English: The STS-135 crew members pose for a photo in front of shuttle Atlantis, which is making its final planned trek from Orbiter Processing Facility-1 to the Vehicle Assembly Building. From left, are Mission Specialist Rex Walheim, Commander Chris Ferguson, Pilot Doug Hurley and Mission Specialist Sandra Magnus. The move called "rollover" is a major milestone in processing for the STS-135 mission, which will deliver the Raffaello multipurpose logistics module packed with supplies, logistics and spare parts to the International Space Station. Targeted to launch in early July, STS-135 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. Inside the VAB, the shuttle will be attached to its external fuel tank and solid rocket boosters. 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.