Exterior of Biosphere 2
|Address||32540 S Biosphere Rd, Oracle, AZ 85739|
|Elevation||3,820 ft (1,164 m)|
|Floor area||3.14 acres (12,700 m2)|
|Grounds||40 acres (160,000 m2)|
Biosphere 2 is an American
Biosphere 2 was originally meant to demonstrate the viability of closed ecological systems to support and maintain human life in outer space.
 It was designed to explore the web of interactions within life systems in a structure with different areas based on various biological
Biosphere 2 was only used twice for its original intended purposes as a closed-system experiment: once from 1991 to 1993, and the second time from March to September 1994. Both attempts, though heavily publicized, ran into problems including low amounts of food and oxygen, die-offs of many animals and plants included in the experiment (though this was anticipated since the project used a strategy of deliberately "species-packing" anticipating losses as the biomes developed), group dynamic tensions among the resident crew, outside politics and a power struggle over management and direction of the project. Nevertheless, the closure experiments set world records in closed ecological systems, agricultural production, health improvements with the high nutrient/low caloric diet the crew followed, and insights into the self-organization of complex biomic systems and atmospheric dynamics.  The second closure experiment achieved total food sufficiency and did not require injection of oxygen. 
In June 1994, during the middle of the second experiment, the managing company, Space Biosphere Ventures, was dissolved, and the facility was left in limbo. Columbia University assumed management of the facility in 1995 and used it to run experiments until 2003. It then looked in danger of being demolished to make way for housing and retail stores, but was taken over for research by the University of Arizona in 2007 and they took full ownership of the structure in 2011.
Biosphere 2 was originally constructed between 1987 and 1991 by Space Biosphere Ventures, a joint venture whose principal officers were
It was named "Biosphere 2" because it was meant to be the second fully self-sufficient