Editing Spaceflight (section)

{{Short description|Flight into or through outer space}}
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[[File:Tracy Caldwell Dyson in Cupola ISS.jpg|thumb|upright=1.5|[[Tracy Caldwell Dyson]] in the [[International Space Station]]'s [[Cupola (ISS module)|Cupola]]]]
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'''Spaceflight''' (or '''space flight''') is an application of [[astronautics]] to fly objects, usually [[spacecraft]], into or through [[outer space]], either [[human spaceflight|with]] or [[uncrewed spaceflight|without humans on board]]. Most spaceflight is uncrewed and conducted mainly with spacecraft such as [[satellite]]s in [[Geocentric orbit|orbit around Earth]], but also includes [[space probe]]s for flights beyond Earth orbit. Such spaceflights operate either by [[telerobotic]] or [[Autonomous robot|autonomous]] control. The first spaceflights began in the 1950s with the launches of the Soviet [[Sputnik program|Sputnik]] satellites and American [[Explorers Program|Explorer]] and [[Project Vanguard|Vanguard]] missions. [[Human spaceflight programs]] include the [[Soyuz programme|Soyuz]], [[China Manned Space Program|Shenzhou]], the past [[Apollo program|Apollo Moon landing]] and the [[Space Shuttle program]]s. Other current spaceflight are conducted to the [[International Space Station]] and to China's [[Tiangong Space Station]].

Spaceflights include the launches of [[Earth observation satellite|Earth observation]] and [[Communications satellite|telecommunications]] satellites, [[Interplanetary spaceflight|interplanetary missions]], the rendezvouses and dockings with [[space station]]s, and [[Human spaceflight|crewed spaceflights]] on [[Space science|scientific]] or [[Space tourism|tourist]] missions.

Spaceflight can be achieved conventionally via [[multistage rocket]]s, which provide the thrust to overcome the force of gravity and propel spacecraft onto [[Sub-orbital spaceflight|suborbital trajectories]]. If the mission is [[Orbital spaceflight|orbital]], the spacecraft usually separates the [[First stage (rocketry)|first stage]] and ignites the [[second stage]], which propels the spacecraft to high enough speeds that it reaches orbit. Once in orbit, spacecraft are at high enough speeds that they fall around the Earth rather than fall back to the surface.

Most spacecraft, and all crewed spacecraft, are designed to [[deorbit]] themselves or, in the case of uncrewed spacecraft in high-energy orbits, to boost themselves into [[graveyard orbit]]s. Used upper stages or failed spacecraft, however, often lack the ability to deorbit themselves. This becomes a major issue when large numbers of uncontrollable spacecraft exist in frequently used orbits, increasing the risk of [[Space debris|debris]] colliding with functional satellites. This problem is exacerbated when large objects, often upper stages, break up in orbit or collide with other objects, creating often hundreds of small, hard to find pieces of debris. This problem of continuous collisions is known as [[Kessler syndrome]].