Though often parodied in books, films, and television, the concept of a "bio-dome" is one that very much exists in real science. Perhaps the most famous attempt at creating a self-sustaining, fully-encapsulated environment was the Biosphere 2 that was constructed between 1987 and 1991 in Oracle, Arizona. It was coined "The largest laboratory of global ecology ever built". Spanning 3.14 acres, this glass enclosure was comprised of "biomes", that were intended to mimic natural habitats. These included rainforest, ocean (complete with a coral reef!), wetlands, grasslands, a fog dessert, an agricultural system, and a human habitat. A system of complex infrastructure provided natural gas energy and a heating/ cooling system that utilized water pipes.
After conducting a series of smaller-scale test modules and extensive training exercises for researchers, two official missions (also known as "closure experiments") were carried out in the Biosphere 2.
The first occurred on September 26, 1991 where eight researchers termed "Biospherians" were hermetically sealed within the structure with the goal of remaining in this "closed ecological life support system" for 2 years without any outside intervention. The purpose of the mission was two-fold: 1) For humans to inhabit a completely self-sustaining environment which balanced waste, water, and the production of food, and 2) Conduct ecological research with the ultimate application being the ability to sustain human life on another planet in the future.
During the first mission, a number of issues presented themselves within the first several months. Fish and plant life grew at unanticipated rates causing mechanical failures as well as problematic changes in the natural habitats. Researchers began exhibiting behavioural changes due to the psychological effects of living in isolation. Oxygen levels began to drop, which caused Biospherians to exhibit physical symptoms, such as weight loss, sleep apnea, chronic hunger, and lethargy. A host of reasons were to blame, including outside seasonal temperatures, microbes in the soil, possible leaks in the physical structure itself, and an unanticipated reaction between exposed concrete and carbon dioxide. Ultimately, it was determined that oxygen would have to be pumped into the facility for medical reasons, which rendered the experiment a failure.
Between the end of mission one and the start of mission two, many upgrades were made to the facility. The second mission started on March 6, 1994 and was expected to last 10 months. A series of management disputes resulted in the mission dissolving within 6 months amid accusations of sabotage and vandalism toward some members of the first crew. These accusations included the opening of an airlock door and the breaking of glass panes leaving the air inside of the biosphere compromised by exposure to the outside.
By 2005 the site was for sale, and it's now owned by the University of Arizona where it functions as an Earth systems science research facility.