Editing Extravehicular activity

{{Short description|Activity done by an astronaut or cosmonaut outside a spacecraft}}
{{Redirect|Spacewalk|other uses}}
{{Use mdy dates|date=October 2019}}
[[File:Volkov during Russian EVA28.jpg|thumb|Cosmonaut [[Sergey Volkov (cosmonaut)|Sergey Volkov]] works outside the International Space Station on August 3, 2011.]]
[[File:Sts114 033.jpg|thumb|upright|[[Stephen Robinson]] riding the [[Canadarm2]] while conducting the first in-flight repair of the Space Shuttle during [[STS-114]] on August 3, 2005. The landmass in the backdrop is the [[Bari, Somalia|Bari region]] of [[Somalia]].]]
'''Extravehicular activity''' ('''EVA''') is any activity done by an [[astronaut]] in [[outer space]] outside a [[spacecraft]]. In the absence of a breathable [[atmosphere of Earth|Earthlike atmosphere]], the astronaut is completely reliant on a [[space suit]] for environmental support. EVA includes '''spacewalks''' and [[Moon|lunar]] or [[planet]]ary surface exploration (commonly known from 1969 to 1972 as '''moonwalks'''). In a stand-up EVA (SEVA), an astronaut stands through an open hatch but does not fully leave the spacecraft.<ref name="standup">{{Cite web|author=NASA|year=2007|title=Stand-Up EVA|url=https://history.nasa.gov/alsj/a15/a15.seva.html|access-date=October 21, 2008|publisher=NASA}}</ref> EVAs have been conducted by the [[Soviet Union]]/Russia, the United States, Canada, the [[European Space Agency]] and China.

On March 18, 1965, [[Alexei Leonov]] became the first human to perform a spacewalk, exiting the [[Voskhod 2]] capsule for 12 minutes and 9 seconds. On July 20, 1969, [[Neil Armstrong]] became the first human to perform a moonwalk, outside his lunar lander on [[Apollo 11]] for 2 hours and 31 minutes. In 1984, [[Svetlana Savitskaya]] became the first woman to perform a spacewalk, conducting EVA outside the [[Salyut 7]] space station for 3 hours and 35 minutes. On the last three Moon missions, astronauts also performed deep-space EVAs on the return to Earth, to retrieve film canisters from the outside of the spacecraft. American Astronauts [[Pete Conrad]], [[Joseph P. Kerwin|Joseph Kerwin]], and [[Paul J. Weitz|Paul Weitz]] also used EVA in 1973 to repair launch damage to [[Skylab]], the United States' first space station.

EVAs may be either tethered (the [[astronaut]] is connected to the spacecraft; oxygen and electrical power can be supplied through an [[umbilical cable]]; no propulsion is needed to return to the spacecraft), or untethered. 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 safety device worn on tethered U.S. EVAs.

==Development history==
[[NASA]] planners invented the term ''extravehicular activity'' (abbreviated with the acronym EVA) in the early 1960s for the [[Apollo program]] to land humans on the Moon, because the astronauts would leave the spacecraft to collect [[moon rock|lunar material samples]] and deploy scientific experiments. To support this, and other Apollo objectives, the [[Project Gemini|Gemini program]] was spun off to develop the capability for astronauts to work outside a two-person Earth orbiting spacecraft. However, the [[Soviet Union]] was fiercely competitive in holding the early lead it had gained in crewed spaceflight, so the [[Communist Party of the Soviet Union|Soviet Communist Party]], led by [[Nikita Khrushchev]], ordered the conversion of its single-pilot [[Vostok (spacecraft)|Vostok]] capsule into a two- or three-person craft named [[Voskhod spacecraft|Voskhod]], in order to compete with [[Gemini program|Gemini]] and [[Apollo (spacecraft)|Apollo]].<ref name="Siddiqi 384-6">{{cite book
 |title= Sputnik and the Soviet Space Challenge
 |last= Siddiqi
 |first= Asif A.
 |year= 2003a
 |publisher= [[University Press of Florida]]
 |location= Gainesville
 |isbn= 0-8130-2627-X
}}</ref> The Soviets were able to launch two Voskhod capsules before U.S. was able to launch its first crewed Gemini.

