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
Baby can wait as expectant dad finishes spacewalk
Space & Earth / Space Exploration
Nov 21, 2009 |
3.7 / 5 (3) |
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(AP) -- A spacewalking astronaut put aside the impending birth of his daughter and blazed through his first-ever venture outside the International Space Station on Saturday.
Astronauts get extra work done in 1st spacewalk (Update)
Space & Earth / Space Exploration
Nov 19, 2009 |
not rated yet |
2
(AP) -- A pair of spacewalking astronauts, one of them a surgeon, hustled through antenna and cable work outside the International Space Station on Thursday and even whipped off an extra chore.
Shuttle Atlantis leaves space station, headed home
Space & Earth / Space Exploration
Nov 25, 2009 |
4 / 5 (1) |
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(AP) -- Atlantis and its seven astronauts have left the International Space Station.
Shuttle, station crews seal hatches for departure
Space & Earth / Space Exploration
Nov 24, 2009 |
5 / 5 (1) |
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(AP) -- After nearly a week together, the crews of shuttle Atlantis and the International Space Station said goodbye Tuesday and closed the hatches between them.
Astronauts rest up after 3 spacewalks
Space & Earth / Space Exploration
Nov 24, 2009 |
4 / 5 (1) |
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(AP) -- The astronauts aboard the orbiting shuttle-station complex are resting after their three successful spacewalks.
Astronauts take spacewalk No. 3 after suit snag
Space & Earth / Space Exploration
Nov 23, 2009 |
5 / 5 (1) |
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(AP) -- A pair of astronauts stepped out on the third and final spacewalk of their shuttle mission Monday, helping to install an enormous oxygen tank at the International Space Station.
Astronaut's baby daughter born as he circles Earth
Space & Earth / Space Exploration
Nov 22, 2009 |
5 / 5 (1) |
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(AP) -- Astronaut Randolph Bresnik jubilantly welcomed his new daughter into the world Sunday as he floated 220 miles above it.
Astronauts board space shuttle Atlantis for launch
Space & Earth / Space Exploration
Nov 16, 2009 |
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(AP) -- Astronauts climbed aboard space shuttle Atlantis on Monday for an afternoon liftoff to the space station, as the sky over the launching site gradually cleared.
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 ...
Space station's new solar wings open easily (Update 2)
Space & Earth / Space Exploration
Mar 20, 2009 |
4.7 / 5 (3) |
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(AP) -- Astronauts successfully unfurled the newly installed solar wings at the international space station Friday, a nerve-racking procedure that went exceedingly well and brought the orbiting outpost to ...
Let there be light: Camera hooked up for Hubble
Space & Earth / Space Exploration
May 14, 2009 |
5 / 5 (9) |
7
(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 ...
NASA analyzing junk that could threaten astronauts
Space & Earth / Space Exploration
Sep 02, 2009 |
4.7 / 5 (3) |
2
(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 |
3 / 5 (2) |
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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 ...
NASA delays shuttle Discovery launch
Space & Earth / Space Exploration
Aug 27, 2009 |
5 / 5 (1) |
1
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.
