Editing Space settlement (section)

==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.<ref name="KoppLean11">{{cite journal |last=Kopp |first=G. |author2=Lean |first2=J. |year=2011 |title=A new, lower value of total solar irradiance: Evidence and climate significance |journal=Geophys. Res. Lett. |volume=38 |issue=1 |pages=L01706 |bibcode=2011GeoRL..38.1706K |doi=10.1029/2010GL045777 |doi-access=free}}</ref> This energy can be used to produce electricity from [[Photovoltaics|solar cells]] or [[heat engine]] based power stations, process ores, provide light for plants to grow and to warm space settlements.

===Outside gravity well===
Earth-to-space settlement trade would be easier than Earth-to-planetary habitat trade, as habitats 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.

===In-situ resource utilization===
Space settlements may be supplied with resources from extraterrestrial places like [[Mars]], [[asteroid]]s, or the [[Moon]] ([[in-situ resource utilization]] [ISRU];<ref name=Doehring /> see [[Asteroid mining]]). One could produce breathing oxygen, drinking water, and rocket fuel with the help of ISRU.<ref name=Doehring /> It may become possible to manufacture solar panels from lunar materials.<ref name=Doehring />

===Asteroids and other small bodies===
Most asteroids have a mixture of materials, that could be mined, and because these bodies do not have substantial gravity wells, it would require low delta-V to [[Asteroid mining|draw materials from them]] and haul them to a construction site.<ref name="Pournelle, Jerrold E. 1977"/><!--there are issues of delta-V to access Main Belt asteroids, but for NEAs, it's less than a GEO-Luna-GEO or L5-Luna-L5... Sad to say, I don't have any of these 3 at hand...-->

There is estimated to be enough material in the main asteroid belt alone to build enough space settlements to equal the habitable surface area of 3,000 Earths.<ref>[https://web.archive.org/web/20100531200205/http://settlement.arc.nasa.gov/75SummerStudy/Chapt7.html#LIM "Limits to Growth"], Chapter 7, ''Space Settlements: A Design Study''. NASA, 1975.</ref>

===Population===
A 1974 estimate assumed that collection of all the material in the main [[asteroid belt]] would allow habitats to be constructed to give an immense total population capacity. Using the free-floating resources of the Solar System, this estimate extended into the trillions.<ref name=cos>{{cite journal | author= O'Neill, Gerard K. | title= The Colonization of Space | journal= Physics Today | volume= 27 | issue= 9 | pages= 32–40 | date= September 1974 | url= http://www.nss.org/settlement/physicstoday.htm | bibcode= 1974PhT....27i..32O | doi= 10.1063/1.3128863| doi-access= free }}</ref>

===Zero g recreation===
If a large area at the rotation axis is enclosed, various zero-g sports are possible, including swimming,<ref>{{cite conference | conference= Space 98: Sixth International Conference and Exposition on Engineering, Construction, and Operations in Space | location= Albuquerque, New Mexico | url= http://www.spacefuture.com/archive/artificial_gravity_swimming_pool.shtml | title= Artificial-Gravity Swimming-Pool | last1= Collins | first1= Patrick |display-authors=etal}} April 26–30, 1998.</ref><ref name="Kalpana" /> [[hang gliding]]<ref>{{cite web |author=Heppenheimer |first=T. A. |date=1977 |title=Colonies in Space, Chapter 11: What's to Do on Saturday Night? |url=http://www.nss.org/settlement/ColoniesInSpace/colonies_chap11.html |access-date=30 January 2012}}</ref> and the use of [[human-powered aircraft]].

===Passenger compartment===
{{See|Space and survival}}
A space settlement can be the passenger compartment of a large spacecraft for colonizing [[asteroid]]s, moons, and planets. It can also function as one for a [[generation ship]] for travel to other planets or distant stars (L. R. Shepherd described a generation starship in 1952 comparing it to a small planet with many people living in it.)<ref>{{cite journal | last= Shepherd | first= L. R. | title= Interstellar Flight | periodical= Journal of the British Interplanetary Society | volume= 11 | date= July 1952 | pages= 149–167}}</ref><ref>{{cite web | title= Les Shepherd, RIP | author= Gilster, Paul | date= 28 February 2012 | website= centauri-dreams.org | url= http://www.centauri-dreams.org/?p=21895 | access-date= 1 January 2015}}</ref>