View source for Astronomy:Human spaceflight

{{Short description|Spaceflight with a crew or passengers}}
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| caption1 = [[Engineering:Apollo 11|Apollo 11]] astronaut [[Biography:Buzz Aldrin|Buzz Aldrin]] on the Moon, 1969
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| caption3 = [[Astronomy:Gemini 4|Gemini 4]] astronaut [[Astronomy:Ed White (astronaut)|Ed White]] in open space, 1965
| caption4 = Japan Aerospace Exploration Agency astronaut Akihiko Hoshide taking a [[Astronomy:Space selfie|space selfie]] in 2012
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'''Human spaceflight''' (also referred to as '''manned spaceflight''' or '''crewed spaceflight''') is [[Engineering:Spaceflight|spaceflight]] with a crew or passengers aboard a [[Engineering:Spacecraft|spacecraft]], often with the spacecraft being operated directly by the onboard human crew. Spacecraft can also be remotely operated from ground stations on Earth, or [[Engineering:Autonomous robot|autonomously]], without any direct human involvement. People trained for spaceflight are called [[Astronaut|astronaut]]s (American or other), ''cosmonauts'' (Russian), or ''taikonauts'' (Chinese); and non-professionals are referred to as spaceflight participants or ''spacefarers''.<ref>{{Cite web|last=Mars|first=Kelli|date=2018-03-27|title=5 Hazards of Human Spaceflight|url=http://www.nasa.gov/hrp/5-hazards-of-human-spaceflight|access-date=2022-02-09|website=NASA}}</ref>

The first human in space was [[Place:Soviet Union|Soviet]] cosmonaut [[Biography:Yuri Gagarin|Yuri Gagarin]], who launched as part of the Soviet Union's Vostok program on [[Astronomy:Cosmonautics Day|12 April 1961]] at the beginning of the [[Astronomy:Space Race|Space Race]]. On 5 May 1961, Alan Shepard became the first American in space, as part of [[Astronomy:Project Mercury|Project Mercury]]. Humans traveled to the Moon nine times between 1968 and 1972 as part of the United States' [[Astronomy:Apollo program|Apollo program]], and have had a continuous presence in space for {{age in years and days|2 November 2000|sep=and}} on the [[Astronomy:International Space Station|International Space Station]] (ISS).<ref>{{cite web |title=Counting the Many Ways the International Space Station Benefits Humanity |date=5 April 2019 |url=https://www.nasa.gov/press-release/counting-the-many-ways-the-international-space-station-benefits-humanity |access-date=4 May 2019}}</ref> On 15 October 2003, the first Chinese taikonaut, Yang Liwei, went to space as part of [[Astronomy:Shenzhou 5|Shenzhou 5]], the first Chinese human spaceflight. As of January 2024, humans have not traveled beyond [[Astronomy:Low Earth orbit|low Earth orbit]] since the [[Engineering:Apollo 17|Apollo 17]] [[Astronomy:List of missions to the Moon|lunar mission]] in December 1972.

Currently, the United States, Russia, and China are the only countries with [[Astronomy:Human spaceflight programs|public or commercial human spaceflight-capable programs]]. [[Astronomy:List of private spaceflight companies|Non-governmental spaceflight companies]] have been working to develop human space programs of their own, e.g. for [[Astronomy:Space tourism|space tourism]] or commercial [[Astronomy:Space research|in-space research]]. The first private human spaceflight launch was a suborbital flight on [[Engineering:SpaceShipOne|SpaceShipOne]] on June 21, 2004. The first commercial [[Engineering:Orbital spaceflight|orbital]] crew launch was by [[Company:SpaceX|SpaceX]] in May 2020, transporting [[Organization:NASA|NASA]] astronauts to the ISS under United States government contract.<ref>{{Cite news|title=SpaceX Astronauts Reach Space Station After Milestone Voyage|url=https://www.bloomberg.com/news/articles/2020-05-30/spacex-set-to-retry-historic-rocket-launch-after-weather-delay|access-date=2020-06-16|newspaper=Bloomberg.com|date=30 May 2020 }}</ref>

== History ==

=== Cold War era ===
{{Main|Astronomy:Space Race}}
[[File:Vostok spacecraft replica.jpg|thumb|180px|Replica of the [[Astronomy:Vostok programme|Vostok]] space capsule, which carried the first human into orbit, at Technik Museum Speyer]]
[[File:Sigma7-1.jpg|thumb|Mercury space capsule, which carried the first Americans into orbit, on display at the Astronaut Hall of Fame, Titusville, Florida]]
[[File:X-15 in flight.jpg|thumb|North American X-15, hypersonic rocket-powered aircraft, which reached the edge of space]]
[[File:As11-40-5886.jpg|thumb|right|Neil Armstrong, one of the first two people to land on the Moon and the first to walk on the lunar surface, July 1969]]

Human spaceflight capability was first developed during the [[History:Cold War|Cold War]] between the United States and the Soviet Union (USSR). These nations developed [[Engineering:Intercontinental ballistic missile|intercontinental ballistic missile]]s for the delivery of [[Engineering:Nuclear weapon|nuclear weapon]]s, producing rockets large enough to be adapted to carry the first artificial satellites into [[Astronomy:Low Earth orbit|low Earth orbit]].

After the first satellites were launched in 1957 and 1958 by the Soviet Union, the US began work on [[Astronomy:Project Mercury|Project Mercury]], with the aim of launching men into orbit. The USSR was secretly pursuing the [[Astronomy:Vostok programme|Vostok program]] to accomplish the same thing, and launched the first human into space, the cosmonaut [[Biography:Yuri Gagarin|Yuri Gagarin]]. On 12 April 1961, Gagarin was launched aboard [[Astronomy:Vostok 1|Vostok 1]] on a Vostok 3KA rocket and completed a single orbit. On 5 May 1961, the US launched its first [[Astronaut|astronaut]], Alan Shepard, on a suborbital flight aboard ''Freedom 7'' on a [[Engineering:Mercury-Redstone Launch Vehicle|Mercury-Redstone rocket]]. Unlike Gagarin, Shepard manually [[Astronomy:Spacecraft attitude control|controlled his spacecraft's attitude]].<ref>{{cite book |last1=Furniss |first1=Tim |title=Praxis manned spaceflight log, 1961–2006 |date=2007 |publisher=Springer |location=New York |isbn=978-0387341750 |page=25}}</ref> On 20 February 1962, [[Biography:John Glenn|John Glenn]] became the first American in orbit, aboard ''Friendship 7'' on a [[Engineering:Atlas LV-3B|Mercury-Atlas rocket]]. The USSR launched five more cosmonauts in Vostok [[Engineering:Space capsule|capsule]]s, including the first woman in space, [[Biography:Valentina Tereshkova|Valentina Tereshkova]], aboard [[Astronomy:Vostok 6|Vostok 6]] on 16 June 1963. Through 1963, the US launched a total of two astronauts in suborbital flights and four into orbit. The US also made two [[Engineering:North American X-15|North American X-15]] flights (90 and 91, piloted by [[Biography:Joseph A. Walker|Joseph A. Walker]]), that exceeded the [[Earth:Kármán line|Kármán line]], the {{convert|100|km}} altitude used by the [[Organization:Fédération Aéronautique Internationale|Fédération Aéronautique Internationale]] (FAI) to denote the edge of space.

In 1961, US President [[Biography:John F. Kennedy|John F. Kennedy]] raised the stakes of the Space Race by setting the goal of landing a man on the [[Astronomy:Moon|Moon]] and returning him safely to Earth by the end of the 1960s.<ref>{{cite AV media |people=Kennedy, John F. |date=25 May 1961 |title=Special Message to Congress on Urgent National Needs |medium=Motion picture (excerpt) |url=http://www.jfklibrary.org/Asset-Viewer/xzw1gaeeTES6khED14P1Iw.aspx |access-date=1 August 2013 |publisher=John F. Kennedy Presidential Library and Museum |location=Boston, MA |id=Accession Number: TNC:200; Digital Identifier: TNC-200-2}}</ref> That same year, the US began the [[Astronomy:Apollo program|Apollo program]] of launching three-man capsules atop the [[Engineering:Saturn (rocket family)|Saturn family of launch vehicles]]. In 1962, the US began [[Astronomy:Project Gemini|Project Gemini]], which flew 10 missions with two-man crews launched by Titan II rockets in 1965 and 1966. Gemini's objective was to support Apollo by developing American orbital spaceflight experience and techniques to be used during the Moon mission.<ref>{{cite web |last1=Loff  |first1=Sarah  |title=Gemini: Stepping Stone to the Moon |url=http://www.nasa.gov/mission_pages/gemini/#.VKi1GsaWt78 |website=Gemini: Bridge to the Moon |publisher=National Aeronautics and Space Administration |access-date=4 January 2015 |archive-url=https://web.archive.org/web/20141221151510/http://www.nasa.gov/mission_pages/gemini/ |archive-date=21 December 2014 |location=Washington, DC |date=21 October 2013 |url-status=dead |df=dmy-all}}</ref>

Meanwhile, the USSR remained silent about their intentions to send humans to the Moon and proceeded to stretch the limits of their single-pilot Vostok capsule by adapting it to a two or three-person [[Astronomy:Voskhod programme|Voskhod]] capsule to compete with Gemini. They were able to launch two orbital flights in 1964 and 1965 and achieved the first spacewalk, performed by Alexei Leonov on [[Astronomy:Voskhod 2|Voskhod 2]], on 8 March 1965. However, the Voskhod did not have Gemini's capability to maneuver in orbit, and the program was terminated. The US Gemini flights did not achieve the first spacewalk, but overcame the early Soviet lead by performing several spacewalks, solving the problem of astronaut fatigue caused by compensating for the lack of gravity, demonstrating the ability of humans to endure two weeks in space, and performing the first [[Astronomy:Space rendezvous|space rendezvous]] and [[Engineering:Docking and berthing of spacecraft|docking]] of spacecraft.

The US succeeded in developing the [[Engineering:Saturn V|Saturn V]] rocket necessary to send the Apollo spacecraft to the Moon, and sent Frank Borman, [[Biography:Jim Lovell|James Lovell]], and [[Biography:William Anders|William Anders]] into 10 orbits around the Moon in [[Engineering:Apollo 8|Apollo 8]] in December 1968. In 1969, [[Engineering:Apollo 11|Apollo 11]] accomplished Kennedy's goal by landing Neil Armstrong and [[Biography:Buzz Aldrin|Buzz Aldrin]] on the Moon on 21 July and returning them safely on 24 July, along with Command Module pilot Michael Collins. Through 1972, a total of six Apollo missions landed 12 men to walk on the Moon, half of which drove [[Astronomy:Lunar Roving Vehicle|electric powered vehicles]] on the surface. The crew of [[Engineering:Apollo 13|Apollo 13]]—[[Biography:Jim Lovell|Jim Lovell]], Jack Swigert, and [[Biography:Fred Haise|Fred Haise]]—survived an in-flight spacecraft failure, they flew by the Moon without landing, and returned safely to Earth.

[[File:Soyuz TMA-7 spacecraft2edit1.jpg|thumb|Soyuz, most serial spacecraft]]
[[File:Salyut 1 and Soyuz drawing.png|thumb|[[Engineering:Salyut 1|Salyut 1]], first crewed space station, with docked Soyuz spacecraft]]

During this time, the USSR secretly pursued [[Astronomy:Soviet crewed lunar programs|crewed lunar orbiting and landing programs]]. They successfully developed the three-person Soyuz spacecraft for use in the lunar programs, but failed to develop the [[Engineering:N1 (rocket)|N1 rocket]] necessary for a human landing, and discontinued their lunar programs in 1974.<ref>{{cite book|title = Challenge To Apollo The Soviet Union and The Space Race, 1945–1974|last = Siddiqi|first = Asif|page = 832|publisher = NASA|url = https://ntrs.nasa.gov/search.jsp?Ntk=all&Ntx=mode%20matchall&Ntt=SP-2000-4408}}</ref> Upon losing the Moon race they concentrated on the development of space stations, using the Soyuz as a ferry to take cosmonauts to and from the stations. They started with a series of Salyut sortie stations from 1971 to 1986.

==== Post-Apollo era ====
[[File:Apollo-Soyuz-Test-Program-artist-rendering.jpg|thumb|Artist's rendering of an Apollo CSM about to dock with a Soyuz spacecraft]]

In 1969, Nixon appointed his vice president, Spiro Agnew, to head a Space Task Group to recommend follow-on human spaceflight programs after Apollo. The group proposed an ambitious [[Astronomy:Space Transportation System|Space Transportation System]] based on a [[Engineering:Space Shuttle design process|reusable Space Shuttle]], which consisted of a winged, internally fueled orbiter stage burning liquid hydrogen, launched with a similar, but larger [[Chemistry:RP-1|kerosene]]-fueled booster stage, each equipped with airbreathing jet engines for powered return to a runway at the Kennedy Space Center launch site. Other components of the system included a permanent, modular space station; reusable [[Engineering:Space tug|space tug]]; and [[Astronomy:NERVA|nuclear]] interplanetary ferry, leading to a [[Astronomy:Human mission to Mars|human expedition to Mars]] as early as 1986 or as late as 2000, depending on the level of funding allocated. However, Nixon knew the American political climate would not support congressional funding for such an ambition, and killed proposals for all but the Shuttle, possibly to be followed by the space station. [[Engineering:Space Shuttle|Plans for the Shuttle were scaled back]] to reduce development risk, cost, and time, replacing the piloted fly-back booster with two reusable [[Engineering:Space Shuttle Solid Rocket Booster|solid rocket booster]]s, and the smaller orbiter would use an expendable [[Engineering:Space Shuttle external tank|external propellant tank]] to feed its hydrogen-fueled [[Engineering:Space Shuttle main engine|main engine]]s. The orbiter would have to make unpowered landings.

