"Current plans call for having Atlantis and Endeavour occupy Pads 39-A and 39-B, respectively, during preparations for the planned May 12 launch of the STS-125 Hubble servicing mission. But NASA officials now are considering launching Atlantis and then rolling Endeavour out to Pad 39-A, said Jeff Hanley, Constellation program manager at NASA's Johnson Space Center in Houston. This would make Pad 39-B available to undergo the three to four months of modifications necessary to support the Ares 1-X flight, he told reporters in a Wednesday press briefing."
Editor's note: After several years of safety-driven planning, Mike Griffin is now allowing Ares schedule pressure to drive the implementation of shuttle safety decisions in a last minute effort to try and salvage Ares. How quickly NASA forgets.