The Voskhod's [[avionics]] required cooling by cabin air to prevent any kind of overheating, therefore an [[airlock]] was required for the spacewalking [[cosmonaut]] to exit and re-enter the cabin while it remained pressurized. Unusually, and by contrast, the Gemini avionics did not require air cooling, allowing the spacewalking astronaut to exit and re-enter the depressurized cabin through an open hatch. Because of this, the [[United States|American]] and [[Soviet Union|Soviet]] space programs developed different definitions for the duration of an EVA. The Soviet (now [[Russia]]n) definition begins when the outer airlock hatch is open and the cosmonaut is in [[vacuum]]. An American EVA began when the astronaut had at least their head outside the spacecraft.<ref>''Walking to Olympus'', p. ix.</ref> The U.S. has changed its EVA definition since.<ref>{{Cite book |last=Dasch |first=E. Julius |url=http://oxfordreference.com/view/10.1093/acref/9780191842764.001.0001/acref-9780191842764 |title=A Dictionary of Space Exploration |date=2018 |publisher=Oxford University Press |editor-last=O’Meara |editor-first=Stephen James |volume=1 |language=en |doi=10.1093/acref/9780191842764.001.0001|isbn=978-0-19-184276-4 }}</ref><ref>{{Cite book |url=https://msis.jsc.nasa.gov/ |title=Man-Systems Integration Standards |publisher=NASA |year=1995 |edition=Revised B |volume=one |location= |language=en |chapter=Extravehicular Activity}}</ref>

===<span class="anchor" id="First spacewalk">First instance</span>===
[[File:FirstSpaceWalk.png|thumb|right|[[Alexei Leonov]] performs the first spacewalk during [[Voskhod 2]].]]

The first EVA was performed on March 18, 1965, by Soviet cosmonaut [[Alexei Leonov]], who spent 12 minutes and 9 seconds outside the [[Voskhod 2]] spacecraft. Carrying a white metal backpack containing 45 minutes' worth of breathing and pressurization oxygen, Leonov had no means to control his motion other than pulling on his {{convert|15.35|m|abbr=on}} tether. After the flight, he claimed this was easy, but his [[space suit]] ballooned from its internal pressure against the vacuum of space, stiffening so much that he could not activate the shutter on his chest-mounted camera.<ref name="portree"/>

At the end of his space walk, the suit stiffening caused a more serious problem: Leonov had to re-enter the capsule through the inflatable cloth airlock, {{convert|1.2|m|abbr=on}} in diameter and {{convert|2.5|m|abbr=on}} long. He improperly entered the airlock head-first and got stuck sideways. He could not get back in without reducing the pressure in his suit, risking "[[decompression sickness|the bends]]". This added another 12 minutes to his time in vacuum, and he was overheated by {{convert|1.8|C-change|F-change}} from the exertion. It would be almost four years before the Soviets tried another EVA. They misrepresented to the press how difficult Leonov found it to work in [[weightlessness]] and concealed the problems encountered until after the end of the [[Cold War]].<ref name="portree">{{cite web |url=http://www.jsc.nasa.gov/history/walking/EVAChron.pdf |title=Walking to Olympus: An EVA Chronology |access-date=2015-07-30 |last1=Portree |first1=David S. F. |first2=Robert C. |last2=Treviño |date=October 1997 |work=Monographs in Aerospace History Series #7 |publisher=NASA History Office |pages=1–2}}</ref><ref name=First-Spacewalk>{{cite web |url=https://www.bbc.co.uk/news/special/2014/newsspec_9035/index.html |title=The First Spacewalk How the first human to take steps in outer space nearly didn't return to Earth |last1=Rincon |first1=Paul |last2=Lachmann |first2=Michael |date=October 13, 2014 |work=BBC News |archive-url=https://web.archive.org/web/20160216020616/http://www.bbc.co.uk/news/special/2014/newsspec_9035/index.html |archive-date=February 16, 2016 |access-date=2014-10-19}}</ref>

===Project Gemini===
[[File:EdWhiteFirstAmericanSpacewalker.1965.ws.jpg|thumb|[[Ed White (astronaut)|Ed White]] performs the first American spacewalk during [[Gemini IV]].]]

The first American spacewalk was performed on June 3, 1965, by [[Ed White (astronaut)|Ed White]] from the second crewed [[Project Gemini|Gemini]] flight, [[Gemini IV]], for 21 minutes. White was tethered to the spacecraft, and his oxygen was supplied through a {{convert|25|ft|adj=on}} [[umbilical cable|umbilical]], which also carried communications and biomedical instrumentation. He was the first to control his motion in space with a [[Hand-Held Maneuvering Unit]], which worked well but only carried enough propellant for 20 seconds. White found his tether useful for limiting his distance from the spacecraft but difficult to use for moving around, contrary to Leonov's claim.<ref name="portree"/> However, a defect in the capsule's hatch latching mechanism caused difficulties opening and closing the hatch, which delayed the start of the EVA and put White and his crewmate at risk of not getting back to Earth alive.<ref name="mcdivittoh">Oral History Transcript / [http://www.jsc.nasa.gov/history/oral_histories/McDivittJA/mcdivittja.pdf James A. McDivitt] / Interviewed by Doug Ward / Elk Lake, Michigan – June 29, 1999.</ref>

No EVAs were planned on the next three Gemini flights. The next EVA was planned to be made by [[David Scott]] on [[Gemini VIII]], but that mission had to be aborted due to a critical spacecraft malfunction before the EVA could be conducted. Astronauts on the next three Gemini flights ([[Eugene Cernan]], [[Michael Collins (astronaut)|Michael Collins]], and [[Richard F. Gordon Jr.|Richard Gordon]]), performed several EVAs, but none was able to successfully work for long periods outside the spacecraft without tiring and overheating. Cernan attempted but failed to test an Air Force [[Astronaut Maneuvering Unit]] which included a self-contained oxygen system.