[[File:Space Shuttle Atlantis landing at KSC following STS-122 (crop).jpg|thumb|Space Shuttle orbiter, first crewed orbital spaceplane]]

In 1973, the US launched the [[Engineering:Skylab|Skylab]] sortie space station and inhabited it for 171 days with three crews ferried aboard an Apollo spacecraft. During that time, President Richard Nixon and Soviet general secretary Leonid Brezhnev were negotiating an easing of Cold War tensions known as détente. During the détente, they negotiated the [[Engineering:Apollo–Soyuz|Apollo–Soyuz]] program, in which an Apollo spacecraft carrying a special docking adapter module would rendezvous and dock with Soyuz 19 in 1975. The American and Soviet crews shook hands in space, but the purpose of the flight was purely symbolic.

The two nations continued to compete rather than cooperate in space, as the US turned to developing the Space Shuttle and planning the space station, which was dubbed ''[[Astronomy:Space Station Freedom|Freedom]]''. The USSR launched three [[Astronomy:Almaz|Almaz]] military sortie stations from 1973 to 1977, disguised as Salyuts. They followed Salyut with the development of ''[[Astronomy:Mir|Mir]]'', the first modular, semi-permanent space station, the construction of which took place from 1986 to 1996. ''Mir'' orbited at an altitude of {{convert|354|km|nmi|abbr=off|sp=us}}, at an [[Astronomy:Orbital inclination|orbital inclination]] of 51.6°. It was occupied for 4,592 days and made a controlled reentry in 2001.

The Space Shuttle started flying in 1981, but the US Congress failed to approve sufficient funds to make ''Space Station Freedom'' a reality. A fleet of four shuttles was built: ''[[Engineering:Space Shuttle Columbia|Columbia]]'', ''[[Engineering:Space Shuttle Challenger|Challenger]]'', ''[[Engineering:Space Shuttle Discovery|Discovery]]'', and ''[[Engineering:Space Shuttle Atlantis|Atlantis]]''. A fifth shuttle, ''[[Engineering:Space Shuttle Endeavour|Endeavour]]'', was built to replace ''Challenger'', which was destroyed in [[Engineering:Space Shuttle Challenger disaster|an accident during launch]] that killed 7 astronauts on 28 January 1986. From 1983 to 1998, twenty-two Shuttle flights carried components for a [[Organization:European Space Agency|European Space Agency]] sortie space station called [[Astronomy:Spacelab|Spacelab]] in the Shuttle payload bay.<ref name=StoryShuttle>{{cite book |title=The Story of the Space Shuttle |author=David Michael Harland |publisher=[[Company:Springer Science+Business Media|Springer]] Praxis |date=2004 |page=[https://archive.org/details/storyofspaceshut0000harl/page/444 444] |isbn=978-1-85233-793-3 |url=https://archive.org/details/storyofspaceshut0000harl/page/444 }}</ref>

[[File:Buran on An-225 (Le Bourget 1989) (cropped).JPEG|thumb|''Buran''-class orbiter, Soviet equivalent of the Space Shuttle orbiter]]

The USSR copied the US's reusable [[Engineering:Space Shuttle orbiter|Space Shuttle orbiter]], which they called ''[[Engineering:Buran programme|Buran]]''-class orbiter or simply ''Buran'', which was designed to be launched into orbit by the expendable Energia rocket, and was capable of robotic orbital flight and landing. Unlike the Space Shuttle, ''Buran'' had no main rocket engines, but like the Space Shuttle orbiter, it used smaller rocket engines to perform its final orbital insertion. A single uncrewed orbital test flight took place in November 1988. A second test flight was planned by 1993, but the program was canceled due to lack of funding and the dissolution of the Soviet Union in 1991. Two more orbiters were never completed, and the one that performed the uncrewed flight was destroyed in a hangar roof collapse in May 2002.

=== US / Russian cooperation ===
[[File:International Space Station after undocking of STS-132.jpg|thumb|right|International Space Station, assembled in orbit by US and Russia]]

The dissolution of the Soviet Union in 1991 brought an end to the Cold War and opened the door to true cooperation between the US and Russia. The Soviet Soyuz and Mir programs were taken over by the Russian Federal Space Agency, which became known as the Roscosmos State Corporation. The Shuttle-Mir Program included American Space Shuttles visiting the ''Mir'' space station, Russian cosmonauts flying on the Shuttle, and an American astronaut flying aboard a Soyuz spacecraft for long-duration expeditions aboard ''Mir''.

In 1993, President Bill Clinton secured Russia's cooperation in converting the planned Space Station ''Freedom'' into the [[Astronomy:International Space Station|International Space Station]] (ISS). Construction of the station began in 1998. The station orbits at an altitude of {{convert|409|km|nmi|sp=us}} and an orbital inclination of 51.65°. Several of the Space Shuttle's 135 orbital flights were to help assemble, supply, and crew the ISS. Russia has built half of the International Space Station and has continued its cooperation with the US.

=== China ===
{{Main|Astronomy:China Manned Space Program}}

[[File:Shenzhou spacecraft assembly.jpg|thumb|right|Chinese [[Engineering:Shenzhou (spacecraft)|Shenzhou]], first non-USSR and non-USA crewed spacecraft]]
China was the third nation in the world, after the USSR and US, to send humans into space. During the [[Astronomy:Space Race|Space Race]] between the two superpowers, which culminated with [[Engineering:Apollo 11|Apollo 11]] landing humans on the Moon, [[Biography:Mao Zedong|Mao Zedong]] and Zhou Enlai decided on 14 July 1967 that China should not be left behind, and initiated their own crewed space program: the top-secret Project 714, which aimed to put two people into space by 1973 with the Shuguang spacecraft. Nineteen PLAAF pilots were selected for this goal in March 1971. The Shuguang-1 spacecraft, to be launched with the CZ-2A rocket, was designed to carry a crew of two. The program was officially canceled on 13 May 1972 for economic reasons.

In 1992, under [[Astronomy:China Manned Space Program|China Manned Space Program]] (CMS), also known as "Project 921", authorization and funding was given for the first phase of a third, successful attempt at crewed spaceflight. To achieve independent human spaceflight capability, China developed the Shenzhou spacecraft and [[Engineering:Long March 2F|Long March 2F]] rocket dedicated to human spaceflight in the next few years, along with critical infrastructures like a new launch site and flight control center being built. The first uncrewed spacecraft, ''Shenzhou 1'', was launched on 20 November 1999 and recovered the next day, marking the first step of the realization of China's human spaceflight capability. Three more uncrewed missions were conducted in the next few years in order to verify the key technologies. On 15 October 2003 ''[[Astronomy:Shenzhou 5|Shenzhou 5]]'', China's first crewed spaceflight mission, put ''Yang Liwei'' in orbit for 21 hours and returned safely back to [[Place:Inner Mongolia|Inner Mongolia]], making China the third nation to launch a human into orbit independently.<ref>{{cite web |title=Shenzhou V |url=http://en.cmse.gov.cn/missions/shenzhouv/ |website=China Manned Space |access-date=25 July 2021}}</ref>

The goal of the second phase of CMS was to make technology breakthroughs in extravehicular activities (EVA, or spacewalk),[[Astronomy:Space rendezvous|space rendezvous]], and [[Engineering:Docking and berthing of spacecraft|docking]] to support short-term human activities in space.<ref name="aboutCMS">{{cite web |title=About CMS |url=http://en.cmse.gov.cn/aboutcms/ |website=China Manned Space |access-date=25 July 2021}}</ref> On 25 September 2008 during the flight of ''[[Astronomy:Shenzhou 7|Shenzhou 7]]'', ''Zhai Zhigang'' and ''Liu Boming'' completed China's first EVA.<ref>{{cite web |title=Shenzhou VII |url=http://en.cmse.gov.cn/missions/shenzhouvii/ |website=China Manned Space |access-date=25 July 2021}}</ref> In 2011, China launched the Tiangong 1 target spacecraft and ''Shenzhou 8'' uncrewed spacecraft. The two spacecraft completed China's first automatic rendezvous and docking on 3 November 2011.<ref>{{cite web |title=Shenzhou VIII |url=http://en.cmse.gov.cn/missions/shenzhouviii/ |website=China Manned Space |access-date=25 July 2021}}</ref> About 9 months later, ''Tiangong 1'' completed the first manual rendezvous and docking with ''[[Astronomy:Shenzhou 9|Shenzhou 9]]'', which carried China's first female astronaut ''Liu Yang''.<ref>{{cite web |title=Shenzhou IX |url=http://en.cmse.gov.cn/missions/shenzhouix/ |website=China Manned Space |access-date=25 July 2021}}</ref>

In September 2016, ''Tiangong 2'' was launched into orbit. It was a space laboratory with more advanced functions and equipment than ''Tiangong 1''. A month later, ''[[Astronomy:Shenzhou 11|Shenzhou 11]]'' was launched and docked with ''Tiangong 2''. Two astronauts entered ''Tiangong 2'' and were stationed for about 30 days, verifying the viability of astronauts' medium-term stay in space.<ref name="spacelab">{{cite web |title=Space Laboratory Missions |url=http://en.cmse.gov.cn/missions/space_laboratory_missions/ |website=China Manned Space |access-date=25 July 2021}}</ref> In April 2017, China's first cargo spacecraft, ''Tianzhou 1'' docked with ''Tiangong 2'' and completed multiple in-orbit propellant refueling tests, which marked the successful completion of the second phase of CMS.<ref name="spacelab"/>

The third phase of CMS began in 2020. The goal of this phase is to build China's own space station, ''Tiangong''.<ref>{{cite web |title=China launches new Long March-5B rocket for space station program |url=http://en.cmse.gov.cn/news/202005/t20200506_46488.html |website=China Manned Space |access-date=26 July 2021 |archive-url=https://web.archive.org/web/20210617054112/http://en.cmse.gov.cn/news/202005/t20200506_46488.html |archive-date=17 June 2021 |date=5 May 2020}}</ref> The first module of ''Tiangong'', the Tianhe core module, was launched into orbit by China's most powerful rocket Long March 5B on 29 April 2021.<ref name="third step">{{cite web |title=Core Module Tianhe Launch a Complete Success &ndash; Construction of China Space Station in Full Swing |url=http://en.cmse.gov.cn/news/202105/t20210528_48002.html |website=China Manned Space |access-date=26 July 2021 |date=30 April 2021}}</ref> It was later visited by multiple cargo and crewed spacecraft and demonstrated China's capability of sustaining Chinese astronauts' long-term stay in space.

According to CMS announcement, all missions of Tiangong Space Station are scheduled to be carried out by the end of 2022.<ref name="CSSplan">{{cite web |title=空间站天和核心舱飞行任务新闻发布会召开 |url=http://www.cmse.gov.cn/ztbd/xwfbh/202106/t20210622_48281.html |website=China Manned Space |access-date=2021-07-13 |archive-url=https://web.archive.org/web/20210713065620/http://www.cmse.gov.cn/ztbd/xwfbh/202106/t20210622_48281.html |archive-date=2021-07-13 |date=2021-04-29 |url-status=live |language=zh}}</ref> Once the construction is completed, ''Tiangong'' will enter the application and development phase, which is poised to last for no less than 10 years.<ref name="CSSplan"/>

=== Abandoned programs of other nations ===
The [[Organization:European Space Agency|European Space Agency]] began development of the [[Engineering:Hermes (spacecraft)|Hermes]] shuttle [[Astronomy:Spaceplane|spaceplane]] in 1987, to be launched on the [[Engineering:Ariane 5|Ariane 5]] expendable launch vehicle. It was intended to dock with the European [[Engineering:Columbus Man-Tended Free Flyer|Columbus space station]]. The projects were canceled in 1992 when it became clear that neither cost nor performance goals could be achieved. No Hermes shuttles were ever built. The Columbus space station was reconfigured as the [[Organization:Columbus (ISS module)|European module of the same name]] on the International Space Station.<ref>{{cite web |title=Columbus laboratory |url=https://www.esa.int/Science_Exploration/Human_and_Robotic_Exploration/Columbus/Columbus_laboratory |website=www.esa.int |publisher=The European Space Agency |access-date=26 October 2022 |language=en}}</ref>

Japan (NASDA) began the development of the [[Engineering:HOPE-X|HOPE-X]] experimental shuttle spaceplane in the 1980s, to be launched on its [[Engineering:H-IIA|H-IIA]] expendable launch vehicle. A string of failures in 1998 led to funding reductions, and the project's cancellation in 2003 in favor of participation in the International Space Station program through the ''Kibō'' Japanese Experiment Module and [[Engineering:H-II Transfer Vehicle|H-II Transfer Vehicle]] cargo spacecraft. As an alternative to HOPE-X, NASDA in 2001 proposed the [[Engineering:Fuji (spacecraft)|Fuji crew capsule]] for independent or ISS flights, but the project did not proceed to the contracting stage.{{Citation needed|date=November 2020}}

From 1993 to 1997, the {{Interlanguage link multi|Japanese Rocket Society|ja|3=日本ロケット協会|vertical-align=sup}}, [[Company:Kawasaki Heavy Industries|Kawasaki Heavy Industries]], and [[Company:Mitsubishi Heavy Industries|Mitsubishi Heavy Industries]] worked on the proposed [[Astronomy:Kankoh-maru|Kankoh-maru]] vertical-takeoff-and-landing [[Astronomy:Single-stage-to-orbit|single-stage-to-orbit]] reusable launch system. In 2005, this system was proposed for space tourism.<ref>{{Cite web |last=Magazin |first=Sia |date=2022-12-02 |title=Kankoh-maru Japan’s Space Tourism Single Stage Reusable Rocket |url=https://siamagazin.com/kankoh-maru-japans-space-tourism-single-stage-reusable-rocket/ |access-date=2023-10-17 |website=Sia Magazin |language=en-US}}</ref>

According to a press release from the Iraqi News Agency dated 5 December 1989, there was only one test of the [[Engineering:Al-Abid|Al-Abid]] space launcher, which Iraq intended to use to develop its own crewed space facilities by the end of the century. These plans were put to an end by the Gulf War of 1991 and the economic hardships that followed.{{Citation needed|date=November 2020}}

