The Biosphere 2 project in Arizona has shown that a complex, small, enclosed, man-made biosphere can support eight people for at least a year, although there were many problems.
The other was the Man in Biosphere project for scientific research.
The Biosphere 2 project intended to explore the possible use of an artificial biosphere (a closed ecosystem) for space colonization.
The $150 million Biosphere project began in September 1991, billed as a utopian planet in a bottle where everything would be recycled in the first large self-contained habitat for humans.
With its reputation tottering, the Biosphere project commissioned an expert review last year and appointed a scientific director.
He financed the Biosphere 2 project, an artificial closed ecological system, which was built between 1987 and 1991.
In 1984, Bass and Allen founded the Biosphere 2 project, which Bass funded with an initial commitment of $30 million.
The total cost of the privately funded Biosphere project has been variously reported as $150 million to $200 million.
The park was the site of a UNESCO Man & Biosphere project on the effects of human interference within the natural forest ecosystem.
The Biosphere 2 project built a dome on Earth that contained a habitable environment.