STS-400

The crew assigned to this mission was a subset of the STS-126 crew:[2][7]

Atlantis (foreground) and Endeavour on LC-39A and LC-39B in 2008.

Three different concept mission plans were 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.[6] It was 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.[7] 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.[6]

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.[1][8]

Diagram showing one of the proposals for crew and equipment transfers during STS-400.

After its most recent mission (STS-123), Endeavour was taken to the Orbiter Processing Facility for routine maintenance. Following the maintenance, Endeavour was on 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 (SRB) began on 11 July 2008. One month later, the external tank arrived at KSC and was mated with the SRBs on 29 August 2008. Endeavour joined the stack on 12 September 2008 and was rolled out to Pad 39B one week later.

Since STS-126 launched before STS-125, Atlantis was rolled back to the VAB on 20 October, and Endeavour rolled around to Launch Pad 39A on 23 October. When it was time to launch STS-125, Atlantis rolled out to pad 39A.[4]

The Mission would not have included the extended heatshield inspection normally performed on flight day two.[1][3] Instead, an inspection would have been performed after the crew was rescued.[1][3] On flight day two, Endeavour would have performed the rendezvous and grapple with Atlantis.[1][7] On flight day three, the first EVA would have been performed.[1][3][7] During the first EVA, Megan McArthur, Andrew Feustel and John Grunsfeld would have set up a tether between the airlocks.[2][3] They would have also transferred a large size Extravehicular Mobility Unit (EMU) and, after McArthur had repressurized, transferred McArthur's EMU back to Atlantis. Afterwards they would have repressurized on Endeavour, ending flight day two activities.[1]

The final two EVA were planned for flight day three.[1][3] During the first, Grunsfeld would have depressurized on Endeavour in order to assist Gregory Johnson and Michael Massimino in transferring an EMU to Atlantis. He and Johnson would then repressurize on Endeavour, and Massimino would have gone back to Atlantis.[1] He, along with Scott Altman and Michael Good would have taken the rest of the equipment and themselves to Endeavour during the final EVA. They would have been standing by in case the RMS system should malfunction.[8] The damaged orbiter would have been commanded by the ground to deorbit and go through landing procedures over the Pacific, with the impact area being north of Hawaii.[2][3] On flight day five, Endeavour would have had a full heat shield inspection, and land on flight day eight.[1][2][3]

This mission could have marked the end of the Space Shuttle program, as it is considered unlikely that the program would have been able to continue with just two remaining orbiters, Discovery and Endeavour.[9]

On Thursday, 21 May 2009, NASA officially released Endeavour from the rescue mission, freeing the orbiter to begin processing for STS-127. This also allowed NASA to continue processing LC-39B for the upcoming Ares I-X launch, as during the stand-down period, NASA installed a new lightning protection system, similar to those found on the Atlas V and Delta IV pads, to protect the newer, taller Ares I rocket from lightning strikes.[10][11]

As a contingency mission, STS-400 was not given official support by NASA for the production of a crew patch or emblem. However artwork was created for use by the mission team as an unofficial emblem by Mike Okuda, who also illustrated the official patch of STS-125.[12]

As described by Paul F. Dye, Lead Flight Director of the mission, the emblem "adopts many of the elements seen in a rescue organization's patch - the square cross, bold letterers and border, and simple design. The idea is that the emblem instantly identifies the rescue organization in a crowd of others. In this case, the Shuttle outlines identify the purpose of our organization."[13] In addition, the emblem contains 11 stars, symbolizing the combined 11 crew-members who would return to earth onboard STS-400.

The first flight crew assigned to the mission created another, more humorous design depicting a St. Bernard with its traditional barrel of brandy replaced by the Hubble Space Telescope. The final flight crew though were unsatisfied with this as a crew patch, and contacted longtime NASA artist Tim Gagnon about creating a new one, but never formally approved a design before the mission was scrubbed.[14]

The first STS-400 flight crew's unofficial patch

• STS-3xx
• STS-127
• Hubble Space Telescope

• CBS Space News – Launch Team --- discontinued
• Updated CBS Space News – Home