STS-125 Pilot Gregory C. Johnson practices driving the armored personnel carrier.

STS-125 Pilot Gregory C. Johnson practices driving the M-113 armored personnel carrier. Behind him are other crew members. The crew members of space shuttle Atlantis' STS-125 mission will each practice driving the M-113 in turn as part of their training on emergency egress procedures. An M-113 will be available to transport the crew to safety in the event of a contingency on the pad before their launch. The crew is at NASA's Kennedy Space Center for a dress launch rehearsal called the terminal countdown demonstration test, or TCDT. It provides astronauts and ground crews with an opportunity to participate in various simulated countdown activities, including equipment familiarization, emergency training and a simulated launch countdown. The STS-125 mission aboard space shuttle Atlantis to service NASA’s Hubble Space Telescope is targeted to launch Oct. 10. Photo credit: NASA/Kim Shiflett