CAPE CANAVERAL, Fla. - At Launch Pad 39A at NASA's Kennedy Space Center in Florida, the payload canister arrives beneath the payload changeout room in the rotating service structure (left). Space shuttle Atlantis is at right. The two tail service masts on the mobile launcher platform flank the engines in front of the wings. The canister carries a cargo of four carriers holding various equipment for the STS-125 mission aboard Atlantis to service NASA’s Hubble Space Telescope. At the pad, the cargo will be moved into the Payload Changeout Room. The changeout room is the enclosed, environmentally controlled portion of the rotating service structure that supports cargo delivery to the pad and subsequent vertical installation into the shuttle’s payload bay. Launch of Atlantis is targeted for Oct. 10. Photo credit: NASA/Troy Cryder