=== United States "Shuttle gap" ===
[[File:STS-135 begins takeoff (cropped).jpg|thumb|STS-135 (July 2011), the final human spaceflight of the United States until 2018]]
[[File:Virgin Galactic SpaceShipTwo "Unity" rollout 19Feb2016, FAITH hangar, Mojave, California.jpg|alt=|thumb|[[Astronomy:VSS Unity|VSS ''Unity'']] Flight VP-03 December 2018, the first human spaceflight from the United States since STS-135 ]]

Under the George W. Bush administration, the [[Astronomy:Constellation program|Constellation program]] included plans for retiring the Space Shuttle program and replacing it with the capability for spaceflight beyond low Earth orbit. In the 2011 United States federal budget, the Obama administration canceled Constellation for being over budget and behind schedule, while not innovating and investing in critical new technologies.<ref>[http://blogs.orlandosentinel.com/news_space_thewritestuff/2008/11/congressional-w.html Congressional watchdog finds NASA's new rocket is in trouble] {{webarchive|url=https://web.archive.org/web/20111129102151/http://blogs.orlandosentinel.com/news_space_thewritestuff/2008/11/congressional-w.html |date=29 November 2011 }}. Orlando Sentinel blog summary of official reports. 3 November 2008</ref> As part of the [[Astronomy:Artemis program|Artemis program]], NASA is developing the [[Engineering:Orion (spacecraft)|Orion]] spacecraft to be launched by the [[Astronomy:Space Launch System|Space Launch System]]. Under the [[Astronomy:Commercial Crew Development|Commercial Crew Development]] plan, NASA relies on transportation services provided by the private sector to reach low Earth orbit, such as [[Engineering:SpaceX Dragon 2|SpaceX Dragon 2]], the [[Engineering:Boeing Starliner|Boeing Starliner]] or Sierra Nevada Corporation's [[Engineering:Dream Chaser|Dream Chaser]]. The period between the retirement of the Space Shuttle in 2011 and the first launch into space of [[Engineering:SpaceShipTwo|SpaceShipTwo]] [[Engineering:VSS Unity VP-03|Flight VP-03]] on 13 December 2018 is similar to the gap between the end of [[Astronomy:Apollo program|Apollo]] in 1975 and the [[Engineering:STS-1|first Space Shuttle flight]] in 1981, and is referred to by a presidential Blue Ribbon Committee as the U.S. human spaceflight gap.

=== Commercial private spaceflight ===
[[File:SpaceShipOne Flight 15P photo D Ramey Logan.jpg|thumb|SpaceShipOne, first private sub-orbital spaceplane]]
[[File:Crew Dragon at the ISS for Demo Mission 1 (cropped).jpg|thumb|right|Crew Dragon, first private orbital spacecraft]]

Since the early 2000s, a variety of [[Engineering:Private spaceflight|private spaceflight]] ventures have been undertaken. As of May 2021, [[Company:SpaceX|SpaceX]] has launched humans to orbit, while [[Company:Virgin Galactic|Virgin Galactic]] has launched crew to a height above {{cvt|80|km}} on a suborbital trajectory.<ref name="spaceshiptwoflight">{{cite web |last=Malik |first= Tariq |title=Virgin Galactic's 4th Powered Test Flight of SpaceShipTwo Unity in Twitter Posts |url=https://www.space.com/42725-virgin-galactic-spaceshiptwo-unity-4th-powered-flight-twitter-updates.html |date=13 December 2018 |archive-url=https://web.archive.org/web/20210427085514/https://www.space.com/42725-virgin-galactic-spaceshiptwo-unity-4th-powered-flight-twitter-updates.html |archive-date=27 April 2021 |website=Space.com |access-date=13 May 2021}}</ref> Several other companies—including [[Company:Blue Origin|Blue Origin]] and Sierra Nevada—develop crewed spacecraft. All four companies plan to fly commercial passengers in the emerging [[Astronomy:Space tourism|space tourism]] market.

[[Company:SpaceX|SpaceX]] has developed Crew Dragon flying on [[Engineering:Falcon 9|Falcon 9]]. It first launched astronauts to orbit and to the ISS in May 2020 as part of the [[Engineering:Crew Dragon Demo-2|Demo-2]] mission. Developed as part of NASA's [[Astronomy:Commercial Crew Development|Commercial Crew Development]] program, the capsule is also available for flights with other customers. A first tourist mission, [[Engineering:Inspiration4|Inspiration4]], launched in September 2021.<ref name=Inspiration4>{{cite web |last1=Atkinson |first1=Ian |title=SpaceX launches Inspiration4, first all-private orbital mission |url=https://www.nasaspaceflight.com/2021/09/spacex-launch-inspiration4/ |website=NASASpaceflight.com |date=15 September 2021 |access-date=16 September 2021}}</ref>

Boeing is developing the [[Engineering:Boeing Starliner|Starliner]] capsule as part of NASA's Commercial Crew Development program, which is launched on a [[Company:United Launch Alliance|United Launch Alliance]] [[Engineering:Atlas V|Atlas V]] launch vehicle.<ref name=nasaAnnounce20140906>{{cite web |title=American Companies Selected to Return Astronaut Launches to American Soil |last=Bolden |first=Charlie |url=http://blogs.nasa.gov/bolden/2014/09/16/american-companies-selected-to-return-astronaut-launches-to-american-soil/ |website=NASA.gov |date=16 September 2014 |access-date=16 September 2014}}</ref> Starliner made an uncrewed flight in December 2019. A second uncrewed flight attempt was scrubbed in August 2021, with a NASA official saying it would likely not launch until 2022.<ref>{{cite web |last1=Clark |first1=Stephen |title=NASA official says Starliner demo mission not likely to launch until next year |url=https://spaceflightnow.com/2021/09/22/nasa-official-says-starliner-demo-mission-not-likely-to-launch-until-next-year/ |website=Spaceflight Now |access-date=23 September 2021}}</ref> A crewed flight is not expected before the second half of 2022.<ref>{{cite web |last1=Berger |first1=Eric |title=Boeing to ground Starliner indefinitely until valve issue solved |url=https://arstechnica.com/science/2021/08/boeing-to-ground-starliner-indefinitely-until-valve-issue-solved/ |website=Ars Technica |date=13 August 2021 |access-date=16 September 2021}}</ref> Similar to SpaceX, development funding has been provided by a mix of government and private funds.<ref name=sn20140921>{{cite news |last1=Foust|first1=Jeff |title=NASA Commercial Crew Awards Leave Unanswered Questions |url=http://www.spacenews.com/article/civil-space/41924nasa-commercial-crew-awards-leave-unanswered-questions |archive-url=https://archive.today/20140921132432/http://www.spacenews.com/article/civil-space/41924nasa-commercial-crew-awards-leave-unanswered-questions |url-status=dead |archive-date=21 September 2014 |access-date=21 September 2014 |work=Space News |date=19 September 2014 |quote="We basically awarded based on the proposals that we were given", Kathy Lueders, NASA commercial crew program manager, said in a teleconference with reporters after the announcement. "Both contracts have the same requirements. The companies proposed the value within which they were able to do the work, and the government accepted that".}}</ref><ref name=NASApress20140916>{{cite web |title=Release 14-256 NASA Chooses American Companies to Transport U.S. Astronauts to International Space Station |url=http://www.nasa.gov/press/2014/september/nasa-chooses-american-companies-to-transport-us-astronauts-to-international |website=www.nasa.gov |publisher=NASA |access-date=29 October 2014}}</ref>

[[Company:Virgin Galactic|Virgin Galactic]] is developing SpaceshipTwo, a commercial suborbital spacecraft aimed at the [[Astronomy:Space tourism|space tourism]] market. It reached space in December 2018.<ref name="spaceshiptwoflight"/>

[[Company:Blue Origin|Blue Origin]] is in a multi-year [[Engineering:Flight test|test]] program of their [[Astronomy:New Shepard|New Shepard]] vehicle and has carried out 16 uncrewed test flights as of September 2021, and one crewed flight carrying founder [[Biography:Jeff Bezos|Jeff Bezos]], his brother Mark Bezos, aviator [[Biography:Wally Funk|Wally Funk]], and 18-year old Oliver Daemen on July 20, 2021.

== Passenger travel via spacecraft ==
Over the decades, a number of spacecraft have been proposed for spaceliner passenger travel. Somewhat analogous to travel by airliner after the middle of the 20th century, these vehicles are proposed to [[Engineering:Space transport|transport]] large numbers of passengers to destinations in space, or on Earth via suborbital spaceflights. To date, none of these concepts have been built, although a few vehicles that carry fewer than 10 persons are currently in the test flight phase of their development process.

One large spaceliner concept currently in early development is the [[Engineering:SpaceX Starship|SpaceX Starship]], which, in addition to replacing the [[Engineering:Falcon 9|Falcon 9]] and [[Engineering:Falcon Heavy|Falcon Heavy]] [[Engineering:Launch vehicle|launch vehicle]]s in the legacy Earth-orbit [[Finance:Space launch market competition|market]] after 2020, has been proposed by SpaceX for long-distance commercial travel on Earth, flying 100+ people suborbitally between two points in under one hour, also known as "Earth-to-Earth".<ref name=rollingstone20171115>{{cite magazine|last1=Strauss|first1=Neil|title=Elon Musk: The Architect of Tomorrow|url=https://www.rollingstone.com/culture/features/elon-musk-inventors-plans-for-outer-space-cars-finding-love-w511747|access-date=15 November 2017|magazine=Rolling Stone|date=15 November 2017}}</ref><ref name=sxEarthToEarth201709>[https://www.youtube.com/watch?time_continue=40&v=zqE-ultsWt0 Starship Earth to Earth], SpaceX, 28 September 2017, accessed 23 December 2017.</ref><ref name=sn20171015c>{{cite news |last=Foust|first=Jeff |url=http://spacenews.com/musk-offers-more-technical-details-on-bfr-system/ |title=Musk offers more technical details on BFR system |work=SpaceNews |date=15 October 2017 |access-date=15 October 2017 |quote=[the] spaceship portion of the BFR, which would transport people on point-to-point suborbital flights or on missions to the moon or Mars, will be tested on Earth first in a series of short hops. ... a full-scale Ship doing short hops of a few hundred kilometers altitude and lateral distance ... fairly easy on the vehicle, as no heat shield is needed, we can have a large amount of reserve propellant and don't need the high area ratio, deep space Raptor engines.}}</ref>

Small [[Astronomy:Spaceplane|spaceplane]] or small [[Engineering:Space capsule|capsule]] suborbital spacecraft have been under development for the past decade or so; {{asof|2017|lc=y}}, at least one of each type is under development. Both [[Company:Virgin Galactic|Virgin Galactic]] and [[Company:Blue Origin|Blue Origin]] have craft in active [[Engineering:New product development|development]]: the [[Engineering:SpaceShipTwo|SpaceShipTwo]] spaceplane and the [[Astronomy:New Shepard|New Shepard]] capsule, respectively. Both would carry approximately a half-dozen passengers up to space for a brief time of zero gravity before returning to the launch location. [[Company:XCOR Aerospace|XCOR Aerospace]] had been developing the Lynx single-passenger spaceplane since the 2000s,<ref>(2012) [http://www.spacexc.com/en/bookings/ SXC - Buying your tickets into space!] {{webarchive |url=https://web.archive.org/web/20130306043002/http://www.spacexc.com/en/bookings/ |date=6 March 2013 }} SXC web page, Retrieved 5 April 2013</ref><ref>{{cite web | last = Staff writers | title = Space Expedition Corporation Announces Wet Lease of XCOR Lynx Suborbital | work = Space Media Network Promotions | publisher = Space-Travel.com  | date = 6 October 2010 | url = http://www.space-travel.com/reports/Space_Experience_Curacao_Announces_Wet_Lease_of_XCOR_Lynx_Suborbital_999.html | access-date = 6 October 2010 }}</ref> but development was halted in 2017.<ref name=sn20171109>{{cite news |last=Foust |first=Jeff |title=XCOR Aerospace Files for Bankruptcy |url=http://spacenews.com/xcor-aerospace-files-for-bankruptcy/ |date=9 November 2017 |work=SpaceNews |access-date=13 May 2021}}</ref>

== Human representation and participation ==

Participation and representation of humanity in space has been an issue ever since the first phase of space exploration.<ref name="Durrani"/> Some rights of non-spacefaring countries have been secured through international [[Astronomy:Space law|space law]], declaring space the "[[Social:Common heritage of mankind|province of all mankind]]", though the sharing of space by all humanity is sometimes criticized as [[Social:Imperialism|imperialist]] and lacking.<ref name="Durrani">{{cite magazine |url=https://www.thenation.com/article/archive/apollo-space-lunar-rockets-colonialism/ |title=Is Spaceflight Colonialism? |author=Haris Durrani |access-date=2 October 2020 |magazine=The Nation|date=19 July 2019}}</ref> In addition to the lack of international inclusion, the inclusion of women and people of color has also been lacking. To make spaceflight more inclusive, organizations such as the ''Justspace Alliance''<ref name="Durrani"/> and IAU-featured ''Inclusive Astronomy''<ref>{{Cite web |url=https://www.inclusiveastronomy.org/ |title=Website of the IAU100 ''Inclusive Astronomy'' project |access-date=18 November 2020 |archive-date=22 December 2021 |archive-url=https://web.archive.org/web/20211222220447/https://www.inclusiveastronomy.org/ |url-status=dead }}</ref> have been formed in recent years.

===Women===
{{Main|Astronomy:Women in space}}

The first woman to ever enter space was [[Biography:Valentina Tereshkova|Valentina Tereshkova]]. She flew in 1963, but it was not until the 1980s that another woman entered space. At the time, all astronauts were required to be military test pilots; women were not able to enter this career, which is one reason for the delay in allowing women to join space crews.<ref>{{Cite web|last=Sinelschikova|first=Yekaterina|date=2020-12-03|title=Why NASA astronauts would not pass the Soviet and Russian selection process|url=https://www.rbth.com/science-and-tech/333087-nasa-soviet-space-selection|access-date=2021-05-23|website=www.rbth.com|language=en-US}}</ref> After the rules were changed, [[Biography:Svetlana Savitskaya|Svetlana Savitskaya]] became the second woman to enter space; she was also from the [[Place:Soviet Union|Soviet Union]]. [[Biography:Sally Ride|Sally Ride]] became the next woman to enter space and the first woman to enter space through the United States program.

