CAPE CANAVERAL, Fla. -- On Launch Pad 39A at NASA's Kennedy Space Center, the Japanese Experiment Module—Pressurized Module is seen in space shuttle Discovery's payload bay as the payload bay doors begin to close. Above the pressurized module is the orbital docking system. The launch of Discovery on its STS-124 mission is targeted for May 31. On the mission, Discovery will transport the pressurized module and the Japanese Remote Manipulator System to the International Space Station. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- Workers in the payload changeout room on Launch Pad 39A at NASA's Kennedy Space Center watch closely as space shuttle Discovery's payload bay doors close around the Japanese Experiment Module—Pressurized Module. The launch of Discovery on its STS-124 mission is targeted for May 31. On the mission, Discovery will transport the pressurized module and the Japanese Remote Manipulator System to the International Space Station. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- On Launch Pad 39A at NASA's Kennedy Space Center, space shuttle Discovery's payload bay doors have successfully closed around the Japanese Experiment Module—Pressurized Module. The launch of Discovery on its STS-124 mission is targeted for May 31. On the mission, Discovery will transport the pressurized module and the Japanese Remote Manipulator System to the International Space Station. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- On Launch Pad 39A at NASA's Kennedy Space Center, a worker watches the progress of space shuttle Discovery's payload bay doors as they close around the Japanese Experiment Module—Pressurized Module. The launch of Discovery on its STS-124 mission is targeted for May 31. On the mission, Discovery will transport the pressurized module and the Japanese Remote Manipulator System to the International Space Station. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- Workers in the payload changeout room on Launch Pad 39A at NASA's Kennedy Space Center check space shuttle Discovery's payload bay doors as they close around the Japanese Experiment Module—Pressurized Module. The launch of Discovery on its STS-124 mission is targeted for May 31. On the mission, Discovery will transport the pressurized module and the Japanese Remote Manipulator System to the International Space Station. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- Workers in the payload changeout room on Launch Pad 39A at NASA's Kennedy Space Center check the placement of space shuttle Discovery's payload bay doors as they close around the Japanese Experiment Module—Pressurized Module. The launch of Discovery on its STS-124 mission is targeted for May 31. On the mission, Discovery will transport the pressurized module and the Japanese Remote Manipulator System to the International Space Station. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- On Launch Pad 39A at NASA's Kennedy Space Center, the Japanese Experiment Module—Pressurized Module is in place in space shuttle Discovery's payload bay as the payload bay doors begin to close. The launch of Discovery on its STS-124 mission is targeted for May 31. On the mission, Discovery will transport the pressurized module and the Japanese Remote Manipulator System to the International Space Station. Photo credit: NASA/Kim Shiflett