Andrew Thomas, back on Earth after 141 days in space, said his return to the unfamiliar tug of gravity was a "bizarre experience" and that he felt "weighted down and heavy." Exhausted and feeling out of sorts, Thomas passed up a planned welcome-home serving of lasagna and Oreo ice cream and cancelled a NASA interview. He did, however, briefly discuss his return with NASA spokesman Bruce Buckingham. "Returning to gravity was a bizarre experience after so long in weightlessness," Thomas said. "I feel weighted down and heavy. I felt like I had bags of weights on my arms and legs. Once on the ground, I took a camera I had been working on on Mir and just remembered how light it used to feel." Thomas was carried off the shuttle as planned, "but I was able to walk a few steps once I was in the crew transport vehicle," he said. "I was more comfortable in the prone position. Eventually I realized I was very tired and just wanted to lay down and be quiet for a while. Generally, I did just fine." Asked about his stay aboard the Russian space station, Thomas said "it was a great flight and I had great views of Australia. The amateur radio guys in Australia kept me appraised of the happenings there." A videotaped NASA interview with Thomas is expected to be released Saturday (exact time TBD). 9:30 p.m. Update: Thomas interview delayed to Saturday A planned NASA interview with astronaut Andrew Thomas was cancelled this evening and rescheduled for Saturday (exact time TBD). A NASA spokeswoman said she was not sure why the interview was called off, but Thomas, back on Earth after 141 days in weightlessness, had been up more than 17 hours at that point and no doubt was exhausted. This status report will be updated when more details become available. 8 p.m. Update: Astronauts describe mission Looking back on the shuttle-Mir program, Discovery flight engineer Wendy Lawrence captured the mood of the moment this evening, saying the most important payoff might well be the trust and friendship that have developed between NASA and its former Cold War rival. "Certainly, there have been a whole host of medical experiments and from the perspective of the U.S. space program, we've learned a great deal about the effects of long-duration stays in space," she said when asked whether the shuttle-Mir program was worth the cost. "Our hope is to take that knowledge and apply it towards a mission to Mars or to go back to the moon. We've had a very broad-based program and we have produced results in many, many areas." But more important, she said, was the transformation that has turned competing space agencies into allies on the high frontier. "I'm a commander in the Navy as is Dom [shuttle pilot Dominic Gorie]," Lawrence said at a post-landing news conference. "We trained to fight against Russia. I know when I was at the Naval Academy some 20 years ago I never thought in my lifetime that I would have an opportunity to go to Russia, much less an opportunity to go to Russia and work side by side with Russian cosmonauts and realize they were just like me. And I really do think that's the benefit to the American taxpayer. At least in the space program, we can call the Russians not only partners but we can call them friends and people that we trust." Looking a bit tired and moving slowly, commander Charles Precourt said "we're happy to be home." "We're just really happy to have seen phase one come to a successful close and we're looking forward to starting construction of the international space station really soon here," he told reporters at a post-landing news conference. Phase one is what NASA calls the shuttle-Mir docking program. "The flight couldn't have been more enjoyable. We launched on time, landed on time and in between was intense. It was exciting, it was different in many ways, we learned a lot. We had overall, I think, a very, very successful joint part of the mission with the Mir and we brought it home ... on time. So from our standpoint, it was a very good concluding mission to a very, very successful program. And I think looking back on it, when I started phase one, it exceeds any expectations I certainly could have had myself." Franklin Chang-Diaz, the third man to fly in space six times, sat by astronaut Andrew Thomas during entry as the Australian-born Thomas returned to Earth after 140 days in space. "He was in really good spirits, he was talking all the time," said Chang-Diaz. "We took a lot of pictures, he was smiling and giving the thumbs up, he was very happy." The shuttle appeared to bounce slightly during touchdown in a shifting crosswind, but Precourt said it was hardly perceptible to