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"930406.DFC" (40329 bytes) was created on 04-06-93 06-Apr-93 Daily File Collection These files were added or updated between 05-Apr-93 at 21:00:00 {Central} and 06-Apr-93 at 21:01:40. =--=--=START=--=--= NASA Spacelink File Name:930406.REL 4/06/93: SCIENTISTS REVEAL NATURE OF EXPLODING, RED SUPERGIANT STAR NASA scientists have direct evidence that red supergiants -- the largest stars known -- end their existence in massive explosions known as supernovae. Until this week, astronomers could only speculate that these explosions represented the death of such stars. "It's a very exciting result and a tremendous advance for stellar astronomy," said Dr. George Sonneborn, of NASA's Goddard Space Flight Center, Greenbelt, Md. "This substantiates decades of work in stellar structure theory," said Sonneborn, a research scientist for NASA's International Ultraviolet Explorer (IUE) satellite, which obtained the new evidence through observations of a new supernova on March 30. "It has long been suspected that red supergiants explode to become supernovae. Now we have first-hand evidence of that." "This clearly is the second most important supernova of the century," said Sonneborn. "It's of major significance." The Type II supernova took place about 12 million light-years from Earth in a galaxy known as M81 in the Ursa Major or Big Bear constellation. It has been designated SN 1993J because it was the tenth supernova discovered this year. IUE's Fast Response Was Critical The supernova's nearness and the quickness with which IUE was able to observe it were critical factors that enabled scientists to verify an aspect of stellar evolution theory. A supergiant is massive -- about the diameter of the solar system out to the planet Jupiter. Stellar evolution theory long has taught that red supergiants can explode to become supernovae. But in the only previous case in which astronomers definitively determined the type of star that produced a supernova explosion, it turned out to be a smaller and hotter blue supergiant. That supernova occurred in 1987, 160,000 light-years away and also was observed by IUE. The difference between red and blue supergiants is that the blue variety are believed to have evolved from red supergiants after shedding much of their extended atmosphere. Thus, blue supergiants are smaller than red supergiants. The satellite's observations of the supernova revealed that the exploding star is surrounded by a thick shell of slowly expanding gas. Heated to very high temperatures by the enormous energy released in the stellar explosion, the ultraviolet emissions from this glowing gas were detected by IUE. A red supergiant loses large amounts of material through a slowly moving wind flowing outward from the star. The presence of this glowing gas in the first observations of the supernova means that it must be close to the explosion and that the star must have been in a red supergiant phase shortly before its demise. In a Type II supernova explosion, the central core of the supergiant star collapses after the star uses up its nuclear fuel. This central implosion sets off an explosion of the outer layers of the star, leaving behind a small, incredibly dense remnant body called a neutron star or possibly a black hole. A black hole derives its name from the theory that its gravity is so powerful not even light can escape it. "A supernova is the most cataclysmic event in the universe," said Goddard's Dr. Yoji Kondo, IUE Project Scientist. "The light it produces for a few weeks is roughly equivalent to the brightness of the whole Milky Way galaxy, which contains a few hundred billion stars." Explosions of these huge stars are not uncommon, but rarely are they observed so close by, Kondo added. "On a cosmic scale, it's practically a next- door neighbor," he said, of SN 1993J which IUE observed after it was first spotted by amateur astronomers in Spain. Prior to the 1987 blue supergiant explosion, the most recent nearby supernova that could be seen without a telescope took place in 1604 and was observed by Johannes Kepler, one of the great German astronomers. Unlike the 1604 and 1987 supernovae, however, the one viewed March 30 was not close enough to be visible to the naked eye. Its brightness was of 9.2 magnitude. A brightness of at least the sixth magnitude would have been necessary for the March 30 supernova to be seen without using a telescope. Learning From SN 1993J Kondo and Sonneborn said much stands to be learned from the March 30 supernova. Because it is so close and because IUE observed it so quickly, scientists will obtain data about the explosion that they otherwise would not