The
Space ShuttleThe Space Shuttle was a manned orbital rocket and spacecraft system operated by NASA on 135 missions from 1981 to 2011. The system combined rocket launch, orbital spacecraft, and re-entry spaceplane with modular add-ons...
/International Space StationThe International Space Station is a habitable, artificial satellite in low Earth orbit. The ISS follows the Salyut, Almaz, Cosmos, Skylab, and Mir space stations, as the 11th space station launched, not including the Genesis I and II prototypes...
Extravehicular Mobility Unit (EMU) is an independent anthropomorphic system that provides environmental protection, mobility, life support, and communications for a
Space ShuttleThe Space Shuttle was a manned orbital rocket and spacecraft system operated by NASA on 135 missions from 1981 to 2011. The system combined rocket launch, orbital spacecraft, and re-entry spaceplane with modular add-ons...
or
International Space StationThe International Space Station is a habitable, artificial satellite in low Earth orbit. The ISS follows the Salyut, Almaz, Cosmos, Skylab, and Mir space stations, as the 11th space station launched, not including the Genesis I and II prototypes...
(ISS) crew member to perform
extra-vehicular activityExtra-vehicular activity is work done by an astronaut away from the Earth, and outside of a spacecraft. The term most commonly applies to an EVA made outside a craft orbiting Earth , but also applies to an EVA made on the surface of the Moon...
(EVA) in earth orbit. Introduced in 1982, it is a two-piece semi-rigid suit, and is currently one of two spacesuits used by crew members on the ISS, the other being the Russian Orlan space suit.
Suit components
The EMU, like the
Apollo/Skylab A7LThe A7L Apollo & Skylab spacesuit is the primary pressure suit worn by NASA astronauts for Project Apollo, the three manned Skylab flights, and the Apollo-Soyuz Test Project between 1968 and the termination of the Apollo program in 1975. The "A7L" designation is used by NASA as the seventh Apollo...
spacesuit, was the result of years of research and development. It consists of a
Hard Upper TorsoA Hard Upper Torso Assembly, or HUT, is a central component of several space suits, notably Roscosmos' Orlan and NASA's Extravehicular Mobility Unit . The fiberglass HUT forms a rigid enclosure about the upper body of the occupant, providing pressure containment for this part of the body...
(HUT) assembly, a
Primary Life Support SystemA Primary Life Support System , is a device connected to an astronaut's or cosmonaut's spacesuit, which allows extra-vehicular activity with maximum freedom, independent of a spacecraft's life support system. The PLSS is generally worn like a backpack...
(PLSS) which incorporates the life support and electrical systems, arm sections, gloves, an Apollo-style "bubble" helmet, the Extravehicular Visor Assembly (EVVA), and a soft Lower Torso Assembly (LTA), incorporating the Body Seal Closure (BSC), waist bearing, brief, legs, and boots. Prior to donning the pressure garment, the crew member puts on a
Maximum Absorbency GarmentA Maximum Absorbency Garment is a piece of clothing NASA astronauts wear during liftoff, landing, and extra-vehicular activity to absorb urine and feces. It is worn by both male and female astronauts. Astronauts can urinate into the MAG, and usually wait to defecate when they return to the...
(MAG) (basically a modified "Depends" incontinence diaper - Urine Collection Devices, or UCDs, are no longer used), and possibly a Thermal Control Undergarment (long johns). The final item donned before putting on the pressure suit is the "
Liquid Cooling and Ventilation GarmentA Liquid Cooling Garment is a form-fitting garment that is used to remove body heat from the wearer in environments where evaporative cooling from sweating and open air convection cooling does not work, or the wearer has a biological problem that hinders self-regulation of body temperature.A...
" (LCVG), which incorporates clear plastic tubing through which chilled liquid
waterWater is a chemical substance with the chemical formula H2O. A water molecule contains one oxygen and two hydrogen atoms connected by covalent bonds. Water is a liquid at ambient conditions, but it often co-exists on Earth with its solid state, ice, and gaseous state . Water also exists in a...
flows for body temperature control, as well as ventilation tubes for waste gas removal.
After donning the LCVG, the astronaut then puts on the LTA. The astronaut then floats into the airlock, dons the HUT, connects the LCVG umbilical to the umbilical in the HUT, and then the two parts of the suit are locked together using the Body Seal Closure. Once the suit is turned on and checked out, the astronaut dons a "
SnoopySnoopy is an fictional character in the long-running comic strip Peanuts, by Charles M. Schulz. He is Charlie Brown's pet beagle. Snoopy began his life in the strip as a fairly conventional dog, but eventually evolved into perhaps the strip's most dynamic character—and among the most recognizable...
cap," a brown and white fabric communications cap dating back to the
ApolloThe Apollo program was the spaceflight effort carried out by the United States' National Aeronautics and Space Administration , that landed the first humans on Earth's Moon. Conceived during the Presidency of Dwight D. Eisenhower, Apollo began in earnest after President John F...
