STS-41-B EVA

Astronaut Bruce McCandless, II, 41-B mission specialist, tests a the manned maneuvering unit (MMU) during an a test involving the trunion pin attachmet device (TPAD) he carries and the shuttle pallet satellite (SPAS-01A), partially visible at bottom of the frame. The Challenger was flying with its aft end aimed toward the Earth. This photo show the astronaut hanging above the open payload bay with the TPAD in his hands.