have gotten. "We'll learn things about supernovae that we never could have until now," said Sonneborn. For instance, astronomers for the first time anticipate studying the stellar wind -- the outflowing of energy -- from this type of star in a fashion not possible before. That's because the light from the supernova illuminated the red supergiant's stellar wind in a way that scientists can see it, Sonneborn said. "The stellar wind will tell us about the late stages of the star's life prior to the explosion," Sonneborn said. "This also is a rare opportunity to study the tenuous gases in the far reaches of the Milky Way galaxy and in the M81 galaxy by observing the absorption caused by such gases upon the spectrum of this bright supernova." NASA's International Ultraviolet Explorer was launched into modified synchronous Earth orbit in January 1978 by a Delta rocket from Cape Canaveral, Fla., in cooperation with the European Space Agency (ESA) and the British Science and Engineering Research Council. It is managed by Goddard Space Flight Center for the Office of Space Science at NASA Headquarters in Washington, D.C. Goddard shares operational control of the satellite with the ESA in Villafranca, Spain. - end - Source:NASA Spacelink Modem:205-895-0028 Internet:192.149.89.61 =--=--=-END-=--=--= =--=--=START=--=--= NASA Spacelink File Name:930406.SHU KSC SHUTTLE STATUS REPORT 4/6/93 KSC SHUTTLE STATUS REPORT Tuesday, April 6, 1993 KSC Contact: Bruce Buckingham Mission: STS-56/ATLAS-2/SSBUV Orbital altitude: 184 sm Vehicle: Discovery/OV-103 Inclination: 57 degrees Location: Launch Pad 39-B Crew Size: 5 Mission Duration: 8 days/6 hours KSC Landing: NET April 16 Launch Date: NET April 8 Launch Window: 1:29 - 3:57am NOTE: Launch of the Shuttle Discovery was aborted this morning at T-11 seconds by the onboard computers when instrumentation on the liquid hydrogen high point bleed valve in the main propulsion system indicated off when it should have indicated on. Follow-up analysis showed the instrumentation was faulty and that the valve was in the proper configuration for launch. Managers will be meeting later this afternoon to further evaluate the situation. At this time, the launch team is working under the 48-hour scrub turn-around schedule with the understanding a final decision will be made later today by the mission management team. If the 48-hour scrub turn-around schedule is verified the countdown clock will be recycled to the T-11 hour mark and paced for a T-0 at 1:29 a.m. Thursday. At this time, there are no plans to rotate the service structure around the vehicle or service the onboard cryogenic fuels. The crew has returned to their quarters in the Operations and Checkout Building and are essentially following their L-2 day timeline. IN WORK TODAY: * Vehicle safing and securing * Liquid hydrogen boiloff * Flight crew equipment destow * Re-configuring OMS/RCS crossfeed heaters * Main engine purging and re-positioning * Re-fill water deluge system WORK SCHEDULED: * Change liquid hydrogen system to an inert gaseous purge * Open pad for non-hazardous work * Begin change-out of time critical mid-deck payloads WORK COMPLETED: * Initial safing and securing of the vehicle * Initiated 48-hour scrub turn-around schedule * Secured liquid oxygen and liquid hydrogen system and began drain back of cryogenic fuels from the external tank STS-56 LAUNCH WEATHER FORECAST The weather forecast for launch of Discovery on April 8 indicates a 30 percent chance of violating launch constraints during the window opening at 1:32 a.m., due to cloud ceilings below 8000 feet and concerns for crosswinds at the Shuttle Landing Facility. There is a 30 percent chance of violating tanking constraints due to lightning within 5 miles of the pad. Tanking is scheduled to begin at 5:12 p.m. Monday. The 24 hour and 48 hour delay predictions show a 20 percent and a 30 percent chance of violation, respectively. SUMMARY OF HOLDS AND HOLD TIMES FOR STS-56 T-27 hours --- 4 hour hold ----------- Sat., 9:00 pm - 1:00 am T-19 hours --- 4 hour hold ----------- Sun., 10:00 am - 2:00 pm T-11 hours -- 13 hour, 12 min. hold - Sun., 10:00 pm - 11:12 am T-6 hours ---- 1 hour hold ---------- Mon., 4:12 pm - 5:12 pm T-3 hours ---- 2 hour hold ---------- Mon., 8:12 pm - 10:12 pm T-20 minutes - 10 minute hold ------- Tues., 12:52 am - 1:02 am T-9 minutes -- 10 minute hold ------- Tues., 1:13 am - 1:23 am SUMMARY OF STS-56 LAUNCH DAY CREW ACTIVITIES Monday/Tuesday 8:37 pm Wake up 9:07 pm Breakfast/Dinner 9:37 pm Weather briefing (CDR, PLT, MS2) 9:37 pm Don flight equipment (MS1, MS3) 9:47 pm Don flight equipment (CDR, PLT, MS2) 10:17 pm Depart for launch pad 39-B 10:47 pm Arrive at white