days, which incorporates a pair of earphones and microphones, allowing the EVA astronaut to communicate with both the crew members in the
orbiterThe Space Shuttle orbiter was the orbital spacecraft of the Space Shuttle program operated by NASA, the space agency of the United States. The orbiter was a reusable winged "space-plane", a mixture of rockets, spacecraft, and aircraft...
and ground controllers in Houston. After donning the "Snoopy cap," the gloves and helmet are then locked on, pressurizing the suit. The suit's regulator and fans activate when the servicing umbilicals are removed and the suit reaches an internal pressure of 4.3 psi (29.6 kPa). A typical EMU can support an astronaut for 8.5 hours, with 30 minutes of reserves in the case of primary life support failure. To perform an EVA from the shuttle, the cabin pressure is reduced from 14.7 psi to 10.2 psi for 24 hours, after which an astronaut must pre-breathe for 45 minutes. For EVAs onboard the ISS, the astronaut must pre-breathe for about four hours.
Specifications
Name: Baseline Extravehicular Mobility Unit Spacesuit
Manufacturer: International Latex Corporation (ILC) Dover and Hamilton Standard (primary life support systems)
Missions: STS-6STS-6 was a NASA Space Shuttle mission conducted using Space Shuttle Challenger, carrying the first Tracking and Data Relay Satellite, TDRS-1, into orbit. Launched on 4 April 1983, STS-6 was the sixth shuttle mission and the first of the ten missions flown by Challenger...
(1983) to
STS-110STS-110 was a Space Shuttle mission to the International Space Station on 8–19 April 2002 flown by Space Shuttle Atlantis. The main purpose was to install the S0 Truss segment, which forms the backbone of the truss structure on the station.- Crew :...
(2002)
Function: orbitIn physics, an orbit is the gravitationally curved path of an object around a point in space, for example the orbit of a planet around the center of a star system, such as the Solar System...
al
Extra-vehicular activityExtra-vehicular activity is work done by an astronaut away from the Earth, and outside of a spacecraft. The term most commonly applies to an EVA made outside a craft orbiting Earth , but also applies to an EVA made on the surface of the Moon...
Operating Pressure: 4.3 psi (29.6 kPa)
EVA Suit Weight: 109 lb (49.4 kg)
Total Shuttle EVA Suit Weight 254 lb (115 kg)
Primary Life Support: 8 hours (480 minutes)
Backup Life Support: 30 minutes
Name: Enhanced Extravehicular Mobility Unit Spacesuit
Manufacturer: International Latex Corporation (ILC) Dover, Hamilton Standard (primary life support systems) and NASA (SAFER)
Missions: 1998 to present
Function: orbitIn physics, an orbit is the gravitationally curved path of an object around a point in space, for example the orbit of a planet around the center of a star system, such as the Solar System...
al
Extra-vehicular activityExtra-vehicular activity is work done by an astronaut away from the Earth, and outside of a spacecraft. The term most commonly applies to an EVA made outside a craft orbiting Earth , but also applies to an EVA made on the surface of the Moon...
Operating Pressure: 4.3 psi (29.6 kPa)
EVA Suit Weight: 122 lb (55.3 kg)
Total Shuttle EVA Suit Weight 275 lb (124.7 kg)
Total ISS EVA Suit Weight 319 lb (145 kg)
Primary Life Support: 8 hours (480 minutes)
Backup Life Support: 30 minutes
Manufacturer
The EMU hardware and accessories (PLSS, helmet, communications cap, and locking rings for the helmet and gloves), is manufactured by the
Hamilton SundstrandHamilton Sundstrand, is a global corporation that manufactures and supports aerospace and industrial products for worldwide markets. It was formed from the merger of Hamilton Standard and Sundstrand Corporation in 1999. A subsidiary of United Technologies Corporation, HS is headquartered in Windsor...
division of United Technologies out of
Windsor Locks, ConnecticutWindsor Locks is a town located in Hartford County, Connecticut, United States. As of the 2000 census, its population was 12,043. It is the site of Bradley International Airport, which serves the Greater Hartford-Springfield region. It is also the site of the New England Air Museum...
, while the suit's soft components (the arms of the HUT and the entire LTU) are produced by
ILC DoverILC Dover, LP is an engineering development and manufacturing company based in Frederica, Delaware. ILC specializes in the use of high-performance flexible materials, serving the aerospace, personal protection, and pharmaceutical industries.Best known for making space suits for NASA, ILC...
out of
Frederica, DelawareFrederica is a town in Kent County, Delaware, United States. It is part of the Dover, Delaware Metropolitan Statistical Area. The population was 774 at the 2010 census...
