KENNEDY SPACE CENTER, FLA. - During Terminal Countdown Demonstration Test (TCDT) activities, the STS-121 crew gets instructions about emergency egress from the pad from Capt. George Hoggard (left), who is astronaut rescue team leader. Crew members are (from left) Mission Specialist Piers Sellers, Pilot Mark Kelly, Mission Specialists Stephanie Wilson and Lisa Nowak, Commander Steven Lindsey, and Mission Specialists Thomas Reiter and Michael Fossum. Part of the training will be driving an M-113, which is an armored personnel carrier. Mission STS-121 is designated for launch on July 1. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. - STS-121 Pilot Mark Kelly takes his turn in an M-113, which is an armored personnel carrier. Behind him can be seen Mission Specialists Lisa Nowak and Thomas Reiter from Germany, who 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

KENNEDY SPACE CENTER, FLA. - Following training in the M-113 armored personnel carrier, the STS-121 crew pose for a photo with Capt. George Hoggard, who is astronaut rescue team leader. From left are Pilot Mark Kelly, Mission Specialist Lisa Nowak, Hoggard, Commander Steven Lindsey, and Mission Specialists Michael Fossum, Stephanie Wilson, Thomas Reiter and Piers Sellers. 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

KENNEDY SPACE CENTER, FLA. - STS-121 Commander Steven Lindsey takes his turn driving an M-113, which is an armored personnel carrier. 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

KENNEDY SPACE CENTER, FLA. - STS-121 Mission Specialist Lisa Nowak takes her turn in an M-113, which is an armored personnel carrier. Behind her, at right, is Mission Specialist Thomas Reiter 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

KENNEDY SPACE CENTER, FLA. - 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

KENNEDY SPACE CENTER, FLA. - STS-121 Mission Specialist Michael Fossum takes his turn in an M-113, which is an armored personnel carrier. 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

KENNEDY SPACE CENTER, FLA. - STS-121 Mission Specialist Piers Sellers takes his turn in an M-113, which is an armored personnel carrier. Behind him are Mission Specialists Lisa Nowak and Thomas Reiter from Germany, who 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

KENNEDY SPACE CENTER, FLA. - STS-121 Mission Specialist Stephanie Wilson takes her turn in an M-113, which is an armored personnel carrier. Behind her, at right, is Mission Specialist Thomas Reiter 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

KENNEDY SPACE CENTER, FLA. - Under the watchful eye of Capt. George Hoggard (left front), who is astronaut rescue team leader, STS-121 Commander Steven Lindsey takes his turn driving an M-113, which is an armored personnel carrier. Behind Lindsey and Hoggard are Mission Specialists Piers Sellers (waving) and Michael Fossum. 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