room and begin ingress 12:02 am Close crew hatch 1:32 am Launch (April 6, 1993) CREW FOR MISSION STS-56 Commander (CDR) Kenneth Cameron Pilot (PLT) Stephen Oswald Payload Commander (MS1) Michael Foale Mission Specialist (MS2) Kenneth Cockrell Mission Specialist (MS3) Ellen Ochoa Mission: STS-55/SL-D2 Orbital Altitude: 160 nm Vehicle: Columbia/OV-102 Inclination: 28.45 degrees Location: Launch Pad 39-A Crew Size: 7 Mission Duration: 8 days/22 hours KSC Landing: May 3 Target Launch Date: NET April 24 IN WORK TODAY: * Securing of main engines following replacement * Hydraulic operations * Close rudder speed brake * Cavity purges * Preparations to open payload bay doors today to replace GAUSS camera film WORK SCHEDULED: * Continue electrical checks on main engines * Reaction control system regulator flow checks (Tuesday) * Preparations to enter spacelab to service experiments (Thursday) WORK COMPLETED: * Main engine installation * Thruster drying and inspections * Liquid hydrogen actuator hose leak checks ----------------------------------------------------------------- Mission: STS-57/Spacehab/EURECA-Retrieval Orbital Alt.: 250 nm Vehicle: Endeavour/OV-105 Inclination: 28 degrees Location: Vehicle Assembly Building Crew Size: 6 Mission Duration: 7days/23 hours Target KSC Landing: May 26 Target Launch Date: May 18 IN WORK TODAY: * Shuttle interface test * T-0 umbilical closeouts and leak checks and cavity purge * Reposition body flap and rudder speed brake WORK SCHEDULED: * SRB hydraulic tests * Begin main engine installation April 12 * Rollout to pad 39-B targeted for NET April 19 WORK COMPLETED: * Electrical mates between orbiter and external tank * Hydraulic circulation and sampling * Liquid oxygen monoball closeouts Source:NASA Spacelink Modem:205-895-0028 Internet:192.149.89.61 =--=--=-END-=--=--= =--=--=START=--=--= NASA Spacelink File Name:930406.SKD Daily News/NASA TV Sked 4/6/93 Daily News Tuesday, April 6, 1993 Two Independence Square, Washington, D.C. Audio Service: 202/358-3014 % STS-56 mission status; % Columbia pre-launch preparations; % Stennis Space Center update. * * * * * * * * * * * * * * * * Space Shuttle Discovery's STS-56 mission was aborted this morning at T-11 seconds. The onboard computers aborted the mission when instrumentation on the liquid hydrogen high point bleed valve in the main propulsion system indicated "off" when it should have indicated "on". Further analysis showed the instrumentation was faulty and that the valve was in the proper configuration for launch. Later this afternoon, managers will meet to evaluate the situation further. At present the launch team is working under the 48-hour scrub turn-around schedule. However, a final decision will be made later today by the mission management team. If management decides to verify the 48-hour scrub turn-around schedule, the countdown clock will be recycled to the T-11 hour mark and launch would be scheduled for 1:29 a.m. Thursday. * * * * * * * * * * * * * * * * Technicians at the Kenndey Space Center continue to prepare the Space Shuttle Columbia for its upcoming STS-55 mission. Columbia is scheduled to launch no earlier than April 24, 1993. Workers are installing the main engines and have completed thruster drying and inspections. Later this week, technicians will continue electrical checks on the main engines and make preparations to enter spacelab to service experiments. * * * * * * * * * * * * * * * * The Stennis Space Center reports that an Early Education Monday program was conducted for approximately 160 kindergarten students from area schools. Personnel at the Teacher Resource Center had the opportunity to participate in a Women in Science and Technology conference held at Pearl River Community College. In preparation for the upcoming Greater Baton Rouge Chamber of Commerce Education Expo, the Visitor Center will set up and staff exhibits this weekend. Attendance is expected to exceed 20,000. * * * * * * * * * * * * * * * * Here's the broadcast schedule for Public Affairs events on NASA TV. Note that all events and times may change without notice and that all times listed are Eastern. Live indicates a program is transmitted live. Tuesday, April 6, 1993 Noon NASA Today News Show. 12:15 pm Aeronautics & Space Report. 12:30 pm America's Wings. 1:00 pm Flight of Apollo 7. 1:30 pm Our Star, The Sun. 2:00 pm Launch Box #3. 2:30 pm Ingredients for Space Travel. 3:00 pm Gemini, The Twins. 3:30 pm Around the Moon. Wednesday, April 7, 1993 Noon NASA Today News. 12:15 pm Areonautics & Space Report. 12:30 pm Aero Oddities. 1:00 pm Legacy of Gemini. 1:30 pm Mercury: Exploration of a Planet. 2:00 pm Virginia Space Consortium : Reach for the Star. 2:30 pm NASA Biosatellite Program. 