In the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida, space shuttle Atlantis is lowered into High Bay 3. In the bay, the shuttle will be mated with its external fuel tank and solid rocket boosters on the mobile launcher platform. After additional preparations are made, the shuttle will be rolled out to Launch Pad 39A for a targeted launch on May 12 on the STS-125 mission to service NASA's Hubble Space Telescope. Photo credit: NASA/Kim Shiflett