Chris Ferguson stands on the walkway to the White Room on Launch Pad 39A at NASA's Kennedy Space Center.

STS-135 Commander Chris Ferguson stands on the walkway to the White Room which provides entry to space shuttle Atlantis' crew compartment on Launch Pad 39A at NASA's Kennedy Space Center in Florida. Atlantis' crew members are at the pad to participate in a launch countdown simulation exercise.

As part of the Terminal Countdown Demonstration Test (TCDT), the crew members are strapped into their seats on Atlantis to practice the steps that will be taken on launch day. Shuttle Atlantis and its crew are targeted to lift off July 8, taking with them the Raffaello multi-purpose logistics module packed with supplies and spare parts to the International Space Station. The STS-135 mission also will fly a system to investigate the potential for robotically refueling existing satellites 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. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts135/index.html. Photo credit: NASA/Jim Grossmann