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
Let there be light: Camera hooked up for Hubble
Space & Earth / Space Exploration
May 14, 2009 |
5 / 5 (9) |
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(AP) -- A pair of spacewalking astronauts overpowered a stubborn bolt and successfully installed a new piano-sized camera in the Hubble Space Telescope on Thursday, the first step to making the observatory ...
Servicing Mission 4 -- the fifth and final visit to Hubble
Space & Earth / Space Exploration
May 01, 2009 |
4.8 / 5 (8) |
2
(PhysOrg.com) -- The combination of Hubble's powerful suite of instruments and its position far above the effects of Earth's atmosphere has consistently produced outstanding scientific results for nineteen ...
Stuck bolt, dead battery bedevil Hubble repairs
Space & Earth / Space Exploration
May 17, 2009 |
4.1 / 5 (9) |
9
(AP) -- Spacewalkers' specially designed tools couldn't dislodge a balky bolt interfering with repairs Sunday at the Hubble Space Telescope, so they took an approach more familiar to people puttering around ...
Spacewalkers pull off toughest Hubble repairs yet
Space & Earth / Space Exploration
May 16, 2009 |
5 / 5 (6) |
3
(AP) -- Spacewalking astronauts gave the Hubble Space Telescope a better view of the cosmos by installing a new high-tech instrument Saturday, then pulled off their toughest job yet: fixing a broken camera.
Astronauts finish repairs on Hubble space telescope
Space & Earth / Space Exploration
May 18, 2009 |
4.5 / 5 (6) |
2
(AP) -- Spacewalking astronauts completed repairs to the Hubble Space Telescope on Monday, leaving it more powerful than ever and able to peer even deeper into the cosmos - almost to the brink of creation. ...
Astronauts have trouble with repair work at Hubble
Space & Earth / Space Exploration
May 15, 2009 |
4.3 / 5 (6) |
1
(AP) -- Spacewalking astronauts had to install a refurbished pair of gyroscopes in the Hubble Space Telescope on Friday after one of the brand new ones refused to go in.
Astronauts say goodbye to Hubble for good (Update)
Space & Earth / Space Exploration
May 19, 2009 |
5 / 5 (5) |
1
(AP) -- Atlantis' astronauts tenderly dropped the Hubble Space Telescope overboard Tuesday, sending the restored observatory off on a new voyage of discovery and bidding it farewell on behalf of the planet.
Spacewalkers equip Hubble with new computer
Space & Earth / Space Exploration
May 15, 2009 |
4.2 / 5 (5) |
0
Spacewalking astronauts upgraded the Hubble telescope for the first time in seven years, equipping the 19-year-old stargazer with a powerful new camera and science computer.
ISS Spacewalkers Test Planetary Protection Concept
Space & Earth / Space Exploration
Mar 23, 2009 |
5 / 5 (4) |
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On March 19th, astronauts onboard the International Space Station checked themselves for microbes before stepping outside on a space walk. It was a first-ever test of planetary protection technology that, ...
NASA clears Atlantis for Monday launch to Hubble
Space & Earth / Space Exploration
May 10, 2009 |
5 / 5 (4) |
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(AP) -- After months of delay, NASA cleared space shuttle Atlantis for a Monday launch to the Hubble Space Telescope.
Astronauts work through repair trouble at Hubble
Space & Earth / Space Exploration
May 15, 2009 |
5 / 5 (4) |
0
(AP) -- Spacewalking astronauts had to put a refurbished pair of gyroscopes into the Hubble Space Telescope after a brand new set refused to go in Friday, but scientists were satisfied nonetheless and confident ...
Astronauts relish space's international food court
Space & Earth / Space Exploration
Sep 05, 2009 |
4.3 / 5 (4) |
0
(AP) -- When it comes to grabbing a bite to eat, the international space station is living up to its first name.
Spacewalk No. 2: Astronauts doing more Hubble work (Update)
Space & Earth / Space Exploration
May 15, 2009 |
4 / 5 (4) |
2
(AP) -- Atlantis' astronauts headed out for another spacewalk Friday, this time to give the Hubble Space Telescope some new, badly needed gyroscopes and batteries.
NASA begins launch countdown for Hubble mission
Space & Earth / Space Exploration
May 08, 2009 |
5 / 5 (3) |
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(AP) -- NASA began the countdown for its final trip to the Hubble Space Telescope on Friday as the astronauts who will attempt the daunting repairs arrived at the launching site.
Atlantis moves in on Hubble to grab telescope (Update)
Space & Earth / Space Exploration
May 13, 2009 |
5 / 5 (3) |
0
(AP) -- Shuttle Atlantis and its crew moved toward the Hubble Space Telescope for a 350-mile-high grab Wednesday that will set the stage for five days of treacherous spacewalking repairs in an orbit littered ...
