^BOpening of Biosphere 2.^b Seven of the Biospherians at the press conference after the opening of Biosphere 2 on 26 September 1993. Left to right are: Mark Van Thillo, Sally Silverstone, Taber MacCallum, Jayne Poynter, Mark Nelson, Linda Leigh and Roy Walford. This 3.1 acre air- and water-tight building had been home to eight occupants for two years. Biosphere 2 was designed to allow study of the possibilities for humans to survive in a totally self-sufficient ecosystem. The costs of this controversial, $150 million project were met from private funds. The Biosphere 2 project building is at Oracle, Arizona.