. The two companies, who were rivals during the early days of Apollo for the contract to build the "Block II" (moonwalking) space suit, teamed up in 1974 against the David Clark Company and
Garrett AiResearchGarrett AiResearch was a manufacturer of turboprop engines and turbochargers, and a pioneer in numerous aerospace technologies. It was previously known as Aircraft Tool and Supply Company, Garrett Supply Company, AiResearch Manufacturing Company, or simply AiResearch...
for the EMU development and construction. During Apollo, the ILC Dover-produced A7L used the
life support backpackA Primary Life Support System , is a device connected to an astronaut's or cosmonaut's spacesuit, which allows extra-vehicular activity with maximum freedom, independent of a spacecraft's life support system. The PLSS is generally worn like a backpack...
, helmet, and locking rings supplied by Hamilton United, but originally, ILC Dover was to just supply the arms and legs of the suit, a similar process that is still going on today.
History
Upon receiving the contract to build the EMU in 1974, Hamilton United and ILC Dover delivered the first EMU units to NASA in 1982. During the research and development phase (1975–1980), a suit being tested caught fire, injuring a technician and forcing a redesign on the regulator and circulation fan. On
STS-4STS-4 was a NASA Space Shuttle mission, using the Space Shuttle Columbia. The mission launched on 27 June 1982 and landed a week later on 4 July. STS-4 was the fourth shuttle mission overall, and was also the fourth mission for the Columbia.-Crew:...
in July 1982, the astronauts practiced donning and doffing the suit in the Shuttle's airlock. The first Shuttle EVA was to occur on
STS-5STS-5 was a NASA Space Shuttle mission, the fifth shuttle mission overall and the fifth flight of the Space Shuttle Columbia. It was the first shuttle mission to deploy communications satellites into orbit...
, but an electrical failure on the circulation fan forced the EVA to be cancelled. The first EVA of the new EMU finally occurred on
STS-6STS-6 was a NASA Space Shuttle mission conducted using Space Shuttle Challenger, carrying the first Tracking and Data Relay Satellite, TDRS-1, into orbit. Launched on 4 April 1983, STS-6 was the sixth shuttle mission and the first of the ten missions flown by Challenger...
when
Story MusgraveFranklin Story Musgrave is an American physician and a retired NASA astronaut. He is currently a public speaker and consultant to both Disney's Imagineering group and Applied Minds in California.-Personal life:...
and Donald Peterson went out in the payload bay of the
Space Shuttle ChallengerSpace Shuttle Challenger was NASA's second Space Shuttle orbiter to be put into service, Columbia having been the first. The shuttle was built by Rockwell International's Space Transportation Systems Division in Downey, California...
and tested techniques to lower the launch cradle of a solid-fuel upper stage used to boost a
Tracking and Data Relay SatelliteA Tracking and Data Relay Satellite is a type of communications satellite that forms part of the Tracking and Data Relay Satellite System used by NASA and other United States government agencies for communications to and from independent "User Platforms" such as satellites, balloons, aircraft,...
(TDRS-A) into a geo-stationary orbit.
Other EVAs followed on the Shuttle, notably those on
STS-41-BSTS-41-B was the tenth NASA Space Shuttle mission, launching on 3 February 1984 and landing on 11 February. It was the fourth flight of the Space Shuttle Challenger. Following STS-9, the flight numbering system for the Space Shuttle program was changed...
(the first
Manned Maneuvering UnitThe Manned Maneuvering Unit is an astronaut propulsion unit which 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...
flight),
STS-41-CSTS-41-C was NASA's 11th Space Shuttle mission, and the fifth mission of Space Shuttle Challenger. The launch on 6 April 1984 was the first direct ascent trajectory for a shuttle mission...
(the
Solar MaxThe Solar Maximum Mission satellite was designed to investigate solar phenomenon, particularly solar flares. It was launched on February 14, 1980....
repair mission), and
STS-51-ASTS-51-A was the second flight of Space Shuttle Discovery, and the 14th flight of NASA's Space Shuttle program. The mission launched from Kennedy Space Center on 8 November 1984, and landed just under eight days later on 16 November....
(where two stranded satellites were retrieved and returned to Earth), but the majority of EMU uses occurred on the servicing missions of the
Hubble Space TelescopeThe Hubble Space Telescope is a space telescope that was carried into orbit by a Space Shuttle in 1990 and remains in operation. A 2.4 meter aperture telescope in low Earth orbit, Hubble's four main instruments observe in the near ultraviolet, visible, and near infrared...
. For those flights, two sets of EVA astronauts would venture out of the orbiter, thus requiring NASA to fly four sets of suits (along with repair parts). 41 EVAs using EMUs had been conducted out of the Space Shuttle airlock prior to the start of ISS assembly in November 1998.
