STS-115 crew members look over the mission payload one more time before launch.

In the payload changeout room on Launch Pad 39B, STS-115 crew members look over the mission payload one more time before launch. Looking up at the payload from left, are mission specialists Steven MacLean, who represents the Canadian Space Agency, Heidemarie Stefanyshyn-Piper, Joseph Tanner, and Daniel Burbank. The mission crew has been at KSC to take part in Terminal Countdown Demonstration Test activities, which include emergency egress training, a simulated launch countdown and the payload familiarization. The TCDT is a prelaunch preparation for the mission that is scheduled to lift off in a window opening Aug. 27. During their 11-day mission to the International Space Station, the STS-115 crew will continue construction of the station and attach the payload elements, the Port 3/4 truss segment with its two large solar arrays. Photo credit: NASA/Cory Huston