3:00 pm Transition Years 3:30 pm Regaining the Edge NASA TV is carried on GE Satcom F2R, transponder 13, C-Band, 72 degrees West Longitude, transponder frequency is 3960 MHz, audio subcarrier is 6.8 MHz, polarization is vertical. Source:NASA Spacelink Modem:205-895-0028 Internet:192.149.89.61 =--=--=-END-=--=--= =--=--=START=--=--= NASA Spacelink File Name:930406A.REL 4/06/93: GIBBONS OUTLINES SPACE STATION REDESIGN GUIDANCE Sarah Keegan Headquarters, Washington, D.C. April 6, 1993 RELEASE: 93-64 Dr. John H. Gibbons, Director, Office of Science and Technology Policy, outlined to the members-designate of the Advisory Committee on the Redesign of the Space Station on April 3, three budget options as guidance to the committee in their deliberations on the redesign of the space station. A low option of $5 billion, a mid-range option of $7 billion and a high option of $9 billion will be considered by the committee. Each option would cover the total expenditures for space station from fiscal year 1994 through 1998 and would include funds for development, operations, utilization, Shuttle integration, facilities, research operations support, transition cost and also must include adequate program reserves to insure program implementation within the available funds. Over the next 5 years, $4 billion is reserved within the NASA budget for the President's new technology investment. As a result, station options above $7 billion must be accompanied by offsetting reductions in the rest of the NASA budget. For example, a space station option of $9 billion would require $2 billion in offsets from the NASA budget over the next 5 years. Gibbons presented the information at an organizational session of the advisory committee. Generally, the members-designate focused upon administrative topics and used the session to get acquainted. They also received a legal and ethics briefing and an orientation on the process the Station Redesign Team is following to develop options for the advisory committee to consider. Gibbons also announced that the United States and its international partners -- the Europeans, Japanese and Canadians -- have decided, after consultation, to give "full consideration" to use of Russian assets in the course of the space station redesign process. To that end, the Russians will be asked to participate in the redesign effort on an as-needed consulting basis, so that the redesign team can make use of their expertise in assessing the capabilities of MIR and the possible use of MIR and other Russian capabilities and systems. The U.S. and international partners hope to benefit from the expertise of the Russian participants in assessing Russian systems and technology. The overall goal of the redesign effort is to develop options for reducing station costs while preserving key research and exploration capabilitiaes. Careful integration of Russian assets could be a key factor in achieving that goal. Gibbons reiterated that, "President Clinton is committed to the redesigned space station and to making every effort to preserve the science, the technology and the jobs that the space station program represents. However, he also is committed to a space station that is well managed and one that does not consume the national resources which should be used to invest in the future of this industry and this nation." NASA Administrator Daniel S. Goldin said the Russian participation will be accomplished through the East-West Space Science Center at the University of Maryland under the leadership of Roald Sagdeev. -end- Source:NASA Spacelink Modem:205-895-0028 Internet:192.149.89.61 =--=--=-END-=--=--= =--=--=START=--=--= NASA Spacelink File Name:5_11_5.TXT 4/06/93: SCIENTISTS REVEAL NATURE OF EXPLODING, RED SUPERGIANT STAR NASA scientists have direct evidence that red supergiants -- the largest stars known -- end their existence in massive explosions known as supernovae. Until this week, astronomers could only speculate that these explosions represented the death of such stars. "It's a very exciting result and a tremendous advance for stellar astronomy," said Dr. George Sonneborn, of NASA's Goddard Space Flight Center, Greenbelt, Md. "This substantiates decades of work in stellar structure theory," said Sonneborn, a research scientist for NASA's International Ultraviolet Explorer (IUE) satellite, which obtained the new evidence through observations of a new supernova on March 30. "It has long been suspected that red supergiants explode to become supernovae. Now we have first-hand evidence of that." "This clearly is the second most important supernova of the century," said Sonneborn. "It's of major significance." The