In bay 3 of the Orbiter Processing Facility a worker waits for the tool storage assembly unit.

In bay 3 of the Orbiter Processing Facility, a worker inside Discovery's payload bay waits for the tool storage assembly unit (near top of photo) to be moved and lowered into the orbiter, where it will be stored. The tools may be used on a spacewalk, yet to be determined, during mission STS-120. In an unusual operation, the payload bay doors had to be reopened after closure to accommodate the storage. Space shuttle Discovery is targeted to launch Oct. 23 to the International Space Station. It will carry the U.S. Node 2, a connecting module, named Harmony, for assembly on the space station. Photo credit: NASA/Amanda Diller