Astronaut Bruce McCandless II, one of two STS-41B mission specialists participating in a historic spacewalk, is a few meters away from the cabin of the Earth-orbiting space shuttle Challenger in this 70mm frame on Feb. 7, 1984. This @science spacewalk represented the first use of a nitrogen-propelled, hand-controlled device called the Manned Maneuvering Unit (MMU), which allows for much greater mobility than that afforded previous spacewalkers who had to use restrictive tethers. Robert L. Stewart later tried out the MMU McCandless is using here, and the two of them tested another similar unit two days later. Inside the spacecraft were astronauts Vance D. Brand, commander; Robert L. Gibson, pilot; and Ronald E. McNair, mission specialist.
Image Credit: NASA
