STS-93
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| Missionsstatistik | |||||
| Missionsnavn: | STS-93 | ||||
| Rumagentur: | NASA | ||||
| Rumfærge: | Columbia | ||||
| Antal besætningsmedlemmer: | 5 Eileen M. Collins Jeffrey S. Ashby Michel Tognini Steven A. Hawley Catherine G. Coleman | ||||
| Affyringsrampe: | LC-39B (KSC) | ||||
| Opsendelse: | 23. juli 1999 04:31:00 UTC | ||||
| Landing: | 28. juli 1999 03:20:35 UTC | ||||
| Landet på: | KSC SLF Runway 33 | ||||
| Varighed: | 4 dage, 22 t, 50 min, 18 sek | ||||
| Antal kredsløb: | 80 | ||||
| Apogæum: | 280 km | ||||
| Perigæum: | 260 km | ||||
| Kredsløbets inklination: | 28,4 grader | ||||
| Masse: | 122.536 kg (ved opsendelse) 99.783 kg (ved landing) 22.781 kg (last) | ||||
| Foto af besætningen | |||||
 Besætningen med en model af Chandra X-ray Observatory, der opsendtes ved missionen. Fra v.: Collins, Hawley, Ashby, Tognini, Coleman | |||||
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STS-93 (Space Transportation System-93) var rumfærgen Columbias 26. rumfærgemission og den 95. gang en rumfærge blev opsendt. Det var den 21. gang en rumfærge blev opsendt om natten. Kaptajn under missionen var Eileen Collins, der derved blev den første kvindelige kaptajn på en rumfærge. Opsendelsen var planlagt til den 20. juli 1999, men problemer under nedtællingen udskød opsendelsen til tre dage senere den 23. juli 1999.
Ved opsendelsen den 23. juli 1999 indtraf en række alvorlige tekniske svigt og fejl, der kunne have medført en katastrofe. Columbia kom dog i kredsløb uden skade på besætning eller last.
Det primære formål med opsendelsen var at bringe rumobservatoriet Chandra X-ray Observatory i kredsløb, hvilket lykkedes.
Columbia landede igen den 28. Juli 1999 ved Kennedy Space Center. Det var den tolvte natlige landing i rumfærgeprogrammets historie. Fem af de natlige landinger havde fundet sted på Edwards Air Force Base i Californien, de øvrige på KSC.
Mandskab
| Astronaut | Funktion |
|---|---|
| Eileen M. Collins | Kaptajn Tredje mission |
| Jeffrey S. Ashby | Pilot Første mission |
| Michel Tognini | Specialist 1 Anden mission |
| Steven A. Hawley | Specialist 2 Femte mission |
| Catherine G. Coleman | Specialist 3 Anden mission |
Problemer ved opsendelsen
STS-93 skulle oprindeligt have været opsendt den 20. juli 1999, men under nedtællingen blev opsendelsen afbrudt blot 7 sekunder inden start af operatøren, der overvågede koncentrationen af hydrogen. Afbrydelsen skyldtes, at et instrument fejlagtigt viste unormalt høje koncentrationer af hydrogen i de sidste sekunder af nedtællingen.[1]
En ny opsendelse blev herefter planlagt til tre dage senere den 23. juli.
Ved opsendelsen den 23. juli rev en mindre metalgenstand sig løs fra Columbias hovedmotor ved start af motorerne. Metalstumpen blev udstødt gennem motorens dysse, hvor metallet ramte dyssens overflade og rev hul på tre mindre kølerør med flydende hydrogen. Denne utilsigtede hændelse og maskinens automatiske reaktion på det konstaterede læk af hydrogen blev ikke registreret som en del af kriterierne for opsendelse og nedtællingen fortsatte uanfægtet. Motor og løfteraketter startede herefter og opsendelsen blev påbegyndt.
Ca. fem sekunder efter lift-off blev den centrale motors primære digitale styringsenhed (DCU-A). og den højre motors digitale back-up styringsenhed (DCU-B) lukket ned på grund af en kortslutning. De to motorer fortsatte dog i drift med de øvrige styringsenheder, indtil kredsløb blev nået. De ekstra styringsenheder i hver motors kontrolenhed reddede missionen fra en potentiel katastrofe, da en standsning af to af rumfærgens tre motorer så tidligt under opsendelsen ville have resulteret i en meget risikabel afbrydelse af missionen[2] uden nogen sikkerhed for succes.[3] Kortslutningen skyldtes dårlig udført kabling, der havde vredet sig mod et skruehoved. Problemet med kablingen førte til, at der efterfølgende blev gennemført et check på alle rumfærgerne.
