Workers prepare the payload mechanism or PGHM that will transfer the cargo in the payload canister.

In the payload changeout room, or PCR, on Launch Pad 39A at NASA's Kennedy Space Center in Florida, workers prepare the payload ground-handling mechanism, or PGHM, that will transfer the cargo in the payload canister. The cargo comprises four carriers holding various equipment for the STS-125 mission aboard space shuttle Atlantis to service NASA’s Hubble Space Telescope. 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