The STS-121 crew pose outside of Space Shuttle Discovery's hatch during prelaunch training at Launch Pad 39B.

The STS-121 crew pose outside of Space Shuttle Discovery's hatch during prelaunch training at Launch Pad 39B. Kneeling in front is Mission Specialist Thomas Reiter of Germany, who represents the European Space Agency. Standing behind are (from left) Mission Specialists Thomas Fossum and Lisa Nowak, Commander Steven Lindsey (center), Pilot Mark Kelly, and Mission Specialists Piers Sellers and 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