View source for Engineering:Spaceflight

{{short description|Flight into or through outer space}}
[[File:The SpaceX Crew Dragon Endeavour approaches the International Space Station (iss065e002231).jpg|thumb|upright=1.2|SpaceX's Crew Dragon capsule approaching the International Space Station in Earth orbit]]

'''Spaceflight''' (or '''space flight''') is an application of [[Earth:Astronautics|astronautics]] to fly objects, usually [[Engineering:Spacecraft|spacecraft]], into or through [[Astronomy:Outer space|outer space]], either [[Astronomy:Human spaceflight|with]] or without humans on board. Most spaceflight is uncrewed and conducted mainly with spacecraft such as [[Astronomy:Satellite|satellite]]s in [[Astronomy:Geocentric orbit|orbit around Earth]], but also includes [[Engineering:Space probe|space probe]]s for flights beyond Earth orbit. Such spaceflight operate either by telerobotic or [[Engineering:Autonomous robot|autonomous]] control. The more complex human spaceflight has been pursued soon after the first orbital satellites and has reached the [[Astronomy:Moon|Moon]] and permanent [[Astronomy:Human presence in space|human presence in space]] around Earth, particularly with the use of space stations. [[Astronomy:Human spaceflight programs|Human spaceflight programs]] include the [[Engineering:Soyuz programme|Soyuz]], [[Astronomy:China Manned Space Program|Shenzhou]], the past [[Astronomy:Apollo program|Apollo Moon landing]] and the [[Engineering:Space Shuttle program|Space Shuttle program]]s. Other current spaceflight are conducted to the [[Astronomy:International Space Station|International Space Station]] and  to China's Tiangong Space Station.

Spaceflight is used for placing in Earth's orbit [[Astronomy:Communications satellite|communications satellite]]s, [[Astronomy:Reconnaissance satellite|reconnaissance satellite]]s, [[Astronomy:Earth observation satellite|Earth observation satellite]]s, but also for [[Astronomy:Space exploration|space exploration]] such as space observatories and space probes, or even for [[Astronomy:Space tourism|space tourism]].

Spaceflight can be achieved with different types of [[Engineering:Space launch|launch system]]s, conventionally by [[Engineering:Rocket launch|rocket launching]], which provide the initial thrust to overcome the force of gravity and propel a spacecraft from the surface of the Earth. Once in space, the motion of a spacecraft—both when unpropelled and when under propulsion—is covered by the area of study called astrodynamics.

Some spacecraft remain in space practically indefinitely, which has created the problem of space pollution in the form of [[Astronomy:Light pollution|light pollution]] and space junk, which is a hazard to spaceflight. Otherwise spacecraft are terminated by atmospheric reentry, in which they disintegrate, or if they do not, their reentry is mostly controlled to safely reach a surface by landing or impacting, often being dumped into the oceanic [[Astronomy:Spacecraft cemetery|spacecraft cemetery]]. Spacecraft have thus been the subject of some space traffic management.


== Terminology ==
There are several terms that refer to a flight into or through [[Astronomy:Outer space|outer space]].

A '''space mission''' refers to a spaceflight intended to achieve an objective. Objectives for space missions may include [[Astronomy:Space exploration|space exploration]], [[Astronomy:Space research|space research]], and national firsts in spaceflight.

'''Space transport''' is the use of spacecraft to transport people or cargo into or through outer space. This may include [[Astronomy:Human spaceflight|human spaceflight]] and [[Engineering:Cargo spacecraft|cargo spacecraft]] flight.

== History ==
{{For timeline|Timeline of spaceflight}}

The first theoretical proposal of space travel using [[Engineering:Rocket|rocket]]s was published by Scottish astronomer and mathematician William Leitch, in an 1861 essay "A Journey Through Space".<ref>{{cite book|first=William |last=Leitch|title=God's Glory in the Heavens|url=https://archive.org/details/godsgloryinheave00leit|year=1867|publisher=A. Strahan}}</ref> More well-known (though not widely outside Russia) is [[Biography:Konstantin Tsiolkovsky|Konstantin Tsiolkovsky]]'s work, "{{lang|ru|Исследование мировых пространств реактивными приборами}}" (''The Exploration of Cosmic Space by Means of Reaction Devices''), published in 1903.

Spaceflight became an engineering possibility with the work of [[Biography:Robert H. Goddard|Robert H. Goddard]]'s publication in 1919 of his paper ''[[Biography:Robert H. Goddard#A Method of Reaching Extreme Altitudes|A Method of Reaching Extreme Altitudes]]''. His application of the [[Astronomy:De Laval nozzle|de Laval nozzle]] to [[Engineering:Liquid-propellant rocket|liquid-fuel rockets]] improved efficiency enough for interplanetary travel to become possible. He also proved in the laboratory that rockets would work in the vacuum of space;{{specify|date=October 2015}} nonetheless, his work was not taken seriously by the public. His attempt to secure an Army contract for a rocket-propelled weapon in the [[Social:World War I|first World War]] was defeated by the November 11, 1918 armistice with Germany. Working with private financial support, he was the first to launch a liquid-fueled rocket in 1926. Goddard's papers were highly influential internationally in his field.

In the course of [[Social:World War II|World War II]] the first guided rockets, the V-2 were developed and employed as weapons by [[Place:Nazi Germany|Nazi Germany]]. At a test flight in June 1944 one such rocket reached space at an altitude of {{convert|189|km|nmi|sp=us|abbr=off}}, becoming the first object in human history to do so.<ref>{{cite book|first=Lucy |last=Rogers|title=It's ONLY Rocket Science: An Introduction in Plain English|url=https://books.google.com/books?id=75b84eC-ulsC&pg=PA25|year=2008|publisher=Springer Science & Business Media|isbn=978-0-387-75377-5|page=25}}</ref> At the end of World War II, most of the V-2 rocket team including its head [[Biography:Wernher von Braun|Wernher von Braun]] surrendered to the United States, and were expatriated to work on American missiles at what became the Army Ballistic Missile Agency, producing missiles such as Juno I and [[Engineering:SM-65 Atlas|Atlas]].

At that time the [[Place:Soviet Union|Soviet Union]] under {{wipe|Joseph Stalin}} was developing [[Engineering:Intercontinental ballistic missile|intercontinental ballistic missile]]s to carry [[Engineering:Nuclear weapon|nuclear weapon]]s as a counter measure to United States bomber planes. The Tsiolkovsky influenced Sergey Korolev became the chief rocket designer, derivatives of his [[Engineering:R-7 Semyorka|R-7 Semyorka]] missiles were used to launch the world's first artificial Earth [[Astronomy:Satellite|satellite]], [[Engineering:Sputnik 1|Sputnik 1]], on October 4, 1957, and later the first human to orbit the Earth, [[Biography:Yuri Gagarin|Yuri Gagarin]] in [[Astronomy:Vostok 1|Vostok 1]], on April 12, 1961.<ref>{{cite web |first=Peter |last=Bond |url=http://findarticles.com/p/articles/mi_qn4158/is_20030407/ai_n12692130 |archive-url=https://web.archive.org/web/20080108073958/http://findarticles.com/p/articles/mi_qn4158/is_20030407/ai_n12692130 |archive-date=January 8, 2008 |title=Obituary: Lt-Gen Kerim Kerimov |work=The Independent |date=April 7, 2003 |via=findarticles.com}}</ref>

The first US satellite was [[Astronomy:Explorer 1|Explorer 1]], launched on February 1, 1958, and the first American in orbit became [[Biography:John Glenn|John Glenn]] in ''Friendship 7'' on February 20, 1962. As director of the [[Organization:Marshall Space Flight Center|Marshall Space Flight Center]], Von Braun oversaw development of a larger class of rocket called [[Engineering:Saturn (rocket family)|Saturn]], which allowed the US to send the first two humans, Neil Armstrong and [[Biography:Buzz Aldrin|Buzz Aldrin]], to the Moon and back on [[Engineering:Apollo 11|Apollo 11]] in July 1969. At the same time, the Soviet Union secretly tried but failed to develop the [[Engineering:N1 (rocket)|N1 rocket]], meant to give them the capability to land humans on the Moon.