Since then, eleven other countries have allowed women astronauts. The first all-female spacewalk occurred in 2018, by [[Biography:Christina Koch|Christina Koch]] and Jessica Meir. These two women had both participated in separate spacewalks with NASA. The first mission to the Moon with a woman aboard is planned for 2024.

Despite these developments, women are still underrepresented among astronauts and especially cosmonauts. More than 600 people have flown in space but only 75 have been women.<ref>{{cite web |title=Celebrating Women's History Month |url=https://www.nasa.gov/mission_pages/station/research/news/whm-recent-female-astronauts |website=NASA|date=21 March 2019 }}</ref> Issues that block potential applicants from the programs, and limit the space missions they are able to go on, are, for example:
* agencies limit women to half as much time in space as men, due to suppositions that women are at greater potential risk for cancer.<ref>{{cite web | url = http://www.space.com/22252-women-astronauts-radiation-risk.html | title = Female Astronauts Face Discrimination from Space Radiation Concerns, Astronauts Say | first = Miriam | last = Kramer | date = 27 August 2013 | access-date = 7 January 2017 | work = Space.com | publisher = Purch}}</ref>
* a lack of space suits sized appropriately for female astronauts.<ref name="clothing">{{cite magazine |last=Sokolowski |first=Susan L.|title= Female astronauts: How performance products like space suits and bras are designed to pave the way for women's accomplishments|url=https://theconversation.com/female-astronauts-how-performance-products-like-space-suits-and-bras-are-designed-to-pave-the-way-for-womens-accomplishments-114346 |date=5 April 2019 | magazine =The Conversation |access-date=10 May 2020 }}</ref>

== Milestones ==

=== By achievement ===
; 12 April 1961
: [[Biography:Yuri Gagarin|Yuri Gagarin]] was the first human in space and the first in Earth orbit, on [[Astronomy:Vostok 1|Vostok 1]].
; 17 July 1962 or 19 July 1963
: Either Robert M. White or [[Biography:Joseph A. Walker|Joseph A. Walker]] (depending on the definition of the space border) was the first to pilot a [[Astronomy:Spaceplane|spaceplane]], the [[Engineering:North American X-15|North American X-15]], on 17 July 1962 (White) or 19 July 1963 (Walker).
; 18 March 1965
: Alexei Leonov was first to [[Astronomy:Extravehicular activity|walk in space]].
; 15 December 1965
: Walter M. Schirra and Tom Stafford were first to perform a [[Astronomy:Space rendezvous|space rendezvous]], piloting their [[Astronomy:Gemini 6A|Gemini 6A]] spacecraft to achieve [[Astronomy:Orbital station-keeping|station-keeping]] {{convert|1|ft|cm|spell=in}} from [[Astronomy:Gemini 7|Gemini 7]] for over 5 hours.
; 16 March 1966
: Neil Armstrong and [[Biography:David Scott|David Scott]] were first to [[Engineering:Docking and berthing of spacecraft|rendezvous and dock]], piloting their [[Astronomy:Gemini 8|Gemini 8]] spacecraft to dock with an uncrewed Agena Target Vehicle.
; 21–27 December 1968
: Frank Borman, [[Biography:Jim Lovell|Jim Lovell]], and [[Biography:William Anders|William Anders]] were the first to travel beyond low Earth orbit (LEO) and the first to orbit the Moon, on the [[Engineering:Apollo 8|Apollo 8]] mission, which orbited the Moon ten times before returning to Earth.
; 26 May 1969
: Apollo 10 reaches the fastest speed ever traveled by a human: 39,897 km/h (11.08 km/s or 24,791 mph), or roughly 1/27,000 of lightspeed.
; 20 July 1969
: Neil Armstrong and [[Biography:Buzz Aldrin|Buzz Aldrin]] were first to land on the Moon, during [[Engineering:Apollo 11|Apollo 11]].
; 14 April 1970
: The crew of [[Engineering:Apollo 13|Apollo 13]] attained pericynthion above the Moon, setting the current record for the highest absolute altitude attained by a crewed spacecraft: {{convert|400,171|km|mi|abbr=off|sp=us}} from Earth.
; Longest time in space
: [[Biography:Valeri Polyakov|Valeri Polyakov]] performed the longest single spaceflight, from 8 January 1994 to 22 March 1995 (437 days, 17 hours, 58 minutes, and 16 seconds). Gennady Padalka has spent the most total time in space on multiple missions, 879 days.
; Longest-duration crewed space station
:The [[Astronomy:International Space Station|International Space Station]] has the longest period of continuous human presence in space, 2 November 2000 to present ({{age in years and days|2 November 2000|sep=and}}). This record was previously held by [[Astronomy:Mir|Mir]], from [[Engineering:Soyuz TM-8|Soyuz TM-8]] on 5 September 1989 to the [[Engineering:Soyuz TM-29|Soyuz TM-29]] on 28 August 1999, a span of 3,644 days (almost 10 years).

=== By nationality or sex ===
; 12 April 1961
: [[Biography:Yuri Gagarin|Yuri Gagarin]] became the first Soviet and the first human to reach space, on [[Astronomy:Vostok 1|Vostok 1]].
; 5 May 1961
: Alan Shepard became the first American to reach space, on ''[[Engineering:Mercury-Redstone 3|Freedom 7]]''.
; 20 February 1962
: [[Biography:John Glenn|John Glenn]] became the first American to orbit the Earth.
; 16 June 1963
: [[Biography:Valentina Tereshkova|Valentina Tereshkova]] became the first woman to go into space and to orbit the Earth.
; 2 March 1978
: Vladimír Remek, a [[Place:Czechoslovakia|Czechoslovakia]]n, became the first non-American and non-Soviet in space, as part of the [[Astronomy:Interkosmos|Interkosmos]] program.
; 2 April 1984
: [[Biography:Rakesh Sharma|Rakesh Sharma]], became the first Indian citizen to reach Earth's orbit.
; 25 July 1984
: [[Biography:Svetlana Savitskaya|Svetlana Savitskaya]] became the first woman to [[Astronomy:Extravehicular activity|walk in space]].
; 15 October 2003
: Yang Liwei became the first Chinese in space and to orbit the Earth, on [[Astronomy:Shenzhou 5|Shenzhou 5]].
; 18 October 2019
: [[Biography:Christina Koch|Christina Koch]] and Jessica Meir conducted the first woman-only [[Astronomy:Extravehicular activity|walk in space]].<ref>{{cite web | url=https://blogs.nasa.gov/spacestation/2019/10/18/nasa-astronauts-wrap-up-historic-all-woman-spacewalk/ | title=NASA Astronauts Wrap Up Historic All-Woman Spacewalk | date=18 October 2019 | first=Mark | last=Garcia | publisher=NASA | access-date=23 January 2020}}</ref>

[[Biography:Sally Ride|Sally Ride]] became the first American woman in space, in 1983. Eileen Collins was the first female Shuttle pilot, and with Shuttle mission [[Engineering:STS-93|STS-93]] in 1999 she became the first woman to command a U.S. spacecraft.

For many years, the USSR (later Russia) and the United States were the only countries whose astronauts flew in space. That ended with the 1978 flight of Vladimir Remek. {{As of|2010}}, citizens from 38 nations (including [[Astronomy:Space tourism|space tourists]]) have flown in space aboard Soviet, American, Russian, and Chinese spacecraft.

== Space programs ==
{{Main list|Astronomy:List of human spaceflight programs}}

Human spaceflight programs have been conducted by the Soviet Union–Russian Federation, the United States, Mainland China, and by American [[Engineering:Private spaceflight|private spaceflight]] companies.


===Current programs===
The following space vehicles and spaceports are currently used for launching human spaceflights:
* [[Engineering:Soyuz programme|Soyuz program]]/[[Engineering:Soyuz (spacecraft)|spacecraft]] (Russia): Launched on [[Engineering:Soyuz (rocket family)|Soyuz launch vehicle]] from Baikonur Cosmodrome. The first crewed flight was in 1967. {{as of|2022|August}}, there have been 149 crewed flights, all of them orbital except one suborbital flight abort and one atmospheric flight abort. The first 66 flights were launched by the [[Place:Soviet Union|Soviet Union]].
* [[Astronomy:China Manned Space Program|China Manned Space Program]]/Shenzhou spacecraft (China): Launched on [[Engineering:Long March (rocket family)|Long March launch vehicle]] from Jiuquan Satellite Launch Center. The first crewed flight was in 2003. {{as of|2023|October}}, there have been 12 crewed orbital flights.
* [[Engineering:SpaceShipTwo|SpaceShipTwo]] (US): Air launched by [[Astronomy:Scaled Composites White Knight Two|White Knight Two]] carrier aircraft taking off from [[Engineering:Spaceport America|Spaceport America]] (the first two were from Mojave Air and Space Port). The first crewed flight was in 2018. {{as of|2022|August}}, there have been four crewed suborbital flights.
* Crew Dragon (US): Launched on [[Engineering:Falcon 9 Block 5|Falcon 9]] launch vehicle from Kennedy Space Center. The first crewed flight was in 2020. {{as of|2022|August}}, there have been seven crewed orbital flights.<ref>{{Cite web|title=NASA Astronauts Launch from America in Test of SpaceX Crew Dragon|url=http://www.nasa.gov/press-release/nasa-astronauts-launch-from-america-in-historic-test-flight-of-spacex-crew-dragon|last=Potter|first=Sean|date=2020-05-30|website=NASA|access-date=2020-05-31}}</ref><ref name=Inspiration4/>
*[[Astronomy:New Shepard|New Shepard]] (US): Launched on New Shepard launch vehicle from Corn Ranch spaceport. The first crewed flight was in 2021. {{as of|2022|August}}, there have been six crewed suborbital flights.

The following space stations are currently maintained in Earth orbit for human occupation:
* [[Astronomy:International Space Station|International Space Station]] (US, Russia, Europe, Japan, Canada) assembled in orbit: altitude {{convert|409|km|nmi|sp=us|abbr=off}}, 51.65° orbital inclination; crews transported by Soyuz or Crew Dragon spacecraft
* Tiangong Space Station (China) assembled in orbit: 41.5° orbital inclination;<ref>{{cite web |last1=McDowell |first1=Jonathan |title=Jonathan's Space Report No. 792 |url=https://planet4589.org/space/jsr/back/news.792.txt |access-date=12 July 2021}}</ref> crews transported by Shenzhou spacecraft

Most of the time, the only humans in space are those aboard the ISS, which generally has a crew of 7, and those aboard Tiangong, which generally has a crew of 3.

[[Organization:NASA|NASA]] and ESA use the term "human spaceflight" to refer to their programs of launching people into space. These endeavors have also formerly been referred to as "manned space missions", though this is no longer official parlance according to NASA style guides, which call for [[Social:Gender-neutral language|gender-neutral language]].<ref>{{cite web |url=https://history.nasa.gov/styleguide.html |title=Style Guide |publisher=[[Organization:NASA|NASA]] |access-date=6 January 2016}}</ref>

===Planned future programs===
Under the [[Astronomy:Indian Human Spaceflight Programme|Indian Human Spaceflight Program]], India was planning to send humans into space on its orbital vehicle [[Engineering:Gaganyaan|Gaganyaan]] before August 2022, but it has been delayed to 2024, due to the COVID-19 pandemic. The [[Astronomy:Indian Space Research Organisation|Indian Space Research Organisation]] (ISRO) began work on this project in 2006.<ref>{{Cite news|title=Scientists Discuss Indian Manned Space Mission|url=https://www.isro.gov.in/update/07-nov-2006/scientists-discuss-indian-manned-space-mission|publisher=Indian Space Research Organisation|date=2006-11-07}}</ref><ref name="Kadursrinivas 2017">{{cite web |last1=Rao |first1=Mukund Kadursrinivas |last2=Murthi |first2=Sridhara, K. R. |last3=Prasad M. Y. S. |title=The Decision for Indian Human Spaceflight Programme – Political Perspectives, National Relevance and Technological Challenges |url=http://eprints.nias.res.in/1359/1/2017-MK-Rao-IAC-17-B3-1-9-IndianHumanSpaceFlightFullPaper.pdf |publisher= International Astronautical Federation}}</ref> The initial objective is to carry a crew of two or three to [[Astronomy:Low Earth orbit|low Earth orbit]] (LEO) for a 3-to-7-day flight in a spacecraft on a [[Engineering:LVM 3|LVM 3]] rocket and return them safely for a water landing at a predefined landing zone. On 15 August 2018, Indian Prime Minister Narendra Modi, declared India will independently send humans into space before the 75th anniversary of independence in 2022.<ref>{{Cite web|url=https://www.firstpost.com/india/independence-day-2018-live-updates-we-will-put-an-indian-on-space-before-2022-says-narendra-modi-at-red-fort-4967431.html|title=Independence Day 2018 Live Updates: 'We will put an Indian on space before 2022,' says Narendra Modi at Red Fort|website=Firstpost.com|date=15 August 2018|access-date=2020-06-21}}</ref> In 2019, ISRO revealed plans for a space station by 2030, followed by a crewed lunar mission. The program envisages the development of a fully-autonomous orbital vehicle capable of carrying 2 or 3 crew members to an about {{cvt|300|km}} low Earth orbit and bringing them safely back home.<ref>{{Cite web|date=11 June 2020|title=ISRO Stalls Launch of Uncrewed Gaganyaan Mission and Chandrayaan-3 Due to COVID-19|url=https://weather.com/en-IN/india/news/news/2020-06-11-isro-stalls-launch-uncrewed-gaganyaan-mission-chandrayaan-3-due-covid-19|access-date=2020-06-13|website=The Weather Channel|language=en-US}}</ref>

Since 2008, the Japan Aerospace Exploration Agency has developed the [[Engineering:H-II Transfer Vehicle|H-II Transfer Vehicle]] cargo-spacecraft-based crewed spacecraft and ''Kibō'' Japanese Experiment Module–based small space laboratory.

