Outside the M-113 armored personnel carrier listen to instructions on its use for emergency exit procedures.

Outside the M-113 armored personnel carrier, STS-120 crew members listen to instructions on its use for emergency exit procedures from Launch Pad 39A. From left are Mission Specialists Daniel Tani and Doug Wheelock, Pilot George Zamka, Mission Specialist Scott Parazynski, Commander Pamela Melroy, and Mission Specialists Paolo Nespoli and Stephanie Wilson. Nespoli represents the European Space Agency. The training is part of terminal countdown demonstration test, or TCDT, activities the crew is undertaking at NASA's Kennedy Space Center. The TCDT also includes equipment familiarization and a simulated launch countdown. Mission STS-120, which will carry the Italian-built U.S. Node 2 to the International Space Station, is targeted for launch on Oct. 23. Photo credit: NASA/Kim Shiflett