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.
Michael Landon Gernhardt is a NASA astronaut and manager of the Environmental Physiology Laboratory, and principal investigator of the Prebreathe Reduction Program (PRP) at the Lyndon B. Johnson Space Center.
A mechanical counterpressure (MCP) suit, partial pressure suit, direct compression suit, or space activity suit (SAS) is an experimental spacesuit which applies stable pressure against the skin by means of skintight elastic garments. The SAS is not inflated like a conventional spacesuit: it uses mechanical pressure, rather than air pressure, to compress the human body in low-pressure environments. Development was begun by NASA and the Air Force in the late 1950s and then again in the late 1960s, but neither design was used. Research is under way at the Massachusetts Institute of Technology (MIT) on a "Bio-Suit" System which is based on the original SAS concept.
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.
ILC Dover, LP is a special engineering development and manufacturing company, globally headquartered in Frederica, Delaware. ILC Dover specializes in the use of high-performance flexible materials, serving the aerospace, personal protection, and pharmaceutical industries.
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 Advanced Crew Escape Suit (ACES), or "pumpkin suit", is a full pressure suit that Space Shuttle crews began wearing after STS-65, for the ascent and entry portions of flight. The suit is a direct descendant of the U.S. Air Force high-altitude pressure suits worn by the two-man crews of the SR-71 Blackbird, pilots of the U-2 and X-15, and Gemini pilot-astronauts, and the Launch Entry Suits (LES) worn by NASA astronauts starting on the STS-26 flight, the first flight after the Challenger disaster. The suit is manufactured by the David Clark Company of Worcester, Massachusetts. Cosmetically the suit is very similar to the LES. ACES was first used in 1994.
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 Mercury space suit was a full-body, high-altitude pressure suit originally developed by the B.F. Goodrich Company and the U.S. Navy for pilots of high-altitude fighter aircraft. It is best known for its role as the spacesuit worn by the astronauts of the Project Mercury spaceflights.
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 Altair spacecraft, previously known as the Lunar Surface Access Module or LSAM, was the planned lander spacecraft component of NASA's cancelled Constellation program. Astronauts would have used the spacecraft for landings on the Moon, which was intended to begin around 2019. The Altair spacecraft was planned to be used both for lunar sortie and lunar outpost missions. On February 1, 2010, U.S. President Barack Obama announced a proposal to cancel the Constellation program, to be replaced with a re-scoped program, effective with the U.S. 2011 fiscal year budget.
A primarylife support system (PLSS), is a device connected to an astronaut or cosmonaut's spacesuit, which allows extra-vehicular activity with maximum freedom, independent of a spacecraft's life support system. A PLSS is generally worn like a backpack. The functions performed by the PLSS include:
An (Integrated) Thermal Micrometeoroid Garment is the outer layer of a space suit. The TMG has three functions: to insulate the suit occupant and prevent heat loss, to shield the occupant from harmful solar radiation, and to protect the astronaut from micrometeoroids and other orbital debris, which could puncture the suit and depressurize it.
The Mark III or MK III (H-1) 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 Krechet-94 is a space suit model developed for lunar excursion during the Soviet crewed lunar program. It was designed by NPP Zvezda. Development began in 1967, concurrently with the Orlan suit for microgravity spacewalks. The developmental model was known simply as Krechet.
A suitport or suitlock is an alternative technology to an airlock, designed for use in hazardous environments including in human spaceflight, especially planetary surface exploration. Suitports present advantages over traditional airlocks in terms of mass, volume, and ability to mitigate contamination by—and of—the local environment.
The Launch Entry Suit (LES), known as the "pumpkin suit", is a partial-pressure suit that was worn by all Space Shuttle crews for the ascent and entry portions of flight from STS-26 (1988) to STS-65 (1994). It was completely phased out by STS-88 and replaced by the ACES suit. The suit was manufactured by the David Clark Company of Worcester, Massachusetts.
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.
A Mars suit or Mars space suit is a space suit for EVAs on the planet Mars. Compared to a suit designed for space-walking in the near vacuum of low Earth orbit, Mars suits have a greater focus on actual walking and a need for abrasion resistance. Mars' surface gravity is 37.8% of Earth's, approximately 2.3 times that of the Moon, so weight is a significant concern, but there are fewer thermal demands compared to open space. At the surface the suits would contend with the atmosphere of Mars, which has a pressure of about 0.6 to 1 kilopascal. On the surface, radiation exposure is a concern, especially solar flare events, which can dramatically increase the amount of radiation over a short time.