[[Organization:NASA|NASA]] is developing a plan to land humans on Mars by the 2030s. The first step has begun with [[Engineering:Artemis 1|Artemis 1]] in 2022, sending an uncrewed [[Engineering:Orion (spacecraft)|Orion]] spacecraft to a [[Astronomy:Distant retrograde orbit|distant retrograde orbit]] around the Moon and returning it to Earth after a 25-day mission.

SpaceX is developing [[Engineering:SpaceX Starship|Starship]], a fully reusable two-stage system, with near-Earth and cislunar applications and an ultimate goal of landing on Mars. The upper stage of the Starship system, also called Starship, has had 9 atmospheric test flights as of September 2021. The first test flight of the fully integrated two-stage system occurred in April 2023. A [[Engineering:Starship HLS|modified version]] of Starship is being developed for the [[Astronomy:Artemis program|Artemis program]].

Several other countries and space agencies have announced and begun human spaceflight programs using natively developed equipment and technology, including Japan ([[Organization:JAXA|JAXA]]), [[Religion:Iran|Iran]] ([[Organization:Iranian Space Agency|ISA]]), and North Korea ([[Organization:National Aerospace Development Administration|NADA]]). The plans for the [[Astronomy:Iranian crewed spacecraft|Iranian crewed spacecraft]] are for a small spacecraft and space laboratory. North Korea's [[Organization:National Aerospace Development Administration|space program]] has plans for crewed spacecraft and small shuttle systems.

=== National spacefaring attempts ===
: ''This section lists all nations which have attempted human spaceflight programs. This is not to be confused with nations with citizens who have traveled into space, including space tourists, flown or intending to fly by a foreign country's or non-domestic private company's space systems – who are not counted in this list toward their country's national spacefaring attempts.''

<!--
: Successfully executed programs are in '''bold'''.
: [[Engineering:Sub-orbital spaceflight|Suborbital]] spaceflights are in ''italics''.
-->

{| class="wikitable"| border=2 cellpadding="4" cellspacing="0" style="margin: 1em 1em 1em 0; border: 1px #aaa solid; border-collapse: collapse; font-size: 90%"
|- style="background:#f9f9b0;"
! Nation/Organization
! Space agency
! Term(s) for space traveler
! First launched astronaut
! Date
! Spacecraft
! Launcher
! Type
|-
| {{Flag|Union of Soviet Socialist Republics}}<br />(1922–1991)
| [[Astronomy:Soviet space program|Soviet space program]]<br />(OKB-1 Design Bureau)
| космонавт&nbsp;(same word in:) {{in lang|ru|uk}}<br />''kosmonavt''<br />cosmonaut<br />Ғарышкер{{in lang|kk}}
| [[Biography:Yuri Gagarin|Yuri Gagarin]]
| 12 April 1961
| Vostok spacecraft
| Vostok
| Orbital
|-
| {{US}}
| [[Organization:NASA|National Aeronautics and Space Administration (NASA)]]
| astronaut<br />spaceflight participant
| Alan Shepard (suborbital)
| 5 May 1961
| Mercury spacecraft
| [[Engineering:Mercury-Redstone Launch Vehicle|Redstone]]
| Suborbital
|-
| {{US}}
| [[Organization:NASA|National Aeronautics and Space Administration (NASA)]]
| astronaut<br />spaceflight participant
| [[Biography:John Glenn|John Glenn]] (orbital)
| 20 February 1962
| Mercury spacecraft
| [[Engineering:Atlas LV-3B|Atlas LV-3B]]
| Orbital
|-
| {{PRC}}
| Space program of the People's Republic of China
| {{nativename|zh-Hans|宇航员}}<br />{{transliteration|zh|yǔhángyuán}}<br />{{nativename|zh-Hans|航天员}}<br />{{transliteration|zh|hángtiānyuán}}
| —
| 1973 (abandoned)
| Shuguang
| [[Engineering:Long March 2A|Long March 2A]]
| Orbital
|-
| {{PRC}}
| Space program of the People's Republic of China
| {{nativename|zh-Hans|宇航员}}<br />{{transliteration|zh|yǔhángyuán}}<br />{{nativename|zh-Hans|航天员}}<br />{{transliteration|zh|hángtiānyuán}}
| —
| 1981 (abandoned)
| Piloted FSW
| [[Engineering:Long March 2|Long March 2]]
| Orbital
|-
| [[File:ESA logo simple.svg|20px]] [[Organization:European Space Agency|European Space Agency]]
| [[Organization:CNES|CNES]] / [[Organization:European Space Agency|European Space Agency (ESA)]]
| ''spationaute'' {{in lang|fr}}<br />astronaut
| —
| 1992 (abandoned)
| [[Engineering:Hermes (spacecraft)|Hermes]]
| Ariane V
| Orbital
|-
| {{Flag|Russia}}<br />
| [[Company:Roscosmos|Roscosmos]] <br />
| космонавт&nbsp;{{in lang|ru}}<br />''kosmonavt''<br />cosmonaut
| Alexander Viktorenko, Alexander Kaleri
| 17 March 1992
| [[Engineering:Soyuz TM-14|Soyuz TM-14]] to MIR
| [[Engineering:Soyuz-U2|Soyuz-U2]]
| Orbital
|-
| {{Flagicon|Iraq|1991}} Ba'athist Iraq<br />(1968–2003){{NoteTag|According to a press release of Iraqi News Agency of 5 December 1989 about the first (and last) test of the Tammouz space launcher, Iraq intended to develop crewed space facilities by the end of the century. These plans were put to an end by the Gulf War of 1991 and the economic hard times that followed.}}
| —
| {{nativename|ar|رجل فضاء }}<br />{{transliteration|ar|rajul faḍāʼ}}<br />{{nativename|ar|رائد فضاء }}<br />{{transliteration|ar|rāʼid faḍāʼ}}<br />{{nativename|ar|ملاح فضائي }}<br />''mallāḥ faḍāʼiy''
| —
| 2001 (abandoned)
| —
| Tammouz 2 or 3
| {{n/a}}
|-
| {{flag|Japan}}
| National Space Development Agency of Japan (NASDA)
| {{nativename|ja|宇宙飛行士}}<br />{{transliteration|ja|uchūhikōshi}} or<br /> {{Nihongo2|アストロノート}}<br /> {{transliteration|ja|asutoronoto}}
| —
| 2003 (abandoned)
| [[Engineering:HOPE-X|HOPE]]
| [[Engineering:H-II|H-II]]
| Orbital
|-
| {{PRC}}
| China Manned Space Agency (CMSA)
| {{nativename|zh-Hans|宇航员}}<br />{{transliteration|zh|yǔhángyuán}}<br />{{nativename|zh-Hans|航天员}}<br />{{transliteration|zh|hángtiānyuán}}<br />taikonaut ({{zh|labels=no|c=太空人 |p=tàikōng rén}})
| Yang Liwei
| 15 October 2003
| [[Engineering:Shenzhou (spacecraft)|Shenzhou spacecraft]]
| [[Engineering:Long March 2F|Long March 2F]]
| Orbital
|-
| {{flag|Japan}}
| {{Interlanguage link multi|Japanese Rocket Society|ja|3=日本ロケット協会|vertical-align=sup}}, [[Company:Kawasaki Heavy Industries|Kawasaki Heavy Industries]] and [[Company:Mitsubishi Heavy Industries|Mitsubishi Heavy Industries]]
| {{nativename|ja|宇宙飛行士}}<br />{{transliteration|ja|uchūhikōshi}} or<br /> {{Nihongo2|アストロノート}}<br /> {{transliteration|ja|asutoronoto}}
| —
| 2000s (abandoned)
| [[Astronomy:Kankoh-maru|Kankoh-maru]]
| [[Astronomy:Kankoh-maru|Kankoh-maru]]
| Orbital
|-
| {{flag|Japan}}
| [[Organization:JAXA|Japan Aerospace Exploration Agency (JAXA)]]
| {{nativename|ja|宇宙飛行士}}<br />{{transliteration|ja|uchūhikōshi}} or<br /> {{Nihongo2|アストロノート}}<br /> {{transliteration|ja|asutoronoto}}
| —
| 2003 (abandoned)
| [[Engineering:Fuji (spacecraft)|Fuji]]
| [[Engineering:H-II|H-II]]
| Orbital
|-
| {{flag|India}}
| [[Astronomy:Indian Space Research Organisation|Indian Space Research Organisation (ISRO)]]
| Vyomanaut <br />&nbsp;{{in lang|sa}}
| —
| 2024<ref>{{cite web|url=https://timesofindia.indiatimes.com/india/gaganyaan-manned-mission-not-before-2023-minister/articleshow/81013233.cms|title=Gaganyaan manned mission not before 2023: Minister |work=the Times of India|date=2021-02-17|author=Surendra Singh}}</ref>
| [[Engineering:Gaganyaan|Gaganyaan]]
| [[Engineering:LVM 3|LVM 3]]
| Orbital
<ref>{{cite news |url = https://tech.economictimes.indiatimes.com/news/technology/four-years-is-tight-but-can-achieve-the-human-spaceflight-isros-k-sivan/65411891 |title = Four years is tight, but can achieve the human spaceflight: ISRO's K Sivan - ETtech |author = ETtech.com |newspaper = The Economic Times |language = en |access-date = 2018-08-15 }}</ref><ref>{{cite news |url = https://www.business-standard.com/article/news-ians/india-will-put-man-in-space-for-seven-days-isro-chairman-118081500485_1.html |title= India will put man in space for seven days: ISRO Chairman |author = IANS |date = 15 August 2018 |work = Business Standard India |access-date = 2018-08-15 }}</ref>
|-
| [[File:ESA logo simple.svg|20px]] [[Organization:European Space Agency|European Space Agency]]
| [[Organization:European Space Agency|European Space Agency (ESA)]]
| astronaut
| —
| 2020 (concept approved in 2009; but full development not begun)<ref>{{cite news |url = http://news.bbc.co.uk/2/hi/science/nature/8139347.stm |work=BBC News |title=Europe targets manned spaceship |date=7 July 2009 |access-date=27 March 2010 |first=Jonathan |last=Amos }}</ref><ref>[http://www.flightglobal.com/articles/2008/05/22/223941/apollo-like-capsule-chosen-for-crew-space-transportation.html Apollo-like capsule chosen for Crew Space Transportation System], 22 May 2008</ref><ref>[http://esamultimedia.esa.int/docs/ATV/infokit/english/Complete_Infokit_ATVreentry.pdf "Jules Verne" Automated Transfer Vehicle (ATV) Re-entry]. Information Kit (PDF). Updated September 2008. European Space Agency. Retrieved on 7 August 2011.</ref><ref>{{cite news |url = http://news.bbc.co.uk/1/hi/sci/tech/7749761.stm |work = BBC News |title = Europe's 10bn-euro space vision |date=26 November 2008 |access-date = 27 March 2010 |first = Jonathan |last = Amos }}</ref>
| [[Engineering:CSTS|CSTS]], [[Engineering:Automated Transfer Vehicle|ARV phase-2]] 
| Ariane V
| Orbital
|-
| {{flag|Japan}}
| [[Organization:JAXA|Japan Aerospace Exploration Agency (JAXA)]]
| {{nativename|ja|宇宙飛行士}}<br />{{transliteration|ja|uchūhikōshi}} or<br /> {{Nihongo2|アストロノート}}<br /> {{transliteration|ja|asutoronoto}}
| —
| TBD
| [[Engineering:H-II Transfer Vehicle|HTV-based spacecraft]]
| [[Engineering:H3 (rocket)|H3]]
| Orbital
|-
| {{flag|Iran}}
| [[Organization:Iranian Space Agency|Iranian Space Agency (ISA)]]
| —
| —
| 2019 (on hold)
| [[Astronomy:Iranian crewed spacecraft|ISA spacecraft]]
| TBD
| Orbital
|-
| {{flag|North Korea}}
| [[Organization:National Aerospace Development Administration|National Aerospace Development Administration (NADA)]]
| —
| —
| 2020s
| [[Organization:National Aerospace Development Administration#Future projects|NADA spacecraft]]
| [[Engineering:Unha|Unha 9]]
| Orbital
|-
| {{flag|Denmark}}
| [[Company:Copenhagen Suborbitals|Copenhagen Suborbitals]]
| astronaut
| —
| 2020s
| [[Engineering:HEAT 1X Tycho Brahe|Tycho Brahe]]
| [[Engineering:HEAT 1X Tycho Brahe|SPICA]]
| Suborbital
<!--
Removed ARCA for Romania. It was a sponsorship fraud system.
-->
|}

<!--
Please, DO NOT INCLUDE Equador. Its human spaceflight program http://exa.ec/ESAA-PECE_files/frame.htm with first suborbital mission ESAA-01 is not based on indigenous technology. It will be one of the first paid client's missions aboard on foreign airplane-launched spacecraft M55X+Explorer system that now is under development by Russian NPOM-Almaz company (former Myasishchev Bureau) according to order of British-US commercial space touristic company [[Company:Space Adventures|Space Adventures]].
-->


== Safety concerns ==
There are two main sources of hazard in space flight: those due to the hostile space environment, and those due to possible equipment malfunctions. Addressing these issues is of great importance for NASA and other space agencies before conducting the first extended crewed missions to destinations such as Mars.<ref name="williams202104">{{cite web |url=https://www.universetoday.com/149835/every-challenge-astronauts-will-face-on-a-flight-to-mars/ |title=Every Challenge Astronauts Will Face on a flight to Mars |last=Williams |first=Matt |date=Feb 4, 2021 |website=Universe Today |access-date=Feb 5, 2021}}</ref>

=== Environmental hazards ===

Planners of human spaceflight missions face a number of safety concerns.

==== Life support ====
{{Main| Engineering:Life support system}}

The basic needs for breathable air and drinkable water are addressed by the [[Engineering:Life support system|life support system]] of the spacecraft.