On November 13, 1966, [[Edwin "Buzz" Aldrin]] became the first to successfully work in space without tiring during [[Gemini XII]], the last Gemini mission. Aldrin worked outside the spacecraft for 2 hours and 6 minutes, in addition to two stand-up EVAs in the spacecraft hatch for an additional 3 hours and 24 minutes. Aldrin's interest in [[scuba diving]] inspired the use of [[Neutral buoyancy simulation as a training aid|underwater EVA training]] to simulate weightlessness, which has been used ever since to allow astronauts to practice techniques of avoiding wasted muscle energy.

===<span class="anchor" id="First EVA crew transfer">First crew transfer</span>===
On January 16, 1969, Soviet cosmonauts [[Aleksei Yeliseyev]] and [[Yevgeny Khrunov]] transferred from [[Soyuz 5]] to [[Soyuz 4]], which were docked together. This was the second Soviet EVA, and it would be almost another nine years before the Soviets performed their third.<ref name="portree"/>

===<span class="anchor" id="Apollo lunar EVA">Apollo missions</span>===
[[File:Aldrin Apollo 11 original.jpg|thumb|right|[[Buzz Aldrin]] walks on the Moon during the pioneering [[Apollo 11]] mission in 1969.]]

American astronauts [[Neil Armstrong]] and [[Buzz Aldrin]] performed the first EVA on the lunar surface on July 21, 1969 ([[UTC]]), after landing their [[Apollo 11]] [[Apollo Lunar Module|Lunar Module]] spacecraft. This first Moon walk, using self-contained [[portable life support system]]s, lasted 2 hours and 36 minutes. A total of fifteen Moon walks were performed among six Apollo crews, including [[Pete Conrad|Charles "Pete" Conrad]], [[Alan Bean]], [[Alan Shepard]], [[Edgar Mitchell]], [[David Scott]], [[James Irwin]], [[John Young (astronaut)|John Young]], [[Charles Duke]], [[Eugene Cernan]], and [[Harrison Schmitt|Harrison "Jack" Schmitt]]. Cernan was the last Apollo astronaut to step off the surface of the Moon.<ref name="portree"/>

[[File:Astronaut Charles Duke with a hammer on the lunar surface - pone.0006614.s003.ogv|thumb|[[Charles Duke]] with a hammer on the lunar surface]]

[[Apollo 15]] [[Apollo command and service module|command module]] pilot [[Al Worden]] made an EVA on August 5, 1971, on the return trip from the Moon, to retrieve a film and data recording canister from the service module. He was assisted by Lunar Module Pilot James Irwin standing up in the Command Module hatch. This procedure was repeated by [[Ken Mattingly]] and Charles Duke on [[Apollo 16]], and by [[Ronald Evans (astronaut)|Ronald Evans]] and Harrison Schmitt on [[Apollo 17]].<ref name="portree"/>

===<span class="anchor" id="Post-Apollo EVAs">Post-Apollo</span>===
The first EVA repairs of a spacecraft were made by [[Pete Conrad|Charles "Pete" Conrad]], [[Joseph P. Kerwin|Joseph Kerwin]], and [[Paul J. Weitz]] on May 26, June 7, and June 19, 1973, on the [[Skylab 2]] mission. They rescued the functionality of the launch-damaged [[Skylab]] [[space station]] by freeing a stuck [[solar panels on spacecraft|solar panel]], deploying a solar heating shield, and freeing a stuck circuit breaker relay. The Skylab 2 crew made three EVAs, and a total of ten EVAs were made by the three Skylab crews.<ref name="portree"/> They found that activities in weightlessness required about 2{{frac|1|2}} times longer than on Earth because many astronauts suffered [[spacesickness]] early in their flights.<ref name="reusestudy">''[https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19790075817_1979075817.pdf Skylab Reuse Study]'', p. 3-53. Martin Marietta and Bendix for NASA, September 1978.</ref>

After Skylab, no more EVAs were made by the United States until the advent of the [[Space Shuttle]] program in the early 1980s. In this period, the Soviets resumed EVAs, making four from the [[Salyut 6]] and [[Salyut 7]] space stations between December 20, 1977, and July 30, 1982.<ref name="portree"/>

