KENNEDY SPACE CENTER, FLA. - At the Shuttle Landing Facility, STS-121 Commander Steven Lindsey gets ready for a training flight in a Shuttle Training Aircraft (STA). He will be practicing landing the orbiter using the STA, which is a modified Grumman American Aviation-built Gulf Stream II jet that was modified to simulate an orbiter’s cockpit, motion and visual cues, and handling qualities. In flight, the STA duplicates the orbiter’s atmospheric descent trajectory from approximately 35,000 feet altitude to landing on a runway. Because the orbiter is unpowered during re-entry and landing, its high-speed glide must be perfectly executed the first time. Space Shuttle Discovery is scheduled to launch July 1 on mission STS-121. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. - After landing at NASA's Kennedy Space Center aboard a Grumman G2 aircraft, Mission Commander Steven Lindsey pauses at a microphone to introduce the crew. Joining him are Mission Specialist Michael Fossum, Pilot Mark Kelly, and Mission Specialists Lisa Nowak (partly visible at left), Stephanie Wilson, Piers Sellers and Thomas Reiter, who represents the European Space Agency. The crew is at the space center to take part in a Terminal Countdown Demonstration Test, or TCDT. Over several days, the crew will practice emergency egress from the pad and suit up in their orange flight suits for the simulated countdown to launch. Space Shuttle Discovery is designated to launch July 1 on mission STS-121. It will carry supplies to the International Space Station. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. - After landing at NASA's Kennedy Space Center aboard a Grumman G2 aircraft, the STS-121 crew gathers at a microphone for the media. Seen here at center is Mission Specialist Lisa Nowak; at left is Pilot Mark Kelly. Other crew members are Mission Commander Steven Lindsey, Pilot Mark Kelly, and Mission Specialists Michael Fossum, Stephanie Wilson, Piers Sellers and Thomas Reiter, who represents the European Space Agency. The crew is at the space center to take part in a Terminal Countdown Demonstration Test, or TCDT. Over several days, the crew will practice emergency egress from the pad and suit up in their orange flight suits for the simulated countdown to launch. Space Shuttle Discovery is designated to launch July 1 on mission STS-121. It will carry supplies to the International Space Station. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. - After their arrival at NASA's Kennedy Space Center, the STS-121 crew poses for a photo. From left are Mission Specialist Michael Fossum, Pilot Mark Kelly, Mission Specialist Lisa Nowak, Commander Steven Lindsey and Mission Specialists Stephanie Wilson, Piers Sellers and Thomas Reiter from Germany, who represents the European Space Agency. The crew is at the space center to take part in a Terminal Countdown Demonstration Test, or TCDT. Over several days, the crew will practice emergency egress from the pad and suit up in their orange flight suits for the simulated countdown to launch. Space Shuttle Discovery is designated to launch July 1 on mission STS-121. It will carry supplies to the International Space Station. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. - After landing at NASA's Kennedy Space Center aboard a Grumman G2 aircraft, the STS-121 crew gathers at a microphone for the media. Seen here at center is Mission Specialist Stephanie Wilson; at right is Piers Sellers. Other crew members are Mission Commander Steven Lindsey, Pilot Mark Kelly, and Mission Specialists Michael Fossum, Lisa Nowak and Thomas Reiter, who represents the European Space Agency. The crew is at the space center to take part in a Terminal Countdown Demonstration Test, or TCDT. Over several days, the crew will practice emergency egress from the pad and suit up in their orange flight suits for the simulated countdown to launch. Space Shuttle Discovery is designated to launch July 1 on mission STS-121. It will carry supplies to the International Space Station. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. - At the Shuttle Landing Facility, the Shuttle Training Aircraft (STA) taxis to the runway with the STS-121 pilot and commander in the cockpit for practice flights. The STA is a modified Grumman American Aviation-built Gulf Stream II jet that was modified to simulate an orbiter’s cockpit, motion and visual cues, and handling qualities. In flight, the STA duplicates the orbiter’s atmospheric descent trajectory from approximately 35,000 feet altitude to landing on a runway. Because the orbiter is unpowered during re-entry and landing, its high-speed glide must be perfectly executed the first time. Space Shuttle Discovery is scheduled to launch July 1 on mission STS-121. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. - During a break in the rain storms from Tropical Storm Alberto, the STS-121 crew arrives at NASA's Kennedy Space Center aboard a Grumman G2 aircraft to take part in a Terminal Countdown Demonstration Test, or TCDT. Greeting the crew is Shuttle Launch Director Mike Leinbach, here shaking hands with Mission Specialist Thomas Reiter, who represents the European Space Agency. Other crew members are Mission Commander Steven Lindsey, Pilot Mark Kelly, and Mission Specialists Piers Sellers, Michael Fossum, Lisa Nowak and Stephanie Wilson. Over several days, the crew will practice emergency egress from the pad and suit up in their orange flight suits for the simulated countdown to launch. Space Shuttle Discovery is designated to launch July 1 on mission STS-121. It will carry supplies to the International Space Station. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. - After landing at NASA's Kennedy Space Center aboard a Grumman G2 aircraft, the STS-121 crew gathers at a microphone for the media. Seen here is Mission Specialist Thomas Reiter from Germany, who represents the European Space Agency. Other crew members are Commander Steven Lindsey, Pilot Mark Kelly, and Mission Specialists Michael Fossum, Lisa Nowak, Stephanie Wilson and Piers Sellers. The crew is at the space center to take part in a Terminal Countdown Demonstration Test, or TCDT. Over several days, the crew will practice emergency egress from the pad and suit up in their orange flight suits for the simulated countdown to launch. Space Shuttle Discovery is designated to launch July 1 on mission STS-121. It will carry supplies to the International Space Station. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. - After landing at NASA's Kennedy Space Center aboard a Grumman G2 aircraft, the STS-121 crew gathers at a microphone for the media. Mission Commander Steven Lindsey is introducing the crew, from left: Mission Specialist Michael Fossum, Pilot Mark Kelly, Mission Specialist Lisa Nowak, Lindsey, Mission Specialists Stephanie Wilson, Piers Sellers and Thomas Reiter, who represents the European Space Agency. The crew is at the space center to take part in a Terminal Countdown Demonstration Test, or TCDT. Over several days, the crew will practice emergency egress from the pad and suit up in their orange flight suits for the simulated countdown to launch. Space Shuttle Discovery is designated to launch July 1 on mission STS-121. It will carry supplies to the International Space Station. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. - After landing at NASA's Kennedy Space Center aboard a Grumman G2 aircraft, the STS-121 crew gathers at a microphone for the media. Seen here at center is Pilot Mark Kelly. Other crew members are Mission Commander Steven Lindsey and Mission Specialists Michael Fossum, Lisa Nowak, Stephanie Wilson, Piers Sellers and Thomas Reiter, who represents the European Space Agency. The crew is at the space center to take part in a Terminal Countdown Demonstration Test, or TCDT. Over several days, the crew will practice emergency egress from the pad and suit up in their orange flight suits for the simulated countdown to launch. Space Shuttle Discovery is designated to launch July 1 on mission STS-121. It will carry supplies to the International Space Station. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. - At the Shuttle Landing Facility, the Shuttle Training Aircraft (STA) waits for the STS-121 pilot and commander to begin their practice flights. The STA is a modified Grumman American Aviation-built Gulf Stream II jet that was modified to simulate an orbiter’s cockpit, motion and visual cues, and handling qualities. In flight, the STA duplicates the orbiter’s atmospheric descent trajectory from approximately 35,000 feet altitude to landing on a runway. Because the orbiter is unpowered during re-entry and landing, its high-speed glide must be perfectly executed the first time. Space Shuttle Discovery is scheduled to launch July 1 on mission STS-121. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. - After landing at NASA's Kennedy Space Center aboard a Grumman G2 aircraft, the STS-121 crew gathers at a microphone for the media. Seen here at center is Mission Specialist Piers Sellers; at left is Mission Specialist Stephanie Wilson. Other crew members are Mission Commander Steven Lindsey, Mission Specialist Michael Fossum, Pilot Mark Kelly, and Mission Specialists Lisa Nowak and Thomas Reiter, who represents the European Space Agency. The crew is at the space center to take part in a Terminal Countdown Demonstration Test, or TCDT. Over several days, the crew will practice emergency egress from the pad and suit up in their orange flight suits for the simulated countdown to launch. Space Shuttle Discovery is designated to launch July 1 on mission STS-121. It will carry supplies to the International Space Station. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. - After landing at NASA's Kennedy Space Center aboard a Grumman G2 aircraft, Mission Commander Steven Lindsey pauses at a microphone to introduce the crew. Joining him are Mission Specialist Michael Fossum, Pilot Mark Kelly, and Mission Specialists Lisa Nowak (partly visible at left), Stephanie Wilson, Piers Sellers and Thomas Reiter, who represents the European Space Agency. The crew is at the space center to take part in a Terminal Countdown Demonstration Test, or TCDT. Over several days, the crew will practice emergency egress from the pad and suit up in their orange flight suits for the simulated countdown to launch. Space Shuttle Discovery is designated to launch July 1 on mission STS-121. It will carry supplies to the International Space Station. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. - After landing at NASA's Kennedy Space Center aboard a Grumman G2 aircraft, the STS-121 crew gathers at a microphone for the media. Seen here is Mission Specialist Michael Fossum. Other crew members are Commander Steven Lindsey, Pilot Mark Kelly, and Mission Specialists Lisa Nowak, Stephanie Wilson, Piers Sellers and Thomas Reiter, who represents the European Space Agency. The crew is at the space center to take part in a Terminal Countdown Demonstration Test, or TCDT. Over several days, the crew will practice emergency egress from the pad and suit up in their orange flight suits for the simulated countdown to launch. Space Shuttle Discovery is designated to launch July 1 on mission STS-121. It will carry supplies to the International Space Station. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. - STS-121 Mission Commander Steven Lindsey talks to the media from the launch pad. He is in the landing area of the slidewire baskets. The crew is at Kennedy for Terminal Countdown Demonstration Test activities. Over several days, the crew will practice emergency egress from the pad and suit up in their orange flight suits for the simulated countdown to launch. Space Shuttle Discovery is designated to launch July 1 on mission STS-121. It will carry supplies to the International Space Station. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. - The STS-121 crew pause in their prelaunch activities to talk to the media. They are standing in the landing area of the slidewire baskets. With the microphone is Pilot Mark Kelly. The crew members are (from left) Mission Specialists Michael Fossum and Lisa Nowak, Kelly, Commander Steven Lindsey, and Mission Specialists Stephanie Wilson, Piers Sellers and Thomas Reiter of Germany, who represents the European Space Agency. The crew is at Kennedy for Terminal Countdown Demonstration Test activities. Over several days, the crew will practice emergency egress from the pad and suit up in their orange flight suits for the simulated countdown to launch. Space Shuttle Discovery is designated to launch July 1 on mission STS-121. It will carry supplies to the International Space Station. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. - At the Shuttle Landing Facility, STS-121 Pilot Mark Kelly gets ready for a training flight in a Shuttle Training Aircraft (STA). He will be practicing landing the orbiter using the STA, which is a modified Grumman American Aviation-built Gulf Stream II jet that was modified to simulate an orbiter’s cockpit, motion and visual cues, and handling qualities. In flight, the STA duplicates the orbiter’s atmospheric descent trajectory from approximately 35,000 feet altitude to landing on a runway. Because the orbiter is unpowered during re-entry and landing, its high-speed glide must be perfectly executed the first time. Space Shuttle Discovery is scheduled to launch July 1 on mission STS-121. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. - STS-121 Mission Specialist Michael Fossum has donned his launch and entry suit in preparation for the simulated countdown he and other crew members will undertake. The crew is taking part in Terminal Countdown Demonstration Test activities, including the dress rehearsal for launch. Mission STS-121 is scheduled to be launched July 1. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. - The STS-121 crew pause in their prelaunch activities to talk to the media, gathered at left. They are standing in the landing area of the slidewire baskets. The crew members facing them are (from left) Mission Specialists Thomas Reiter of Germany, who represents the European Space Agency, Piers Sellers, Stephanie Wilson, Commander Steven Lindsey, Pilot Mark Kelly, and Mission Specialists Lisa Nowak and Michael Fossum. The crew is at Kennedy for Terminal Countdown Demonstration Test activities. Over several days, the crew will practice emergency egress from the pad and suit up in their orange flight suits for the simulated countdown to launch. Space Shuttle Discovery is designated to launch July 1 on mission STS-121. It will carry supplies to the International Space Station. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. - STS-121 Mission Specialist Stephanie Wilson signals all is well after donning her launch and entry suit in preparation for the simulated countdown she and other crew members will undertake. The crew is taking part in Terminal Countdown Demonstration Test activities, including the dress rehearsal for launch. Mission STS-121 is scheduled to be launched July 1. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. - STS-121 Mission Specialist Thomas Reiter wears his launch and entry suit in preparation for the simulated countdown he and other crew members will undertake. Reiter is from Germany and represents the European Space Agency. The crew is taking part in Terminal Countdown Demonstration Test activities, including the dress rehearsal for launch. Mission STS-121 is scheduled to be launched July 1. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. - The suited STS-121 crew members walk to the bus that will take them to Launch Pad 39B for a simulated countdown. On the left, back to front, are Mission Specialists Stephanie Wilson and Lisa Nowak, and Pilot Mark Kelly. On the right, back to front, are Mission Specialists Thomas Reiter of Germany, Piers Sellers and Michael Fossum, and Commander Steven Lindsey. Reiter represents the European Space Agency. The crew is taking part in Terminal Countdown Demonstration Test activities, including the dress rehearsal for launch. Mission STS-121 is scheduled to be launched July 1. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. - The STS-121 crew pause in their prelaunch activities to talk to the media. They are standing in the landing area of the slidewire baskets. At the microphone is Commander Steven Lindsey. Behind him are (from left) Mission Specialists Michael Fossum and Lisa Nowak, Pilot Mark Kelly and Mission Specialists Stephanie Wilson, Piers Sellers and Thomas Reiter of Germany, who represents the European Space Agency. The crew is at Kennedy for Terminal Countdown Demonstration Test activities. Over several days, the crew will practice emergency egress from the pad and suit up in their orange flight suits for the simulated countdown to launch. Space Shuttle Discovery is designated to launch July 1 on mission STS-121. It will carry supplies to the International Space Station. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. - STS-121 Mission Specialist Thomas Reiter prepares to leap from the slidewire basket during training on emergency egress procedures from the launch pad. Above him is Mission Specialist Piers Sellers; at lower left is Mission Specialist Stephanie Wilson. The crew is at Kennedy for Terminal Countdown Demonstration Test activities, including emergency egress training from the pad. They will also suit up in their orange flight suits for a simulated countdown to launch. Discovery is designated to launch July 1 on mission STS-121. It will carry supplies to the International Space Station. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. - During a pause in their prelaunch activities at the pad, the STS-121 crew talk to the media. They are standing in the landing area of the slidewire baskets. With the microphone is Mission Specialist Piers Sellers. Next to him are Mission Specialists Stephanie Wilson and Thomas Reiter of Germany, who represents the European Space Agency. The crew is at Kennedy for Terminal Countdown Demonstration Test activities. Over several days, the crew will practice emergency egress from the pad and suit up in their orange flight suits for the simulated countdown to launch. Space Shuttle Discovery is designated to launch July 1 on mission STS-121. It will carry supplies to the International Space Station. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. - The STS-121 crew pause in their prelaunch activities to talk to the media. They are standing in the landing area of the slidewire baskets. With the microphone is Mission Specialist Piers Sellers. The crew members are (from left) Mission Specialists Michael Fossum and Lisa Nowak, Pilot Mark Kelly, Commander Steven Lindsey, and Mission Specialists Stephanie Wilson, Sellers, and Thomas Reiter of Germany, who represents the European Space Agency. The crew is at Kennedy for Terminal Countdown Demonstration Test activities. Over several days, the crew will practice emergency egress from the pad and suit up in their orange flight suits for the simulated countdown to launch. Space Shuttle Discovery is designated to launch July 1 on mission STS-121. It will carry supplies to the International Space Station. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. - The STS-121 crew have breakfast in the Operations and Checkout Building at NASA's Kennedy Space Center before suiting up for the simulated countdown at the launch pad. Seated left to right are Mission Specialists Thomas Reiter of Germany and Michael Fossum, Pilot Mark Kelly, Commander Steven Lindsey, and Mission Specialists Lisa Nowak, Piers Sellers and Stephanie Wilson. Reiter represents the European Space Agency. The crew is taking part in Terminal Countdown Demonstration Test activities, including the dress rehearsal for launch. Mission STS-121 is scheduled to be launched July 1. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. - Some of the STS-121 crew practices getting into a slidewire basket on Launch Pad 39B. At left is Mission Specialist Lisa Nowak; in front of her is Mission Specialist Michael Fossum. In the background are Commander Steven Lindsey and Mission Specialists Stephanie Wilson, Thomas Reiter and Piers Sellers. The crew is at Kennedy for Terminal Countdown Demonstration Test activities, including emergency egress training from the pad. They will also suit up in their orange flight suits for a simulated countdown to launch. Discovery is designated to launch July 1 on mission STS-121. It will carry supplies to the International Space Station. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. - STS-121 Pilot Mark Kelly is helped with his glove after donning his launch and entry suit in preparation for the simulated countdown he and other crew members will undertake. The crew is taking part in Terminal Countdown Demonstration Test activities, including the dress rehearsal for launch. Mission STS-121 is scheduled to be launched July 1. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. - During a pause in their prelaunch activities at the pad, the STS-121 crew talk to the media. They are standing in the landing area of the slidewire baskets. With the microphone is Mission Specialist Stephanie Wilson. The crew is at Kennedy for Terminal Countdown Demonstration Test activities. Over several days, the crew will practice emergency egress from the pad and suit up in their orange flight suits for the simulated countdown to launch. Space Shuttle Discovery is designated to launch July 1 on mission STS-121. It will carry supplies to the International Space Station. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. - STS-121 Commander Steven Lindsey has his helmet secured to his launch and entry suit in preparation for the simulated countdown he and other crew members will undertake. The crew is taking part in Terminal Countdown Demonstration Test activities, including the dress rehearsal for launch. Mission STS-121 is scheduled to be launched July 1. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. - The STS-121 crew listens to instructions on emergency egress from the pad. The crew members are (from left) Pilot Mark Kelly, Mission Specialists Piers Sellers, Lisa Nowak, Stephanie Wilson and Thomas Reiter, Commander Steven Lindsey, and Mission Specialist Michael Fossum. Reiter is from Germany and represents the European Space Agency. The crew is at Kennedy for Terminal Countdown Demonstration Test activities, including emergency egress training from the pad. They will also suit up in their orange flight suits for a simulated countdown to launch. Discovery is designated to launch July 1 on mission STS-121. It will carry supplies to the International Space Station. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. - During emergency egress training at the pad, STS-121 crew members Piers Sellers, Stephanie Wilson and Thomas Reiter, all mission specialists, learn how to exit the slidewire basket on the ground. The crew is at Kennedy for Terminal Countdown Demonstration Test activities, including emergency egress training from the pad. They will also suit up in their orange flight suits for a simulated countdown to launch. Discovery is designated to launch July 1 on mission STS-121. It will carry supplies to the International Space Station. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. - The STS-121 crew pose for the media, concluding a press conference held in the landing area of the slidewire baskets. The crew members facing them are (from left) The crew members are (from left) Mission Specialists Michael Fossum and Lisa Nowak, Pilot Mark Kelly, Commander Steven Lindsey, and Mission Specialists Stephanie Wilson, Piers Sellers and Thomas Reiter of Germany, who represents the European Space Agency. The crew is at Kennedy for Terminal Countdown Demonstration Test activities. Over several days, the crew will practice emergency egress from the pad and suit up in their orange flight suits for the simulated countdown to launch. Space Shuttle Discovery is designated to launch July 1 on mission STS-121. It will carry supplies to the International Space Station. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. - During emergency egress training at the pad, STS-121 Mission Specialist Stephanie Wilson prepares to jump to the ground from the slidewire basket in the landing area. Helping her above are Mission Specialists Piers Sellers and Thomas Reiter. The crew is at Kennedy for Terminal Countdown Demonstration Test activities, including emergency egress training from the pad. They will also suit up in their orange flight suits for a simulated countdown to launch. Discovery is designated to launch July 1 on mission STS-121. It will carry supplies to the International Space Station. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. - STS-121 Mission Specialist Lisa Nowak is helped with her boot after donning her launch and entry suit in preparation for the simulated countdown she and other crew members will undertake. The crew is taking part in Terminal Countdown Demonstration Test activities, including the dress rehearsal for launch. Mission STS-121 is scheduled to be launched July 1. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. - Some of the STS-121 crew practices getting into a slidewire basket on Launch Pad 39B while others watch. In the basket are Mission Specialists Piers Sellers, Stephanie Wilson and Thomas Reiter. Behind them are Commander Steven Lindsey, Mission Specialists Lisa Nowak and Michael Fossum, and Pilot Mark Kelly. The crew is at Kennedy for Terminal Countdown Demonstration Test activities, including emergency egress training from the pad. They will also suit up in their orange flight suits for a simulated countdown to launch. Discovery is designated to launch July 1 on mission STS-121. It will carry supplies to the International Space Station. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. - STS-121 Mission Specialist Piers Sellers signals okay after donning his launch and entry suit in preparation for the simulated countdown he and other crew members will undertake. The crew is taking part in Terminal Countdown Demonstration Test activities, including the dress rehearsal for launch. Mission STS-121 is scheduled to be launched July 1. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. - STS-121 Mission Specialist Lisa Nowak prepares to leap from the slidewire basket during training on emergency egress procedures from the launch pad. At left is Mission Specialist Michael Fossum. The crew is at Kennedy for Terminal Countdown Demonstration Test activities, including emergency egress training from the pad. They will also suit up in their orange flight suits for a simulated countdown to launch. Discovery is designated to launch July 1 on mission STS-121. It will carry supplies to the International Space Station. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. - The STS-121 crew pause in their prelaunch activities to talk to the media, gathered at left. They are standing in the landing area of the slidewire baskets. The crew members facing them are (from left) Mission Specialists Thomas Reiter of Germany, who represents the European Space Agency, Piers Sellers, Stephanie Wilson, Commander Steven Lindsey, Pilot Mark Kelly, and Mission Specialists Lisa Nowak and Michael Fossum. The crew is at Kennedy for Terminal Countdown Demonstration Test activities. Over several days, the crew will practice emergency egress from the pad and suit up in their orange flight suits for the simulated countdown to launch. Space Shuttle Discovery is designated to launch July 1 on mission STS-121. It will carry supplies to the International Space Station. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. - The suited STS-121 crew members stride out of the Operations and Checkout Building on their way to Launch Pad 39B for a simulated countdown. Leading the way are Pilot Mark Kelly (left) and Commander Steven Lindsey. Behind Kelly are Mission Specialists Lisa Nowak, Stephanie Wilson and Thomas Reiter of Germany, who represents the European Space Agency. Behind Lindsey are Mission Specialists Michael Fossum and Piers Sellers. The crew is taking part in Terminal Countdown Demonstration Test activities, including the dress rehearsal for launch. Mission STS-121 is scheduled to be launched July 1. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. - During emergency egress training at the pad, the STS-121 crew pose for a photo on the upper level in front of Space Shuttle Discovery's external tank. From left are Mission Specialists Piers Sellers, Thomas Reiter and Lisa Nowak, Commander Steven Lindsey, Mission Specialist Stephanie Wilson, Pilot Mark Kelly and Mission Specialist Michael Fossum. The crew is at Kennedy for Terminal Countdown Demonstration Test activities, including emergency egress training from the pad. They will also suit up in their orange flight suits for a simulated countdown to launch. Discovery is designated to launch July 1 on mission STS-121. It will carry supplies to the International Space Station. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. - During emergency egress training at the pad, the STS-121 crew poses for a photo on the upper level. From left are Mission Specialist Thomas Reiter, Commander Steven Lindsey, Pilot Mark Kelly, and Mission Specialists Stephanie Wilson, Michael Fossum, Lisa Nowak and Piers Sellers. Behind them can be seen the top of a solid rocket booster and the external tank, part of the configuration for Space Shuttle Discovery. The crew is at Kennedy for Terminal Countdown Demonstration Test activities, including emergency egress training from the pad. They will also suit up in their orange flight suits for a simulated countdown to launch. Discovery is designated to launch July 1 on mission STS-121. It will carry supplies to the International Space Station. Photo credit: NASA/Kim Shiflett