The crew members receive instruction on emergency egress during a walkdown of the level of the fixed service structure at Launch Pad 39A.

During Terminal Countdown Demonstration Test activities, the Mission STS-117 crew members receive instruction on emergency egress during a walkdown of the 195-foot level of the fixed service structure at Launch Pad 39A. From the left are Mission Specialists Steven Swanson, Danny Olivas and Patrick Forrester, Pilot Lee Archambault, Commander Rick Sturckow and Mission Specialist James Reilly. The TCDT also includes M-113 armored personnel carrier training, and a simulated launch countdown. The mission payload aboard Space Shuttle Atlantis is the S3/S4 integrated truss structure, along with a third set of solar arrays and batteries. The crew of six astronauts will install the truss to continue assembly of the International Space Station. Photo credit: NASA/Kim Shiflett