Members of the STS-120 crew during training with the M-113 armoured personel carrier during the Terminal Countdown Demonstration Test (TCDT) at NASA's Kennedy Space Center, Florida. Left to right: NASA astronauts Stephanie Wilson and George Zamka and ESA astronaut Paolo Nespoli. The TCDT provides the astronauts and ground crew with an opportunity to participate in various launch preparation activities, including equipment familiarisation, emergency training and the simulated countdown.