Thomas or the rest of the crew. "Nobody noticed it bounced," he said. "I knew it because I was at the controls. We had a little kiss of the wheels as I corrected for the crosswind and the sink rate was essentially zero when it happened. So nobody knew it except me." Asked how Thomas coped with his return to the tug of Earth's gravity, Precourt said returning astronauts are "relieved and thrilled" to get back home "and "Andy was no exception." "But they're also struggling physically," Precourt said. "Andy's words were, 'Charlie, would you stop that high-G turn?' Because it felt to him like one G [gravity] was more like four Gs. So he was very much feeling the effects of the return to gravity. But you know, he was off the vehicle at the same pace as the others have come off. He relaxed in his chair and ... was in really good spirits." 5:55 p.m. Update: Goldin hails phase one program At a brief post-landing ceremony in front of Discovery, Precourt gave NASA Administrator Daniel Goldin three mementos of the shuttle-Mir program: An American flag carried to Mir with astronaut Norm Thagard in March 1995; a wrench used by spacewalking cosmonauts; and an optical disk symbolizing the scientific return from the program. "We're very, very proud to be part of the concluding flight of the phase one program," Precourt told Goldin. "Thank you very much for supporting this program and making us all so successful." "Thank you, Charlie," Goldin replied. "This is a wonderful, wonderful handover. It's not the end, it's just the start of a new phase. ... We're moving ahead, we're not moving backwards. And it's also symbolic of the incredible change we've had in our world where when we started out we didn't know each other. And now, we really know the Russians. And we know with certainty we're going to open up the universe to benefit this planet." Frank Culbertson, the veteran shuttle commander who ultimately gave up an opportunity to fly again to manage the shuttle-Mir program, said the end of the phase one program marked "a happy and sad moment." "It's wonderful to see it successful completed," he said. "I am extremely happy we were able to do what we set out to do, which was to take seven Americans to the Mir and bring them home safely. But even better, we learned how to work better together in space, we're better prepared to operate the international space station and we did what we said we were going to do. ... Only history will tell how successful we were. But I think we'll see this was the right way to go and we'll go much, much further as we do it together." 2:30 p.m. Update: Shuttle Discovery glides to windy landing The shuttle Discovery settled to a windy touchdown at the Kennedy Space Center today, bringing NASA's final Mir resident back to Earth after 141 days in space and closing the books on the shuttle-Mir program after nine successful docking missions. With commander Charles Precourt and pilot Dominic Gorie at the controls, the black-and-white spaceplane swooped to a slightly bumpy, tire-smoking touchdown on runway 15 at 2:00:00 p.m. to close out a four-million-mile voyage spanning 154 complete orbits since blastoff June 2. "Houston, Discovery, wheels stopped," Precourt radioed mission control as Discovery coasted to a stop. Shifting crosswinds on final approach appeared to make the landing a bit bumpier than usual, but no problem for the veteran commander. "Welcome home, Discovery," called astronaut Scott Horowitz in Houston. "Nice crosswind landing, Charlie. Congrats to you and your crew on a successful final shuttle flight to the Mir and a super job on completing phase one. And Andy, they'll have your lasagna and Oreo cookie ice cream waiting when you get there." Touchdown marked the end of an odyssey for Australian-born astronaut Andrew Thomas, who spent 130 days aboard the Mir space station as NASA's seventh and final long-duration resident. From launch in January to landing today, Thomas logged 140 days and 15 hours in space, boosting America's cumulative total over seven such flights to 977 days, the last 812 days in a row. Asked last week what he wanted for his first meal back on Earth, Thomas ordered lasagna and Oreo ice cream. Sounding healthy and in good spirits after landing, Thomas called Horowitz from his seat on Discovery's lower deck to thank mission control for the ride home. "Greetings to you and everyone at MCC," he said. "I want to thank you all for bringing me home and giving me a great ride, I really enjoyed it. And as you said, I'm looking forward to that first meal. Thank everyone there very much on my behalf." "Everyone's smiling, Andy," Horowitz