When the United States resumed EVAs on April 7, 1983, astronauts started using an [[Extravehicular Mobility Unit]] (EMU) for self-contained life support independent of the spacecraft. STS-6 was the first Space Shuttle mission during which a spacewalk was conducted. Also, for the first time, American astronauts used an airlock to enter and exit the spacecraft like the Soviets. Accordingly, the American definition of EVA start time was redefined to when the astronaut switches the EMU to battery power.<ref>{{cite news|title=Second all-female spacewalk devoted to space station battery replacements|author=William Harwood|date=January 15, 2020|url=https://www.cbsnews.com/news/second-all-female-spacewalk-nasa-astronauts-space-station-live-stream-today-2020-01-15/
|publisher=CBS News|access-date=May 25, 2023}}</ref>

Numerous EVAs were conducted during the assembly of the [[International Space Station|ISS]], often using the [[Quest Joint Airlock]], designed to support both U.S. EMUs, and Russian Orlan space suits.

===<span class="anchor" id="Chinese EVA">By China</span>===
[[File:Shenzhou-15 spacewalk.jpg|Astronaut Fei Junlong performing a spacewalk on the Tiangong Space Station|thumb]]
[[China]] became the third [[country]] to independently carry out an EVA on September 27, 2008, during the [[Shenzhou 7]] mission. Chinese taikonaut [[Zhai Zhigang]] completed a 22-minute spacewalk wearing the Chinese-developed [[Feitian space suit]], with taikonaut [[Liu Boming (astronaut)|Liu Boming]] wearing the Russian-derived [[Orlan space suit]] assisting him in the process. Zhai completely exited the craft, while Liu stood by at the airlock, straddling the portal.

Since 2021, China has carried out several more EVAs lasting several hours for the construction of the [[Tiangong space station]]. In December 2024 China's [[Cai Xuzhe]] and [[Song Lingdong]] set the current record for the longest EVA at 9 hours and six minutes.<ref name=":0" /><ref name=":1">{{Cite web |author1=Mike Wall |date=2024-12-18 |title=Chinese astronauts perform record-breaking 9-hour spacewalk outside Tiangong space station (video) |url=https://www.space.com/space-exploration/human-spaceflight/chinese-astronauts-conduct-record-breaking-9-hour-spacewalk-outside-tiangong-space-station-photos |access-date=2025-01-14 |website=Space.com |language=en-US}}</ref> 

=== By SpaceX ===
American company [[SpaceX]] conducted the first private sector-financed EVA on September 12, 2024. Entrepreneur [[Jared Isaacman]] and SpaceX engineer [[Sarah Gillis]] briefly ventured outside a [[SpaceX Dragon|Dragon]] capsule, for a stand-up EVA (SEVA) during the [[Polaris Dawn]] mission to conduct [[Space suit|spacesuit]] mobility testing. <ref>{{Cite news |last=Patel-Carstairs |first=Sunita |date=12 September 2024 |title=SpaceX Polaris Dawn: Billionaire Jared Isaacman becomes first person to take part in private spacewalk |url=https://news.sky.com/story/spacex-polaris-dawn-billionaire-jared-isaacman-becomes-first-person-to-take-part-in-private-spacewalk-13213265 |url-status=live |archive-url=https://web.archive.org/web/20240912121617/https://news.sky.com/story/spacex-polaris-dawn-billionaire-jared-isaacman-becomes-first-person-to-take-part-in-private-spacewalk-13213265 |archive-date=12 September 2024 |access-date=12 September 2024 |work=[[Sky News]]}}</ref> The other two crew members were exposed to the vacuum of space in the capsule, but did not leave it.<ref>{{cite news|url=https://www.space.com/spacex-polaris-dawn-first-private-spacewalk|title=SpaceX Polaris Dawn astronauts perform historic 1st private spacewalk in orbit (video)|publisher=space.com|date=12 September 2024|access-date=12 September 2024}}</ref> SpaceX plans to launch at least two more missions involving an EVA,<ref>{{cite web|url=https://thetimes.com/world/us-world/article/polaris-dawn-spacex-what-comes-next-commercial-space-85258s8rv |newspaper=[[The Times]] |date=September 12, 2024 |first=Jacqui |last=Goddard |title=SpaceX's success redefines the commercial space frontier, but what's next? |access-date=September 12, 2024}}</ref> including one that involves SpaceX's still-in-development [[SpaceX Starship|Starship]] launch vehicle.<ref>{{cite web|url=https://www.washingtonpost.com/technology/2024/09/12/spacex-polaris-dawn-spacewalk-astronauts/ |first=Christian |last=Davenport |newspaper=[[The Washington Post]] |date=September 12, 2024 |title=SpaceX Polaris astronauts complete first spacewalk by private citizens |access-date=September 12, 2024}}</ref>

