Related topics: international space station , space station
Extra-vehicular activity
hideExtra-vehicular activity (EVA) 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 (a spacewalk), but also applies to an EVA made on the surface of the Moon (a moonwalk). In the later lunar landing missions (Apollo 15, 16, and 17) the command module pilot (CMP) did an EVA to retrieve film canisters on the return trip; he was assisted by the lunar module pilot (LMP) who remained at the open CM hatch. These trans-Earth EVAs were the only spacewalks ever conducted in deep space.
Due to the different designs of the early spacecraft, the American and Soviet space programs also define an EVA differently. Russians define an EVA as occurring when a cosmonaut is in a vacuum. An American EVA begins when the astronaut switches the Extravehicular Mobility Unit (EMU) to battery power. A "Stand-up" EVA (SEVA) is where the astronaut does not fully exit a spacecraft, but is completely reliant on the spacesuit for environmental support. Its name derives from the astronaut "standing up" in the open hatch, usually to film or assist a spacewalking astronaut.
EVAs may be either tethered (the astronaut is connected to the spacecraft, oxygen can be supplied through a tube, no propulsion is needed to return to the spacecraft) or untethered. When the tether performs life support functions such as providing oxygen, it is called an umbilical. Untethered spacewalks were only performed on three missions in 1984 using the Manned Maneuvering Unit (MMU), and on a flight test in 1994 of the Simplified Aid for EVA Rescue (SAFER). A SAFER is a safety device worn on tethered U.S. EVAs, since the capability of returning to the spacecraft is essential.
As of 2009[update], Russia, the United States, and China are the only countries with a demonstrated capability to conduct an EVA.
For more information about Extra-vehicular activity, read the full article at
Wikipedia.
This text uses material from Wikipedia and is available under the GNU Free Documentation License.
News tagged with spacewalk
Atlantis 'Go' For Launch to Station on Nov. 16
Space & Earth / Space Exploration
Oct 29, 2009 |
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(PhysOrg.com) -- NASA's space shuttle Atlantis is targeted to begin an 11-day flight to the International Space Station with a Nov. 16 launch from the Kennedy Space Center in Florida. Liftoff is scheduled ...
NASA Portable Hyperbaric Chamber Technology Finds Home on Earth
Space & Earth / Space Exploration
Oct 13, 2009 |
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(PhysOrg.com) -- NASA has signed a patent license agreement with a California company to improve the medical community's access to hyperbaric chambers used to treat many medical conditions and emergencies.
NASA Invites Young People to Take Virtual Space Station Spacewalks
Space & Earth / Space Exploration
Oct 06, 2009 |
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(PhysOrg.com) -- Imagine the thrill of floating out of the International Space Station and into the emptiness of space and what it would be like to work on the orbiting science laboratory.
China picks first female astronaut candidates
Space & Earth / Space Exploration
Sep 17, 2009 |
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(AP) -- China's military-backed space program has selected 45 astronaut candidates, including its first women hopefuls, for a training program less than a year after the country completed its first spacewalk.
Astronauts take mission's 3rd and final spacewalk
Space & Earth / Space Exploration
Sep 06, 2009 |
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(AP) -- Two spacewalking astronauts took on cable and antenna work at the international space station Saturday in their final trek outside, but encountered last-minute difficulty with a connector and had ...
Discovery astronauts ready for final spacewalk
Space & Earth / Space Exploration
Sep 05, 2009 |
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Astronauts of the US space shuttle Discovery will venture again into outer space Saturday on a third and final spacewalk of their mission designed to help complete the International Space Station.
Astronauts relish space's international food court
Space & Earth / Space Exploration
Sep 05, 2009 |
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(AP) -- When it comes to grabbing a bite to eat, the international space station is living up to its first name.
Big chunk of space junk misses space station
Space & Earth / Space Exploration
Sep 04, 2009 |
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(AP) -- A big piece of space junk safely sped by the international space station and shuttle Discovery, missing by less than a mile.
Spacewalk performed despite approaching space junk
Space & Earth / Space Exploration
Sep 03, 2009 |
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(AP) -- Two astronauts stepped out on a spacewalk to install a new tank of space station coolant Thursday as a large piece of orbiting junk headed their way.
NASA analyzing junk that could threaten astronauts
Space & Earth / Space Exploration
Sep 02, 2009 |
4.7 / 5 (3) |
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(AP) -- A piece of space junk was drifting toward the shuttle-station complex and its 13 astronauts Wednesday, though NASA officials said the threat would not delay an upcoming spacewalk.
Spacewalkers tackle hefty tank removal in orbit
Space & Earth / Space Exploration
Sep 01, 2009 |
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(AP) -- A pair of spacewalkers successfully tackled a hefty tank removal job at the international space station Tuesday as their crewmates unloaded comedian Stephen Colbert's namesake treadmill for all "those ...
Astronauts gear up for first spacewalk of mission
Space & Earth / Space Exploration
Sep 01, 2009 |
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(AP) -- It's moving and spacewalking day in orbit.
NASA delays shuttle Discovery launch
Space & Earth / Space Exploration
Aug 27, 2009 |
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NASA on Thursday delayed the launch of the space shuttle Discovery until 0359 GMT Saturday so mission specialists could review tests on a faulty valve, the US space agency said.
Space shuttle Endeavour readies return to Earth
Space & Earth / Space Exploration
Jul 28, 2009 |
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The space shuttle Endeavour undocked from the International Space Station on Tuesday to take photographs of the orbiting research facility before final maneuvers to prepare its return home.
Astronauts Complete Final Spacewalk of STS-127 Mission
Space & Earth / Space Exploration
Jul 27, 2009 |
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(PhysOrg.com) -- The joint crew of Endeavour and the International Space Station completed the fifth and final spacewalk of the mission.
