Space shuttle Atlantis is bathed in xenon lights and takes center stage in this aerial image taken from a NASA helicopter.

Space shuttle Atlantis, attached to its bright-orange external fuel tank and twin solid rocket boosters, is bathed in xenon lights and takes center stage on Launch Pad 39A at NASA's Kennedy Space Center in Florida in this aerial image taken from a NASA helicopter.

Atlantis and its crew of four -- Commander Chris Ferguson, Pilot Doug Hurley and Mission Specialists Sandy Magnus and Rex Walheim -- are scheduled to lift off at 11:26 a.m. EDT on July 8 to deliver the Raffaello multi-purpose logistics module packed with supplies and spare parts to the International Space Station. Atlantis also will fly the Robotic Refueling Mission experiment that will investigate the potential for robotically refueling existing satellites in orbit. In addition, Atlantis will return with 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. For more information, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts135/index.html. Photo credit: NASA/Frank Michaux