KENNEDY SPACE CENTER, FLA. -- On Launch Pad 39B at NASA's Kennedy Space Center, the payload canister holding Space Shuttle Discovery's payloads nears the payload changeout room on the rotating service structure. The red umbilical lines are still attached. The payload changeout room provides an environmentally clean or "white room" condition in which to receive a payload transferred from a protective payload canister. After the shuttle arrives at the pad, the rotating service structure will close around it and the payloads, which include the multi-purpose logistics module and integrated cargo carrier, will then be transferred from the changeout room into Discovery's payload bay. Discovery's launch to the International Space Station on mission STS-121 is targeted for July 1 in a launch window that extends to July 19. During the 12-day mission, crew members will test new hardware and techniques to improve shuttle safety. Photo credit: NASA/Kim Shiflett