With the building of the ISS, Hamilton Sundstrand and ILC Dover refined the existing Shuttle EMU by making the suit modular. This allowed the EMU to be left on the ISS for up to 2 years and resized on-orbit to fit various crew members. They also made provisions for increased battery capacity, the
Simplified Aid for EVA RescueSimplified Aid for EVA Rescue is a small, self-contained, propulsive backpack system used to provide free-flying mobility for a Space Shuttle or International Space Station crewmember during extra-vehicular activity...
(SAFER), improved cameras and radios, and a new caution and warning system. Another feature incorporated into the ISS suits included an additional battery to power heaters built into the glove, allowing astronauts to keep their hands warm during nighttime passages on each 95-minute orbit.
Currently, the ISS EMU and the Russian ORLAN are used by crews of all nationalities on the International Space Station. The two EMUs are stored within the Quest Joint Airlock.
Future use and proposed replacement
NASA continues to use the EMU in the wake of the retirement of the Space Shuttle in 2011. When preparing for For the
Constellation ProgramConstellation Program is a human spaceflight program within NASA, the space agency of the United States. The stated goals of the program were to gain significant experience in operating away from Earth's environment, develop technologies needed for opening the space frontier, and conduct...
, a now-cancelled series of missions to the ISS,
MoonThe Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...
, and
MarsMars is the fourth planet from the Sun in the Solar System. The planet is named after the Roman god of war, Mars. It is often described as the "Red Planet", as the iron oxide prevalent on its surface gives it a reddish appearance...
which was planned to commence in 2015, NASA planned to replace the EMU and the ACES pressure suit with a new
Constellation Space SuitThe Constellation Space Suit was a planned full pressure suit system that would have served as an intra-vehicular activity and Extra-vehicular activity garment for the proposed Project Constellation flights, which were planned to begin after the Space Shuttle retired...
system, derived from the ACES suit and the ILC Dover-developed and -tested
Mark IIIThe Mark III or MK III is a NASA space suit technology demonstrator built by ILC Dover. While heavier than other suits , the Mark III is more mobile, and is designed for a relatively high operating pressure.The Mark III is a rear-entry suit, unlike the EMU currently in use, which is a waist-entry...
and
I-SuitThe I-Suit is a spacesuit model constructed by ILC Dover. The suit began as an EVA mobility demonstrator, developed to meet a contract awarded by NASA to ILC in 1997 for an all-soft suit....
space suit systems.
The new suit would have been designed, depending upon the configration, to protect the astronaut during launch, in-flight emergencies, reentry and landing, and both microgravity and lunar EVAs. It was planned to feature common hardware and the modular features used in the ACES and EMU suits.
On June 11, 2008, NASA awarded a contract for
Oceaneering InternationalOceaneering International Inc. is an applied technology company based in Houston, Texas, U.S.A. that provides engineered services and hardware to customers who operate in marine, space, and other environments...
for the development and manufacturing of the new suits, with the
David Clark CompanyDavid Clark Company, Inc. is an American manufacturer, best known for noise attenuating headsets with boom microphones for use in military aviation, commercial aviation, industry and professional communication in high-noise environments...
and United Space Alliance being two of seven contractors in the new endeavor. Oceaneering beat out the Hamilton Sundstrand/ILC Dover partnership in the manufacturing of the new space suit.
However, an Aug. 15, 2008 a NASA Press release stated that a compliance issue requires the termination of the contract for the Constellation Space Suit System with
Oceaneering InternationalOceaneering International Inc. is an applied technology company based in Houston, Texas, U.S.A. that provides engineered services and hardware to customers who operate in marine, space, and other environments...
, Inc. of Houston for the convenience of the government.
Later, NASA announced that effective March 2, 2009 "NASA has awarded an interim letter contract to
Oceaneering InternationalOceaneering International Inc. is an applied technology company based in Houston, Texas, U.S.A. that provides engineered services and hardware to customers who operate in marine, space, and other environments...
Inc. of Houston to begin work on the design, development and production of a new spacesuit system for the Constellation Program. The new contract featured a Hamilton Sundstrand/ILC Dover partnership.
The cancellation of the Constellation Program in 2010 leaves the suit's current status uncertain.
See also
- SAFER
Simplified Aid for EVA Rescue is a small, self-contained, propulsive backpack system used to provide free-flying mobility for a Space Shuttle or International Space Station crewmember during extra-vehicular activity...
- Hard Upper Torso
A Hard Upper Torso Assembly, or HUT, is a central component of several space suits, notably Roscosmos' Orlan and NASA's Extravehicular Mobility Unit . The fiberglass HUT forms a rigid enclosure about the upper body of the occupant, providing pressure containment for this part of the body...
- Liquid Cooling and Ventilation Garment
A Liquid Cooling Garment is a form-fitting garment that is used to remove body heat from the wearer in environments where evaporative cooling from sweating and open air convection cooling does not work, or the wearer has a biological problem that hinders self-regulation of body temperature.A...
External links