Astronaut Bruce McCandless II approaches his maximum distance from the Earth-orbiting Space Shuttle Challenger in this 70mm frame photographed by his fellow crewmembers onboard the reusable vehicle. McCandless is in the midst of the first “field” tryout of the nitrogen-propelled, hand-controlled back-pack device called the manned maneuvering unit (MMU). Astronaut Robert L. Stewart got a chance to test the same unit a while later in the lengthy EVA session while the two spacewalkers were photographed and monitored by their fellow crewmembers in Challenger’s cabin. Those inside were Astronauts Vance D. Brand, Robert L. Gibson and Dr. Ronald E. McNair.
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