Mission Specialists Heidemarie Stefanyshyn-Piper front and Daniel Burbank head practicing emergency egress procedures.

STS-115 Mission Specialists Heidemarie Stefanyshyn-Piper (front) and Daniel Burbank head for the slidewire baskets on Launch Pad 39B, practicing emergency egress procedures. The activity follows a simulated launch countdown, part of Terminal Countdown Demonstration Test activities. 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