Ever since spaceflight has been widely employed for placing satellites into orbit around Earth for a broad range of purposes, for sending uncrewed spacecraft exploring space beyond the Moon and having continuous crewed [[Astronomy:Human presence in space|human presence in space]] with a series of space stations, from the ''Salyut'' program to the [[Astronomy:International Space Station|International Space Station]].

== Phases ==
=== Launch ===
{{Main|Engineering:Space launch}}
Rockets are the only means currently capable of reaching orbit or beyond. Other [[Astronomy:Non-rocket spacelaunch|non-rocket spacelaunch]] technologies have yet to be built, or remain short of orbital speeds.
A [[Engineering:Rocket launch|rocket launch]] for a spaceflight usually starts from a spaceport (cosmodrome), which may be equipped with launch complexes and [[Engineering:Launch pad|launch pad]]s for vertical rocket launches and runways for takeoff and landing of carrier airplanes and winged spacecraft. Spaceports are situated well away from human habitation for noise and safety reasons. [[Engineering:Intercontinental ballistic missile|ICBMs]] have various special launching facilities.

A launch is often restricted to certain [[Engineering:Launch window|launch window]]s. These windows depend upon the position of celestial bodies and orbits relative to the launch site. The biggest influence is often the rotation of the Earth itself. Once launched, orbits are normally located within relatively constant flat planes at a fixed angle to the axis of the Earth, and the Earth rotates within this orbit.

A [[Engineering:Launch pad|launch pad]] is a fixed structure designed to dispatch airborne vehicles. It generally consists of a launch tower and flame trench. It is surrounded by equipment used to erect, fuel, and maintain launch vehicles. Before launch, the rocket can weigh many hundreds of tonnes. The [[Engineering:Space Shuttle Columbia|Space Shuttle ''Columbia'']], on [[Engineering:STS-1|STS-1]], weighed {{convert|2030|tonne|lb}} at takeoff.

=== Reaching space ===
The most commonly used definition of [[Astronomy:Outer space|outer space]] is everything beyond the [[Earth:Kármán line|Kármán line]], which is {{convert|100|km|mi|sp=us}} above the Earth's surface. The United States sometimes defines outer space as everything beyond {{convert|50|mi|km|sp=us}} in altitude.

[[Engineering:Rocket|Rocket]] engines are the only currently practical means of reaching space. Conventional airplane engines cannot reach space due to the lack of oxygen. Rocket engines expel [[Chemistry:Rocket propellant|propellant]] to provide forward [[Thrust|thrust]] that generates enough [[Astronomy:Delta-v|delta-v]] (change in velocity) to reach orbit.

For crewed launch systems [[Astronomy:Launch escape system|launch escape system]]s are frequently fitted to allow astronauts to escape in the case of emergency.

==== Alternatives ====
{{Main|Astronomy:Non-rocket spacelaunch}}

Many ways to reach space other than rocket engines have been proposed. Ideas such as the [[Astronomy:Space elevator|space elevator]], and [[Engineering:Momentum exchange tether|momentum exchange tether]]s like rotovators or [[Engineering:Skyhook (structure)|skyhooks]] require new materials much stronger than any currently known. Electromagnetic launchers such as [[Physics:Launch loop|launch loop]]s might be feasible with current technology. Other ideas include rocket assisted aircraft/spaceplanes such as Reaction Engines Skylon (currently in early stage development), [[Astronomy:Scramjet|scramjet]] powered spaceplanes, and [[Engineering:Rocket-based combined cycle|RBCC]] powered spaceplanes. Gun launch has been proposed for cargo.

=== Leaving orbit ===
{{Main|Astronomy:Escape velocity|Astronomy:Parking orbit}}
[[Image:RIAN archive 510848 Interplanetary station Luna 1 - blacked.jpg|thumb|upright|Launched in 1959, [[Engineering:Luna 1|Luna 1]] was the first known artificial object to achieve escape velocity from the Earth ''(replica pictured)''.<ref>{{cite web|url=https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1959-012A |title=NASA – NSSDC – Spacecraft – Details |publisher=Nssdc.gsfc.nasa.gov |access-date=November 5, 2013}}</ref>]]

Achieving a closed orbit is not essential to lunar and interplanetary voyages. Early Soviet space vehicles successfully achieved very high altitudes without going into orbit. [[Organization:NASA|NASA]] considered launching [[Astronomy:Apollo program|Apollo]] missions directly into lunar trajectories but adopted the strategy of first entering a temporary [[Astronomy:Parking orbit|parking orbit]] and then performing a separate burn several orbits later onto a lunar trajectory.<ref name="lauwin">{{cite web |url=https://history.nasa.gov/afj/launchwindow/lw1.html |title=Apollo lunar landing launch window: The controlling factors and constraints |publisher=NASA }}</ref>

The parking orbit approach greatly simplified Apollo mission planning in several important ways. It acted as a "time buffer" and substantially widened the allowable [[Engineering:Launch window|launch window]]s. The parking orbit gave the crew and controllers several hours to thoroughly check out the spacecraft after the stresses of launch before committing it for a long journey to the Moon.<ref name="lauwin"/>

Apollo missions minimized the performance penalty of the parking orbit by keeping its altitude as low as possible. For example, [[Engineering:Apollo 15|Apollo 15]] used an unusually low parking orbit of {{cvt|92.5|x|91.5|nmi|km}} which is not sustainable for very long due to friction with the Earth's atmosphere, but the crew would only spend three hours before reigniting the [[Astronomy:S-IVB|S-IVB]] third stage to put them on a lunar-bound trajectory.<ref name=launch>{{cite web |url=https://history.nasa.gov/afj/ap15fj/01launch_to_earth_orbit.html |title=Launch and Reaching Earth Orbit |year=1998 |editor-last=Woods |editor-first=W. David |editor-last2=O'Brien |editor-first2=Frank |work=Apollo 15 Flight Journal |publisher=NASA |access-date=September 5, 2018 |archive-url=https://web.archive.org/web/20171225233954/https://history.nasa.gov/afj/ap15fj/01launch_to_earth_orbit.html |archive-date=December 25, 2017 |url-status=live |df=mdy-all }}</ref>

Robotic missions do not require an abort capability or radiation minimization, and because modern launchers routinely meet "instantaneous" launch windows, space probes to the Moon and other planets generally use direct injection to maximize performance. Although some might coast briefly during the launch sequence, they do not complete one or more full parking orbits before the burn that injects them onto an Earth escape trajectory.

The escape velocity from a celestial body decreases with altitude above that body. However, it is more fuel-efficient for a craft to burn its fuel as close to the ground as possible; see [[Astronomy:Oberth effect|Oberth effect]] and reference.<ref name="Escape Velocity of Earth">[http://van.physics.uiuc.edu/qa/listing.php?id=1053 Escape Velocity of Earth]. Van.physics.uiuc.edu. Retrieved on 2011-10-05.</ref> This is another
way to explain the performance penalty associated with establishing the safe perigee of a parking orbit.

=== Astrodynamics ===
{{Main|Astronomy:Orbital mechanics}}

Astrodynamics is the study of spacecraft trajectories, particularly as they relate to gravitational and propulsion effects. Astrodynamics allows for a spacecraft to arrive at its destination at the correct time without excessive propellant use. An orbital maneuvering system may be needed to maintain or change orbits.

Non-rocket orbital propulsion methods include [[Physics:Solar sail|solar sail]]s, [[Physics:Magnetic sail|magnetic sail]]s, plasma-bubble magnetic systems, and using gravitational slingshot effects.

