In Orbiter Processing Facility-1 at NASA's Kennedy Space Center in Florida, technicians move an aft access platform into place behind shuttle Atlantis, following the installation of the spacecraft's three main engines.
Atlantis is being prepared for the "launch on need," or potential rescue mission, for the final planned shuttle flight, Endeavour's STS-134 mission. For more information, visit www.nasa.gov/shuttle. Photo credit: NASA/Kim Shiflett