Space habitats

A space habitat (also called a space colony, space settlement, orbital habitat, orbital settlement or orbital colony) is a type of space station, intended as a permanent settlement rather than as a simple way-station or other specialized facility. No space habitats have yet been constructed but many design proposals have been made, with varying degrees of realism, by both engineers and science fiction authors.

The term space habitat is sometimes used more broadly to include colonies built on the surface of a body other than Earth, such as the Moon, Mars or an asteroid. This article concentrates on self-contained structures built in micro-g environment.

Several motivations for building space colonies have been proposed:

(See: Reasons for space colonization or Space and survival.)

A number of arguments are made for space habitats having a number of advantages:

Space has an abundance of light produced from the Sun. In Earth orbit, this amounts to 1400 watts of power per square meter. This energy can be used to produce electricity from solar cells or heat engine based power stations, process ores, provide light for plants to grow and to warm space colonies.

Earth-to-space habitat trade would be easier than Earth-to-planetary colony trade, as colonies orbiting Earth will not have a gravity well to overcome to export to Earth, and a smaller gravity well to overcome to import from Earth.

Space habitats may be supplied with resources from extraterrestrial places like Mars, asteroids, or the Moon (in-situ resource utilization [ISRU]; see Asteroid mining). One could produce breathing oxygen, drinking water, and rocket fuel with the help of ISRU. It may become possible to manufacture solar panels from Lunar materials.

Most asteroids are a mixture of materials, virtually all stable elements on the periodic table can be found in the asteroids and comets and more importantly, because these bodies do not have substantial gravity wells, it is very easy to draw materials from them and haul them to a construction site.

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