Astronaut Bruce McCandless II, STS-41B mission specialist, tests a “cherry-picker” type device during the Feb. 7, 1984, historic spacewalk. The spacewalk, in which Astronauts McCandless and Robert L. Stewart participated, marked two firsts–initial use of both the Mobile Foot Restraint (MFR) attached to the Remote Manipulator System (RMS) arm here, and the Manned Maneuvering Unit (MMU) backpack (not seen in this frame).
The space shuttle Challenger was flying with its aft end aimed toward the Earth. This photograph clearly shows where the MFR connects to the end effector of the Canadian-built RMS arm. The two spacewalkers were monitored and photographed by their fellow crewmembers, astronauts Vance D. Brand, commander; Robert L. Gibson, pilot; and Ronald E. McNair, mission specialist. The three remained in the cabin for another spacewalk two days later.