The crew walks out of the Operations and Checkout Building to the waiting Astrovan at NASA's Kennedy Space Center in Florida.

During a simulated launch countdown, the STS-135 crew walks out of the Operations and Checkout Building to the waiting Astrovan at NASA's Kennedy Space Center in Florida. As part of the Terminal Countdown Demonstration Test (TCDT), the crew members are driven to Kennedy's Launch Pad 39A and then are strapped into space shuttle Atlantis to practice the steps that will be taken on launch day. On the front row are STS-135 Pilot Doug Hurley (left) and Commander Chris Ferguson; second row; are Mission Specialists Sandy Magnus and Rex Walheim.

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/Kim Shiflett