Working in Space: "Building Toward New Heights" 1987 NASA Johnson Space Center
Published on Jan 8, 2017
'To realize the goals of lunar colonies and Space Station, humans must first adapt to working in the space environment. This program showcases the on-orbit work already accomplished by Shuttle astronauts including testing the Manned Maneuvering Unit on flight 41-B, repairing the Solar Maximum satellite on flight 41-C, retrieving two communications satellites on flight 51-A, "fly-swatting" the SYNCOM satellite on flight 51-D, and salvaging the very same satellite on flight 51-I.'
NASA film JSC-852
The Manned Maneuvering Unit (MMU) is an astronaut propulsion unit that was used by NASA on three Space Shuttle missions in 1984. The MMU allowed the astronauts to perform untethered EVA spacewalks at a distance from the shuttle. The MMU was used in practice to retrieve a pair of faulty communications satellites, Westar VI and Palapa B2. Following the third mission the unit was retired from use. A smaller successor, the Simplified Aid For EVA Rescue (SAFER), was first flown in 1994, and is intended for emergency use only...
In 1966, the US Air Force developed an Astronaut Maneuvering Unit (AMU), a self-contained rocket pack very similar to the MMU. This was planned to be tested during Project Gemini on an EVA by Eugene Cernan on Gemini 9A on June 5, 1966. However, the test had to be cancelled because Cernan, tired and overheated, sweated so profusely that his helmet visor fogged before he could get to the AMU mounted on the back of the spacecraft. Astronauts did not learn how to work during EVA without tiring until the final Gemini 12 mission, but no AMU was carried on that flight. Since there was no real need for self-contained astronaut EVA flight in the Apollo and Skylab programs, the idea had to wait for the advent of the Space Shuttle program, though several maneuvering device designs were tested inside Skylab.
The MMU was used on three Shuttle missions in 1984. It was first tested on February 7 during mission STS-41-B by astronauts Bruce McCandless II and Robert L. Stewart. Two months later during mission STS-41-C, astronauts James van Hoften and George Nelson attempted to use the MMU to capture the Solar Maximum Mission satellite and to bring it into the orbiter's payload bay for repairs and servicing. The plan was to use an astronaut-piloted MMU to grapple the SMM with the Trunion Pin Attachment Device (TPAD) mounted between the hand controllers of the MMU, null its rotation rates, and allow the Shuttle to bring it into the Shuttle's payload bay for stowage. Three attempts to grapple the satellite using the TPAD failed. The TPAD jaws could not lock onto Solar Max because of an obstructing grommet on the satellite not included in the blueprints for the satellite. This led to an improvised plan which nearly ended the satellite's mission... The ground support engineers then stabilized the satellite and nulled its rotation rates for capture with the orbiter's robotic arm, the Shuttle Remote Manipulator System (SRMS)... Their successful work increased the lifespan of the satellite.
The final MMU mission was STS-51-A, which flew in November 1984. The propulsion unit was used to retrieve two communication satellites, Westar VI and Palapa B2, that did not reach their proper orbits because of faulty propulsion modules. Astronauts Joseph P. Allen and Dale Gardner captured the two satellites and brought them into the Orbiter payload bay for stowage and return to Earth.
After a safety review following the Space Shuttle Challenger disaster, the MMU was judged too risky for further use and it was found many activities planned for the MMU could be done effectively with manipulator arms or traditional tethered EVAs... Although the MMU was envisioned as a natural aid for constructing the International Space Station, with its retirement, NASA developed different tethered spacewalk approaches.
The two operational, flown flight units MMU #2 and #3 were stored by NASA in a clean room at Lockheed in Denver through 1998. NASA transferred flight article #3 to the National Air and Space Museum in 1998, which now hangs suspended in the hall above the Space Shuttle Discovery. In 2013 flight article #2 was displayed next to the Space Shuttle Atlantis in its new home at the Kennedy Space Center Visitor Complex...
Public domain film from NASA, slightly cropped to remove uneven edges, with the aspect ratio corrected, and one-pass brightness-contrast-color correction & mild video noise reduction applied.
The soundtrack was also processed with volume normalization, noise reduction, clipping reduction, and/or equalization (the resulting sound, though not perfect, is far less noisy than the original).https://www.youtube.com/watch?v=EOBjC7_Iyc4?t=001