{{multiple image
 |direction = vertical
 |align     = right
 |width     = 200
 |image1    = Space Shuttle Atlantis in the sky on July 21, 2011, to its final landing.jpg
 |image2    = Keyhole capsule recovery.jpg
 |caption1  = Ionized gas trail from [[Engineering:Space Shuttle|Shuttle]] reentry
 |caption2  = Recovery of Discoverer&nbsp;14 return capsule by a C-119 airplane
}}

=== Transfer energy ===
The term "transfer energy" means the total amount of [[Physics:Energy|energy]] imparted by a rocket stage to its payload.  This can be the energy imparted by a first stage of a [[Engineering:Launch vehicle|launch vehicle]] to an upper stage plus payload, or by an upper stage or spacecraft [[Engineering:Apogee kick motor|kick motor]] to a [[Engineering:Spacecraft|spacecraft]].<ref>{{cite book |title=Space Flight: History, Technology, and Operations |author=Lance K. Erickson |year=2010 |page=187 |publisher=Government Institutes }}</ref><ref>{{cite press release |title=Musk pre-launch backgrounder on Falcon 9 Flight 20 |url=http://www.spacex.com/news/2015/12/21/background-tonights-launch |date=22 December 2015 |access-date=28 December 2015 |publisher=SpaceX |archive-date=8 March 2017 |archive-url=https://web.archive.org/web/20170308172650/http://www.spacex.com/news/2015/12/21/background-tonights-launch |url-status=dead }}</ref>

=== Reaching space station ===
{{main|Astronomy:Space rendezvous|Engineering:Docking and berthing of spacecraft}}
In order to reach towards a space station, a spacecraft would have to arrive at the same [[Physics:Orbit|orbit]] and approach to a very close distance (e.g. within visual contact). This is done by a set of orbital maneuvers called [[Astronomy:Space rendezvous|space rendezvous]].

After rendezvousing with the space station, the space vehicle then docks or berths with the station. Docking refers to joining of two separate free-flying space vehicles,<ref name=her>{{citation|url=https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20110010964.pdf|title=ISS Interface Mechanisms and their Heritage|first1=John |last1=Cook|first2=Valery |last2=Aksamentov|first3=Thomas |last3=Hoffman|first4=Wes |last4=Bruner|date=1 January 2011|publisher=Boeing|access-date=31 March 2015|location=Houston, Texas|quote=Docking is when one incoming spacecraft rendezvous with another spacecraft and flies a controlled collision trajectory in such a manner so as to align and mesh the interface mechanisms. The spacecraft docking mechanisms typically enter what is called soft capture, followed by a load attenuation phase, and then the hard docked position which establishes an air-tight structural connection between spacecraft. Berthing, by contrast, is when an incoming spacecraft is grappled by a robotic arm and its interface mechanism is placed close to the stationary interface mechanism. Then typically there is a capture process, coarse alignment and fine alignment, and then structural attachment.|via=NASA}}</ref><ref name="nasa20090317">{{cite web |title=International Docking Standardization |url=https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20090014038_2009013104.pdf |publisher=NASA |access-date=2011-03-04 |page=15|date=2009-03-17 |quote=Docking: The joining or coming together of two separate free flying space vehicles}}</ref><ref name=ARDS>{{cite book|last=Fehse|first=Wigbert|title=Automated Rendezvous and Docking of Spacecraft|publisher=Cambridge University Press|location=Cambridge, UK|date=2003|isbn=978-0521824927}}</ref><ref name="AdvanDock">{{cite web|title=Advanced Docking/Berthing System – NASA Seal Workshop |url=http://gltrs.grc.nasa.gov/reports/2005/CP-2005-213655-VOL1/15Robertson.pdf |publisher=NASA |access-date=2011-03-04 |page=15 |date=2004-11-04 |quote=Berthing refers to mating operations where an inactive module/vehicle is placed into the mating interface using a Remote Manipulator System-RMS. Docking refers to mating operations where an active vehicle flies into the mating interface under its own power. |url-status=dead |archive-url=https://web.archive.org/web/20110922084406/http://gltrs.grc.nasa.gov/reports/2005/CP-2005-213655-VOL1/15Robertson.pdf |archive-date=September 22, 2011 }}</ref> while berthing refers to mating operations where an inactive vehicle is placed into the mating interface of another space vehicle by using a [[Engineering:Robotic arm|robotic arm]].<ref name=her/><ref name=ARDS/><ref name=AdvanDock/>

=== Reentry ===
Vehicles in orbit have large amounts of kinetic energy. This energy must be discarded if the vehicle is to land safely without vaporizing in the atmosphere. Typically this process requires special methods to protect against [[Astronomy:Aerodynamic heating|aerodynamic heating]]. The theory behind reentry was developed by Harry Julian Allen. Based on this theory, reentry vehicles present blunt shapes to the atmosphere for reentry. Blunt shapes mean that less than 1% of the kinetic energy ends up as heat reaching the vehicle, and the remainder heats up the atmosphere.

=== Landing and recovery ===
The [[Astronomy:Project Mercury|Mercury]], [[Astronomy:Project Gemini|Gemini]], and Apollo capsules all [[Engineering:Splashdown|splashed down]] in the sea. These capsules were designed to land at relatively low speeds with the help of a parachute. Soviet/Russian capsules for [[Engineering:Soyuz (spacecraft)|Soyuz]] make use of a big parachute and braking rockets to touch down on land. [[Astronomy:Spaceplane|Spaceplane]]s like the [[Engineering:Space Shuttle|Space Shuttle]] land like a [[Engineering:Glider (aircraft)|glider]].

After a successful landing the spacecraft, its occupants, and cargo can be recovered. In some cases, recovery has occurred before landing: while a spacecraft is still descending on its parachute, it can be snagged by a specially designed aircraft. This mid-air retrieval technique was used to recover the film canisters from the [[Engineering:Corona (satellite)|Corona]] spy satellites.

== Types ==
=== Uncrewed ===
[[File:Pathfinder01.jpg|thumb|''[[Engineering:Sojourner (rover)|Sojourner]]'' takes its Alpha particle X-ray spectrometer measurement of Yogi Rock on Mars.]]
[[Image:messenger.jpg|thumb|The ''[[Astronomy:MESSENGER|MESSENGER]]'' spacecraft at Mercury (artist's interpretation)]]
{{Main|Engineering:Uncrewed spacecraft}}
{{excerpt|Uncrewed spacecraft|only=paragraphs}}

=== Human ===
{{Main|Astronomy:Human spaceflight}}
[[File:ISS-20 Robert Thirsk at the Minus Eighty Degree Laboratory Freezer.jpg|thumb|[[Astronomy:International Space Station|ISS]] crew member stores samples.]]

The first human spaceflight was [[Astronomy:Vostok 1|Vostok 1]] on April 12, 1961, on which [[Astronaut|cosmonaut]] [[Biography:Yuri Gagarin|Yuri Gagarin]] of the USSR made one orbit around the Earth. In official Soviet documents, there is no mention of the fact that Gagarin parachuted the final seven miles.<ref>[https://web.archive.org/web/20020419041313/http://www.astronautix.com/flights/vostok1.htm Vostok 1]. Astronautix.com. Retrieved on 2011-10-05.</ref> As of 2020, the only spacecraft regularly used for human spaceflight are Soyuz, Shenzhou, and Crew Dragon. The U.S. [[Engineering:Space Shuttle|Space Shuttle]] fleet operated from April 1981 until July 2011. [[Engineering:SpaceShipOne|SpaceShipOne]] has conducted two human suborbital spaceflights.

=== Sub-orbital ===
{{Main| Engineering:Sub-orbital spaceflight}}
[[Image:X-15 flying.jpg|thumb|The [[Engineering:North American X-15|North American X-15]] in flight. X-15 flew above {{cvt|100|km}} twice and both of the flights were piloted by Joe Walker (astronaut).]]

On a [[Engineering:Sub-orbital spaceflight|sub-orbital spaceflight]] the spacecraft reaches space and then returns to the atmosphere after following a (primarily) ballistic trajectory. This is usually because of insufficient [[Astronomy:Specific orbital energy|specific orbital energy]], in which case a suborbital flight will last only a few minutes, but it is also possible for an object with enough energy for an orbit to have a trajectory that intersects the Earth's atmosphere, sometimes after many hours. [[Astronomy:Pioneer 1|Pioneer 1]] was NASA's first [[Engineering:Space probe|space probe]] intended to reach the Moon. A partial failure caused it to instead follow a suborbital trajectory to an altitude of {{convert|113854|km|mi|sp=us}} before reentering the Earth's atmosphere 43 hours after launch.