På grund af lækken i hydrogen-røret i højre motor, konstaterede motorens sensor formindsket kraft, da hydrogenen ikke blev brændt af i motoren.[4] For at kompensere for den manglende kraft, forhøjede kontrolsystemet mængden af oxygen i forbrændingen. Den manglende hydrogen og den forhøjede mængde oxygen resulterede i, at højre motors forbrænding skete med et forhold mellem oxygen/hydrogen på 8:1 frem for det normale 6,03:1. Dette resulterede i, at motoren brændte mere oxygen af, hvorfor alle tre motorer standsede tidligere end planlagt ved slutningen af opstigningen. Det uventede standsning af motorerne betød, at Columbias hastighed ved lukningen af motorerne var 4,6 m/s langsommere end planlagt.[5] Columbia nåede dog sit planlagte kredsløb og gennemførte missionen som planlagt. Den utilsigtede hændelse medførte ændringer i procedurerne for vedligeholdelse af rumfærgerne.
Missionens formål
Det primære formål med STS-93 missionen var opsendelsen af rumobservatoriet Chandra X-ray Observatory (oprindelig kaldet Advanced X-ray Astrophysics Facility) samt Chandras raketsystem, der skulle bringe Chandra ud i et fjernere kredsløb. Ved opsendelsen var Chandra det mest avancerede røntgenobservatorium, der nogensinde var bygget. Det var designet til at observere røntgenstråling fra høj-energi områder i Universet, såsom supernovarester.
Udover rumobservatoriet Chandra medbragte STS-93 en række instrumenter til gennemførelse af forskellige eksperimenter. De udførte eksperimenter var: Midcourse Space Experiment (MSX), Shuttle Ionospheric Modification with Pulsed Local Exhaust (SIMPLEX), Southwest Ultraviolet Imaging System (SWUIS), eksperimentet Gelation of Sols: Applied Microgravity Research (GOSAMR), Space Tissue Loss – B (STL-B) eksperimentet, Light mass Flexible Solar Array Hinge (LFSAH) eksperiment, Cell Culture Module (CCM), Shuttle Amateur Radio Experiment – II (SAREX – II), EarthKAM, Plant Growth Investigations in Microgravity (PGIM), Commercial Generic Bioprocessing Apparatus (CGBA), Micro-Electrical Mechanical System (MEMS), og eksperimentet Biological Research in Canisters (BRIC).
Noter
- ^ Hale, Wayne. "STS-93: Keeping Eileen on the Ground, Part 1". Wayne Hale's Blog. Hentet 22. oktober 2014.
- ^ "Contingency Aborts 21007/31007" (PDF). nasa.gov. Arkiveret fra originalen (PDF) 26. februar 2015. Hentet 9. november 2014.
- ^ Hale, Wayne. "STS-93: Dualing computers". Wayne Hale's Blog. Hentet 26. oktober 2014.
- ^ Greene, William D. "Inside The J-2X Doghouse: Engine Control — Open versus Closed Loop". Liquid Rocket Engines (J-2X, RS-25, general). NASA. Hentet 22. oktober 2014.
- ^ Hale, Wayne. "STS-93: We don't need any more of those". Wayne Hale's Blog. Hentet november 2014.
{{cite web}}: Tjek datoværdier i:|accessdate=(hjælp)
Eksterne links
- NASA PAO side om STS-93 Arkiveret 14. maj 2011 hos Wayback Machine
- STS-93 Missionens operative leder om opsendelsen
- Lydfil fra opsendelsen
- STS-93 ArkiverArkiveret 5. august 2011 hos Wayback Machine på NASA.gov
- STS-93 Video Highlights Arkiveret 15. juli 2014 hos Wayback Machine
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Medier brugt på denne side
At Launch Pad 39-B, the Chandra X-ray Observatory sits inside the payload bay of Space Shuttle Columbia, waiting for the doors to close. Chandra is the primary payload on mission STS-93, scheduled to launch aboard Columbia July 20 at 12:36 a.m. EDT. The combined Chandra/Inertial Upper Stage, seen here, measures 57 feet long and weighs 50,162 pounds. Fully deployed with solar arrays extended, the observatory measures 45.3 feet long and 64 feet wide. The world's most powerful X-ray telescope, Chandra will allow scientists from around the world to see previously invisible black holes and high-temperature gas clouds, giving the observatory the potential to rewrite the books on the structure and evolution of our universe
The five astronauts assigned to fly aboard the Space Shuttle Columbia early next year for the STS-93 mission pose with a small model of their primary payload-the Advanced X-ray Astrophysics Facility (AXAF). Collins, mission commander; Steven A. Hawley, mission specialist; Jeffrey S. Ashby, pilot; Michel Tognini and Catherine G. Coleman, both mission specialists. Tognini represents France's Centre National d'Études Spatiales (CNES). The scheduled five-day mission will feature the deployment of AXAF, which will enable scientists to conduct comprehensive studies of exotic phenomena in the universe. Among bodies studied will be exploding stars, quasars and black holes.