==Milestones==

===Capability milestones===
* The first untethered spacewalk was made by American [[Bruce McCandless II]] on February 7, 1984, during the [[Space Shuttle Challenger|Space Shuttle ''Challenger'']] mission [[STS-41-B]], using the [[Manned Maneuvering Unit]]. He was subsequently joined by [[Robert L. Stewart]] during the 5-hour, 55-minute spacewalk. A self-contained spacewalk was first attempted by [[Eugene Cernan]] in 1966 on [[Gemini 9A]], but Cernan could not reach the maneuvering unit without tiring.
* The first metalwork in open space, consisting of welding, brazing and metal spraying, was conducted by Soviet cosmonauts [[Svetlana Savitskaya]] and [[Vladimir Dzhanibekov]] on July 25, 1984. A specially designed multipurpose tool was used to perform these activities during a 3-hour, 30-minute EVA outside the Salyut 7 space station.<ref name="Salyut7Welding1">{{Cite web|url=http://www.astronautix.com/flights/salt7ep4.htm|title=Encyclopedia Astronautica Salyut 7 EP-4|publisher=Astronautix.com|author=Mark Wade|access-date=November 18, 2011|url-status=dead|archive-url=https://web.archive.org/web/20111111213510/http://www.astronautix.com/flights/salt7ep4.htm|archive-date=November 11, 2011}}</ref><ref name="Salyut7Welding2">{{Cite web|url=http://www.aws.org/about/time_by5.html|title=A pictorial history of welding as seen through the pages of the Welding Journal|publisher=American Welding Society|access-date=November 18, 2011|archive-date=April 18, 2012|archive-url=https://web.archive.org/web/20120418151442/http://www.aws.org/about/time_by5.html|url-status=dead}}</ref><ref name="Salyut7Welding3">{{Cite web|url=http://ruspace.blogspot.com/2009/07/space-welding-anniversary.html|title=Space welding anniversary|date=July 16, 2009|access-date=November 18, 2011|publisher=RuSpace.com}}</ref>
* The first three-person EVA was performed on May 13, 1992, as the third EVA of [[STS-49]], the maiden flight of ''[[Space Shuttle Endeavour|Endeavour]]''.<ref name="sts49">{{Cite web|url=http://science.ksc.nasa.gov/shuttle/missions/sts-49/mission-sts-49.html|title=STS-49|access-date=December 7, 2007|publisher=NASA|year=2001|author=NASA|archive-date=February 17, 2013|archive-url=https://web.archive.org/web/20130217182153/http://science.ksc.nasa.gov/shuttle/missions/sts-49/mission-sts-49.html|url-status=dead}}</ref> [[Pierre J. Thuot|Pierre Thuot]], [[Richard Hieb]], and [[Thomas Akers]] conducted the EVA to hand-capture and repair a non-functional [[Intelsat]] VI-F3 [[satellite]]. {{As of|2021}} it was the only three-person EVA.<ref>[http://www.nasa.gov/audience/foreducators/spacesuits/facts/facts-index.html Facts about spacesuits and spacewalks (NASA.gov)] {{webarchive|url=https://web.archive.org/web/20130603133402/http://www.nasa.gov/audience/foreducators/spacesuits/facts/facts-index.html |date=2013-06-03 }}</ref>
* The first EVA to perform an [[STS-114#In-flight repair|in-flight repair of the Space Shuttle]] was by American [[Stephen Robinson|Steve Robinson]] on August 3, 2005, during "Return to Flight" mission [[STS-114]]. Robinson was sent to remove two protruding gap fillers from [[Space Shuttle Discovery|''Discovery'']]'s heat shield, after engineers determined there was a small chance they could affect the shuttle upon re-entry. Robinson successfully removed the loose material while ''Discovery'' was docked to the [[International Space Station]].
* The longest spacewalk is 9 hours and six minutes performed by [[Cai Xuzhe]] and [[Song Lingdong]] on December 17, 2024.<ref name=":0">{{Cite web|url=https://english.news.cn/20241218/c7b6f2f3a13445b9a8da0084287dd047/c.html|title=Update: Shenzhou-19 crew completes first extravehicular activities|access-date=2024-12-17|work=[[Xinhua News Agency]]|date=2024-12-17|author=Huaxia}}</ref><ref name=":1" /> The previous record was held by U.S. astronauts [[James S. Voss|James Voss]] and [[Susan Helms]], who made eight hours and 56 minutes EVA outside [[Space Shuttle Discovery]] on March 11, 2001.<ref>{{Cite web
 | author = Guinness World Records
 | title = Longest spacewalk
 | url = https://www.guinnessworldrecords.com/world-records/66075-longest-spacewalk
 | website = Guinness World Records
 | access-date = 2024-12-18
}}</ref>


[[File:Bruce McCandless II during EVA in 1984.jpg|thumb|right|Untethered U.S. astronaut [[Bruce McCandless II|Bruce McCandless]] uses a [[manned maneuvering unit]]. Photo taken by [[Robert L. Gibson|Robert "Hoot" Gibson]].]]
[[File:Three Crew Members Capture Intelsat VI - GPN-2000-001035.jpg|thumb|Capture of Intelsat VI in 1992 on [[STS-49]]. This hand-capture of a satellite is the only EVA to date to be performed by three astronauts.]]

