The company that owns Biosphere 2 Center, 3.1 glass-enclosed acres designed to simulate the Earth's environment, has put the site up for sale.
The company is also selling 70 other buildings on the center's 140-acre campus 16 miles north of Tucson, said Christopher Bannon, general manager of Decisions Investment Corp. of Fort Worth, Texas.
"We'd love to see the Biosphere 2 used as a research activity, but we know that may not be the end result," he said last week.
Texas billionaire Ed Bass, president of Decisions Investment, spent more than $200 million to build Biosphere 2 in the 1980s as a prototype for a space colony.
The closed ecological site 16 miles north of Tucson contained miniatures of Earth's rainforest, ocean, desert and other environmental features.
In 1991, eight "biospherians" were sealed inside for a two-year stay. But the project was plagued by rising costs and other setbacks and Columbia University assumed responsibility for the site under a management agreement, turning it into a research and education facility.
The relationship with Columbia ended in September 2003 and Biosphere 2 has been open as a tourist destination.