replied. "Welcome home." "And Houston, Discovery, one more thing. Could you ask the CDR [commander] to stop this high-G turn?" Thomas joked, perhaps feeling a bit dizzy as he began re-adjusting to gravity. "OK, we'll tell him to stop the hot rod," Horowitz said. The shuttle-Mir flights were intended to serve as a training ground for NASA and the Russian Space Agency to perfect the command and control techniques that will be needed when the two agencies begin building the international space station later this year. The phase one program, as the shuttle-Mir flights were called, also gave NASA a chance to gain experience in long-duration spaceflight while the Russians were able to use the shuttle to ferry critical supplies and fresh water to Mir. Today's landing marked the end of a remarkably successful program, all the more so, perhaps, given the problems encountered aboard Mir last year when a fire and a collision raised questions about the station's safety. While Russia plans to operate Mir for another year or so, NASA is shifting gears and setting its sights on the international space station. NASA originally hoped to begin building the new station this summer, but funding problems in Russia have delayed first flight to late November. As a result, NASA now faces a five-month shuttle launch hiatus with the next flight scheduled for Oct. 29. That's when Discovery and Mercury astronaut John Glenn will return to space. As with all returning Mir visitors, Thomas made the trip back to Earth resting on his back in a special recumbent seat on Discovery's lower deck. A flight surgeon was standing by to assist him as his body begins the long re-adaptation to Earth's gravity after more than four months in weightlessness. "Right away, we'll bring Andy to family and friends, he'll have a few minutes with them," said Tom Marshburn, a NASA flight surgeon. "Soon after that, he needs to fulfill the life sciences requirements. Usually, an hour and a half to two hours - potentially three hours - are required to fulfill that. After that, Andy has two hours that he can start doing some rehabilitation workouts. ... That'll be tailored purely to what Andy feels at the time." The rehabilitation period will last 45 days and "most of the time will be spent concentrating on Andy's physical rehabilitation, just making sure that he has a slow, progressive and safe return to normal functioning," Marshburn said. "He will have some life sciences requirements to fulfill during this 45 days. The first week will be fairly intense but after that, that will slack off. But typically his schedule will not take more than six hours per day. We like to give our long-duration crew members enough time to relax and to rest, to get back to their normal life and friends and families as much as possible." Thomas's crewmates - Precourt, Gorie, flight engineer Wendy Lawrence, Franklin Chang-Diaz, Janet Kavandi and Russian cosmonaut Valery Ryumin - were expected to walk off the shuttle an hour or so after touchdown for a traditional post-flight inspection of the orbiter. Ryumin was on board specifically to assess the Mir station's overall health and with today's landing, he has logged 372 days in space on four flights, putting him 13th in the world for time in space. Here's an updated list of the top 18 space endurance record holders (source: Rob Navias, NASA public affairs): 1. Valery Polyakov............679 days: 2 flights 2. Anatoly Solovyev...........652 days: 5 flights 3. Musa Manarov...............541 days: 2 flights 4. Alexander Viktorenko.......489 days: 4 flights 5. Sergei Krikalev............472 days: 3 flights 6. Yuri Romanenko.............430 days: 3 flights 7. Alexander Volkov...........392 days: 3 flights 8. Vladimir Titov.............387 days: 4 flights 9. Vasily Tsibliev............383 days: 2 flights 10. Yuri Usachev..............376 days: 2 flights 11. Leonid Kizim..............375 days: 3 flights 12. Alexander Serebrov........374 days: 4 flights 13. Valery Ryumin.............372 days: 4 flights 14. Sergei Avdeyev............368 days: 2 flights 15. Vladimir Solovyev.........362 days: 2 flights 16. Victor Afanasyev..........357 days: 2 flights 17. Alexander Kaleri..........343 days: 2 flights 18. Vladimir Lyakhov..........333 days: 3 flights Discovery's crew will spend the night at the Kennedy Space Center and fly back to the Johnson Space Center in Houston on Saturday. A news conference with Precourt and other crew members (but not Thomas) is expected later today In the meantime, here are the updated landing numbers: ................KSC........EAFB........WS........Total Night landings..04.........05..........00........09 