Type II supernova took place about 12 million light-years from Earth in a galaxy known as M81 in the Ursa Major or Big Bear constellation. It has been designated SN 1993J because it was the tenth supernova discovered this year. IUE's Fast Response Was Critical The supernova's nearness and the quickness with which IUE was able to observe it were critical factors that enabled scientists to verify an aspect of stellar evolution theory. A supergiant is massive -- about the diameter of the solar system out to the planet Jupiter. Stellar evolution theory long has taught that red supergiants can explode to become supernovae. But in the only previous case in which astronomers definitively determined the type of star that produced a supernova explosion, it turned out to be a smaller and hotter blue supergiant. That supernova occurred in 1987, 160,000 light-years away and also was observed by IUE. The difference between red and blue supergiants is that the blue variety are believed to have evolved from red supergiants after shedding much of their extended atmosphere. Thus, blue supergiants are smaller than red supergiants. The satellite's observations of the supernova revealed that the exploding star is surrounded by a thick shell of slowly expanding gas. Heated to very high temperatures by the enormous energy released in the stellar explosion, the ultraviolet emissions from this glowing gas were detected by IUE. A red supergiant loses large amounts of material through a slowly moving wind flowing outward from the star. The presence of this glowing gas in the first observations of the supernova means that it must be close to the explosion and that the star must have been in a red supergiant phase shortly before its demise. In a Type II supernova explosion, the central core of the supergiant star collapses after the star uses up its nuclear fuel. This central implosion sets off an explosion of the outer layers of the star, leaving behind a small, incredibly dense remnant body called a neutron star or possibly a black hole. A black hole derives its name from the theory that its gravity is so powerful not even light can escape it. "A supernova is the most cataclysmic event in the universe," said Goddard's Dr. Yoji Kondo, IUE Project Scientist. "The light it produces for a few weeks is roughly equivalent to the brightness of the whole Milky Way galaxy, which contains a few hundred billion stars." Explosions of these huge stars are not uncommon, but rarely are they observed so close by, Kondo added. "On a cosmic scale, it's practically a next- door neighbor," he said, of SN 1993J which IUE observed after it was first spotted by amateur astronomers in Spain. Prior to the 1987 blue supergiant explosion, the most recent nearby supernova that could be seen without a telescope took place in 1604 and was observed by Johannes Kepler, one of the great German astronomers. Unlike the 1604 and 1987 supernovae, however, the one viewed March 30 was not close enough to be visible to the naked eye. Its brightness was of 9.2 magnitude. A brightness of at least the sixth magnitude would have been necessary for the March 30 supernova to be seen without using a telescope. Learning From SN 1993J Kondo and Sonneborn said much stands to be learned from the March 30 supernova. Because it is so close and because IUE observed it so quickly, scientists will obtain data about the explosion that they otherwise would not have gotten. "We'll learn things about supernovae that we never could have until now," said Sonneborn. For instance, astronomers for the first time anticipate studying the stellar wind -- the outflowing of energy -- from this type of star in a fashion not possible before. That's because the light from the supernova illuminated the red supergiant's stellar wind in a way that scientists can see it, Sonneborn said. "The stellar wind will tell us about the late stages of the star's life prior to the explosion," Sonneborn said. "This also is a rare opportunity to study the tenuous gases in the far reaches of the Milky Way galaxy and in the M81 galaxy by observing the absorption caused by such gases upon the spectrum of this bright supernova." NASA's International Ultraviolet Explorer was launched into modified synchronous Earth orbit in January 1978 by a Delta rocket from Cape Canaveral, Fla., in cooperation with the European Space Agency (ESA) and the British Science and Engineering Research Council. It is managed by Goddard Space Flight Center for the Office of Space Science at NASA Headquarters in Washington, D.C. Goddard shares operational control of the satellite with the ESA in Villafranca, Spain. - end - Source:NASA Spacelink Modem:205-895-0028 