Biosphere Project

The design of the Biosphere habitats was the work of an international team of hundreds of engineers, scientists, and specialists in agriculture and diverse life species. The site in the Arizona desert was chosen because of the relative ease, in the United States, of obtaining building permits and of importing the species that would reside in the Biosphere. The project was funded by Ed Bass, a billionaire from Texas, and initiated by John Allen, a leading ecologist. The name was chosen in deference to Earth; there was no Biosphere 1 Project because our home planet is the original biosphere. The five wild zones, the human "microcity," and the farm were selected to show diversity representing planet Earth but also to improve survival of as many species as possible. Roof heights for each zone had to be selected to allow air and rain to rise and fall as it does in nature, sunlight was essential to the survival of all zones, and the habitats had to be somewhat separated so desert life would not relocate to the rainforest.

To be perfectly isolated, Biosphere 2 needed a floor separating it from the supporting ground. After the groundbreaking in 1987, construction of this sealed floor began. To support the extensive glass, steel spaceframes consisting of 5-ft (1.5-m) lengths of strong but lightweight tubular steel were constructed. During building, the glass panes were lifted by cranes into place and sealed with liquid silicone to retain interior air and moisture and keep out the exterior. The surface of Biosphere 2 consists of 170,000 sq ft (15,794 sq m) of glass. Because of the purpose of the project and the huge expanse of glass, Biosphere 2 was nicknamed the "Glass Ark". The dome-like lungs were needed to equalize air pressure as the air inside Biosphere expands under the heat of the sun; the domes do not provide or replenish any of Biosphere's air, they only provide room for heated air to evacuate.

A smaller Biosphere module was made as a proving ground. The test module was only 1/400th of the size of Biosphere. The test module was sealed to make sure it was leakproof, then a living test was performed using plants. A plants-only habitat was installed, along with the correct moisture and air balance, and the module was sealed for a month. Opening the door and smelling the air immediately indicated whether or not the test had succeeded; if the plants had not adjusted to this environment, they would have produced gas that smelled. The test was a success with healthy, growing plants.

In 1988, the first of three humans moved into the test module for a three-day period. John Allen had his health monitored constantly as he lived exclusively on a small tropical garden and in the fully sealed environment. The second scientist occupied the module for a five-day-long test, and the third lived in the module for three weeks. These three early experimenters were all amazed at the cause-and-effect relationships they witnessed in the module, which were much more obvious than those in the larger world.

Mechanical devices were needed to regulate the temperature and to provide rain, but the moisture supply remained constant in Biosphere 2. Soil-bed reactors were constructed to use the properties of soil and its microbes to clean the air. An artificial mountain was built to provide streamflow by gravity to add moisture to the rainforest, flow past the savanna, enter the marsh, and empty in the ocean.

The animal residents of the biomes were chosen by the captain of each biome. No large predators were allowed, and many species were rejected because their needs were greater than the scale of Biosphere 2 could support. Hummingbirds were an easy choice because they are surprisingly hardy and are excellent pollinators. Bees, bats, moths, and butterflies were also brought in as pollinators. About 40 land dwelling species included snakes, reptiles, and turtles. The resident mammals were bats and bushbabies. Of Earth's thousands of species of insects, ants, termites, and cockroaches were chosen to share the habitat because they break down dead plants and animals into recyclable materials that benefit the Biosphere. Oysters and crabs were brought in to populate the replica ocean. Even a small coral reef was incorporated in the Biosphere 2 ocean. The plants were equally important and included medicinal plants, the agave, the jojoba, rubber trees, mosses, ferns, and trees that produce gums and soaps. Plants and animals that were imported into the United States were quarantined before being allowed in Biosphere 2.

The Human Habitat or microcity was also given special consideration to prevent the scientists from experiencing "cabin fever" or any feeling of being trapped. Windows look out over all other parts of the Biosphere, and each Biospherian had a private apartment with an upstairs bedroom and a downstairs sitting room. The bathrooms were equipped with showers and toilets; but shower time was limited to conserve water, and toilet paper was forbidden. Drinking water was collected from moisture produced by the plants in the Biosphere. The Habitat also includes laboratory space, a medical clinic, an exercise room, recreation facilities, and a communications center. Kitchen, cooking, and cleanup duties were all shared.

The farm for the humans' food consisted of eighteen separate garden plots designed to produce three crops per year. Beans, potatoes, and peanuts for protein were key elements of the farm. Oats, barley, and rice were grown; and the grains were used by the Biospherians to bake bread. Fruits included pineapple, guava, apples, bananas, grapes, strawberries, oranges, and papayas; these produced not only fruit but juice and jam. Sugar cane was grown as a sweetener. The Biospherians all received special training before they were finally selected for their assignments. Physical fitness courses, training in emergencies, skin diving classes (to care for the ocean), and special training in cooking were all provided.

The pulse of Biosphere was monitored constantly by extensive instrumentation. The functions of the limited external systems were carefully controlled, and internal health including moisture, temperature, and other vitals were also monitored both by the Biospherians and scientists working beyond the containment. It was up to the Biospherians to adjust living conditions for all the Biosphere's residents, but external monitoring provided a final check on the safety of the Biosphere population.