The most generally recognized boundary of space is the [[Earth:Kármán line|Kármán line]] {{cvt|100|km}} above sea level. (NASA alternatively defines an astronaut as someone who has flown more than {{cvt|50|mi|km|order=flip}} above sea level.) It is not generally recognized by the public that the increase in potential energy required to pass the Kármán line is only about 3% of the orbital energy (potential plus kinetic energy) required by the lowest possible Earth orbit (a circular orbit just above the Kármán line.) In other words, it is far easier to reach space than to stay there. On May 17, 2004, [[Engineering:Civilian Space eXploration Team|Civilian Space eXploration Team]] launched the GoFast rocket on a suborbital flight, the first amateur spaceflight. On June 21, 2004, [[Engineering:SpaceShipOne|SpaceShipOne]] was used for the first [[Engineering:Private spaceflight|privately funded]] [[Astronomy:Human spaceflight|human spaceflight]].

=== Point-to-point ===
Point-to-point, or Earth to Earth transportation, is a category of [[Engineering:Sub-orbital spaceflight|sub-orbital spaceflight]] in which a spacecraft provides rapid transport between two terrestrial locations.<ref name="nsp_ete">
{{cite web
 |url=https://www.nasaspaceflight.com/2020/12/earth-to-earth-supersonic-airliners/
 |title=Preparing for "Earth to Earth" space travel and a competition with supersonic airliners
 |last=Burghardt 
 |first=Thomas
 |date=December 26, 2020
 |website=NASA Spaceflight
 |access-date=January 29, 2021
 |quote=The most prevalent concept for suborbital Earth to Earth transportation comes from none other than Elon Musk and SpaceX. Primarily designed for transporting large payloads to Mars for the purpose of colonization, the next generation Starship launch system offers a bonus capability for transporting large amounts of cargo around Earth.
}}
</ref> A conventional airline route between [[Place:London|London]] and [[Place:Sydney|Sydney]], a flight that normally lasts over twenty hours, could be traversed in less than one hour.<ref>{{cite web | url=http://www.spacex.com/sites/spacex/files/making_life_multiplanetary_transcript_2017.pdf | title=Becoming a Multiplanet Species | date=29 September 2017 | series=68th annual meeting of the International Astronautical Congress in Adelaide, Australia | publisher=SpaceX | access-date=15 April 2018 | archive-date=8 August 2018 | archive-url=https://web.archive.org/web/20180808022709/http://www.spacex.com/sites/spacex/files/making_life_multiplanetary_transcript_2017.pdf | url-status=dead }}</ref> While no company offers this type of transportation today, [[Company:SpaceX|SpaceX]] has revealed plans to do so as early as the 2020s using [[Engineering:SpaceX Starship|Starship]]. Suborbital spaceflight over an intercontinental distance requires a vehicle velocity that is only a little lower than the velocity required to reach low Earth orbit.<ref>{{cite web|first=David |last=Hoerr |url=http://www.thespacereview.com/article/1118/1 |title=Point-to-point suborbital transportation: sounds good on paper, but… |work=The Space Review |date=May 5, 2008 |access-date=November 5, 2013}}</ref> If rockets are used, the size of the rocket relative to the payload is similar to an Intercontinental Ballistic Missile (ICBM). Any intercontinental spaceflight has to surmount problems of heating during atmosphere re-entry that are nearly as large as those faced by orbital spaceflight.

=== Orbital ===
{{Main| Engineering:Orbital spaceflight}}
[[File:S68-27366.jpg|thumb|upright|Apollo 6 heads into orbit.]]
A minimal [[Engineering:Orbital spaceflight|orbital spaceflight]] requires much higher velocities than a minimal sub-orbital flight, and so it is technologically much more challenging to achieve. To achieve orbital spaceflight, the tangential velocity around the Earth is as important as altitude. In order to perform a stable and lasting flight in space, the spacecraft must reach the minimal [[Astronomy:Orbital speed|orbital speed]] required for a [[Physics:Orbit|closed orbit]].

=== Interplanetary ===
{{Main|Astronomy:Interplanetary spaceflight|Engineering:Interplanetary mission}}

[[Astronomy:Interplanetary spaceflight|Interplanetary spaceflight]] is flight between planets within a single [[Astronomy:Planetary system|planetary system]]. In practice, the use of the term is confined to travel between the planets of our [[Astronomy:Solar System|Solar System]]. Plans for future crewed interplanetary spaceflight missions often include final vehicle assembly in Earth orbit, such as NASA's [[Astronomy:Constellation program|Constellation program]] and Russia's [[Engineering:Kliper|Kliper]]/[[Astronomy:Parom|Parom]] tandem.

=== Interstellar ===
{{Main|Engineering:Interstellar travel}}

''[[Astronomy:New Horizons|New Horizons]]'' is the fifth spacecraft put on an escape trajectory leaving the [[Astronomy:Solar System|Solar System]].  ''Voyager 1'', ''Voyager 2'', ''Pioneer 10'', ''Pioneer 11'' are the earlier ones.  The one farthest from the Sun is ''[[Astronomy:Voyager 1|Voyager 1]]'', which is more than 100 [[Astronomy:Astronomical unit|AU]] distant and is moving at 3.6 AU per year.<ref>{{cite web|url=http://www.heavens-above.com/solar-escape.asp
 |title=Spacecraft escaping the Solar System
 |publisher=Heavens-Above GmbH
 |url-status=dead  |archive-url=https://web.archive.org/web/20070427184732/http://www.heavens-above.com/solar-escape.asp |archive-date=April 27, 2007 }}</ref> In comparison, [[Astronomy:Proxima Centauri|Proxima Centauri]], the closest star other than the Sun, is 267,000 AU distant. It will take ''Voyager 1'' over 74,000 years to reach this distance.<!-- This still borders on original research, but is at least consistent with cited sources. --> Vehicle designs using other techniques, such as [[Physics:Nuclear pulse propulsion|nuclear pulse propulsion]] are likely to be able to reach the nearest star significantly faster. Another possibility that could allow for human interstellar spaceflight is to make use of [[Physics:Time dilation|time dilation]], as this would make it possible for passengers in a fast-moving vehicle to travel further into the future while aging very little, in that their great speed slows down the rate of passage of on-board time.  However, attaining such high speeds would still require the use of some new, advanced method of [[Astronomy:Spacecraft propulsion|propulsion]]. Dynamic soaring as a way to travel across interstellar space has been proposed as well.<ref name="SA-20221206">{{cite news |last=Mcrae |first=Mike |title='Dynamic Soaring' Trick Could Speed Spacecraft Across Interstellar Space |url=https://www.sciencealert.com/dynamic-soaring-trick-could-speed-spacecraft-across-interstellar-space |date=6 December 2022 |work=ScienceAlert |accessdate=6 December 2022 }}</ref><ref name="FST-20221128">{{cite journal |last1=Larrouturou |first1=Mathias N. |last2=Higgns |first2=Andrew J. |last3=Greason |first3=Jeffrey K. |title=Dynamic soaring as a means to exceed the solar wind speed |date=28 November 2022 |journal=  Frontiers in Space Technologies|volume=3 |doi=10.3389/frspt.2022.1017442 |arxiv=2211.14643 |bibcode=2022FrST....317442L |doi-access=free }}</ref>

=== Intergalactic ===
{{Main|Astronomy:Intergalactic travel}}

Intergalactic travel involves spaceflight between galaxies, and is considered much more technologically demanding than even interstellar travel and, by current engineering terms, is considered science fiction. However, theoretically speaking, there is nothing to conclusively indicate that intergalactic travel is impossible. To date several academics have studied intergalactic travel in a serious manner.<ref name="burruss">{{cite journal | first1 = Robert Page | last1 = Burruss | first2= J. | last2= Colwell | title = Intergalactic Travel: The Long Voyage From Home | journal = The Futurist | date=September–October 1987 | volume= 21 | issue= 5 | pages = 29–33}}</ref><ref>{{cite journal | author= Fogg, Martyn | title= The Feasibility of Intergalactic Colonisation and its Relevance to SETI | journal= Journal of the British Interplanetary Society | volume= 41 | number= 11 | date= November 1988 | pages= 491–496 | url= https://www.academia.edu/4166742 | bibcode= 1988JBIS...41..491F }}</ref><ref>{{cite journal | author= Armstrong, Stuart | author2= Sandberg, Anders | url= http://www.fhi.ox.ac.uk/intergalactic-spreading.pdf | title=Eternity in six hours: intergalactic spreading of intelligent life and sharpening the Fermi paradox | journal= Acta Astronautica | year= 2013 | volume= 89 | page= 1 | publisher= Future of Humanity Institute, Philosophy Department, Oxford University| doi= 10.1016/j.actaastro.2013.04.002 | bibcode= 2013AcAau..89....1A }}</ref>

== Spacecraft ==
{{Main|Engineering:Spacecraft}}
[[Image:Apollo16LM.jpg|thumb|right|An Apollo Lunar Module on the lunar surface]]

Spacecraft are vehicles designed to operate in space.