===Personal cumulative duration records===
* Russian [[Anatoly Solovyev]] holds both the [[List of cumulative spacewalk records|record for most EVAs and for the greatest cumulative duration spent in EVA]] (16 EVAs; 82 hr and 22 min over 4 Mir missions between July 1990 and January 1998).
* [[Michael Lopez-Alegria]] holds the American record (10 EVAs; 67 hr and 40 min over 2 Shuttle and 1 ISS missions between October 2000 and February 2007).
* [[Thomas Pesquet]] holds the European (and non-U.S./Russian) record (6 EVAs; 39 hr and 54 min over 2 ISS missions between January 2017 and August 2021).<ref>{{Cite web|title=Thomas Pesquet - EVA experience|url=http://www.spacefacts.de/eva/international/english/pesquet_thomas.htm|access-date=2022-01-17|website=www.spacefacts.de}}</ref>
* [[Sunita Williams]] holds the record for the most cumulative duration spent for a [[woman]] (62 hr and 6 min). However, [[Peggy Whitson]] holds the record for most EVAs by a woman (10 EVAs over 3 ISS missions between August 2002 and May 2017).

===National, ethnic and gender firsts===
* The first woman to perform an EVA was Soviet [[Svetlana Savitskaya]] on July 25, 1984, while aboard the [[Salyut 7]] space station. Her EVA lasted 3 hours and 35 minutes.
** The first American woman to perform an EVA was on October 11, 1984, by [[Kathryn D. Sullivan]] during [[STS-41-G]].
** The first two women to perform an EVA together and the first all-female EVA team were [[Christina Koch]] and [[Jessica Meir]] on October 18, 2019, during [[Expedition 61]] on the [[International Space Station]].<ref>{{Cite web|url=https://www.youtube.com/watch?v=Iji5hTQ3CUo| archive-url=https://ghostarchive.org/varchive/youtube/20211211/Iji5hTQ3CUo| archive-date=2021-12-11 | url-status=live|title=NASA Astronauts Spacewalk Outside the International Space Station on Oct. 18|date=October 18, 2019|publisher=NASA|via=YouTube|access-date=October 18, 2019}}{{cbignore}}</ref><ref>{{cite web|url=https://www.nu.nl/buitenland/6004873/voor-het-eerst-maakt-vrouwelijk-duo-ruimtewandeling-bij-iss.html|title=Voor het eerst maakt vrouwelijk duo ruimtewandeling bij ISS|language=nl|website=nu.nl|date=October 18, 2019|trans-title=For the first time a female duo is taking a space walk at ISS}}</ref><ref>{{cite web |url=https://blogs.nasa.gov/spacestation/2019/10/18/nasa-tv-is-live-now-broadcasting-first-all-woman-spacewalk/ |title=NASA TV is Live Now Broadcasting First All-Woman Spacewalk |last=Garcia |first=Mark |date=18 October 2019 |website=NASA Blogs |publisher=NASA |access-date=18 October 2019 }}</ref>
** The first female Asian and Chinese woman to perform an EVA was [[Wang Yaping]] on 8 November 2021, outside the Chinese [[Tiangong space station]].
** The first Native American woman to perform a space walk was [[Nicole Aunapu Mann]] on January 20, 2023, during [[Expedition 68]] on the [[International Space Station]].<ref>{{Cite web|url=https://www.kristv.com/news/national/nasa-astronaut-becomes-first-native-american-woman-to-conduct-spacewalk|title=NASA astronaut becomes first Native American woman to conduct spacewalk|date=January 23, 2023|website=KRIS 6 News Corpus Christi}}</ref>
* The first EVA by a non-Soviet, non-American was made on December 9, 1988, by [[Jean-Loup Chrétien]] of [[France]] during a three-week stay on the [[Mir]] space station.
* The first EVA by a black African-American was on February 9, 1995, by [[Bernard A. Harris Jr.|Bernard A. Harris Jr]] during [[STS-63]].
* The first EVA by a Japanese astronaut was made on November 25, 1997, by [[Takao Doi]] during [[STS-87]].
* The first EVA by a Swiss astronaut was made on December 23, 1999, by [[Claude Nicollier]] during [[STS-103]].
* The first EVA by an Australian-born person was on March 13, 2001, by [[Andy Thomas]] (although he is a naturalized U.S. citizen).
*The first EVA by a Canadian astronaut was made on April 22, 2001, by [[Chris Hadfield]] along with NASA astronaut [[Scott E. Parazynski|Scott Parazynski]] during mission [[STS-100]] to install [[Canadarm2]] on the [[International Space Station]].<ref>{{Cite web|url=http://www.asc-csa.gc.ca/eng/astronauts/about-the-job/spacewalks.asp|title=Spacewalks|website=www.asc-csa.gc.ca|date=June 17, 2016|language=en|access-date=2018-11-17}}</ref>
* The first EVA by a Swedish astronaut was made on December 12, 2006, by [[Christer Fuglesang]].
* The first EVA by a Chinese astronaut was made on September 27, 2008, by [[Zhai Zhigang]] during [[Shenzhou 7]] mission. The spacewalk, using a [[Feitian space suit]], made China the third country to independently carry out an EVA.
* The first EVA by an Italian astronaut was made on July 9, 2013, by [[Luca Parmitano]] along with NASA Astronaut [[Chris Cassidy]] during [[Expedition 36]] on the [[International Space Station]].
* The first EVA by a British astronaut was on January 15, 2016, by [[Tim Peake]].<ref name="BBC_Rincon">{{cite news | url=https://www.bbc.co.uk/news/science-environment-35273912 | last=Rincon | first=Paul | title=Tim Peake on historic spacewalk | date=January 5, 2016 | work=BBC News | access-date=2016-09-10}}</ref>
** Although British-American [[Michael Foale]] carried out an EVA on February 9, 1995, he flew as an American astronaut in NASA's program.<ref name="BBC_Rincon"/>
* The first EVA by an Arab astronaut was made on April 28, 2023, by [[United Arab Emirates|Emirati]] astronaut [[Sultan Al Neyadi]].<ref>{{cite web |last1=Clark |first1=Stephen |title=Watch live: First Arab spacewalker heads outside International Space Station – Spaceflight Now |url=https://spaceflightnow.com/2023/04/28/us-eva-86-coverage/ |access-date=28 April 2023 |date=28 April 2023}}</ref>
<!-- [[WP:NFCC]] violation: [[File:China's first spacewalk.jpg|Zhai Zhigang waving the Chinese flag while performing an EVA|thumb]] -->
[[File:STS-116 spacewalk 1.jpg|thumb|[[International Space Station]] assembly EVA made during the [[STS-116]] mission. [[Robert Curbeam]] (with red stripes) together with [[Christer Fuglesang]] over [[Cook Strait]], [[New Zealand]].]]
[[File:SolovyevEVA.jpg|thumbnail|[[Anatoly Solovyev]] holds the record for time spent during spacewalks: 82+ hours over 16 separate outings, seen here performing an EVA outside [[Mir]] space station in 1997.]]

