An astronaut propulsion unit (or astronaut maneuvering unit) is used to move an astronaut relative to the spaceship during a spacewalk. The first astronaut propulsion unit was the Hand-Held Maneuvering Unit (HHMU) used on Gemini 4.
An astronaut propulsion unit (or astronaut maneuvering unit) is used to move an astronaut relative to the spaceship during a spacewalk. The first astronaut propulsion unit was the Hand-Held Maneuvering Unit (HHMU) used on Gemini 4.
The Hand-Held Maneuvering Unit was the EVA "zip" gun used by Ed White on the Gemini 4 mission in 1965. The hand-held gun held several pounds of nitrogen, [1] and allowed limited movement around the Gemini spacecraft. It was also used by astronaut Michael Collins on the Gemini 10 mission in 1966.
The United States Air Force (USAF) Astronaut Maneuvering Unit (AMU) was designed by the U.S. Air Force, which was planning to use the Gemini spacecraft as part of the Manned Orbiting Laboratory (MOL). The AMU was a backpack using hydrogen peroxide as the fuel. The total delta-v capability of the AMU was about 250 feet per second (76.2 meters per second), roughly three times that of the MMU. The astronaut would strap on the AMU like a backpack, and maneuver around using two hand controllers like that of the later MMU. Because of the fuel, which came out as a hot gas, the astronaut's suit had to be modified with the addition of woven metal "pants" made of Chromel-R metal cloth. The AMU was carried aboard the Gemini 9 mission, but was not tested because the astronaut, Eugene Cernan, had difficulty maneuvering from the Gemini cabin to the AMU storage place, at the back of the spacecraft, and overheated, causing his helmet faceplate to fog up. The AMU was also meant to be launched and flown on-board Gemini 12, and to fly untethered from the Gemini spacecraft, but was scrubbed two months before the mission. [2] NASA chief astronaut Deke Slayton later speculated in his autobiography that the AMU may have been developed for the MOL program because the Air Force "thought they might have the chance to inspect somebody else's satellites." [3]
In 1973, the Automatically Stabilized Maneuvering Unit (ASMU) was test-flown aboard Skylab during the Skylab 3 [4] and 4 missions. Tested inside of the orbiting laboratory, it used nitrogen gas allowing both unsuited and suited testing of the unit. The Skylab AMU was the closest to the Shuttle MMU, but was not used outside the spacecraft because the EVAs were conducted with the astronauts attached to life support umbilicals, and to prevent damage to the delicate solar arrays on the Apollo Telescope Mount.
The Foot Controlled Maneuvering Unit was tested within Skylab. The purpose of it was to free the astronaut's hands. It was propelled by cold, high-pressured nitrogen gas located in a tank on the back. [5] It was tested both suited and unsuited.
The Manned Maneuvering Unit (MMU) is a propulsion backpack which was used by NASA astronauts 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.
The Soviet Union also used a cosmonaut propulsion system on flights to the space station Mir. The SPK (or UMK, UPMK [6] ) was larger than the Space Shuttle MMU, contained oxygen instead of nitrogen and was attached to a safety tether. Despite the tether, the SPK allowed the cosmonaut, wearing the self-contained Orlan spacesuit, to "fly around" the orbiting complex, allowing access to areas nearly impossible to access otherwise. Though tested on Mir in 1990, the cosmonauts preferred using the Strela crane (equivalent to the Mobile Servicing System). The SPK, which was left attached to the outside to the Kvant-2 module, was destroyed when Mir re-entered the atmosphere after decommissioning.
