STS-121 Mission Specialist Thomas Reiter is taking his turn driving an M-113, which is an armored personnel carrier. Reiter is from Germany and represents the European Space Agency. The STS-121 crew is taking turns driving the M-113 as part of Terminal Countdown Demonstration Test activities, which include emergency egress training from the pad and a simulated countdown. Mission STS-121 is designated for launch on July 1. Photo credit: NASA/Kim Shiflett