http://www.aviationweek.com/aw/gener...&channel=space

Oct 8, 2008
By Frank Morring, Jr. and Craig Covault/Aerospace Daily & Defense Report
Spaceflight planners at NASA are scrambling to rearrange the space shuttle flight manifest in the wake of last month's electronics failure on the Hubble Space Telescope.
With two shuttles already on the pad for a mission to service Hubble when the serious data-transmission problem forced a postponement, managers must find the best way to work around the delayed mission to avoid losing precious flight time as the shuttle's scheduled 2010 retirement looms.
Present planning has the shuttle Atlantis rolling back to the Vehicle Assembly Building at Kennedy Space Center (KSC) from Pad 39A on Oct. 20. Atlantis had been scheduled to launch on Oct. 14 on the STS-125 Hubble-servicing mission, but now it will wait until sometime after February 2009 for another chance to fly the mission.
Its payload - two new instruments and a supply of replacement batteries, gyros and other hardware designed to keep the Hubble operating at upgraded capability for at least five more years - will be pulled back into the pad's rotating service structure on Oct. 7. It will stay there until it is returned to the Payload Handling and Servicing Facility on Oct. 13.
Eventually, crews will repack the payload to include a spare Control Unit/Science Data Formatter to replace the one that failed Sept. 27. The backup unit is undergoing testing at Goddard Space Flight Center to ensure that it will restore full redundancy to the telescope's data-handling system (Aerospace DAILY, Oct. 1).
Meanwhile, the shuttle Endeavour, which was sent to Pad 39B to serve as a rescue craft in case Atlantis was damaged on ascent, will be moved to Pad 39A on Oct. 25 for launch on the STS-126 mission to the International Space Station (ISS) as planned. Its rescue payload will be replaced at the pad with the ISS payload - a mix of logistics, prepositioned spare parts and some last-minute hardware to lubricate both big solar alpha rotary joints on the station to keep them turning the station's solar array wings more smoothly.
Launch of Endeavour on STS-126 is now scheduled for Nov. 14, two days earlier that it would have been had Atlantis been able to launch this month. Without the need to refurbish Pad 39A, crews can gain back the two days getting Endeavour ready to go there.
The schedule after that is still uncertain. If the Hubble program can get the backup hardware ready and the mission replanned in time, Atlantis will fly the STS-125 servicing mission in February 2009, with the shuttle Discovery acting as rescue vehicle. If it takes longer to prepare the modified Hubble mission, Discovery is tentatively set to fly STS-119 and deliver the final ISS solar array wing to orbit in February.
In that scenario Endeavour, back from the November station-logistics flight, will be processed to replay the role of rescue craft to a Hubble servicing mission before being prepared for the STS-127 mission to the station in May 2009.
The continued need to have Pad 39B available for a Hubble rescue mission is forcing a delay in the flight-test of the Ares I-X vehicle, a test bed designed to validate the basic design of the Ares I crew launch vehicle that will follow the shuttle into space. The pad can't be modified fully to accommodate the test vehicle until it is no longer needed for the shuttle.
Originally scheduled for April 15, 2009, the mission has been pushed back until June 2009 officially, but KSC managers believe that it could slip to November-December 2009.