Biosphere 2

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Biosphere 2 is a structure built to be an artificial closed ecological system in Oracle, Arizona (USA) by John Polk Allen, Space Biosphere Ventures and others. Constructed between 1987 and 1989, it was used to test if and how people could live and work in a closed biosphere, while carrying out scientific experiments. It explored the possible use of closed biospheres in space colonization, and also allowed the study and manipulation of a biosphere without harming Earth's. The name comes from the idea that it is modeled on the first biosphere, which is Earth. The funding for the $200,000,000 project came from Edward Bass.

As of June 2006, the structure is no longer maintained in an airtight state, and the property, which is in exurban Tucson, is slated to be redeveloped for a planned community.[1]

1 History
2 Engineering
3 Science
- 3.1 Criticism
4 See also
5 External links
6 References

[edit] History

[edit] Missions

The project conducted two sealed missions: the first from September 26,1991 to September 26, 1993 and the second for six months in 1994. The inaugural crew included medical doctor and researcher Roy Walford, Jane Poynter, Taber MacCallum, Mark Nelson, Sally Silverstone, Abigail Alling, Mark Van Thillo and Linda Leigh.

Bananas grew very well in the structure, and formed a significant source of food. Other crops included sweet potato.

However, not all was well. During the first mission, oxygen levels began falling at a steady pace of 0.3% per month.

This continued to the point where the atmosphere inside resembled that of a community at an elevation of over 4,000 feet (1,200 m). Eventually, oxygen levels fell to dangerously low levels, harming some of the participants.^{[citation needed]} As a result, pure oxygen had to be pumped in from the outside. Since oxygen and other supplies were provided, the project lost considerable credibility.

These atmospheric issues were partly caused by low light levels. The weather that year was unusually overcast, reducing photosynthesis. In addition, a side effect of the building construction meant that the structure's support beams blocked a significant fraction of the light.

Many suspected the drop in oxygen was due to microbes in the soil. The agricultural, savanna and rain forest sections had all been infused with microbes in order to encourage plant growth. In addition, the overall quantity of carbon installed in the soil at the beginning of the experiment was too high. It was now felt that these microbes were consuming too much oxygen, converting the carbon in the soil into carbon dioxide and removing the oxygen from the air.

One problem critics of this theory have cited was that microbes breathing that much oxygen would also be creating a massive amount of carbon dioxide. So the jump in CO₂ this caused would have been greater than what was actually detected in the atmosphere readings. Further investigation revealed that the concrete at the base of the facility had been absorbing much of this carbon dioxide as it cured. This effect absorbed a large portion of the carbon dioxide being produced by the microbes which in turn had been depleting the facility's oxygen supply.

According to the general biology textbook "Biology" by Neil Campbell and Jane Reece, Biosphere 2 suffered also from CO₂ levels that "fluctuated wildly" and that most of the vertebrate species and all of the pollinating insects died. There were even great numbers of cockroaches and other pests to contend. Ants were not deliberately introduced into the habitat, but the local tramp species did very well in the structure.

[edit] Columbia University

In 1995 the Biosphere 2 owners transferred management to Columbia University. Since 1996, hundreds of college students have spent at least one semester at the Biosphere 2 Center campus (as of 2003). The site has its own hotel and conference center. Columbia has since divested itself of all Biosphere-related responsibilities.

[edit] For sale

On January 10, 2005 Decisions Investments Corporation, owners of Biosphere 2, announced that the Biosphere 2 campus was for sale. They preferred a research use to be found for the complex but were not excluding buyers with different intentions, such as universities, churches, resorts, spas, etc. Finally, in February, 2006, Fairfield Homes agreed to purchase Biosphere 2 and use its 1600 acres (650 hectares) to build a planned community. Biosphere 2 is still open for tours and plans to be open into the future.

[edit] Engineering

Biosphere 2 from the inside. Seen here are the Savanna (foreground) and Ocean (background) sections.

The Coastal Fog Desert section of Biosphere on 2 August 2005.

Like Project Apollo, Biosphere 2 is an achievement of engineering more than science. The above-ground physical structure of Biosphere 2 was made of steel tubing and high-performance glass and steel frames. The frame and glazing materials were designed and made to specification by a firm run by a one-time student of Buckminster Fuller, Peter Pearce (Peter Pearce & Associates). The window seals and structures had to be designed to be almost perfectly airtight, such that the air exchange would be extremely slow, to avoid damage to the experimental results.

The structure was notable for how it dealt with atmospheric expansion. During the day, the heat from the sun caused the air inside to expand and during the night it cooled and contracted. To avoid having to deal with the huge forces that maintaining a constant volume would create, the structure had large diaphrams kept in domes called "lungs". These permitted the structure to remain at ambient pressure at all times, without allowing air in or out of the habitat. Essentially this permitted the building to grow larger during the day, and shrink during the night.

Since opening a window was impossible, the structure also required huge air conditioners to control the temperature and avoid killing the plants within. For every unit of solar energy that entered the structure, the air conditioners would expend approximately three to cool the habitat back down.

[edit] Science

A special issue of the Ecological engineering journal edited by B.D.V. Marino and Howard T. Odum (1999) represents the most comprehensive assemblage of collected papers and findings from Biosphere 2. The papers range from calibrated models that describe the system metabolism, hydrologic balance, and heat and humidity, to papers that describe rainforest, mangrove, ocean, and agronomic system development in this carbon dioxide-rich environment.

[edit] Criticism

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An interesting consequence of the experiment is that it showed the difficulty of copying the functions of the natural capital of the Earth biosphere with infrastructural capital constructed by humans with present technology. Despite expenditure of over $150 million, this attempt at a new biosphere did not sustain eight humans for even a relatively short period of time (a space colony's biosphere would need to last for decades or even centuries).

[edit] See also

BIOS-3 a closed ecosystem at the Institute of Biophysics in Krasnoyarsk, Siberia, in what was then the Soviet Union.
The 1996 movie Bio-Dome was set in a Biosphere-2-like enclosed environment.
Eden Project
Jane Poynter, crewmember of first Biosphere 2 enclosure.
Roy Walford bionaut and anti-aging researcher.
The song 'Old Black Dawning' by Frank Black is about Biosphere 2.