Biosphere 2 is a 3.15-acre (12,700 m2) structure originally built to be an artificial, materially-closed ecological system in Oracle, Arizona (USA) by Space Biosphere Ventures, a joint venture whose principal officers were John P. Allen, inventor and Executive Director, and Margret Augustine, CEO. Constructed between 1987 and 1991, it was used to explore the complex web of interactions within life systems in a structure that included five areas based on natural biomes and an agricultural area and human living/working space to study the interactions between humans, farming and technology with the rest of nature. It also explored the possible use of closed biospheres in space colonization, and allowed the study and manipulation of a biosphere without harming Earth's. The name comes from Earth’s biosphere, Biosphere 1, Earth's life system and the only biosphere currently known. Funding for the project came primarily from the joint venture’s financial partner, Ed Bass' Decisions Investment, and cost $200 million from 1985 to 2007, including land, support research greenhouses, test module and staff facilities.