STS-127 crew members exit the Operations and Checkout Building for a simulated launch countdown.

STS-127 crew members exit the Operations and Checkout Building on their way to Launch Pad 39A at NASA's Kennedy Space Center in Florida for a simulated launch countdown. Leading the way, at right, is Commander Mark Polansky. From left, clockwise, are Pilot Doug Hurley and Mission Specialists Christopher Cassidy, Tim Kopra, Dave Wolf, Tom Marshburn and Julie Payette, who represents the Canadian Space Agency. The crew is at Kennedy for a launch dress rehearsal called the terminal countdown demonstration test, or TCDT, which includes emergency exit training and equipment familiarization. Endeavour's STS-127 mission is the final of three flights dedicated to the assembly of the Japanese Kibo laboratory complex on the International Space Station. Endeavour's launch is scheduled for June 13 at 7:17 a.m. EDT. Photo credit: NASA/Kim Shiflett