Internet:192.149.89.61 =--=--=-END-=--=--= =--=--=START=--=--= NASA Spacelink File Name:6_10_8.TXT GIBBONS OUTLINES SPACE STATION REDESIGN GUIDANCE Sarah Keegan Headquarters, Washington, D.C. April 6, 1993 RELEASE: 93-64 Dr. John H. Gibbons, Director, Office of Science and Technology Policy, outlined to the members-designate of the Advisory Committee on the Redesign of the Space Station on April 3, three budget options as guidance to the committee in their deliberations on the redesign of the space station. A low option of $5 billion, a mid-range option of $7 billion and a high option of $9 billion will be considered by the committee. Each option would cover the total expenditures for space station from fiscal year 1994 through 1998 and would include funds for development, operations, utilization, Shuttle integration, facilities, research operations support, transition cost and also must include adequate program reserves to insure program implementation within the available funds. Over the next 5 years, $4 billion is reserved within the NASA budget for the President's new technology investment. As a result, station options above $7 billion must be accompanied by offsetting reductions in the rest of the NASA budget. For example, a space station option of $9 billion would require $2 billion in offsets from the NASA budget over the next 5 years. Gibbons presented the information at an organizational session of the advisory committee. Generally, the members-designate focused upon administrative topics and used the session to get acquainted. They also received a legal and ethics briefing and an orientation on the process the Station Redesign Team is following to develop options for the advisory committee to consider. Gibbons also announced that the United States and its international partners -- the Europeans, Japanese and Canadians -- have decided, after consultation, to give "full consideration" to use of Russian assets in the course of the space station redesign process. To that end, the Russians will be asked to participate in the redesign effort on an as-needed consulting basis, so that the redesign team can make use of their expertise in assessing the capabilities of MIR and the possible use of MIR and other Russian capabilities and systems. The U.S. and international partners hope to benefit from the expertise of the Russian participants in assessing Russian systems and technology. The overall goal of the redesign effort is to develop options for reducing station costs while preserving key research and exploration capabilitiaes. Careful integration of Russian assets could be a key factor in achieving that goal. Gibbons reiterated that, "President Clinton is committed to the redesigned space station and to making every effort to preserve the science, the technology and the jobs that the space station program represents. However, he also is committed to a space station that is well managed and one that does not consume the national resources which should be used to invest in the future of this industry and this nation." NASA Administrator Daniel S. Goldin said the Russian participation will be accomplished through the East-West Space Science Center at the University of Maryland under the leadership of Roald Sagdeev. -end- Source:NASA Spacelink Modem:205-895-0028 Internet:192.149.89.61 =--=--=-END-=--=--= =--=--=START=--=--= NASA Spacelink File Name:6_2_18_5.TXT NOTE: This file is too large {27855 bytes} for inclusion in this collection. The first line of the file: - Current Two-Line Element Sets #169 - Source:NASA Spacelink Modem:205-895-0028 Internet:192.149.89.61 =--=--=-END-=--=--= =--=--=START=--=--= NASA Spacelink File Name:6_2_2_44_5.TXT 4/6/93: SPACELINK NOTE- Previously issued launch status annoucements for STS-56 follow. KSC SHUTTLE STATUS REPORT 4/6/93 NOTE: Launch of the Shuttle Discovery was aborted this morning at T-11 seconds by the onboard computers when instrumentation on the liquid hydrogen high point bleed valve in the main propulsion system indicated off when it should have indicated on. Follow-up analysis showed the instrumentation was faulty and that the valve was in the proper configuration for launch. Managers will be meeting later this afternoon to further evaluate the situation. At this time, the launch team is working under the 48-hour scrub turn-around schedule with the understanding a final decision will be made later today by the mission management team. If the 48-hour scrub turn-around schedule is verified the countdown clock will be recycled to the T-11 hour mark and paced for a T-0 at 1:29 a.m. Thursday. At this time, there are no plans to rotate the service structure around the vehicle or