KENNEDY SPACE CENTER, FLA. - At Launch Pad 39B, the payloads for mission STS-121 are being moved from the payload changeout room into Space Shuttle Discovery's payload bay. At lower right is the multi-purpose logistics module Leonardo. Above it is the integrated cargo carrier that holds the mobile transporter reel assembly the astronauts will replace on the station and a spare pump module. Discovery is scheduled to launch at 3:48 p.m. July 1 carrying a crew of seven on the 12-day mission to the International Space Station. Photo credit: NASA/Charisse Nahser

KENNEDY SPACE CENTER, FLA. - At Launch Pad 39B, the open doors of Space Shuttle Discovery's payload bay show the cargo the orbiter will carry into orbit. At the lower end is multi-purpose logistics module Leonardo. Above it is the integrated cargo carrier that holds the mobile transporter reel assembly the astronauts will replace on the station and a spare pump module. Discovery is scheduled to launch at 3:48 p.m. July 1 carrying a crew of seven on the 12-day mission to the International Space Station. Photo credit: NASA/Charisse Nahser

KENNEDY SPACE CENTER, FLA. - At Launch Pad 39B, the payloads for mission STS-121 are being moved from the payload changeout room into Space Shuttle Discovery's payload bay. Here, the multi-purpose logistics module Leonardo is being transferred. Other payloads include the integrated cargo carrier that holds the mobile transporter reel assembly the astronauts will replace on the station and a spare pump module. Discovery is scheduled to launch at 3:48 p.m. July 1 carrying a crew of seven on the 12-day mission to the International Space Station. Photo credit: NASA/Charisse Nahser

KENNEDY SPACE CENTER, FLA. - At Launch Pad 39B, the payloads for mission STS-121 are being moved from the payload changeout room into Space Shuttle Discovery's payload bay. Seen in the background is the multi-purpose logistics module Leonardo. Other payloads include the integrated cargo carrier that holds the mobile transporter reel assembly the astronauts will replace on the station and a spare pump module. Discovery is scheduled to launch at 3:48 p.m. July 1 carrying a crew of seven on the 12-day mission to the International Space Station. Photo credit: NASA/Charisse Nahser