Space shuttle Atlantis on Launch Pad 39A is viewed across the lagoon at NASA's Kennedy Space Center in Florida. Atlantis is targeted to launch May 12 on the STS-125 mission to upgrade NASA's Hubble Space Telescope. Endeavour will be prepared on the pad for liftoff in the unlikely event that a rescue mission is necessary following space shuttle Atlantis' launch May 12 on the STS-125 mission to upgrade NASA's Hubble Space Telescope. After Atlantis is cleared to land, Endeavour will move to Launch Pad 39A for its upcoming STS-127 mission to the International Space Station, targeted to launch June 13. Photo credit: NASA/Jack Pfaller