Biosphere 2

Biosphere 2 was a closed ecosystem spread over 3 acres which amongst many other things has its own rainforest, desert, ocean, and lungs. It was an attempt to create a closed ecological system that could be used in space. 8 people lived in the dome for two years, who only needed additional oxygen and one hospital visit. It rained way too much in the desert, and the jungle got too dry. It experienced extensive oxygen loss due to the concrete used in the structure, which absorbed oxygen. Also, since there was no wind, trees failed to develop stress wood and all tree fell down before maturation. The experiment was deemed a failure, and the glass dome is now used as a research facility.