==== Medical issues ====

Astronauts may not be able to quickly return to Earth or receive medical supplies, equipment, or personnel if a medical emergency occurs. The astronauts may have to rely for long periods on limited resources and medical advice from the ground.

The possibility of [[Medicine:Blindness|blindness]] and of bone loss have been associated with human space flight.<ref name="NYT-20140127">{{cite news |last=Chang |first=Kenneth |title=Beings Not Made for Space |url=https://www.nytimes.com/2014/01/28/science/bodies-not-made-for-space.html |date=27 January 2014 |work={{wipe|The New York Times}} |access-date=27 January 2014 }}</ref><ref name="Wired-20120723">{{cite magazine |last=Mann |first=Adam |title=Blindness, Bone Loss, and Space Farts: Astronaut Medical Oddities |url=https://www.wired.com/wiredscience/2012/07/medicine-psychology-space/ |date=23 July 2012 |magazine=Wired |access-date=23 July 2012 }}</ref>

On 31 December 2012, a [[Organization:NASA|NASA]]-supported study reported that spaceflight may harm the brains of astronauts and accelerate the onset of [[Medicine:Alzheimer's disease|Alzheimer's disease]].<ref name="PLOS-20121231">{{cite journal |last1=Cherry |first1=Jonathan D. |last2=Frost |first2=Jeffrey L. |last3=Lemere |first3=Cynthia A. |last4=Williams |first4=Jacqueline P. |last5=Olschowka |first5=John A. |last6=O'Banion |first6=M. Kerry |title=Galactic Cosmic Radiation Leads to Cognitive Impairment and Increased Aβ Plaque Accumulation in a Mouse Model of Alzheimer's Disease |doi=10.1371/journal.pone.0053275 |volume=7 |issue=12 |page=e53275 |journal=PLoS ONE  |pmid=23300905 |date=2012 |pmc=3534034|bibcode=2012PLoSO...753275C |doi-access=free }}</ref><ref name="SpaceRef-20130101">{{cite web |title=Study Shows that Space Travel is Harmful to the Brain and Could Accelerate Onset of Alzheimer's |url=http://spaceref.com/news/viewpr.html?pid=39650 |date=1 January 2013 |publisher=SpaceRef |access-date=7 January 2013 }}</ref><ref name="NasaWatch-20130103">{{cite web |last=Cowing |first=Keith |title=Important Research Results NASA Is Not Talking About (Update) |url=http://nasawatch.com/archives/2013/01/important-resea.html |date=3 January 2013 |publisher=NASA Watch |access-date=7 January 2013 }}</ref>

In October 2015, the NASA Office of Inspector General issued a [[Astronomy:Effect of spaceflight on the human body|health hazards report]] related to [[Astronomy:Space exploration|space exploration]], which included the potential hazards of a [[Astronomy:Human mission to Mars|human mission to Mars]].<ref name="AP-20151029">{{cite news |last=Dunn |first=Marcia |title=Report: NASA needs better handle on health hazards for Mars |url=http://apnews.excite.com/article/20151029/us-sci-space-travel-health-6dfd5b2c76.html |date=29 October 2015 |agency=Associated Press |access-date=30 October 2015 }}</ref><ref name="NASA-20151029oig">{{cite web |author=Staff |title=NASA's Efforts to Manage Health and Human Performance Risks for Space Exploration (IG-16-003) |url=https://oig.nasa.gov/audits/reports/FY16/IG-16-003.pdf |date=29 October 2015 |work=[[Organization:NASA|NASA]] |access-date=29 October 2015 }}</ref>

On 2 November 2017, scientists reported, based on [[Physics:Magnetic resonance imaging|MRI studies]], that significant changes in the position and structure of the brain have been found in astronauts who have taken [[Astronomy:Effect of spaceflight on the human body|trips in space]]. Astronauts on longer space trips were affected by greater brain changes.<ref name="NEJM-20171102">{{cite journal |author=Roberts, Donna R. |display-authors=0 |title=Effects of Spaceflight on Astronaut Brain Structure as Indicated on MRI |date=2 November 2017 |journal=New England Journal of Medicine |volume=377 |issue=18 |pages=1746–1753  |doi=10.1056/NEJMoa1705129 |pmid=29091569 |s2cid=205102116 |doi-access=free }}</ref><ref name="QTZ-20171103">{{cite web |last=Foley |first=Katherine Ellen |title=Astronauts who take long trips to space return with brains that have floated to the top of their skulls |url=https://qz.com/1119668/space-travel-changes-astronauts-brains/ |date=3 November 2017 |work=Quartz |access-date=3 November 2017 }}</ref>

Researchers in 2018 reported, after detecting the presence on the [[Astronomy:International Space Station|International Space Station]] (ISS) of five ''[[Biology:Enterobacter|Enterobacter bugandensis]]'' bacterial strains, none [[Biology:Pathogen|pathogen]]ic to humans, that [[Biology:Microorganism|microorganism]]s on ISS should be carefully monitored to assure a healthy environment for [[Astronaut|astronaut]]s.<ref name="EA-20181122">{{cite web |author=BioMed Central |title=ISS microbes should be monitored to avoid threat to astronaut health |url=https://www.eurekalert.org/pub_releases/2018-11/bc-ims112018.php |date=22 November 2018 |work=EurekAlert! |access-date=25 November 2018 }}</ref><ref name="BMC-20181123">{{cite journal |author=Singh, Nitin K. |display-authors=0 |title=Multi-drug resistant Enterobacter bugandensis species isolated from the International Space Station and comparative genomic analyses with human pathogenic strains |date=23 November 2018 |journal=BMC Microbiology |volume=18 |issue=1 |page=175 |doi=10.1186/s12866-018-1325-2 |pmid=30466389 |pmc=6251167 |doi-access=free }}</ref>

In March 2019, NASA reported that latent [[Biology:Virus|virus]]es in humans may be activated during space missions, possibly adding more risk to astronauts in future deep-space missions.<ref name="EA-20190315">{{cite news |author=Staff |title=Dormant viruses activate during spaceflight &ndash; NASA investigates - The stress of spaceflight gives viruses a holiday from immune surveillance, putting future deep-space missions in jeopardy |url=https://www.eurekalert.org/pub_releases/2019-03/f-dva031519.php |date=15 March 2019 |work=EurekAlert! |access-date=16 March 2019 }}</ref>

On 25 September 2021, CNN reported that an alarm had sounded during the [[Engineering:Inspiration4|Inspiration4]] Earth-orbital journey on the [[Engineering:SpaceX Dragon 2|SpaceX Dragon 2]]. The alarm signal was found to be associated with an apparent toilet malfunction.<ref name="CNN-20210925">{{cite news |last=Wattles |first=Jackie |title=An alarm went off on SpaceX's all-tourist space flight. The problem was the toilet |url=https://www.cnn.com/2021/09/25/tech/spacex-toilet-waste-management-system-scn/index.html |date=25 September 2021 |work=CNN |access-date=25 September 2021 }}</ref>

===== Microgravity =====
[[File:Space fluid shift.gif|thumb|The effects of microgravity on fluid distribution around the body (greatly exaggerated)]]

Medical data from astronauts in low Earth orbits for long periods, dating back to the 1970s, show several adverse effects of a microgravity environment: loss of [[Biology:Bone|bone]] density, decreased muscle strength and endurance, postural instability, and reductions in aerobic capacity. Over time these [[Biology:Deconditioning|deconditioning]] effects can impair astronauts' performance or increase their risk of injury.<ref>
{{cite web|url=http://exploration.grc.nasa.gov/Exploration/Advanced/Human/Exercise/ |title=Exploration Systems Human Research Program – Exercise Countermeasures |work=NASA |url-status=dead |archive-url=https://web.archive.org/web/20081011052437/http://exploration.grc.nasa.gov/Exploration/Advanced/Human/Exercise/ |archive-date=11 October 2008 }}</ref>

In a weightless environment, astronauts put almost no weight on the back [[Biology:Muscle|muscle]]s or leg muscles used for standing up, which causes the muscles to weaken and get smaller. Astronauts can lose up to twenty per cent of their muscle mass on spaceflights lasting five to eleven days. The consequent loss of strength could be a serious problem in case of a landing emergency.<ref>{{cite web|url = https://www.nasa.gov/pdf/64249main_ffs_factsheets_hbp_atrophy.pdf|title = NASA Information: Muscle Atrophy|access-date = 20 November 2015|website = NASA}}</ref> Upon returning to Earth from [[Engineering:Long-duration spaceflight|long-duration]] flights, astronauts are considerably weakened and are not allowed{{by whom|date=October 2020}}<!-- is this rule USSR, USA, India, China, ... or do we have a source that indicates this is a truth for all astronauts in all nations states? --> to drive a car for twenty-one days.<ref>{{cite web|title = Earth Living Is Tough for Astronaut Used to Space|url = http://www.space.com/21413-hadfield-astronaut-health-return-earth.html|website = Space.com|date = 3 June 2013|access-date = 21 November 2015}}</ref>

Astronauts experiencing weightlessness will often lose their orientation, get [[Medicine:Motion sickness|motion sickness]], and lose their sense of direction as their bodies try to get used to a weightless environment. When they get back to Earth, they have to readjust and may have problems standing up, focusing their gaze, walking, and turning. Importantly, those motor disturbances only get worse the longer the exposure to weightlessness.<ref>{{cite news | url=https://abcnews.go.com/Technology/story?id=3830060&page=1 | last=Watson | first=Traci | date=11 November 2007 | title=Readjusting to gravity anti-fun for astronauts | publisher=ABC News | access-date=14 February 2020}}</ref> These changes can affect the ability to perform tasks required for approach and landing, docking, remote manipulation, and emergencies that may occur while landing.<ref>{{Cite journal|last1=Eddy|first1=D. R.|last2=Schiflett|first2=S. G.|last3=Schlegel|first3=R. E.|last4=Shehab|first4=R. L.|date=August 1998|title=Cognitive performance aboard the life and microgravity spacelab|url=https://pubmed.ncbi.nlm.nih.gov/11541924|journal=Acta Astronautica|volume=43|issue=3–6|pages=193–210|doi=10.1016/s0094-5765(98)00154-4|issn=0094-5765|pmid=11541924|bibcode=1998AcAau..43..193E}}</ref>

In addition, after long space flight missions, male astronauts may experience severe [[Biology:Visual system|eyesight]] problems, which may be a major concern for future deep space flight missions, including a crewed mission to the planet [[Astronomy:Mars|Mars]].<ref name="Mader-2011">{{cite journal|author=Mader, T. H. |display-authors=0 |title=Optic Disc Edema, Globe Flattening, Choroidal Folds, and Hyperopic Shifts Observed in Astronauts after Long-duration Space Flight|date=2011 |journal=Ophthalmology |volume=118 |issue=10|pages=2058–2069 |doi=10.1016/j.ophtha.2011.06.021 |pmid=21849212|s2cid=13965518 |url=http://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1068&context=nasapub }}</ref><ref name="Puiu-20111109">{{cite web |last=Puiu |first=Tibi |title=Astronauts' vision severely affected during long space missions|url=http://www.zmescience.com/medicine/astronaut-eyesight-damage-weightlessness-3214143/|date=9 November 2011 |publisher=zmescience.com |access-date=9 February 2012 }}</ref><ref name="CNN-20120109">[http://www.cnn.com/video/#/video/us/2012/02/09/pkg-zarrella-astronaut-vision.cnnCNN News (CNN-TV, 02/09/2012) – Video (02:14) – Male Astronauts Return With Eye Problems]. CNN (9 February 2012). Retrieved on 22 November 2016.</ref><ref name="Space-20120313">{{cite web|title=Spaceflight Bad for Astronauts' Vision, Study Suggests |url=http://www.space.com/14876-astronaut-spaceflight-vision-problems.html |date=13 March 2012 |publisher=Space.com |access-date=14 March 2012 }}</ref><ref name="Radiology-20120313">{{cite journal |author=Kramer, Larry A. |display-authors=0 |title=Orbital and Intracranial Effects of Microgravity: Findings at 3-T MR Imaging |journal=Radiology |volume=263 |issue=3 |pages=819–27 |doi=10.1148/radiol.12111986 |pmid=22416248 |date=13 March 2012 }}</ref><ref name="WIRED-20140212">{{cite magazine |last=Fong, MD |first=Kevin |title=The Strange, Deadly Effects Mars Would Have on Your Body |url=https://www.wired.com/opinion/2014/02/happens-body-mars/ |date=12 February 2014 |magazine=Wired |access-date=12 February 2014 }}</ref> Long space flights can also alter a space traveler's eye movements.<ref>{{cite journal |last1=Alexander |first1=Robert |last2=Macknik |first2=Stephen |last3=Martinez-Conde |first3=Susana |title=Microsaccades in applied environments: Real-world applications of fixational eye movement measurements |journal=Journal of Eye Movement Research |date=2020 |volume=12 |issue=6 |doi=10.16910/jemr.12.6.15 |pmid=33828760 |pmc=7962687 |doi-access=free }}</ref>

===== Radiation =====
[[File:PIA17601-Comparisons-RadiationExposure-MarsTrip-20131209.png|thumb|right|Comparison of Radiation Doses – includes the amount detected on the trip from Earth to Mars by the [[Astronomy:Radiation assessment detector|RAD]] on the MSL (2011–2013)<ref name="SCI-20130531a">{{cite journal |last=Kerr |first=Richard |title=Radiation Will Make Astronauts' Trip to Mars Even Riskier |date=31 May 2013 |journal=Science |volume=340 |issue=6136 |page=1031 |doi=10.1126/science.340.6136.1031 |pmid=23723213 |bibcode=2013Sci...340.1031K}}</ref>]]

