A space settlement (also called a space habitat, spacestead, space city or space colony) is a settlement in outer space, sustaining more extensively habitation facilities in space than a general space station or spacecraft. Possibly including closed ecological systems, its particular purpose is permanent habitation. No space settlement has been constructed yet, but many design concepts, with varying degrees of realism, have been introduced in science-fiction or proposed for actual realization. Space settlements include orbital settlements (also called orbital habitat, orbital stead, orbital city or orbital colony) around the Earth or any other celestial body, as well as cyclers and interstellar arks, as generation ships or world ships. Space settlements are a form of extraterrestrial settlements, which more broadly includes habitats built on or within a body other than Earth, such as a settlement developed from a moonbase, a Mars habitat or an asteroid.
Definition A space settlement is any large-scale habitation facility in outer space, or more particularly in an orbit. The International Astronautical Federation has differentiated space settlements to space habitats and space infrastructure the following way:
Habitat: pressurized volume(s) within which humans live and work, including relevant facilities for life support. Settlement: group of permanently inhabited habitats installed near each other, possibly interconnected. Infrastructure: set of constructed elements supporting habitats and/or settlements such as (and not limited to): power plant, water plant, greenhouse and waste management facilities, communication facilities, transportation facilities, EVAs, roads, spaceport, research platforms, and so on. While not automatically constituting a colonial entity, a space settlement can be an element of a space colony. The term "space colony" has been viewed critically, prompting Carl Sagan to propose the term space city.
History
The idea of space settlements either in fact or fiction goes back to the second half of the 19th century. "The Brick Moon", a fictional story written in 1869 by Edward Everett Hale, is perhaps the first treatment of this idea in writing. In 1903, space pioneer Konstantin Tsiolkovsky speculated about rotating cylindrical space settlements in Beyond Planet Earth. In 1929 John Desmond Bernal speculated about giant space settlements. Dandridge M. Cole in the late 1950s and 1960s speculated about hollowing out asteroids and then rotating them to use as settlements in various magazine articles and books, notably Islands In Space: The Challenge Of The Planetoids.
O'Neill – The High Frontier
Around 1970, near the end of Project Apollo (1961–1972), Gerard K. O'Neill, an experimental physicist at Princeton University, was looking for a topic to tempt his physics students, most of them freshmen in engineering. He hit upon the idea of assigning them feasibility calculations for large space-settlements. To his surprise, the habitats seemed feasible even in very large sizes: cylinders 8 km (5 mi) in diameter and 32 km (20 mi) long, even if made from ordinary materials such as steel and glass. Also, the students solved problems such as radiation protection from cosmic rays (almost free in the larger sizes), getting naturalistic Sun angles, provision of power, realistic pest-free farming and orbital attitude control without reaction motors. O'Neill published an article about these colony concepts in Physics Today in 1974. He expanded the article in his 1976 book The High Frontier: Human Colonies in Space.
NASA Ames/Stanford 1975 Summer Study
The result motivated NASA to sponsor a couple of summer workshops led by O'Neill. Several concepts were studied, with sizes ranging from 1,000 to 10,000,000 people, including versions of the Stanford torus. Three concepts were presented to NASA: the Bernal Sphere, the Toroidal Colony and the Cylindrical Colony.
O'Neill's concepts had an example of a payback scheme: construction of solar power satellites from lunar materials. O'Neill did not emphasize the building of solar power satellites as such, but rather offered proof that orbital manufacturing from lunar materials could generate profits. He and other participants presumed that once such manufacturing facilities had started production, many profitable uses for them would be found, and the colony would become self-supporting and begin to build other colonies as well. The concept studies generated a notable groundswell of public interest. One effect of this expansion was the founding of the L5 Society in the U.S., a group of enthusiasts that desired to build and live in such colonies. The group was named after the space-colony orbit which was then believed to be the most profitable, a kidney-shaped orbit around either of Earth's lunar Lagrange points 5 or 4.
Space Studies Institute In 1977 O'Neill founded the Space Studies Institute, which initially funded and constructed some prototypes of the new hardware needed for a space colonization effort, as well as producing a number of feasibility studies. One of the early projects, for instance, involved a series of functional prototypes of a mass driver, the essential technology for moving ores efficiently from the Moon to space colony orbits.
Motivation
There are a range of arguments for space settlements, including:
As a base for crewed space exploration Relieving Earth of industry and population pressure Recreational habitation, either as visitors or residents at space (see space hotel) Economic growth, developing access to resources in space and a space economy, without destroying ecosystems and displacing peoples on Earth Space colonization, claiming extraterrestrial space for settler colonial independence For survival of human civilization and the biosphere, in case of a disaster on the Earth (natural or man-made)
Advantages A number of arguments are made for space settlements having a number of advantages:
Access to solar energy 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 settlements.
… excerpt ends here. Continue reading the full article.