The first 'true spacecraft' is sometimes said to be [[Engineering:Apollo Lunar Module|Apollo Lunar Module]],<ref>[https://history.nasa.gov/SP-350/ch-10-3.html Apollo Expeditions to the Moon: Chapter 10]. History.nasa.gov (1969-03-03). Retrieved on 2011-10-05.</ref> since this was the only crewed vehicle to have been designed for, and operated only in space; and is notable for its non-aerodynamic shape.

=== Propulsion ===
{{Main|Astronomy:Spacecraft propulsion}}

Spacecraft today predominantly use [[Engineering:Rocket|rocket]]s for [[Astronomy:Spacecraft propulsion|propulsion]], but other propulsion techniques such as ion drives are becoming more common, particularly for uncrewed vehicles, and this can significantly reduce the vehicle's mass and increase its [[Astronomy:Delta-v|delta-v]].

=== Launch systems ===
{{main|Engineering:Launch vehicle}}

Launch systems are used to carry a payload from Earth's surface into outer space.

==== Expendable ====
{{Main|Engineering:Expendable launch system}}
Most current spaceflight uses [[Astronomy:Multistage rocket|multi-stage]] expendable launch systems to reach space.

==== Reusable ====
{{Main|Astronomy:Reusable launch system}}
The first reusable spacecraft, the X-15, was air-launched on a suborbital trajectory on 19 July 1963. The first partially reusable orbital spacecraft, the [[Engineering:Space Shuttle|Space Shuttle]], was launched by the USA on the 20th anniversary of [[Biography:Yuri Gagarin|Yuri Gagarin]]'s flight, on 12 April 1981. During the Shuttle era, six orbiters were built, all of which flown in the atmosphere and five of which flown in space. The ''[[Engineering:Space Shuttle Enterprise|Enterprise]]'' was used only for approach and landing tests, launching from the back of a [[Engineering:Boeing 747|Boeing 747]] and gliding to deadstick landings at Edwards AFB, California. The first Space Shuttle to fly into space was the ''[[Engineering:Space Shuttle Columbia|Columbia]]'', followed by the ''[[Engineering:Space Shuttle Challenger|Challenger]]'', ''[[Engineering:Space Shuttle Discovery|Discovery]]'', ''[[Engineering:Space Shuttle Atlantis|Atlantis]]'', and ''[[Engineering:Space Shuttle Endeavour|Endeavour]]''. The ''Endeavour'' was built to replace the ''Challenger'', which was [[Engineering:STS-51-L|lost]] in January 1986. The ''Columbia'' [[Engineering:Space Shuttle Columbia disaster|broke up]] during reentry in February 2003.

The first automatic partially reusable spacecraft was the ''Buran'' (''Snowstorm''), launched by the USSR on 15 November 1988, although it made only one flight. This [[Astronomy:Spaceplane|spaceplane]] was designed for a crew and strongly resembled the US Space Shuttle, although its drop-off boosters used liquid propellants and its main engines were located at the base of what would be the external tank in the American Shuttle. Lack of funding, complicated by the dissolution of the USSR, prevented any further flights of Buran.

The Space Shuttle was retired in 2011 due mainly to its old age. The Shuttle's human transport role is to be replaced by the [[Engineering:SpaceX Dragon 2|SpaceX Dragon 2]] and CST-100 in the 2020s. The Shuttle's heavy cargo transport role is now done by commercial launch vehicles.

[[Company:Scaled Composites|Scaled Composites]] [[Engineering:SpaceShipOne|SpaceShipOne]] was a reusable suborbital spaceplane that carried pilots Mike Melvill and Brian Binnie on consecutive flights in 2004 to win the Ansari X Prize. [[Company:The Spaceship Company|The Spaceship Company]] has built its successor [[Engineering:SpaceShipTwo|SpaceShipTwo]]. A fleet of SpaceShipTwos operated by [[Company:Virgin Galactic|Virgin Galactic]] planned to begin reusable [[Engineering:Private spaceflight|private spaceflight]] carrying paying passengers ([[Astronomy:Space tourism|space tourists]]) in 2008, but this was delayed due to an accident in the propulsion development.<ref>[http://www.flightglobal.com/news/articles/virgin-galactics-spaceshiptwo-plans-held-up-by-testing-accident-217949/ Launch aircraft development continues while suborbital ship awaits investigation into fatal explosion in California], retrieved 2012-01-27.</ref>

[[Company:SpaceX|SpaceX]] achieved the first vertical soft landing of a re-usable orbital rocket stage on December 21, 2015, after delivering 11 [[Engineering:Orbcomm OG-2|Orbcomm OG-2]] commercial satellites into [[Astronomy:Low Earth orbit|low Earth orbit]].<ref>{{cite web|url=https://twitter.com/SpaceX/status/679114269485436928|title=SpaceX on Twitter|work=Twitter}}</ref>

The first Falcon 9 second flight occurred on 30 March 2017.<ref>{{cite news|url=https://www.theguardian.com/science/video/2017/mar/31/spacex-successfuly-launches-first-recycled-rocket-video|title=SpaceX {{sic|nolink=y|reason=error in source|successful|y}} launches first recycled rocket – video|date=31 March 2017|agency=Reuters|work=The Guardian}}</ref> SpaceX now routinely recovers and reuses [[Engineering:SpaceX reusable launch system development program|their first stages, with the intent of reusing fairings as well]].<ref>{{Cite web | url=https://www.space.com/spacex-reuse-payload-fairing-starlink-launch.html |title = SpaceX Recovered Falcon Heavy Nose Cone, Plans to Re-fly it This Year (Photos)|website = Space.com| date=12 April 2019 }}</ref> SpaceX is now developing a fully reusable super heavy lift rocket known as [[Engineering:SpaceX Starship|Starship]], hoped to drastically reduce the price of space exploration due to being fully reusable.

{{multiple image
 | total_width = 
 | align  = center
 | image1 = X-15 flying.jpg
 | caption1 = The X-15 pulling away from its drop launch plane
 | image2 = Space Shuttle Columbia launching.jpg
 | caption2 = The {{OV|102}} seconds after engine ignition on mission [[Engineering:STS-1|STS-1]]
 | image3 = SpaceShipOne Flight 15P photo D Ramey Logan.jpg
 | caption3 = [[Engineering:SpaceShipOne|SpaceShipOne]] after its flight into space, 21 June 2004
 | image4 = ORBCOMM-2 (23282658734).jpg
 | caption4 = Falcon 9 Flight 20's first stage landing vertically on Landing Zone 1 in December 2015 
}}

== Challenges ==
{{main|Astronomy:Human spaceflight|Astronomy:Effect of spaceflight on the human body}}

=== Safety ===
{{Main|Astronomy:List of spaceflight-related accidents and incidents}}

All launch vehicles contain a huge amount of energy that is needed for some part of it to reach orbit. There is therefore some risk that this energy can be released prematurely and suddenly, with significant effects. When a [[Engineering:Delta II|Delta II]] rocket exploded 13 seconds after launch on January 17, 1997, there were reports of store windows {{convert|10|mi|km}} away being broken by the blast.<ref>{{cite news | url = http://www.cnn.com/TECH/9701/17/rocket.explosion/index.html | title = Unmanned rocket explodes after liftoff | publisher = CNN }}</ref>

Space is a fairly predictable environment, but there are still risks of accidental depressurization and the potential failure of equipment, some of which may be very newly developed.