Without proper shielding, the crews of missions beyond low Earth orbit might be at risk from high-energy protons emitted by [[Astronomy:Solar particle event|solar particle event]]s (SPEs) associated with [[Astronomy:Solar flare|solar flare]]s. If estimated correctly, the amount of radiation that astronauts would be exposed to from a solar storm similar to that of the most powerful in recorded history, the [[Astronomy:Carrington Event|Carrington Event]], would result in acute radiation sickness at least, and could even be fatal "in a poorly shielded spacecraft".<ref>{{cite web |url=https://www.newscientist.com/article/dn7142 |title= Superflares could kill unprotected astronauts|work=New Scientist |date=21 March 2005 |first=Stephen |last=Battersby}}</ref>{{better source needed|reason=Citation does not differentiate between solar flares and solar particle events.|date=December 2021}} Another storm that could have inflicted a potentially lethal dose of radiation on astronauts outside Earth's protective [[Astronomy:Magnetosphere|magnetosphere]] occurred during the [[Engineering:Space Age|Space Age]], shortly after [[Engineering:Apollo 16|Apollo 16]] landed and before [[Engineering:Apollo 17|Apollo 17]] launched.<ref>{{cite journal |last = Lockwood |first = Mike |author2 = M. Hapgood |title = The Rough Guide to the Moon and Mars |journal = Astron. Geophys. |volume = 48 |issue = 6 |pages = 11–17 |date = 2007 |doi = 10.1111/j.1468-4004.2007.48611.x |bibcode = 2007A&G....48f..11L |doi-access = free }}</ref> This solar storm, [[Astronomy:August 1972 solar storm|which occurred in August 1972]], could potentially have caused any astronauts who were exposed to it to suffer from acute radiation sickness, and may even have been lethal for those engaged in [[Astronomy:Extravehicular activity|extravehicular activity]] or on the lunar surface.<ref>{{cite journal |last = Parsons |first = Jennifer L. |author2 = L. W. Townsend |title = Interplanetary Crew Dose Rates for the August 1972 Solar Particle Event |journal = Radiat. Res. |volume = 153 |issue = 6 |pages = 729–733 |date = 2000 |doi = 10.1667/0033-7587(2000)153[0729:ICDRFT]2.0.CO;2 |pmid = 10825747 |bibcode = 2000RadR..153..729P |s2cid = 25250687 }}</ref>

Another type of radiation, galactic [[Astronomy:Cosmic ray|cosmic ray]]s, presents further challenges to human spaceflight beyond low Earth orbit.<ref>{{cite book|isbn=978-0-309-10264-3|url=http://www.nap.edu/catalog.php?record_id=11760 |title=Space Radiation Hazards and the Vision for Space Exploration |publisher=NAP |date=2006| doi=10.17226/11760 }}</ref>

There is also some scientific concern that extended spaceflight might slow down the body's ability to protect itself against diseases,<ref>{{cite journal|doi=10.1189/jlb.0309167 |title=Could spaceflight-associated immune system weakening preclude the expansion of human presence beyond Earth's orbit|date=2009|last1=Gueguinou|first1=N.|last2=Huin-Schohn|first2=C.|last3=Bascove|first3=M.|last4=Bueb|first4=J.-L.|last5=Tschirhart|first5=E.|last6=Legrand-Frossi|first6=C.|last7=Frippiat|first7=J.-P.|journal=Journal of Leukocyte Biology|volume=86|issue=5|pages=1027–1038|pmid=19690292|doi-access=}}</ref> resulting in a weakened [[Biology:Immune system|immune system]] and the activation of dormant [[Biology:Virus|virus]]es in the body. [[Physics:Radiation|Radiation]] can cause both short- and long-term consequences to the bone marrow stem cells from which blood and immune-system cells are created. Because the interior of a spacecraft is so small, a weakened immune system and more active viruses in the body can lead to a fast spread of infection.<ref>{{cite web |last1=Sohn |first1=Rebecca |title=How do viruses affect astronauts in space? |url=https://www.space.com/viruses-in-space-astronaut-health-impacts |website=Space.com |date=7 March 2022 |publisher=Future US |access-date=20 October 2022}}</ref>

===== Isolation =====

During long missions, astronauts are isolated and confined in small spaces. [[Medicine:Depression (mood)|Depression]], anxiety, [[Social:Cabin fever|cabin fever]], and other psychological problems may occur more than for an average person and could impact the crew's safety and mission success.<ref>{{Cite journal|last=Flynn|first=Christopher F.|date=1 June 2005|title=An Operational Approach to Long-Duration Mission Behavioral Health and Performance Factors|url=http://www.ingentaconnect.com/contentone/asma/asem/2005/00000076/A00106s1/art00007|journal=Aviation, Space, and Environmental Medicine|volume=76|issue=6|pages=B42–B51|pmid=15943194}}</ref> NASA spends millions of dollars on psychological treatments for astronauts and former astronauts.<ref>{{Cite book |title=Space psychology and psychiatry |date=2008 |publisher=Springer |last1=Kanas |first1=Nick |last2=Manzey |first2=Dietrich |isbn=9781402067709 |edition=2nd |location=Dordrecht |oclc=233972618}}</ref> To date, there is no way to prevent or reduce mental problems caused by extended periods of stay in space.

Due to these mental disorders, the efficiency of astronauts' work is impaired; and sometimes they are brought back to Earth, incurring the expense of their mission being aborted.<ref>{{Cite news |url=https://www.theguardian.com/science/2014/oct/05/hallucinations-isolation-astronauts-mental-health-space-missions|title=Isolation and hallucinations: the mental health challenges faced by astronauts |last=Bell|first=Vaughan|date=5 October 2014|work=The Observer|access-date=2019-02-01|language=en-GB |issn=0029-7712}}</ref> A Russian expedition to space in 1976 was returned to Earth after the cosmonauts reported a strong odor that resulted in a fear of fluid leakage; but after a thorough investigation, it became clear that there was no leakage or technical malfunction. It was concluded by NASA that the cosmonauts most likely had [[Unsolved:Phantosmia|hallucinated the smell]].

It is possible that the mental health of astronauts can be affected by the changes in the sensory systems while in prolonged space travel.

===== Sensory systems =====
During astronauts' spaceflight, they are in an extreme environment. This, and the fact that little change is taking place in the environment, will result in the weakening of sensory input to the astronauts' seven senses.

* [[Physics:Hearing|Hearing]] – In the space station and spacecraft there are no noises from the outside, as there is no medium that can transmit sound waves. Although there are other team members who can talk to each other, their voices become familiar and do not stimulate the sense of hearing as much. Mechanical noises become familiar, as well.
* Sight – Because of weightlessness, the body's liquids attain an equilibrium that is different from what it is on the Earth. For this reason, an astronaut's face swells and presses on the eyes; and therefore their vision is impaired. The landscape surrounding the astronauts is constant, which lessens visual stimulations. Due to cosmic rays, astronauts may see flashes.
* [[Biology:Sense of smell|Smell]] – The space station has a permanent odor described as the smell of gunpowder. Due to the zero gravity, the bodily fluids rise to the face and prevent the sinuses from drying up, which dulls the sense of smell.
* [[Biology:Taste|Taste]] – The sense of taste is directly affected by the sense of smell and therefore when the sense of smell is dulled, the sense of taste is also. The astronauts' food is bland, and there are only certain foods that can be eaten. The food comes only once every few months, when supplies arrive, and there is little or no variety.
* Touch – There are almost no stimulating changes in physical contact. There is almost no human physical contact during the journey.
* The [[Biology:Vestibular system|vestibular system]] (motion and equilibrium system) – Due to the lack of gravity, all the movements required of the astronauts are changed, and the vestibular system is damaged by the extreme change.
* The [[Biology:Proprioception|proprioception system]] (the sense of the relative position of one's own parts of the body and strength of effort being employed in movement) – As a result of weightlessness, few forces are exerted on the astronauts' muscles; and there is less stimulus to this system.

=== Equipment hazards ===
Space flight requires much higher velocities than ground or air transportation, and consequently requires the use of high [[Physics:Energy density|energy density]] propellants for launch, and the dissipation of large amounts of energy, usually as heat, for safe reentry through the Earth's atmosphere.

==== Launch ====
[[File:Sts33-e204.jpg|thumb|There was no practical way for the {{OV|99}}'s crew to safely abort before the [[Engineering:Space Shuttle Challenger disaster|vehicle's violent disintegration]]]]

Since rockets have the potential for fire or explosive destruction, [[Engineering:Space capsule|space capsule]]s generally employ some sort of [[Astronomy:Launch escape system|launch escape system]], consisting either of a tower-mounted solid-fuel rocket to quickly carry the capsule away from the [[Engineering:Launch vehicle|launch vehicle]] (employed on [[Astronomy:Project Mercury|Mercury]], [[Engineering:Apollo (spacecraft)|Apollo]], and Soyuz, the escape tower being discarded at some point after launch, at a point where an abort can be performed using the spacecraft's engines), or else [[Engineering:Ejection seat|ejection seat]]s (employed on Vostok and [[Astronomy:Project Gemini|Gemini]]) to carry astronauts out of the capsule and away for individual parachute landings.

Such a launch escape system is not always practical for multiple-crew-member vehicles (particularly [[Astronomy:Spaceplane|spaceplane]]s), depending on the location of egress hatch(es). When the single-hatch Vostok capsule was modified to become the 2 or 3-person [[Engineering:Voskhod (spacecraft)|Voskhod]], the single-cosmonaut ejection seat could not be used, and no escape tower system was added. The two Voskhod flights in 1964 and 1965 avoided launch mishaps. The [[Engineering:Space Shuttle|Space Shuttle]] carried ejection seats and escape hatches for its pilot and copilot in early flights; but these could not be used for passengers who sat below the flight deck on later flights, and so were discontinued.

There have been only two in-flight launch aborts of a crewed flight. The first occurred on [[Engineering:Soyuz 7K-T No.39|Soyuz 18a]] on 5 April 1975. The abort occurred after the launch escape system had been jettisoned when the launch vehicle's spent second stage failed to separate before the third stage ignited and the vehicle strayed off course. The crew finally managed to separate the spacecraft, firing its engines to pull it away from the errant rocket, and both cosmonauts landed safely. The second occurred on 11 October 2018 with the launch of [[Engineering:Soyuz MS-10|Soyuz MS-10]]. Again, both crew members survived.

In the first use of a launch escape system on the launchpad, before the start of a crewed flight, happened during the planned [[Engineering:Soyuz 7K-ST No. 16L|Soyuz T-10a]] launch on 26 September 1983, which was aborted by a launch vehicle fire 90 seconds before liftoff. Both cosmonauts aboard landed safely.

The only crew fatality during launch occurred on 28 January 1986, when the [[Engineering:Space Shuttle Challenger disaster|Space Shuttle ''Challenger'']] broke apart 73 seconds after liftoff, due to the failure of a [[Engineering:Space Shuttle Solid Rocket Booster|solid rocket booster]] seal, which caused the failure of the [[Engineering:Space Shuttle external tank|external fuel tank]], resulting in an explosion of the fuel and separation of the boosters. All seven crew members were killed.

==== Extravehicular activity ====
Despite the ever-present risks related to mechanical failures while working in open space, no [[Astronomy:Extravehicular activity|spacewalking]] astronaut has ever been lost. There are various safety requirements for spacewalking astronauts, including the use of [[Engineering:Space tether|tethers]] and sometimes supplementary anchors. In an emergency where these safety measures fail, a spacewalking astronaut would most probably float away into space, impelled by whatever forces were acting on the astronaut at the time of breaking loose. This astronaut may even be sent spinning with little to no recourse, since [[Physics:Aerodynamics|aerodynamic]] maneuvers that might stabilize fall trajectory on Earth would have little effect in [[Astronomy:Outer space#Environment|the near-perfect vacuum of space]]. At the right angle and velocity, the astronaut might even re-enter the Earth's atmosphere, which would cause them to burn up before they could reach the ground. [[Organization:NASA|NASA]] has protocols for such situations: astronauts would be wearing an emergency jetpack that would automatically counter any tumbling. NASA's plan states that astronauts should then take manual control of the jetpack and fly back to safety.{{citation needed|date=October 2020}}

However, if the jetpack's {{convert|3|lb}} of fuel runs out, and if there is no other astronaut in close proximity to help, or if the [[Engineering:Airlock|airlock]] is irreparably damaged, the outcome would certainly be fatal. At this time, there is no spacecraft to save an astronaut floating in space, as the only craft with a rescue-ready air-locked compartment — [[Engineering:Space Shuttle retirement|the Space Shuttle]] — retired {{age|July 2011|{{CURRENTMONTHNAME}} {{CURRENTYEAR}}}} years ago. There is approximately one litre of water available via a straw in an astronaut's helmet. The astronaut<!-- use gender-neutral language, see MOS:GENDER --> would have roughly 7.5 hours of breathable air before it ran out, likely causing death by suffocation.<ref>{{cite web|last1=Sofge |first1=Eric |title=What Happens If An Astronaut Floats Off In Space? |url=https://www.popsci.com/technology/article/2013-09/what-happens-if-astronaut-floats-space/ |website=Popular Science|date=30 September 2013}}</ref>

==== Reentry and landing ====

The single pilot of [[Engineering:Soyuz 1|Soyuz 1]], [[Biography:Vladimir Komarov|Vladimir Komarov]], was killed when his capsule's parachutes failed during an emergency landing on 24 April 1967, causing the capsule to crash.

On 1 February 2003, the crew of seven aboard the {{OV|102}} were [[Engineering:Space Shuttle Columbia disaster|killed on reentry]] after completing a [[Engineering:STS-107|successful mission in space]]. A wing-leading-edge reinforced carbon-carbon heat shield had been damaged by a piece of frozen [[Engineering:Space Shuttle external tank|external tank]] foam insulation that had broken off and struck the wing during launch. Hot reentry gasses entered and destroyed the wing structure, leading to the breakup of the [[Engineering:Space Shuttle orbiter|orbiter vehicle]].

==== Artificial atmosphere ====
There are two basic choices for an artificial atmosphere: either an Earth-like mixture of oxygen and an inert gas such as nitrogen or helium, or pure oxygen, which can be used at lower than standard atmospheric pressure. A nitrogen–oxygen mixture is used in the International Space Station and Soyuz spacecraft, while low-pressure pure oxygen is commonly used in space suits for [[Astronomy:Extravehicular activity|extravehicular activity]].

