The STS-115 crew poses for the media before a conference on Launch Pad 39B.

The STS-115 crew poses for the media before a press conference on Launch Pad 39B. Seen left to right are Mission Specialist Steven MacLean, Commander Brent Jett, Mission Specialist Daniel Burbank, Pilot Chris Ferguson, and Mission Specialists Heidemarie Stefanyshyn-Piper and Joseph Tanner. MacLean is with the Canadian Space Agency. The mission crew is at KSC for Terminal Countdown Demonstration Test activities that are preparation for launch on Space Shuttle Atlantis, scheduled to take place in a window that opens Aug. 27. Behind the crew is the shuttle, surrounded by the fixed and rotating service structures, with the orange external tank and while solid rocket boosters showing. The TCDT culminates in a simulated launch countdown. 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