The 21KS [6] system is a completely new design for Orlan-DMA spacesuit not using a safety tether, but air jet engines. This system was similar to MMU. It was automatically stabilized, used 6 degrees of freedom, weighed less than 180 kg, had a delta-v of 30 m/s, practical speed of 1 m/s, and an emergency mode that allows for rotational acceleration of 8°/s^2. [7]
The Simplified Aid For EVA Rescue (SAFER) is a smaller backpack propulsion system intended as a safety device during space walks. It contains 1.4 kg of gaseous nitrogen, which provides much less delta-v capability than the MMU, roughly 10 feet per second (3 meters per second). However SAFER is less complex, less expensive and simpler to use than the MMU, and the limited delta-v is sufficient for the intended rescue-only task. Other Crew Self Rescue (CSR) devices of which prototypes have been developed include an inflatable pole, a telescoping pole, a bi-stem pole and a bola-type lasso device (astrorope) the drifting astronaut could throw to hook to the space station.
Extravehicular activity (EVA) is any activity done by an astronaut in outer space outside a spacecraft. In the absence of a breathable Earthlike atmosphere, the astronaut is completely reliant on a space suit for environmental support. EVA includes spacewalks and lunar or planetary surface exploration. In a stand-up EVA (SEVA), an astronaut stands through an open hatch but does not fully leave the spacecraft. EVAs have been conducted by the Soviet Union/Russia, the United States, Canada, the European Space Agency and China.
A space suit or spacesuit is a garment worn to keep a human alive in the harsh environment of outer space, vacuum and temperature extremes. Space suits are often worn inside spacecraft as a safety precaution in case of loss of cabin pressure, and are necessary for extravehicular activity (EVA), work done outside spacecraft. Space suits have been worn for such work in Earth orbit, on the surface of the Moon, and en route back to Earth from the Moon. Modern space suits augment the basic pressure garment with a complex system of equipment and environmental systems designed to keep the wearer comfortable, and to minimize the effort required to bend the limbs, resisting a soft pressure garment's natural tendency to stiffen against the vacuum. A self-contained oxygen supply and environmental control system is frequently employed to allow complete freedom of movement, independent of the spacecraft.
STS-6 was the sixth NASA Space Shuttle mission and the maiden flight of the Space ShuttleChallenger. Launched from Kennedy Space Center on April 4, 1983, the mission deployed the first Tracking and Data Relay Satellite, TDRS-1, into orbit, before landing at Edwards Air Force Base on April 9, 1983. STS-6 was the first Space Shuttle mission during which a spacewalk was conducted, and hence was the first in which the Extravehicular Mobility Unit (EMU) was used.
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 extravehicular 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.
Gemini 9A was a 1966 crewed spaceflight in NASA's Gemini program. It was the seventh crewed Gemini flight, the 13th crewed American flight and the 23rd spaceflight of all time. The original crew for Gemini 9, command pilot Elliot See and pilot Charles Bassett, were killed in a crash on February 28, 1966, while flying a T-38 jet trainer to the McDonnell Aircraft plant in St. Louis, Missouri to inspect their spacecraft. Their deaths promoted the backup crew, Thomas P. Stafford and Eugene Cernan, to the prime crew. The mission was renamed Gemini 9A after the original May 17 launch was scrubbed when the mission's Agena Target Vehicle was destroyed after a launch failure. The mission was flown June 3–6, 1966, after launch of the backup Augmented Target Docking Adaptor (ATDA). Stafford and Cernan rendezvoused with the ATDA, but were unable to dock with it because the nose fairing had failed to eject from the docking target due to a launch preparation error. Cernan performed a two-hour extravehicular activity, during which it was planned for him to demonstrate free flight in a self-contained rocket pack, the USAF Astronaut Maneuvering Unit. He was unable to accomplish this due to stress, fatigue, and overheating.
STS-41-B was NASA's tenth Space Shuttle mission and the fourth flight of the Space ShuttleChallenger. It launched on 3 February 1984, and landed on 11 February 1984 after deploying two communications satellites. It was also notable for including the first untethered spacewalk.
Bruce McCandless II was a United States Navy officer and aviator, electrical engineer, and NASA astronaut. In 1984, during the first of his two Space Shuttle missions, he completed the first untethered spacewalk by using the Manned Maneuvering Unit.