In 2004 the International Association for the Advancement of Space Safety was established in the Netherlands to further international cooperation and scientific advancement in space systems safety.<ref>{{cite web |url=http://www.congrex.nl/07a02/ |archive-url=https://archive.today/20120724193521/http://www.congrex.nl/07a02/ |url-status=dead |archive-date=24 July 2012 |title= The second IAASS: Introduction |access-date=3 January 2009 |work=Congrex |publisher=European Space Agency}}</ref>

=== Weightlessness ===
{{Main|Physics:Weightlessness}}
[[Image:Foale ZeroG.jpg|thumb|upright=1.1|Astronauts on the [[Astronomy:International Space Station|ISS]] in weightless conditions. Michael Foale can be seen exercising in the foreground.]]

In a microgravity environment such as that provided by a spacecraft in orbit around the Earth, humans experience a sense of "weightlessness." Short-term exposure to microgravity causes [[Astronomy:Space adaptation syndrome|space adaptation syndrome]], a self-limiting nausea caused by derangement of the [[Biology:Vestibular system|vestibular system]]. Long-term exposure causes multiple health issues. The most significant is bone loss, some of which is permanent, but microgravity also leads to significant [[Biology:Deconditioning|deconditioning]] of muscular and cardiovascular tissues.

=== Radiation ===
Once above the atmosphere, radiation due to the Van Allen belts, [[Physics:Solar radiation|solar radiation]] and cosmic radiation issues occur and increase. Further away from the Earth, [[Astronomy:Solar flare|solar flare]]s can give a fatal radiation dose in minutes, and the [[Astronomy:Health threat from cosmic rays|health threat from cosmic radiation]] significantly increases the chances of cancer over a decade exposure or more.<ref>[https://science.nasa.gov/science-news/science-at-nasa/2002/16sep_rightstuff/ Super Spaceships], ''[[Organization:NASA|NASA]]'', 16 September 2002, Retrieved 25 October 2011.</ref>

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

In human spaceflight, the [[Engineering:Life support system|life support system]] is a group of devices that allow a human being to survive in outer space. [[Organization:NASA|NASA]] often uses the phrase Environmental Control and Life Support System or the acronym ECLSS when describing these systems for its [[Astronomy:Human spaceflight|human spaceflight]] missions.<ref>{{cite web|url=https://science.nasa.gov/headlines/y2000/ast13nov_1.htm |title=Breathing Easy on the Space Station |publisher=NASA |url-status=dead |archive-url=https://web.archive.org/web/20080921141609/https://science.nasa.gov/headlines/y2000/ast13nov_1.htm |archive-date=2008-09-21 }}</ref> The life support system may supply: air, [[Chemistry:Water|water]] and food. It must also maintain the correct body temperature, an acceptable pressure on the body and deal with the body's waste products. Shielding against harmful external influences such as radiation and micro-meteorites may also be necessary. Components of the life support system are life-critical, and are designed and constructed using [[Engineering:Safety engineering|safety engineering]] techniques.

=== Space weather ===
{{Main|Astronomy:Space weather}}
[[Image:Aurora-SpaceShuttle-EO.jpg|thumb|upright=1.1|[[Aurora (astronomy)|Aurora australis]]
and [[Engineering:Space Shuttle Discovery|''Discovery'']], May 1991]]

Space weather is the concept of changing environmental conditions in [[Astronomy:Outer space|outer space]]. It is distinct from the concept of [[Earth:Weather|weather]] within a planetary atmosphere, and deals with phenomena involving ambient [[Physics:Plasma|plasma]], magnetic fields, [[Physics:Radiation|radiation]] and other [[Physics:Matter|matter]] in space (generally close to Earth but also in interplanetary, and occasionally [[Astronomy:Interstellar medium|interstellar medium]]). "Space weather describes the conditions in space that affect Earth and its technological systems. Our space weather is a consequence of the behavior of the Sun, the nature of Earth's magnetic field, and our location in the Solar System."<ref>[http://www7.nationalacademies.org/ssb/SSB_Space_weather97.pdf Space Weather: A Research Perspective] {{Webarchive|url=https://web.archive.org/web/20090326235324/http://www7.nationalacademies.org/ssb/SSB_Space_weather97.pdf |date=2009-03-26 }}, National Academy of Sciences, 1997</ref>

Space weather exerts a profound influence in several areas related to space exploration and development. Changing geomagnetic conditions can induce changes in atmospheric density causing the rapid degradation of spacecraft altitude in [[Astronomy:Low Earth orbit|Low Earth orbit]]. Geomagnetic storms due to increased solar activity can potentially blind sensors onboard spacecraft, or interfere with on-board electronics. An understanding of space environmental conditions is also important in designing shielding and life support systems for crewed spacecraft.

=== Environmental considerations ===
Exhaust pollution of rockets depends on the produced exhausts by the propellants reactions and the location of exhaustion. They mostly exhaust [[Chemistry:Greenhouse gas|greenhouse gas]]es and sometimes toxic components. Particularly at higher levels of the atmosphere the potency of exhausted gases as greenhouse gases increases considerably

.<ref name="Gammon 2021"/> Many solid rockets have chlorine in the form of [[Chemistry:Perchlorate|perchlorate]] or other chemicals, and this can cause temporary local holes in the ozone layer. Re-entering spacecraft generate nitrates which also can temporarily impact the ozone layer. Most rockets are made of metals that can have an environmental impact during their construction.
While spaceflight altogether pollutes at a fraction of other human activities, it still does pollute heavily if calculated per passenger.<ref name="Gammon 2021">{{cite web | last=Gammon | first=Katharine | title=How the billionaire space race could be one giant leap for pollution | website=the Guardian | date=2021-07-19 | url=http://www.theguardian.com/science/2021/jul/19/billionaires-space-tourism-environment-emissions | access-date=2022-05-05}}</ref>

In addition to the atmospheric effects there are effects on the near-Earth space environment. There is the possibility that orbit could become inaccessible for generations due to exponentially increasing [[Astronomy:Space debris|space debris]] caused by spalling of satellites and vehicles ([[Earth:Kessler syndrome|Kessler syndrome]]). Many launched vehicles today are therefore designed to be re-entered after use.

=== Regulation ===
{{Main|Astronomy:Space law}}

A wide range of issues such as space traffic management or liability have been issues of spaceflight regulation.

Participation and representation of all humanity in spaceflight is an issue of international [[Astronomy:Space law|space law]] ever since the first phase of space exploration.<ref name="Durrani"/> Even though some rights of non-spacefaring countries have been secured, sharing of space for all humanity is still criticized as [[Social:Imperialism|imperialist]] and lacking, understanding spaceflight as a resource.<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 |date=19 July 2019|magazine=The Nation}}</ref>

== Applications ==
{{Further|Astronomy:Human presence in space}}
[[File:S74-15583skylabsunview.jpg|thumb|upright=1.75|This shows an extreme ultraviolet view of the Sun (the Apollo Telescope Mount SO82A Experiment) taken during [[Engineering:Skylab 3|Skylab 3]], with the Earth added for scale. On the right an image of the Sun shows a helium emissions, and there is an image on the left showing emissions from iron. One application for spaceflight is to take observation hindered or made more difficult by being on Earth's surface. Skylab included a massive crewed solar observatory that revolutionized solar science in the early 1970s using the Apollo-based space station in conjunction with crewed spaceflights to it.]]
Current and proposed applications for spaceflight include:
* [[Astronomy:Earth observation satellite|Earth observation satellite]]s such as spy satellites, [[Engineering:Weather satellite|weather satellite]]s
* [[Astronomy:Space exploration|Space exploration]]
* Communication satellites
* [[Engineering:Satellite television|Satellite television]]
* [[Earth:Satellite navigation|Satellite navigation]]
* [[Astronomy:Space tourism|Space tourism]]
* Protecting Earth from [[Astronomy:Potentially hazardous object|potentially hazardous object]]s
* [[Engineering:Space colonization|Space colonization]]

Most early spaceflight development was paid for by governments. However, today major launch markets such as communication satellites and satellite television are purely commercial, though many of the launchers were originally funded by governments.

