[1][2][3][4] Due to the much lower orbital inclination of the HST compared to the ISS, the shuttle crew would have been unable to use the International Space Station as a "safe haven", and NASA would not have been able to follow the usual plan of recovering the crew with another shuttle at a later date.

[4] It was planned that after the STS-125 mission in October 2008, Launch Complex 39B would undergo the conversion for use in Project Constellation for the Ares I-X rocket.

[4] Several of the members on the NASA mission management team said at the time (2009) that single-pad operations were possible, but the decision was made to use both pads.

[1][3][7] During the first EVA, Megan McArthur, Andrew Feustel and John Grunsfeld would have set up a tether between the airlocks.

[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.

[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.

[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.

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 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.