Related topics: international space station , space station



Extra-vehicular activity

hide

Extra-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

results timeline


Shuttle Atlantis leaves space station, headed home (AP)

Shuttle Atlantis leaves space station, headed home

Space & Earth / Space Exploration

created Nov 25, 2009 | popularity 4 / 5 (1) | comments 0

(AP) -- Atlantis and its seven astronauts have left the International Space Station.


Shuttle, station crews seal hatches for departure (AP)

Shuttle, station crews seal hatches for departure

Space & Earth / Space Exploration

created Nov 24, 2009 | popularity 5 / 5 (1) | comments 0

(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

created Nov 24, 2009 | popularity 4 / 5 (1) | comments 0

(AP) -- The astronauts aboard the orbiting shuttle-station complex are resting after their three successful spacewalks.


Astronauts take spacewalk No. 3 after suit snag (AP)

Astronauts take spacewalk No. 3 after suit snag

Space & Earth / Space Exploration

created Nov 23, 2009 | popularity 5 / 5 (1) | comments 0

(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 (AP)

Astronaut's baby daughter born as he circles Earth

Space & Earth / Space Exploration

created Nov 22, 2009 | popularity 5 / 5 (1) | comments 0

(AP) -- Astronaut Randolph Bresnik jubilantly welcomed his new daughter into the world Sunday as he floated 220 miles above it.


Baby can wait as expectant dad finishes spacewalk (AP)

Baby can wait as expectant dad finishes spacewalk

Space & Earth / Space Exploration

created Nov 21, 2009 | popularity 3.7 / 5 (3) | comments 0

(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 (AP)

Astronauts get extra work done in 1st spacewalk (Update)

Space & Earth / Space Exploration

created Nov 19, 2009 | popularity not rated yet | comments 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.


Astronauts board space shuttle Atlantis for launch (AP)

Astronauts board space shuttle Atlantis for launch

Space & Earth / Space Exploration

created Nov 16, 2009 | popularity not rated yet | comments 0

(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.


Atlantis 'Go' For Launch to Station on Nov. 16

Atlantis 'Go' For Launch to Station on Nov. 16

Space & Earth / Space Exploration

created Oct 29, 2009 | popularity 5 / 5 (2) | comments 0

(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

created Oct 13, 2009 | popularity not rated yet | comments 0

(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

created Oct 06, 2009 | popularity 5 / 5 (1) | comments 0

(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

created Sep 17, 2009 | popularity 4.3 / 5 (3) | comments 0

(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 (AP)

Astronauts take mission's 3rd and final spacewalk

Space & Earth / Space Exploration

created Sep 06, 2009 | popularity 3 / 5 (1) | comments 0

(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 ...


Image from NASA video shows the International Space Station above the South Pacific

Discovery astronauts ready for final spacewalk

Space & Earth / Space Exploration

created Sep 05, 2009 | popularity 5 / 5 (1) | comments 0

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 (AP)

Astronauts relish space's international food court

Space & Earth / Space Exploration

created Sep 05, 2009 | popularity 4.3 / 5 (4) | comments 0

(AP) -- When it comes to grabbing a bite to eat, the international space station is living up to its first name.