Astronaut Bruce McCandless II, one of two 41-B mission specialists, participating in a historical Extravehicular Activity (EVA), is a few meters away from the cabin of the Earth-orbiting space shuttle Challenger in this 70mm frame.
This EVA 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 space-walkers who had to use restrictive tethers.
Robert L. Stewart, mission specialist, later tried out the MMU McCandless is using here. 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.