==Commemoration==
The first spacewalk, made by Soviet cosmonaut Alexei Leonov, was commemorated in 1965 with several Eastern Bloc stamps (see [[Alexei Leonov#Stamps]]). Since the Soviet Union did not publish details of the Voskhod spacecraft at the time, the spaceship depiction in the stamps was purely fictional.

The [[U.S. Post Office]] issued a postage stamp in 1967 commemorating [[Ed White (astronaut)|Ed White]]'s first American spacewalk. The engraved image has an accurate depiction of the [[Gemini IV]] spacecraft and White's [[space suit]].<ref>Scotts Specialized Catalogue of United States Postage Stamps</ref>

{|
|[[File:Soviet Union-1965-Stamp-0.10. Voskhod-2. First Spacewalk.jpg|thumb|center|{{center|[[Soviet space exploration history on Soviet stamps|Alexei Leonov, Voskhod 2, First Spacewalk]]}}{{center|U.S.S.R. commemorative issue of 1965}}]]
|[[File:US Space Walk 1967 Issue-5c.jpg|thumb|center|{{center|[[U.S. space exploration history on U.S. stamps#Accomplishments in Space Commemorative Issue of 1967|Accomplishments in Space]]}}{{center|U.S. Commemorative Issue of 1967}}]]
|}

==Designations==
NASA "spacewalkers" during the Space Shuttle program were designated as EV-1, EV-2, EV-3 and EV-4 (assigned to mission specialists for each mission, if applicable).<ref>{{cite web |url=http://www.nasa.gov/centers/marshall/news/background/facts/evarm.html_prt.htm |title=Extravehicular Activity Radiation Monitoring (EVARM) |date=2001-10-01 |publisher=[[NASA]] |access-date=November 17, 2009 |archive-date=November 24, 2010 |archive-url=https://web.archive.org/web/20101124150337/http://www.nasa.gov/centers/marshall/news/background/facts/evarm.html_prt.htm |url-status=dead }}</ref><ref>{{cite web|url=http://www.nasa.gov/centers/marshall/news/background/facts/evarm.html|title=Extravehicular Activity Radiation Monitoring (EVARM)|date=2001-10-01|publisher=Marshall Space Flight Center|access-date=November 17, 2009|archive-date=November 24, 2010|archive-url=https://web.archive.org/web/20101124150337/http://www.nasa.gov/centers/marshall/news/background/facts/evarm.html|url-status=dead}}</ref>

