Remembering Bruce McCandless II

Posted on Wed, January 10, 2018

Bruce McCandless and the Manned Maneuvering Unit (MMU)

On February 7, 1984 during Space Shuttle mission STS 41-B, astronaut Bruce McCandless made the first untethered spacewalk as he flew some 300 feet from the Shuttle in the first test of the MMU. This image was taken several days later on February 11.

Bruce McCandless II (1937-2017) is immortalized in this iconic photograph of an astronaut flying solo high above Earth. He was the first human being to do a spacewalk without a safety tether linked to a spacecraft.

On February 7, 1984, on Space Shuttle Challenger’s STS 41-B mission, McCandless donned a backpack mobility device—the Manned Maneuvering Unit—and ventured about 320 ft (98 m) away from the vehicle, becoming the first human satellite. Using hand controllers to operate the MMU’s nitrogen gas thrusters, he moved just enough faster than the shuttle’s 17,500 miles per hour orbital velocity to open the distance between him and the spacecraft. His solo ride lasted 1 hour and 22 minutes.

McCandless received the National Air and Space Museum Trophy in 1985 for this bold achievement. The Manned Maneuvering Unit he flew is now displayed at the Museum’s Steven F. Udvar-Hazy Center in Chantilly, Virginia.

Bruce McCandless was the youngest of 19 astronauts selected in 1966. He served as the voice of Mission Control during the Apollo 11 mission in 1969, talking with Neil Armstrong and Buzz Aldrin during their historic walk on the Moon, and also during Apollo 14 in 1971. He worked on developing an earlier maneuvering unit tested on Skylab in 1973-74 and then on design and testing of the shuttle-era Manned Maneuvering Unit. McCandless also had a keen interest in developing tools for extravehicular activity, and a tether latch that he perfected became known as the McTether, also in the Museum’s collection.

His second flight occurred in April 1990, on Discovery’s STS-31 mission to deploy the Hubble Space Telescope. McCandless and crewmate Kathryn Sullivan came within moments of doing a well-rehearsed spacewalk when one of the telescope's solar arrays briefly failed to deploy, but it was not needed.

A portrait of NASA astronaut Bruce McCandless II,

Astronaut Bruce McCandless II, October 1982. Credit: NASA Johnson Space Center.

McCandless graduated second in his class at the U.S. Naval Academy in 1958 and became a naval aviator in 1960. He served in Fighter Squadron VF-102 until 1964, including duty on board the aircraft carrier USS Enterprise during its involvement in the Cuban Missile Crisis in 1962. McCandless logged 5,000 hours in jet aircraft and 312 hours in space.

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