service the onboard cryogenic fuels. The crew has returned to their quarters in the Operations and Checkout Building and are essentially following their L-2 day timeline. IN WORK TODAY: * Vehicle safing and securing * Liquid hydrogen boiloff * Flight crew equipment destow * Re-configuring OMS/RCS crossfeed heaters * Main engine purging and re-positioning * Re-fill water deluge system WORK SCHEDULED: * Change liquid hydrogen system to an inert gaseous purge * Open pad for non-hazardous work * Begin change-out of time critical mid-deck payloads WORK COMPLETED: * Initial safing and securing of the vehicle * Initiated 48-hour scrub turn-around schedule * Secured liquid oxygen and liquid hydrogen system and began drain back of cryogenic fuels from the external tank STS-56 LAUNCH WEATHER FORECAST The weather forecast for launch of Discovery on April 8 indicates a 30 percent chance of violating launch constraints during the window opening at 1:32 a.m., due to cloud ceilings below 8000 feet and concerns for crosswinds at the Shuttle Landing Facility. There is a 30 percent chance of violating tanking constraints due to lightning within 5 miles of the pad. Tanking is scheduled to begin at 5:12 p.m. Monday. The 24 hour and 48 hour delay predictions show a 20 percent and a 30 percent chance of violation, respectively. SUMMARY OF HOLDS AND HOLD TIMES FOR STS-56 T-27 hours --- 4 hour hold ----------- Sat., 9:00 pm - 1:00 am T-19 hours --- 4 hour hold ----------- Sun., 10:00 am - 2:00 pm T-11 hours -- 13 hour, 12 min. hold - Sun., 10:00 pm - 11:12 am T-6 hours ---- 1 hour hold ---------- Mon., 4:12 pm - 5:12 pm T-3 hours ---- 2 hour hold ---------- Mon., 8:12 pm - 10:12 pm T-20 minutes - 10 minute hold ------- Tues., 12:52 am - 1:02 am T-9 minutes -- 10 minute hold ------- Tues., 1:13 am - 1:23 am SUMMARY OF STS-56 LAUNCH DAY CREW ACTIVITIES Monday/Tuesday 8:37 pm Wake up 9:07 pm Breakfast/Dinner 9:37 pm Weather briefing (CDR, PLT, MS2) 9:37 pm Don flight equipment (MS1, MS3) 9:47 pm Don flight equipment (CDR, PLT, MS2) 10:17 pm Depart for launch pad 39-B 10:47 pm Arrive at white room and begin ingress 12:02 am Close crew hatch 1:32 am Launch (April 6, 1993) CREW FOR MISSION STS-56 Commander (CDR) Kenneth Cameron Pilot (PLT) Stephen Oswald Payload Commander (MS1) Michael Foale Mission Specialist (MS2) Kenneth Cockrell Mission Specialist (MS3) Ellen Ochoa 3/30/93: ATLAS 2 LAUNCH DATE SET, SPACELAB D-2 MISSION RESCHEDULED Ed Campion Headquarters, Washington, D.C. March 30, 1993 LAUNCH ADVISORY NASA today announced that Space Shuttle Discovery with the STS-56/ATLAS 2 payload will be the next mission to fly with launch scheduled for April 6, 1993 at 1:32 a.m. EDT. Space Shuttle Columbia and the STS-55/Spacelab D-2 payload, which experienced a launch scrub on March 22, has been assigned a new target launch date of no earlier than April 24. The decision for STS-56 to be the next mission flown came after the main engine team finished analyzing the purge valve which caused the STS-55 launch scrub. The team's investigation concluded that the valve from the number 3 main engine failed to operate properly because of contamination that had been in the valve since it was manufactured. The team also determined that this condition could exist in other engines. A series of tests designed to reveal such a condition have been performed on Discovery and one suspect valve from one engine is being removed and replaced. "Flying the missions in this order is the most effective use of all our resources" said Shuttle Director Tom Utsman. "The early April launch of the ATLAS 2 mission will give scientists the opportunity to observe changes in the Earth's ozone during the seasonal transition between spring and summer in the northern hemisphere. At the same time, the launch team at Kennedy will be working to get Columbia back to launch configuration for launch on April 24. NASA is very pleased with the cooperation given by our friends in the German space agency. They have been involved as all possible options were considered. Their willingness to let the STS-56 mission have an early April launch will give the ATLAS folks the chance to collect some very important data on the Earth's ozone." As part of the effort to have Columbia ready at the earliest possible date, all three main engines are being removed and will be replaced with ones originally scheduled for use during the STS-57 mission with Space Shuttle Endeavour . The STS-57 mission, which will involve the first flight of the SPACEHAB commercial payload and the retrieval of the European Space Agency's EURECA satellite, is now scheduled to fly in late May. The rest of the Space Shuttle missions planned for 1993 will