The use of a gas mixture carries the risk of [[Medicine:Decompression sickness|decompression sickness]] (commonly known as "the bends") when transitioning to or from the pure oxygen space suit environment. There have been instances of injury and fatalities caused by suffocation in the presence of too much nitrogen and not enough oxygen.
* In 1960, McDonnell Aircraft test pilot G.B. North passed out and was seriously injured when testing a Mercury cabin–space suit atmosphere system in a vacuum chamber, due to nitrogen-rich air leaking from the cabin into his space suit feed.<ref>{{cite journal |last=Giblin |first=Kelly A. |date=Spring 1998 |title =Fire in the Cockpit! |journal=American Heritage of Invention & Technology |volume=13 |issue=4 |publisher=American Heritage Publishing |url=http://www.americanheritage.com/articles/magazine/it/1998/4/1998_4_46.shtml |archive-url=https://web.archive.org/web/20081120153024/http://www.americanheritage.com/articles/magazine/it/1998/4/1998_4_46.shtml |archive-date=20 November 2008 |access-date=23 March 2011}}</ref> This incident led NASA to decide on a pure oxygen atmosphere for the Mercury, Gemini, and Apollo spacecraft.
* In 1981, three pad workers were killed by a nitrogen-rich atmosphere in the aft engine compartment of the {{OV|102}} at the [[Astronomy:Kennedy Space Center Launch Complex 39|Kennedy Space Center Launch Complex 39]].<ref>[https://web.archive.org/web/20010605212352/http://www-lib.ksc.nasa.gov/lib/chrono.html 1981 KSC Chronology Part 1 – pages 84, 85, 100; Part 2 – pages 181, 194, 195], NASA</ref>
* In 1995, two pad workers were similarly killed by a nitrogen leak in a confined area of the [[Engineering:Ariane 5|Ariane 5]] launch pad at [[Organization:Guiana Space Centre|Guiana Space Centre]].<ref>[http://www.esa.int/esaCP/Pr_17_1995_p_EN.html "Fatal accident at the Guiana Space Centre"], ''ESA Portal'', 5 May 1993</ref>

A pure oxygen atmosphere carries the risk of fire. The original design of the Apollo spacecraft used pure oxygen at greater than atmospheric pressure prior to launch. An electrical fire started in the cabin of [[Engineering:Apollo 1|Apollo 1]] during a ground test at Cape Kennedy Air Force Station Launch Complex 34 on 27 January 1967, and spread rapidly. The high pressure, increased by the fire, prevented removal of the plug door hatch cover in time to rescue the crew. All three astronauts—Gus Grissom, [[Astronomy:Ed White (astronaut)|Ed White]], and Roger Chaffee—were killed.<ref name="SP4029">{{cite book |last=Orloff |first=Richard W. |title=Apollo by the Numbers: A Statistical Reference |url=https://history.nasa.gov/SP-4029/SP-4029.htm |access-date=12 July 2013 |series=NASA History Series |orig-year=First published 2000 |date=September 2004 |work=NASA History Division, Office of Policy and Plans |publisher=NASA |location=Washington, D.C. |isbn=978-0-16-050631-4 |lccn=00061677 |id=NASA SP-2000-4029 |chapter=Apollo 1 – The Fire: 27 January 1967 |chapter-url=https://history.nasa.gov/SP-4029/Apollo_01a_Summary.htm}}</ref> This led NASA to use a nitrogen–oxygen atmosphere before launch, and low-pressure pure oxygen only in space.

==== Reliability ====

The March 1966 [[Astronomy:Gemini 8|Gemini 8]] mission was aborted in orbit when an attitude control system thruster stuck in the on position, sending the craft into a dangerous spin that threatened the lives of Neil Armstrong and [[Biography:David Scott|David Scott]]. Armstrong had to shut the control system off and use the reentry control system to stop the spin. The craft made an emergency reentry and the astronauts landed safely. The most probable cause was determined to be an electrical short due to a [[Physics:Static electricity|static electricity]] discharge, which caused the thruster to remain powered even when switched off. The control system was modified to put each thruster on its own isolated circuit.

The third lunar landing expedition, [[Engineering:Apollo 13|Apollo 13]], in April 1970, was aborted and the lives of the crew—[[Biography:Jim Lovell|James Lovell]], Jack Swigert, and [[Biography:Fred Haise|Fred Haise]]—were threatened after the failure of a cryogenic [[Physics:Liquid oxygen|liquid oxygen]] tank en route to the Moon. The tank burst when electrical power was applied to internal stirring fans in the tank, causing the immediate loss of all of its contents, and also damaging the second tank, causing the gradual loss of its remaining oxygen over a period of 130 minutes. This in turn caused a loss of electrical power provided by [[Physics:Fuel cell|fuel cell]]s to the command spacecraft. The crew managed to return to Earth safely by using the [[Engineering:Apollo Lunar Module|lunar landing craft]] as a "life boat". The tank failure was determined to be caused by two mistakes: the tank's drain fitting had been damaged when it was dropped during factory testing, necessitating the use of its internal heaters to boil out the oxygen after a pre-launch test; which in turn damaged the fan wiring's electrical insulation because the thermostats on the heaters did not meet the required voltage rating due to a vendor miscommunication.

The crew of [[Engineering:Soyuz 11|Soyuz 11]] were killed on 30 June 1971 by a combination of mechanical malfunctions; the crew were asphyxiated due to cabin decompression following the separation of their descent capsule from the service module. A cabin ventilation valve had been jolted open at an altitude of {{convert|168|km}} by the stronger-than-expected shock of explosive separation bolts, which were designed to fire sequentially, but in fact had fired simultaneously. The loss of pressure became fatal within about 30 seconds.<ref>{{Cite web|url=https://history.nasa.gov/SP-4209/ch8-2.htm|title=The Partnership: A History of the Apollo–Soyuz Test Project|access-date=20 October 2007|publisher=NASA|year=1974|author=NASA|archive-url=https://web.archive.org/web/20070823124845/https://history.nasa.gov/SP-4209/ch8-2.htm|archive-date=23 August 2007}}</ref>

=== Fatality risk ===
{{Further|Astronomy:List of spaceflight-related accidents and incidents}}

{{As of|2015|December}}, 23 crew members have died in accidents aboard spacecraft. Over 100 others have died in accidents during activities directly related to spaceflight or testing.

{| class="wikitable"
|-
!Date
!Mission
!Accident cause
!Deaths
!Cause of death
|-
| 27 January 1967
| [[Engineering:Apollo 1|Apollo 1]]
| Electrical fire in the cabin, spread quickly by {{convert|16.7|psi|bar|abbr=on}} pure oxygen atmosphere and flammable nylon materials in cabin and space suits, during pre-launch test; inability to remove plug door hatch cover due to internal pressure; rupture of cabin wall allowed outside air to enter, causing heavy smoke and soot
| style="text-align: center;" | 3
| [[Medicine:Cardiac arrest|Cardiac arrest]] from [[Chemistry:Carbon monoxide|carbon monoxide]] poisoning
|-
| 24 April 1967
| [[Engineering:Soyuz 1|Soyuz 1]]
| Malfunction of primary landing parachute, and entanglement of reserve parachute; loss of 50% electrical power and spacecraft control problems necessitating emergency abort
| style="text-align: center;"| 1
| Trauma from crash landing
|-
| 15 November 1967
| [[Engineering:X-15 Flight 3-65-97|X-15 Flight 3-65-97]]
| The accident board found that the cockpit instrumentation had been functioning properly, and concluded that pilot Michael J. Adams had lost control of the X-15 as a result of a combination of distraction, misinterpretation of his instrumentation display, and possible vertigo. The electrical disturbance early in the flight degraded the overall effectiveness of the aircraft's control system and further added to pilot workload.
| style="text-align: center;"| 1
| Vehicle breakup
|-
| 30 June 1971
| [[Engineering:Soyuz 11|Soyuz 11]]
| Loss of cabin pressurization due to valve opening upon Orbital Module separation before re-entry
| style="text-align: center;"| 3
| Asphyxia
|-
| 28 January 1986
| STS-51L [[Engineering:Space Shuttle Challenger disaster|Space Shuttle ''Challenger'']]
| Failure of [[O-ring]] inter-segment seal in one [[Engineering:Space Shuttle Solid Rocket Booster|Solid Rocket Booster]] in extreme cold launch temperature, allowing hot gases to penetrate casing and burn through a strut connecting booster to the [[Engineering:Space Shuttle external tank|External Tank]]; tank failure; rapid combustion of fuel; orbiter breakup from abnormal aerodynamic forces
| style="text-align: center;"| 7
| Asphyxia from cabin breach, or trauma from water impact<ref>{{cite web|url=https://history.nasa.gov/kerwin.html |title=Report from Joseph P. Kerwin, biomedical specialist from the Johnson Space Center in Houston, Texas, relating to the deaths of the astronauts in the Challenger accident |work=NASA |url-status=dead |archive-url=https://web.archive.org/web/20130103015825/https://history.nasa.gov/kerwin.html |archive-date=3 January 2013 }}</ref>
|-
| 1 February 2003
| [[Engineering:STS-107|STS-107]] [[Engineering:Space Shuttle Columbia disaster|Space Shuttle ''Columbia'']]
| Damaged reinforced carbon-carbon heat shield panel on wing's leading edge, caused by a piece of [[Engineering:Space Shuttle external tank|External Tank]] foam insulation broken off during launch; penetration of hot atmospheric gases during re-entry, leading to structural failure of the wing, loss of control and disintegration of the orbiter
| style="text-align: center;"| 7
| Asphyxia from cabin breach, trauma from dynamic load environment as orbiter broke up<ref>{{cite web |title=Columbia Crew Survival Investigation Report |url=http://www.nasa.gov/pdf/298870main_SP-2008-565.pdf |website=NASA.gov |publisher=NASA}}</ref>
|-
| 31 October 2014
| [[Engineering:SpaceShipTwo|SpaceShipTwo]] [[Engineering:VSS Enterprise crash|VSS ''Enterprise'' powered drop-test]]
| Copilot error: premature deployment of "feathering" descent air-braking system caused the disintegration of the vehicle in flight; pilot survived, copilot died
| style="text-align: center;"| 1
| Trauma from crash
|}

== See also ==
* [[Astronomy:List of human spaceflight programs|List of human spaceflight programs]]
* [[Astronomy:List of human spaceflights|List of human spaceflights]]
**[[Astronomy:List of human spaceflights, 1961–1970|1961–1970]]
**[[Astronomy:List of human spaceflights, 1971–1980|1971–1980]]
**[[Astronomy:List of human spaceflights, 1981–1990|1981–1990]]
**[[Astronomy:List of human spaceflights, 1991–2000|1991–2000]]
**[[Astronomy:List of human spaceflights, 2001–2010|2001–2010]]
**[[Astronomy:List of human spaceflights, 2011–present|2011–2020]]
**[[Astronomy:List of human spaceflights, 2021–present|2021–present]]
* [[Astronomy:List of spaceflight records|List of spaceflight records]]
* [[Engineering:List of crewed spacecraft|List of crewed spacecraft]]
* Animals in space
* [[Biology:Monkeys and apes in space|Monkeys and apes in space]]
* [[Astronomy:Crewed Mars rover|Crewed Mars rover]]
* [[Biography:Commercial astronaut|Commercial astronaut]]
* [[Astronomy:Mars to Stay|Mars to Stay]]
* [[Company:NewSpace|NewSpace]]
* [[Medicine:Space medicine|Space medicine]]
* [[Astronomy:Tourism on the Moon|Tourism on the Moon]]
* [[Astronomy:Women in space|Women in space]]

== Notes ==
{{NoteFoot}}

== References ==
{{Reflist}}

== Further reading ==
* Darling, David. ''The complete book of spaceflight. From Apollo 1 to Zero gravity''. Wiley, Hoboken NJ 2003, {{ISBN|0-471-05649-9}}.
* Haeuplik-Meusburger: ''Architecture for Astronauts – An Activity based Approach''. Springer Praxis Books, 2011, {{ISBN|978-3-7091-0666-2}}.
* Larson, Wiley J. (ed.). ''Human spaceflight – mission analysis and design''. McGraw-Hill, New York NY 2003, {{ISBN|0-07-236811-X}}.
* Pyle, Rod. ''Space 2.0: How Private Spaceflight, a Resurgent NASA, and International Partners are Creating a New Space Age'' (2019), overview of space exploration [https://www.amazon.com/dp/1944648453/ excerpt]
* Spencer, Brett. "The Book and the Rocket: The Symbiotic Relationship between American Public Libraries and the Space Program, 1950–2015."
* Reneau, Allyson (ed.). ''Moon First and Mars Second: A Practical Approach to Human Space Exploration'' (2020) [https://www.amazon.com/Moon-First-Mars-Second-SpringerBriefs/dp/3030542297/ excerpt]
* Smith, Michael G., Michelle Kelley, and Mathias Basner. "A brief history of spaceflight from 1961 to 2020: An analysis of missions and astronaut demographics." ''Acta Astronautica'' 175 (2020): 290–299.

== External links ==
* [http://spaceflight.nasa.gov/ NASA Human Space Flight (United States of America)]
* [https://web.archive.org/web/20070802015842/http://solarsystem.nasa.gov/missions/profile.cfm?MCode=Human_Spaceflight Human Spaceflight Profile] by [http://solarsystem.nasa.gov NASA's Solar System Exploration]
* [http://www.nasaconstellation.com Transitioning to the NASA Constellation Program]
* [https://web.archive.org/web/20190404044029/http://spaceflighthistory.com/ U.S. Spaceflight History]

{{Future spaceflights}}
{{Crewed spacecraft}}
{{Public sector space agencies}}
{{Spaceflight}}
{{NASA space program}}
{{Russian space program}}
{{Inspace}}
{{Space exploration lists and timelines}}
{{Solar System}}


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

{{Sourceattribution|Human spaceflight}}