Editing Generation ship (section)

===Biosphere===
Such a ship would have to be entirely self-sustaining, providing [[life support system|life support]] for everyone aboard. It must have extraordinarily reliable systems that could be maintained by the ship's inhabitants over long periods of time. This would require testing whether thousands of humans could survive on their own before sending them beyond the reach of help. Small artificial closed ecosystems, such as [[Biosphere 2]], have been built in an attempt to examine the engineering challenges of such a system, with mixed results.<ref>{{cite web |url=https://www.vice.com/en/article/biosphere-2-how-a-sci-fi-stunt-turned-into-the-worlds-biggest-earth-science-lab/ |title=Biosphere 2: How a Sci-Fi Stunt Turned Into the World's Biggest Earth Science Lab |last=Merchant |first=Brian |date=June 10, 2013 |website=Motherboard |publisher=Vice Media LLC |archive-url=https://web.archive.org/web/20160819124432/http://motherboard.vice.com/blog/biosphere-2-how-a-sci-fi-stunt-turned-into-the-worlds-biggest-earth-science-lab |archive-date=August 19, 2016 |url-status=live }}</ref>