Day landings....40.........40..........01........81 TOTAL...........44.........45..........01........90 Most recent.....06/12/98...03/31/96....03/30/82 1 p.m. Update: Shuttle Discovery drops out of orbit Flying upside down and backward over the Indian Ocean southeast of India, commander Charles Precourt and pilot Dominic Gorie fired the shuttle Discovery's twin orbital maneuvering system rockets at 12:52:25 p.m. for four minutes and eight seconds, putting the spacecraft on course for a 2 p.m. landing at the Kennedy Space Center. The rocket firing went smoothly with no apparent problems from a suspect propellant valve in the left-side engine. Telemetry Thursday indicated the valve was stuck open, which could have caused the engine to burn longer than desired. Flight controllers told Precourt to be ready for a manual cutoff, but the engine worked normally. This status report will be updated after Discovery lands or as conditions warrant. 10:30 a.m. Update: Cargo bay doors closed for entry Astronaut Janet Kavandi closed the shuttle Discovery's cargo bay doors on time today just before 10:20 a.m., setting the stage for a deorbit rocket firing at 12:52 p.m. Touchdown remains scheduled for 2:00:05 p.m. and while there's a chance the sea breeze could create a low deck of broken clouds, flight controllers appear optimistic about an on-time landing. There are no technical problems of any significance with the shuttle, but flight controllers have reviewed contingency procedures in case of problems with Discovery's left-side orbital maneuvering system rocket. The shuttle is equipped with two such OMS engines, which provide the braking power to drop the ship out of orbit. Entry flight director Wayne Hale said Thursday telemetry indicated a valve in the left-side braking rocket might have stuck open after an earlier test firing. It's thought to be a bad indicator and not a real problem, but it's worth keeping in mind. In the event of an OMS engine failure, the shuttle's computers are programmed to fire the operational engine longer than planned to make up for the lost thrust. Smaller steering jets also can be fired depending on how much braking power is needed. The crew can abort the automatic firing depending on the nature of the failure. Again, no one believes there's a problem and I mention all this just for the record. 7 a.m. Update: Discovery crew gears up for landing The Discovery astronauts are readying the shuttle for re-entry and landing today to close out NASA's ninth and final mission to the Russian Mir space station. Bringing Andrew Thomas back to Earth after 140.6 days in space, Discovery is scheduled to touch down on runway 33 at the Kennedy Space Center at 2 p.m. A second landing opportunity is available one orbit later at 3:36 p.m., but good weather is expected for an on-time re-entry. Here are the numbers: ORBIT...TIME............EVENT 154.....12:52:11 p.m....Deorbit rocket firing 155.....02:00:05 p.m....Landing at KSC, runway 33 155.....02:28:55 p.m....Deorbit rocket firing 156.....03:35:55 p.m....Landing at KSC, runway 15 Commander Charles Precourt and his crew will transition to the deorbit timeline just before 9 a.m. to make final preparations. Here's the timeline: 08:52 a.m....Deorbit preparations begin 10:12 a.m....The shuttle's payload bay doors are closed 10:34 a.m....Flight computers are loaded with OPS-3 entry software 10:58 a.m....The crew reviews entry procedures 11:27 a.m....The astronauts don their pressure suits 12:31 p.m....Mission control "go" for deorbit rocket firing 12:52 p.m....Deorbit ignition 01:28 p.m....Entry interface 02:00 p.m....Landing at KSC And so, flying high above the southern Indian Ocean, Precourt and pilot Dominic Gorie plan to fire Discovery's twin orbital maneuvering system rockets at 12:52 p.m. for four minutes and 11 seconds, slowing the shuttle by 282 mph and dropping the low point, or perigee, of its orbit into the atmoshere. The spacecraft will fall into the discernible atmosphere 400,000 feet above the Pacific Ocean at 1:28 p.m. From there, it's just 5,064 miles to touchdown, a distance Discovery will cover in 32 minutes flat. For those of you who keep up with such trivia, this will be the 44th shuttle landing at KSC, the 15th in a row and the 16th in the last 17 dating back to February 1995. ................KSC........EAFB........WS........Total Night landings..04.........05..........00........09 Day landings....39.........40..........01........80 TOTAL...........43.........45..........01........89 Most recent.....05/03/98...03/31/96....03/30/82 ===================================================================