Space shuttle Atlantis' rocket booster stack presents an unusual sight at NASA's Kennedy Space Center.

Space shuttle Atlantis' external fuel tank-solid rocket booster stack, atop a mobile launcher platform, presents an unusual sight – without the shuttle – as it is transferred from high bay 1 to high bay 3 in the Vehicle Assembly Building at NASA's Kennedy Space Center. It is being moved to high bay 3 to make room for the ET-SRB stack for space shuttle Endeavour. Atlantis is targeted for launch on the STS-125 mission on May 12 to service NASA's Hubble Space Telescope. Endeavour will fly on the STS-127 mission to the International Space Station and bring the final segments for Japan's Kibo laboratory. Photo credit: NASA/Tim Jacobs