The crew of STS-135 from right Sandy Magnus Doug Hurley Chris Ferguson and Rex Walheim pose for a group photo.

The crew of STS-135, from right, Sandy Magnus, Doug Hurley, Chris Ferguson and Rex Walheim pose for a group photo as the space shuttle Atlantis (out of frame) is moved from the Orbiter Processing facility to the Vehicle Assembly Building at NASA?s Kennedy Space Center in Florida on May 17, 2011. The move, known as rollover, is a milestone in the preparation for launch as the orbiter leaves its processing hangar to be prepped for its final flight. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool