Crew of Biosphere 2 Exits After Two Years Summary

  • Last updated on November 10, 2022

The Biosphere 2 project both demonstrated the feasibility of colonizing outer space in self-sustaining artificial environments and publicized scientific efforts to solve existing ecological problems.

Summary of Event

On September 26, 1993, four men and four women emerged from two years of isolation in a futuristic ecosystem in the Sonoran Desert in Arizona. The human-made ecosystem was called Biosphere 2; Earth itself was considered to be the prototype, or Biosphere 1. The eight “biospherians” marched out of Biosphere 2, a 3.15-acre terrarium, to an elaborate welcoming ceremony that included impressionistic flute music and what one reporter described as “New Age oratory.” The two-year experiment, a combination of science and media hype, was criticized by some scientists but was praised by others for helping to popularize scientific concerns and win public support for further experimentation. Biosphere 2[Biosphere two] Environmental awareness [kw]Crew of Biosphere 2 Exits After Two Years (Sept. 26, 1993) [kw]Biosphere 2 Exits After Two Years, Crew of (Sept. 26, 1993) Biosphere 2[Biosphere two] Environmental awareness [g]North America;Sept. 26, 1993: Crew of Biosphere 2 Exits After Two Years[08700] [g]United States;Sept. 26, 1993: Crew of Biosphere 2 Exits After Two Years[08700] [c]Health and medicine;Sept. 26, 1993: Crew of Biosphere 2 Exits After Two Years[08700] [c]Environmental issues;Sept. 26, 1993: Crew of Biosphere 2 Exits After Two Years[08700] Bass, Edward Perry Alling, Abigail Leigh, Linda MacCallum, Taber Poynter, Jane Silverstone, Sally Thillo, Mark Van Walford, Roy Zabel, Bernd

The creation of Biosphere 2 was possible only because of the work conducted by scientists and technologists over the preceding hundreds of years. The crew members—Abigail Alling, Linda Leigh, