NASA Photograph Taken on Skylab 3

NASA Photograph Taken on Skylab 3

In the photograph astronaut Jack R. Lousma flies the Automatically Stabilized Maneuvering Unit (ASMU) in the forward dome area of the Orbital Workshop of America’s Skylab space station. The ASMU was a jetpack worn by astronauts to allow them to complete maneuvers in space without a lifeline back to the spacecraft. Propelled by compressed nitrogen, the operator could move forward or backward, side to side, or up and down - as well as rotating. Powerful gyroscopes inside the backpack hold the astronaut steady.

The idea of a jetpack to allow astronauts to complete tasks outside the spacecraft, such as retrieving satellites, had been around since the 1960s. The ASMU was developed as a test version, for astronauts to trial the technology inside the safety of Skylab in 1973. Two other maneuvering systems were tested at the same time; a hand-held “zip-gun” and a foot controlled maneuvering unit. The ASMU was by far the favourite of the astronauts.

The results from the Skylab experiments were used to improve the design, which was later developed into the Manned Maneuvering Unit (MMU). Astronaut Bruce McCandless II used the MMU to make the first untethered EVA on Space Shuttle mission STS-41B in 1984. He flew 300 feet from the Orbiter, a distance that has not been exceeded since.