The Extravehicular Mobility Unit (EMU) is an independent anthropomorphic spacesuit that provides environmental protection, mobility, life support, and communications for astronauts performing extravehicular activity (EVA) in Earth orbit. Introduced in 1981, it is a two-piece semi-rigid suit, and is currently one of two types of EVA spacesuits used by crew members on the International Space Station (ISS), the other being the Russian Orlan space suit. It was used by NASA's Space Shuttle astronauts prior to the end of the Shuttle program in 2011.
Simplified Aid For EVA Rescue (SAFER) is a small, self-contained, propulsive backpack system worn during spacewalks, to be used in case of emergency only. If an untethered astronaut were to lose physical contact with the vessel, it would provide free-flying mobility to return to it. It is worn on spacewalks outside the International Space Station (ISS), and was worn on spacewalks outside the Space Shuttle. So far, there has not been an emergency in which it was needed. SAFER is a small, simplified version of the Manned Maneuvering Unit (MMU), which was used for regular maneuvering.
Project Gemini was NASA's second human spaceflight program. Conducted between projects Mercury and Apollo, Gemini started in 1961 and concluded in 1966. The Gemini spacecraft carried a two-astronaut crew. Ten Gemini crews and 16 individual astronauts flew low Earth orbit (LEO) missions during 1965 and 1966.
William Frederick Fisher is an American physician and a former NASA astronaut. Fisher went into space in 1985 on board the Space Shuttle. He retired from NASA in 1992 and returned to the full-time practice of medicine. His time at NASA coincided with that of his former wife and fellow astronaut Anna Lee Fisher. He is also the great grandson of Pony Express rider William Frederick Fisher
The Apollo/Skylab space suit is a class of space suits used in Apollo and Skylab missions. The names for both the Apollo and Skylab space suits were Extravehicular Mobility Unit (EMU). The Apollo EMUs consisted of a Pressure Suit Assembly (PSA) aka "suit" and a Portable Life Support System (PLSS) that was more commonly called the "backpack". The A7L was the PSA model used on the Apollo 7 through 14 missions.
The Orlan space suit is a series of semi-rigid one-piece space suit models designed and built by NPP Zvezda. They have been used for spacewalks (EVAs) in the Russian space program, the successor to the Soviet space program, and by space programs of other countries, including NASA.
The Gemini spacesuit is a spacesuit worn by American astronauts for launch, in-flight activities and landing. It was designed by NASA based on the X-15 high-altitude pressure suit. All Gemini spacesuits were developed and manufactured by the David Clark Company in Worcester, Massachusetts.
The Hand-Held Maneuvering Unit (HHMU), also known as the maneuvering gun, or informally as "the zip gun", was the first astronaut propulsion unit. It was first used by astronaut Ed White during the first American "spacewalk", on Gemini 4, June 3, 1965. Different models of HHMU were present on Gemini 4, 8, 10, and 11, but were only used on Gemini 4 and 10. It was also used aboard Skylab.
The Constellation Space Suit was a planned full pressure suit system that would have served as an intra-vehicular activity (IVA) and extra-vehicular activity (EVA) garment for the proposed Project Constellation flights. The design of the suit was announced by NASA on June 11, 2008, and it was to be manufactured by Houston, Texas-based Oceaneering International, the 4th company after the David Clark Company, Hamilton Sundstrand, and ILC Dover to produce life-support hardware, as a prime contractor, for in-flight space use.
Neutral buoyancy simulation with astronauts immersed in a neutral buoyancy pool, in pressure suits, can help to prepare astronauts for the difficult task of working while outside a spacecraft in an apparently weightless environment.
Charles Edward "Ed" Whitsett Jr. (1936-1993) was a USAF officer and NASA engineer specializing in solutions for effective human movement in zero gravity. The pinnacle of his work was the astronaut maneuvering unit (MMU) which enabled satellite rescue and repair. For this capability, Whitsett along with NASA, Martin Marietta, Bruce McCandless, and Walter W. Bollendonk received the 1984 Robert J. Collier Trophy for "the greatest achievement in aeronautics or astronautics in America."