Launch of STS-93
This scene represents the end of NASA's STS-1 mission and the beginning of STS-2 in that the orbiter Columbia is arriving at Kennedy Space Center in Florida to begin the lengthy process of preparing it for STS-2. The vehicle landed at Dryden Flight Research Center on April 14 after an historic 2 1/3 day flight in Earth orbit. It was mated to this 747 aircraft, titled NASA 905, and flown over the USA to its Florida destination. It was later removed from atop NASA 905 and moved to the orbiter processing facility for the beginning of refurbishment.
Designed by the crew members, this is the mission insignia for the STS-96 space flight, the second Space Shuttle mission dedicated to the assembly of the International Space Station (ISS). The crew patch highlights the major themes of the Station Program: Earth-directed research, the advancement of human space exploration, and international cooperation. The Space Shuttle Discovery is depicted shortly after reaching orbit as the crew prepares to carry out the first docking with the new Station. At this early stage in its construction, ISS consists of two modules: Zarya and Unity, shown orbiting Earth. The triangular shape of the patch represents building on the knowledge and experience of earlier missions, while the three vertical bars of the astronaut emblem point toward future human endeavors in space. The five-pointed star that tops the astronaut emblem in this depiction is symbolic of the five space agencies participating in the development of ISS: NASA, the Russian Space Agency, the European Space Agency, the National Space Development Agency of Japan, and the Canadian Space Agency. The blend of red, white, and blue is a tribute to the nationalities of the crew members who are from the United States, Canada, and Russia.
A view of Space Shuttle Columbia's vertical stabiliser, OMS engines and Space Shuttle Main Engines (SSMEs) following the landing of STS-93 on 27 July 1999. Three small holes in the liquid hydrogen tubes inside the nozzle on main engine number 3 are visible, the cause of a hydrogen leak during the mission's launch on 23 July 1999.
Designed by the crewmembers, the STS-103 emblem depicts the Space Shuttle Discovery approaching the Hubble Space Telescope (HST) prior to its capture and berthing. The purpose of the mission is to remove and replace some of the Telescope's older and out-of-date systems with newer, more reliable and more capable ones, and to make repairs to HST's exterior thermal insulation that has been damaged by more than nine years of exposure to the space environment. The horizontal and vertical lines centered on the Telescope symbolize the ability to reach and maintain a desired attitude in space, essential to the instrument's scientific operation. The preservation of this ability is one of the primary objectives of the mission. After the flight, the Telescope will resume its successful exploration of deep space and will continue to be used to study solar system objects, stars in the making, late phases of stellar evolution, galaxies and the early history of the universe. HST, as represented on this emblem was inspired by views from previous servicing missions, with its solar arrays illuminated by the Sun, providing a striking contrast with the blackness of space and the night side of Earth.
- The NASA insignia design for Shuttle flights is reserved for use by the astronauts and for other official use as the NASA Administrator may authorize. Public availability has been approved only in the form of illustrations by the various news media. When and if there is any change in this policy, which is not anticipated, it will be publicly announced.
Emblem of Nasa's STS-93 mission.
- The STS-93 mission patch, as designed by the five crew members. The STS-93 mission carried the Chandra X-Ray Observatory into low Earth orbit initiating its planned five-year astronomy mission. Chandra is the third of NASA’s great observatories, following the Hubble Space Telescope and the Compton Gamma Ray Observatory. Chandra provides scientists an order-of-magnitude improvement over current capabilities at X-Ray wavelengths. Observations of X-Ray emissions from energetic galaxies and clusters, as well as black holes, promise to greatly expand current understanding of the origin and evolution of our universe. The STS-93 patch depicts Chandra separating from the Space Shuttle Columbia after a successful deployment. A spiral galaxy is shown in the background as a possible target for Chandra observations. The two flags represent the international crew, consisting of astronauts from both the United States and France.