stay in their planned order and schedule. -end- 3/25/93: LAUNCH ADVISORY: STS-56 FLIGHT READINESS REVIEW COMPLETED Jim Cast Headquarters, Washington, D.C. March 25, 1993 George Diller Kennedy Space Center, Fla. The Flight Readiness Review for the launch of STS- 56/Discovery was held today with no major issues identified. Shuttle managers will set a target launch date next week after resolution of the problem which caused last's Monday's engine shutdown on Space Shuttle Columbia. The primary STS-56 payload, ATLAS 2, will investigate the sun's energy output and the Earth's middle-atmosphere chemical makeup and how these factors affect levels of Earth's ozone, which prevents much of the sun's harmful ultraviolet radiation from reaching the Earth's surface. The 8-day STS-56 mission will be commanded by Kenneth Cameron and piloted by Steven Oswald. Three mission specialists will round out the five-person crew: Michael Foale, Kenneth Cockrell and Ellen Ochoa. Source:NASA Spacelink Modem:205-895-0028 Internet:192.149.89.61 =--=--=-END-=--=--= =--=--=START=--=--= NASA Spacelink File Name:6_2_2_44_7.TXT STS-56 elements for April 8 launch The next launch attempt for STS-56 will be on Thursday morning, April 8. The Thursday launch window opens at 05:29 UTC. STS-56 1 00056U 93 98.28867013 .00055200 00000-0 16200-3 0 68 2 00056 57.0020 178.6504 0011289 286.7156 73.2672 15.91759473 24 Satellite: STS-56 Catalog number: 00056 Epoch time: 93098.28867013 = ( 8 APR 93 06:55:41.10 UTC) Element set: JSC-006 Inclination: 57.0020 deg RA of node: 178.6504 deg Space Shuttle Flight STS-56 Eccentricity: .0011289 Prelaunch Keplerian Elements Arg of perigee: 286.7156 deg Launch: 8 APR 93 05:29 UTC Mean anomaly: 73.2672 deg Mean motion: 15.91759473 rev/day G. L. Carman Decay rate: 5.52000e-04 rev/day~2 NASA Johnson Space Center Epoch rev: 2 G.L.CARMAN SPACELINK NOTE: The following State Vectors were issued for the April 6 launch date. They have not been updated at this time, but we have chosen to leave them on the system until the updated set is released. STS-56 PREDICTED FLIGHT DAY 1 VECTOR STS-56 FLIGHT DAY 1 STATE VECTOR (PREDICTED) ON ORBIT OPERATIONS (Posted 04/05/93 by Roger Simpson) The following vector for the flight of STS-56 is provided by NASA Johnson Space Center, Flight Design and Dynamics Division for use in ground track plotting programs. The vector represents the predictied trajectory of Discovery during on orbit operations, after the OMS-2 maneuver. The vector assumes an on time launch. Questions regarding these postings may be addressed to Roger Simpson, Mail Code DM4, L. B. J. Space Center, Houston, Texas 77058, Telephone (713) 483-1928. Lift off Time : 1993/096/05:32:00.000 Lift off Date : 04/06/93 Vector Time (GMT) : 096/06:11:37.730 Vector Time (MET) : 000/00:39:37.730 Orbit Count : 1 Weight : 226210.0 LBS Drag Coefficient : 2.00 Drag Area : 1250.0 SQ FT M50 Elements Keplerian Elements ----------------------- -------------------------- X = 21625753.7 FT A = 3606.8795 NM Y = -2634617.3 FT E = 0.000769 Z = 2232596.4 FT I (M50) = 57.03115 DEG Xdot = 3832.167081 FT/S Wp (M50) = 155.44198 DEG Ydot = 13509.654128 FT/S RAAN (M50) = 176.86540 DEG Zdot = -21119.722462 FT/S / N (True) = 17.57853 DEG Anomalies \ M (Mean) = 17.55193 DEG Ha = 161.0500 NM Hp = 159.3600 NM Mean of 1950 (M50) : Inertial, right-handed Cartesian system whose Coordinate System origin is the center of the earth. The epoch is the beginning of the Besselian year 1950. X axis: Mean vernal equinox of epoch Z axis: Earth's mean rotational axis of epoch Y axis: Completes right-hand system A: Semi-major axis E: Eccentricity N: True anomaly I: Inclination M: Mean anomaly Wp: Argument of perigee Ha: Height of apogee RAAN: Right ascension of ascending node Hp: Height of perigee Source:NASA Spacelink Modem:205-895-0028 Internet:192.149.89.61 =--=--=-END-=--=--= =--=--=START=--=--= NASA Spacelink File Name:6_8_3_4_61.TXT MAGELLAN STATUS REPORT 4/2/93 Magellan Significant Events for Week Ending 4-2-93 1. The Magellan spacecraft is operating normally in Venus orbit, transmitting a signal which is used to collect gravity data. 2. Preparations for aerobraking continue to go well. Changes to the on-board attitude control software were uplinked this week and are being verified by memory readout. 3. Magellan has completed 7122 orbits of Venus and is now 53 days from the end of Cycle 4 and the start of the Transition Experiment. Significant Events for Next Week 1. No special activities as preparations for aerobraking continue on schedule. Source:NASA Spacelink Modem:205-895-0028 Internet:192.149.89.61 =--=--=-END-=--=--= =--=END OF COLLECTION---COLLECTED 10 FILES---COMPLETED 22:36:49=--=