Astronaut Propulsion Unit
Encyclopedia
Hand-Held Maneuvering Unit
The EVA "zip" gun used by Edward WhiteEdward Higgins White
Edward Higgins White, II was an engineer, United States Air Force officer and NASA astronaut. On June 3, 1965, he became the first American to "walk" in space. White died along with fellow astronauts Gus Grissom and Roger Chaffee during a pre-launch test for the first manned Apollo mission at...
on the Gemini 4
Gemini 4
Gemini 4 was the second manned space flight in NASA's Project Gemini, occurring in June 1965. It was the tenth manned American spaceflight . Astronauts James McDivitt and Edward H. White, II circled the Earth 66 times in four days, making it the first US flight to approach the five-day flight of...
mission in 1965. The hand-held gun held several pounds of nitrogen, and allowed limited movement around the Gemini spacecraft. It was also used by astronaut Michael Collins
Michael Collins (astronaut)
Michael Collins is a former American astronaut and test pilot. Selected as part of the third group of fourteen astronauts in 1963, he flew in space twice. His first spaceflight was Gemini 10, in which he and command pilot John Young performed two rendezvous with different spacecraft and Collins...
on the Gemini 10
Gemini 10
-Backup crew:-Mission parameters:*Mass: *Perigee: *Apogee: *Inclination: 28.87°*Period: 88.79 min-Docking:*Docked: July 19, 1966 - 04:15:00 UTC*Undocked: July 20, 1966 - 19:00:00 UTC-Space walk:...
mission in 1966.
USAF Astronaut Maneuvering Unit
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 LaboratoryManned Orbiting Laboratory
The Manned Orbiting Laboratory , originally referred to as the Manned Orbital Laboratory, was part of the United States Air Force's manned spaceflight program, a successor to the cancelled Boeing X-20 Dyna-Soar military reconnaissance space plane project...
, which was a backpack, using hydrogen peroxide
Hydrogen peroxide
Hydrogen peroxide is the simplest peroxide and an oxidizer. Hydrogen peroxide is a clear liquid, slightly more viscous than water. In dilute solution, it appears colorless. With its oxidizing properties, hydrogen peroxide is often used as a bleach or cleaning agent...
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 present-day MMU. Because of the fuel, which comes out as a hot gas, the astronaut's suit had to be modified with the addition of woven steel "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
Gemini 12
-Backup crew:-Mission parameters:*Mass: *Perigee: *Apogee: *Inclination: 28.87°*Period: 88.87 min-Docking:*Docked: November 12, 1966 - 01:06:00 UTC*Undocked: November 13, 1966 - 20:18:00 UTC-Space walk:...
, and to fly untethered from the Gemini spacecraft but was scrubbed two months before the mission.
Automatically Stabilized Maneuvering Unit (ASMU)
In 1973, the ASMU was flown aboard the Skylab 3Skylab 3
Skylab 3 was the second manned mission to Skylab. The Skylab 3 mission started July 28, 1973, with the launch of three astronauts on the Saturn IB rocket, and lasted 59 days, 11 hours and 9 minutes...
mission. Tested inside of the orbiting laboratory, it used nitrogen gas and allowing both unsuited and suited testing of the unit. The Skylab AMU was the closest to the Shuttle MMU, but was not used outside of 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
Apollo Telescope Mount
The Apollo Telescope Mount, or ATM, is the name of a solar observatory that was attached to Skylab, the first US space station.The ATM was one of a number of projects that came out of the late 1960s Apollo Applications Program, which studied a wide variety of ways to use the infrastructure...
.
Foot Controlled Maneuvering Unit (FCMU)
Tested within Skylab. The purpose of it was to free the astronaut's hands. It was propelled by cold, high-pressured nitrogenNitrogen
Nitrogen is a chemical element that has the symbol N, atomic number of 7 and atomic mass 14.00674 u. Elemental nitrogen is a colorless, odorless, tasteless, and mostly inert diatomic gas at standard conditions, constituting 78.08% by volume of Earth's atmosphere...
gas located in a tank on the back. It was tested both suited and unsuited.
Manned Maneuvering Unit
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.Soviet SPK
The former Soviet UnionSoviet Union
The Soviet Union , officially the Union of Soviet Socialist Republics , was a constitutionally socialist state that existed in Eurasia between 1922 and 1991....
also used a cosmonaut propulsion system on flights to the space station Mir
Mir
Mir was a space station operated in low Earth orbit from 1986 to 2001, at first by the Soviet Union and then by Russia. Assembled in orbit from 1986 to 1996, Mir was the first modular space station and had a greater mass than that of any previous spacecraft, holding the record for the...
. The SPK (or UMK, UPMK, 21KS) 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
Orlan space suits
thumb|right|270px|Cosmonaut [[Maksim Surayev]] next to two Orlan-MK modelsAn Orlan space suit |sea eagle]]) is a series of semi-rigid one-piece space suit models designed and built by NPP Zvezda. They have been used for spacewalks in the Russian space program, the successor to the Soviet space...
, 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
Strela (crane)
The Strela cranes are four cargo cranes used to move cosmonauts and components around the exterior of the Soviet/Russian space station Mir and the Russian Orbital Segment of the International Space Station...
(equivalent to the Mobile Servicing System
Mobile Servicing System
The Mobile Servicing System , better known by its primary component Canadarm2, is a robotic system and associated equipment on the International Space Station...
). The SPK, which was left attached to the outside to the Kvant-2
Kvant-2
Kvant-2 was the third module and second major addition to the Mir space station. Its primary purpose was to deliver new science experiments, better life support systems, and an airlock to Mir. It was launched on November 26, 1989 on a Proton rocket. It docked to Mir on December 6...
module, was destroyed when Mir re-entered the atmosphere after decommissioning.
SAFER
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 nitrogenNitrogen
Nitrogen is a chemical element that has the symbol N, atomic number of 7 and atomic mass 14.00674 u. Elemental nitrogen is a colorless, odorless, tasteless, and mostly inert diatomic gas at standard conditions, constituting 78.08% by volume of Earth's atmosphere...
, 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
Bola
Bola, from Spanish and Portuguese meaning ball, may refer to:* Bolas, throwing weapon made of weights on the ends of interconnected cord* Bola , a volcano on the island of New Britain in Papua New Guinea* Bola, Togo...
-type lasso device (astrorope) the drifting astronaut could throw to hook to the space station.