File:STS-135 Atlantis is lowered toward the MLP.jpg

English: In the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida, shuttle Atlantis is lowered toward the mobile launcher platform where it will be joined with its external fuel tank and solid rocket boosters. Commander Chris Ferguson, Pilot Doug Hurley and Mission Specialists Sandra Magnus and Rex Walheim are expected to launch in mid-July, taking with them the Raffaello multi-purpose logistics module packed with supplies, logistics and spare parts. The STS-135 mission also will fly a system to investigate the potential for robotically refueling existing spacecraft and return a failed ammonia pump module to help NASA better understand the failure mechanism and improve pump designs for future systems. STS-135 will be the 33rd flight of Atlantis, the 37th shuttle mission to the space station, and the 135th and final mission of NASA's Space Shuttle Program.