[[Engineering:Private spaceflight|Private spaceflight]] is a rapidly developing area: space flight that is not only paid for by corporations or even private individuals, but often provided by [[Astronomy:List of private spaceflight companies|private spaceflight companies]]. These companies often assert that much of the previous high cost of access to space was caused by governmental inefficiencies they can avoid. This assertion can be supported by much lower published launch costs for private space launch vehicles such as [[Engineering:Falcon 9|Falcon 9]] developed with private financing. Lower launch costs and excellent safety will be required for the applications such as space tourism and especially space colonization to become feasible for expansion.

==Spacefaring==
{{anchor|Spacefaring nations}}
[[File:List of countries by spaceflight development.svg|thumb|400px|Map showing countries with spaceflight capability
{{legend|#1d4066|Countries with independently developed human spaceflight programs}}
{{legend|#0d7288|Countries that have operated at least one human spaceflight program, if not independently}}
{{legend|#58becf|Countries seeking to develop a human spaceflight program but also have developed or currently own a launch vehicle}}
{{legend|#7b9eab|Countries who operate a launch vehicle and a satellite but currently have no plans to develop a crewed space vehicle}}
{{legend|#dbba23|Countries seeking to develop a launch vehicle}}
{{legend|#d3cc87|Countries who operate an orbiting satellite but do not own a launch vehicle or have plans to produce one}}
{{legend|#000000|Countries who have a launch vehicle but do not currently operate a satellite}}
]]
To be '''spacefaring''' is to be capable of and active in the operation of [[Engineering:Spacecraft|spacecraft]]. It involves a knowledge of a variety of topics and development of specialised skills including: [[Earth:Aeronautics|aeronautics]]; [[Earth:Astronautics|astronautics]]; programs to train [[Astronaut|astronaut]]s; [[Astronomy:Space weather|space weather]] and forecasting; spacecraft operations; operation of various equipment; spacecraft design and construction; atmospheric takeoff and reentry; [[Astronomy:Orbital mechanics|orbital mechanics]] (a.k.a. astrodynamics); communications; engines and rockets; execution of evolutions such as towing, microgravity construction, and space docking; cargo handling equipment, dangerous cargos and cargo storage; spacewalking; dealing with emergencies; survival at space and first aid; fire fighting; life support. The degree of knowledge needed within these areas is dependent upon the nature of the work and the type of vessel employed. "Spacefaring" is analogous to seafaring.

There has never been a crewed mission outside the [[Astronomy:Earth|Earth]]–[[Astronomy:Moon|Moon]] system. However, the United States, Russia, China, [[Organization:European Space Agency|European Space Agency]]  (ESA) countries, and a few corporations and enterprises have plans in various stages to travel to [[Astronomy:Mars|Mars]] (see [[Astronomy:Human mission to Mars|Human mission to Mars]]).

Spacefaring entities can be [[Earth:Sovereign state|sovereign state]]s, supranational entities, and private [[Company:Corporation|corporation]]s. Spacefaring nations are those capable of independently building and launching craft into space.<ref>{{Cite web|url=http://dictionary.reference.com/search?q=spacefaring|title=spacefaring - Definitions from Dictionary.com<!-- Bot generated title -->}}</ref><ref>{{Cite web|url=https://www.bartleby.com/|archiveurl=https://web.archive.org/web/20050326210048/http://www.bartleby.com/61/70/S0597000.html|url-status=dead|title=Homework Help and Textbook Solutions &#124; bartleby|archivedate=March 26, 2005|website=www.bartleby.com}}</ref><ref>{{Cite web|url=https://www.thefreedictionary.com/space-faring+nation|title=space-faring nation|website=TheFreeDictionary.com}}</ref> A growing number of private entities have become or are becoming spacefaring. 

=== Global coordination ===
The [[Organization:United Nations Office for Outer Space Affairs|United Nations Office for Outer Space Affairs]] (UNOOSA) has been the main multilateral body servicing international contact and exchange on space activity among spacefaring and non-spacefaring states.

===Crewed spacefaring nations===
{{Further|Astronomy:Human spaceflight}}

Currently {{wipe|Russia}}, the {{wipe|United States}} and {{wipe|China}} are the only crewed spacefaring [[Earth:Nation|nation]]s.
Spacefaring nations listed by date of first crewed launch:
# [[Place:Soviet Union|Soviet Union]] ({{wipe|Russia}}) (1961)
# {{wipe|United States}} (1961)
# {{wipe|China}} (2003)

===Uncrewed spacefaring nations===
{{Further|Engineering:Timeline of first orbital launches by country}}
The following nations or organizations have developed their own launch vehicles to launch uncrewed spacecraft into orbit either from their own territory or with foreign assistance (date of first launch in parentheses):<ref>{{Cite web|url=http://www.spacetoday.org/Satellites/Iran/IranianSat.html|title=Space Today Online - Iran space satellite launch|website=www.spacetoday.org}}</ref>

# [[Place:Soviet Union|Soviet Union]] (1957)
# {{wipe|United States}} (1958)
# {{wipe|France}} (1965)
# Italy (1967)★
# {{wipe|Australia}}  (1967)★
# {{wipe|Japan}} (1970)
# {{wipe|China}} (1970)
# {{wipe|United Kingdom}} (1971)
# [[Organization:European Space Agency|European Space Agency]] (1979)
# {{wipe|India}} (1980)
# [[Place:Israel|Israel]] (1988)
# {{wipe|Ukraine}} (1991)*<ref>{{cite web|title=Launches of Ukrainian LV|url=http://www.nkau.gov.ua/nsau/catalogNEW.nsf/zapuskbydataE!OpenView&Start=117|work=State Space Agency of Ukraine|access-date=20 April 2014}}</ref>
# {{wipe|Russia}} (1992)*
# [[Religion:Iran|Iran]] (2009)<ref name=space20140101>{{cite news|title=Iran Launches Small Earth-Watching Satellite Into Orbit: Report|url=http://www.space.com/14464-iran-launches-small-satellite-orbit.html|access-date=2014-01-01|newspaper=space.com|date=2012-02-03}}</ref>
# North Korea (2012)<ref>{{cite news|url=https://www.bbc.co.uk/news/world-asia-20690338|title=North Korea defies warnings to launch rocket|publisher=BBC|date=12 December 2012|access-date=12 December 2012}}</ref>
# {{wipe|South Korea}} (2013)★<ref name=xinhua20130130>{{cite news|title=S. Korea successfully launches space rocket|url=http://news.xinhuanet.com/english/world/2013-01/30/c_132138953.htm|access-date=2013-02-10|newspaper=xinhuanet.com|date=2013-01-30|url-status=dead|archive-url=https://web.archive.org/web/20130204012038/http://news.xinhuanet.com/english/world/2013-01/30/c_132138953.htm|archive-date=2013-02-04}}</ref>
# [[Earth:New Zealand|New Zealand]] (2018)★
* *Previously a major region in the Soviet Union
* ★Launch vehicle fully or partially developed by another country

Also several countries, such as Canada, Italy, and Australia, had semi-independent spacefaring capability, launching locally-built satellites on foreign launchers. Canada had designed and built satellites (''[[Engineering:Alouette 1|Alouette 1]]'' and [[Engineering:Alouette 2|2]]) in 1962 and 1965 which were orbited using U.S. launch vehicles. Italy has designed and built several satellites, as well as pressurized modules for the [[Astronomy:International Space Station|International Space Station]]. 
Early Italian satellites were launched using vehicles provided by NASA, first from [[Organization:Wallops Flight Facility|Wallops Flight Facility]] in 1964 and then from a spaceport in Kenya (San Marco Platform) between 1967 and 1988;{{citation needed|date=February 2013}} 
Italy has led the development of the Vega rocket programme within the European Space Agency since 1998.<ref name="ESA Vega Programme">{{cite web | url=http://www.esa.int/Our_Activities/Launchers/Launch_vehicles/Vega3/Vega_programme | title=Vega Programme | publisher=ESA | work=www.esa.int | access-date=February 10, 2013 | archive-date=March 14, 2016 | archive-url=https://web.archive.org/web/20160314131009/http://www.esa.int/Our_Activities/Launchers/Launch_vehicles/Vega3/Vega_programme | url-status=dead }}</ref>
The {{wipe|United Kingdom}} abandoned its independent space launch program in 1972 in favour of co-operating with the European Launcher Development Organisation (ELDO) on launch technologies until 1974. Australia abandoned its launcher program shortly after the successful launch of [[Engineering:WRESAT|WRESAT]], and became the only non-European member of ELDO.

