STS-400

Infobox Space mission
mission_name = STS-400
insignia = Shuttle_Patch.png shuttle = Discovery
launch_pad = LC-39B, KSC
launch = TBD
landing = TBD
duration = 7 Days
altitude = convert|570|km|mi|abbr=on
inclination = 28.5 degrees
crew_photo = STS-400 Crew.jpg
crew_caption = crew of STS-400
previous = STS-125
next = Unknown
footnotes =

STS-400 was an unflown Space Shuttle contingency support (Launch on Need) mission which would have used "Endeavour" to rescue the crew of "Atlantis" had a major problem occur during STS-125, the final Hubble Space Telescope servicing mission (HST SM-4). "Endeavour" was rolled to the launch pad for this purpose, but then STS-125 was delayed. STS-401 is the contingency support flight currently being planned which would use "Discovery" for this purpose.

Due to the orbital path of the HST, the shuttle crew will be unable to use the International Space Station as a safe haven and follow the usual plan of recovering the crew with another shuttle at a later date. Instead, NASA has developed a plan to conduct a shuttle-to-shuttle rescue mission, similar to proposed rescue missions for pre-ISS flights.Cite web|url=http://www.nasaspaceflight.com/content/?id=4489|title=Hubble Servicing Mission moves up|date=2006-05-09|accessdate=2007-10-16|publisher=NASASpaceflight.com|year=2007|author=Chris Bergin|language=English] Cite web|url=http://www.nasaspaceflight.com/content/?cid=4683|title=NASA Evaluates Rescue Options for Hubble Mission|accessdate=2007-10-16|date=2006-07-31|publisher=NASASpaceflight.com|year=2007|author=John Copella|language=English] This rescue mission would be launched only seven days after call up, as the maximum time the crew can remain aboard the damaged orbiter is 23 to 28 days. For this mission, the rescue shuttle is rolled to its launch pad before the planned STS-125 launch, creating a rare scenario of two shuttles being on the launch pads at the same time. After the STS-125 mission, launch pad 39B will continue the conversion for use in Project Constellation for the Ares I and Ares V rockets.

Crew

The crew assigned to this mission is the flight deck crew for STS-123 [NASA (2008-06-16 [http://www.nasa.gov/mission_pages/shuttle/shuttlemissions/hst_sm4/overview.html STS-125: The Final Visit] Retrieved on 2008-06-25.]

* Dominic Gorie (5) - Commander
* Gregory H. Johnson (2) - Pilot
* Robert L. Behnken (2) - Mission Specialist 1
* Michael Foreman (2) - Mission Specialist 2

Number in parentheses indicates number of spaceflights by each individual prior and including this mission if flown

Early mission plans

Three different concept mission plans have been evaluated. The first would be to use a shuttle-to-shuttle docking, where the rescue shuttle docks with the damaged shuttle, by flying upside down and backwards, relative to the damaged shuttle. It is unclear whether this would be practical, as the forward structure of either orbiter could collide with the payload bay of the other, resulting in damage to both orbiters. The second option that was evaluated, would be for the rescue orbiter to rendezvous with the damaged orbiter, and perform station-keeping while using its Remote Manipulator System (RMS) to transfer crew from the damaged orbiter. This mission plan would result in heavy fuel consumption. The third concept would be for the damaged orbiter to grapple the rescue orbiter using its RMS, eliminating the need for station-keeping. The rescue orbiter would then transfer crew using its RMS, as in the second option, and would be more fuel efficient than the station-keeping option.

The concept that was eventually decided upon was a modified version of the third concept. The rescue orbiter would use its RMS to grapple the end of the damaged orbiter's RMS.Cite web|url=http://www.nasaspaceflight.com/content/?cid=5252|title=STS-400 - NASA draws up their Hubble rescue plans|accessdate=2007-10-16|publisher=NASASpaceflight.com|date=2007-11-10|author=Chris Bergin|language=English]

Preparations

After its most recent mission (STS-123), Endeavour was taken to the Orbiter Processing Facility for routine maintenance. Afterwards, Endeavour sat stand-by for STS-326 which would have been flown in the case that STS-124 would not have been able to return to Earth safely. Stacking of the Solid Rocket Boosters began on July 11, 2008. One month later, the External Tank arrived at KSC and was mated with the SRBs on August 29, 2008. Endeavour joined the stack on September 12, 2008 and was rolled out to Pad 39B one week later.

Shuttle Discovery is considered to replace Endeavour as NASA will launch STS-126 before STS-125 due to problems with Hubble. It is likely that the mission would be renumbered STS-401 to indicate the change of orbiter vehicle. [cite web|url=http://www.nasaspaceflight.com/2008/10/forward-plan-sts-126-rolling-to-pad-39a-in-two-weeks-sts-125-back-to-vab/|title=Forward Plan: STS-126 rolling to Pad 39A in two weeks - STS-125 back to VAB|accessdate=2008-10-01|publisher=NASASpaceFlight.com]

Mission Plan

The Mission would begin with extended heatshield inspection using the Orbiter Boom Sensor System on flightday two. On the same day it is planned to rendezvous and grapple with Atlantis as well as to perform the first EVA during wich Megan McArthur, Andrew Feustel and John Grunsfeld would set up a tether between the airlocks. They would also transfer a big size and, after she'd repress, McArthur's EMU back to Atlantis. Afterwards they would repress on Endeavour ending flightday two activities.

The final two EVA are planned for flight day three. During the first of them Grunsfeld would depress on Endeavour in order to help Gregory Johnson and Michael Massimino in transfering an EMU to Atlantis and vour ACS-Suits to Endeavour. He and Johnson would then repress on Endeavour and Massimino would go back to Atlantis. He, along with Scott Altman and Michael Good would then bring the final ACS-Suits and themselves to Endeavour during the final EVA. They would also be standing by in case the RMS system should malfunction. The rescue orbiter would then land normally, and the damaged orbiter would be disposed of through a destructive re-entry over the Pacific with the impact area being north of Hawaii.

This mission would likely end the Space Shuttle program, as it is highly infeasible that the program could continue with just two orbiters. [cite news | last = Watson | first = Traci | title = The mission NASA hopes won't happen | publisher = USA Today| date = 2005-03-22 | url = http://www.usatoday.com/tech/science/space/2005-03-22-shuttle-cover_x.htm | accessdate = 2006-09-13 ]

ee also

*STS-125
*STS-3xx
*Hubble Space Telescope

References

External links

* [http://www.cbsnews.com/network/news/space/currentglance.html#PERSONNEL CBS Space News - Launch Team]