The open doors of the payload canister reveal its cargo to service NASA's Hubble Space Telescope.

On Launch Pad 39A at NASA's Kennedy Space Center in Florida, the open doors of the payload canister reveal its cargo -- four carriers holding various equipment for the STS-125 mission aboard space shuttle Atlantis to service NASA’s Hubble Space Telescope. From top to bottom are the Multi-Use Logistic Equipment carrier, the Flight Support System carrier, the Orbital Replacement Unit Carrier and the Super Lightweight Interchangeable Carrier. The doors are open to the payload changeout room, or PCR. The cargo will be transferred into the PCR via the payload ground-handling mechanism, or PGHM. The PGHM removes payloads from a transportation canister and installs them into the shuttle. It is essentially NASA’s largest fork-lift. Atlantis is targeted to launch Oct. 10. Photo credit: NASA/Jim Grossmann