External fuel tank is lowered into high bay 1 for joining with the twin solid rocket boosters on the mobile launcher platform.

In the Vehicle Assembly Building (VAB) at NASA's Kennedy Space Center in Florida, external fuel tank, ET-138, for space shuttle Atlantis' STS-135 mission, is lowered into high bay-1 for joining with the twin solid rocket boosters on the mobile launcher platform. Shuttle Atlantis' move, or "rollover," from Orbiter Processing Facility-1 to the VAB is targeted for May 10. Once there it will be mated with the external tank and boosters. Atlantis and its crew of four will deliver the Raffaello multipurpose logistics module packed with supplies and spare parts to the International Space Station. STS-135 is targeted to launch June 28, and will be the last spaceflight for the Space Shuttle Program. Photo credit: NASA/Jack Pfaller