==Camp-out procedure==
For EVAs from the [[International Space Station]], NASA employed a [[Quest Joint Airlock#Camp-out procedure|''camp-out'' procedure]] to reduce the risk of decompression sickness.<ref name="tanner">{{Cite web|url=http://www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts115/interview_tanner.html|title=Preflight Interview: Joe Tanner|access-date=February 8, 2008|publisher=NASA|year=2006|author=NASA|archive-date=May 12, 2013|archive-url=https://web.archive.org/web/20130512135522/http://www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts115/interview_tanner.html|url-status=dead}}</ref> This was first tested by the Expedition 12 crew. During a camp-out, astronauts sleep overnight in the [[Quest Joint Airlock|airlock]] prior to an EVA, lowering the air pressure to {{convert|10.2|psi|abbr=on}}, compared to the normal station pressure of {{convert|14.7|psi|abbr=on}}.<ref name="tanner"/> Spending a night at the lower air pressure helps flush nitrogen from the body, thereby preventing "[[Decompression sickness|the bends]]".<ref>{{cite web | title = International Space Station Status Report #06-7 | url = http://spaceflight.nasa.gov/spacenews/reports/issreports/2006/iss06-7.html | archive-url = https://web.archive.org/web/20060615191754/http://spaceflight.nasa.gov/spacenews/reports/issreports/2006/iss06-7.html | url-status = dead | archive-date = 2006-06-15 | publisher = NASA|author=NASA|access-date=2006-02-17}}</ref><ref>{{cite web | url = http://www.nasa.gov/mission_pages/station/expeditions/campout.html | title = Pass the S'mores Please! Station Crew 'Camps Out' | publisher = NASA | author = NASA | access-date = 2006-04-01 | archive-date = May 12, 2013 | archive-url = https://web.archive.org/web/20130512155656/http://www.nasa.gov/mission_pages/station/expeditions/campout.html | url-status = dead }}</ref> More recently astronauts have been using the In-Suit Light Exercise protocol rather than camp-out to prevent decompression sickness.<ref>{{cite web | url = https://www.nasa.gov/feature/eva-physiology | title = EVA Physiology | publisher = NASA | author = NASA | date = February 26, 2015 | access-date = 2018-04-27 }}</ref><ref>{{cite web | url = https://ntrs.nasa.gov/search.jsp?R=20110007150 | title = In-Suit Light Exercise (ISLE) Prebreathe Protocol Peer Review Assessment. Volume 1 | publisher = NASA | author1 = Brady, Timothy K. |author2=Polk, James D. | date = February 2011 | access-date = 2018-04-27 }}</ref>

== See also ==
{{Portal|Spaceflight}}
{{div col}}
* [[List of longest spacewalks]]
* [[List of cumulative spacewalk records]]
* [[List of International Space Station spacewalks]]
* [[List of Tiangong space station spacewalks]]
* [[List of Mir spacewalks]]
* [[List of spacewalkers]]
* [[List of spacewalks since 2015]]
* [[List of spacewalks 2000–2014]]
* [[List of spacewalks and moonwalks 1965–1999]]
* [[Suitport]]
* ''[[The Age of Pioneers]]'', 2017 film about the first spacewalk
{{div col end}}

==References==
{{Reflist}}

==External links==
{{Commons category|Extra-vehicular activity|Extravehicular activity}}
* [http://www.jsc.nasa.gov/history/walking/EVAChron.pdf NASA JSC Oral History Project ''Walking to Olympus: An EVA Chronology'' PDF document.]
* [https://web.archive.org/web/20150501064914/http://www.tabpimps.com/result/wallpaper/spacewalk/ Astronaut space walk picture]
* [https://web.archive.org/web/20030204093245/http://spaceboy.nasda.go.jp/note/yujin/e/yuj101_eva_e.html NASDA Online Space Notes]
* [https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19730064704_1973064704.pdf Apollo Extravehicular mobility unit. Volume 1: System description – 1971 (PDF document)]
* [https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19730064705_1973064705.pdf Apollo Extravehicular mobility unit. Volume 2: Operational procedures – 1971 (PDF document)]
* [https://web.archive.org/web/20050416080320/http://trs.nis.nasa.gov/archive/00000173/01/tmx64855.pdf Skylab Extravehicular Activity Development Report – 1974 (PDF document)]
* [https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19900001621_1990001621.pdf Analysis of the Space Shuttle Extravehicular Mobility Unit – 1986 (PDF document)]
* [https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19940017339_1994017339.pdf NASA Space Shuttle EVA tools and equipment reference book – 1993 (PDF document)]
* [http://esamultimedia.esa.int/docs/celsius/infokit/english/05_EVASupportInfo.pdf Preparing for an American EVA on the ISS – 2006]

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{{Spaceflight}}
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[[Category:Human spaceflight]]
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