===Suborbital===
Considering merely launching an object beyond the [[Earth:Kármán line|Kármán line]] to be the minimum requirement of spacefaring, [[Place:Nazi Germany|Germany]], with the [[Engineering:V-2 rocket|V-2 rocket]], became the first spacefaring nation in 1944.<ref>''Peenemünde,'' Walter Dornberger, Moewig, Berlin 1984. {{ISBN|3-8118-4341-9}}.</ref> The following nations have only achieved suborbital spaceflight capability by launching indigenous [[Engineering:Rocket|rocket]]s or [[Engineering:Missile|missile]]s or both into suborbital space:

# [[Place:Nazi Germany|Nazi Germany]] (June 20, 1944)
# [[Place:East Germany|East Germany]] (April 12, 1957)
# {{wipe|Canada}} (September 5, 1959)
# [[Place:Lebanon|Lebanon]] (November 21, 1962)
# {{wipe|Switzerland}} (October 27, 1967)
# {{wipe|Argentina}} (April 16, 1969)
# {{wipe|Brazil}} (September 21, 1976)
# {{wipe|Spain}} (February 18, 1981)
# West Germany (March 1, 1981)
# Iraq (June 1984)
# {{wipe|South Africa}} (June 1, 1989)
# Sweden (May 8, 1991)
# Yemen (May 12, 1994)
# {{wipe|Pakistan}} (April 6, 1998)
# Taiwan (December 15, 1998)
# [[Place:Syria|Syria]] (September 1, 2000)
# Indonesia (September 29, 2004)
# Democratic Republic of the Congo (2007)
# [[Earth:New Zealand|New Zealand]] (November 30, 2009)
# {{wipe|Norway}} (September 27, 2018)
# Netherlands (September 19, 2020)<ref>{{Cite web|title=T-Minus Engineering - T-Minus DART|url=http://www.t-minus.nl/products/dart|access-date=2020-09-19|website=www.t-minus.nl}}</ref><ref>{{Cite web|title=Couriermail.com.au {{!}} Subscribe to The Courier Mail for exclusive stories|url=https://www.couriermail.com.au/subscribe/news/1/?sourceCode=CMWEB_WRE170_a_GGL&dest=https://www.couriermail.com.au/news/south-australia/southern-launch-to-attempt-second-rocket-launch-to-the-edge-of-space-from-koonibba-in-outback-south-australia/news-story/624294b7d5b34107e1f5ba162a3898da&memtype=anonymous&mode=premium&nk=7934fb08cbe5fff84b7aa72030829bbd-1600479859&v21suffix=97-a|access-date=2020-09-19|website=www.couriermail.com.au}}</ref><ref>{{Cite web|date=2020-09-14|title=Australia re-enters the space race|url=https://cosmosmagazine.com/space/exploration/australia-re-enters-the-space-race/|access-date=2020-09-19|website=Cosmos Magazine|language=en-AU}}</ref><ref>{{Cite web|title=Australian Space Agency|url=https://twitter.com/ausspaceagency/status/1307121671300673540|access-date=2020-09-19|website=Twitter|language=en}}</ref><ref>{{Cite web|title=Southern Launch|url=https://forum.nasaspaceflight.com/index.php?topic=46926.60|access-date=2020-09-19|website=forum.nasaspaceflight.com}}</ref><ref>{{Cite web|title=Upcoming Launches|url=https://southernlaunch.space/upcominglaunches|access-date=2020-09-19|website=Southern Launch|language=en-AU}}</ref><ref>{{Cite web|title=Successful fire|url=https://twitter.com/southernlaunch/status/1307117421648654337|access-date=2020-09-19|website=Twitter|language=en}}</ref>
#[[Place:Turkey|Turkey]] (October 29, 2020)

== See also ==

{{Div col|colwidth=25em}}
* {{annotated link|Engineering:List of crewed spacecraft}}
* {{annotated link|Astronomy:List of Solar System probes}}
* {{annotated link|Astronomy:List of spaceflight records}}
* {{annotated link|Engineering:List of uncrewed spacecraft by program}}
* {{annotated link|Software:Orbiter (simulator)}}
* {{annotated link|Engineering:Private spaceflight}}
* {{annotated link|Medicine:Space and survival}}
* {{annotated link|Engineering:Space advocacy}}
* {{annotated link|Engineering:Space colonization}}
* {{annotated link|Engineering:Space logistics}}
* [[Engineering:Space travel in science fiction|Space travel in science fiction]]
* {{annotated link|Astronomy:Spacecraft propulsion}}
* {{annotated link|Engineering:Timeline of artificial satellites and space probes}}
* {{annotated link|Astronomy:Timeline of Solar System exploration}}
* {{annotated link|Astronomy:Soviet space exploration history on Soviet stamps}}
* {{annotated link|Astronomy:U.S. space exploration history on U.S. stamps}}
* {{annotated link|Astronomy:Kardashev scale}}
{{Div col end}}
{{clear right}}

== References ==
{{Reflist}}

== Further reading ==
* Erik Gregerson (2010): ''An Explorer's Guide to the Universe – Unmanned Space Missions'', Britannica Educational Publishing, {{ISBN|978-1-61530-052-5}} (eBook)
* Sarah Scoles, "Why We'll Never Live in Space: The technological, biological, psychological and ethical challenges to leaving Earth", vol. 329, no. 3 (October 2023), pp. 22–29. "Perhaps the most significant concern is [[Physics:Radiation|radiation]], something that is manageable for today's astronauts flying in low-Earth orbit but would be a bigger deal for people traveling farther and for longer." (p. 25.) "On the edge of terrestrial frontiers, people were seeking, say, gold or more farmable land. In space, explorers can't be sure of the value proposition at their destination." (p. 27.) "Harmful extraterrestrial microbes could return with astronauts or equipment – a planetary-protection risk called backward [[Chemistry:Contamination|contamination]]." (p. 28.)
* Rebecca Boyle, "A Space Settler Walks into a Dome...: A very funny book about why living on [[Astronomy:Mars|Mars]] is a terrible idea" (review of Kelly Weinersmith and [[Biography:Zach Weinersmith|Zach Weinersmith]], ''A City on Mars: Can We Settle Space, Should We Settle Space, and Have We Really Thought This Through?'', Penguin Press, 2023), ''Scientific American'', vol. 329, no. 4 (November 2023), p. 93.

== External links ==
{{Library resources box}}
* Aerospace engineering at Wikiversity
* [https://web.archive.org/web/20020705003646/http://www.astronautix.com/index.html Encyclopedia Astronautica]
* [http://www2.jpl.nasa.gov/basics/ Basics of Spaceflight]
* {{cite web |author = Tedd E. Hankins |author2 = H. Paul Shuch | url = http://www.qsl.net/n/n6tx/prose/ham/manned.pdf | title = Reflections – manned vs. unmanned spaceflight |date=1987-03-04 |access-date=2011-04-15}}

{{Spaceflight}}
{{Space exploration lists and timelines}}
{{Solar System}}


[[Category:Spaceflight| ]]

{{Sourceattribution|Spaceflight}}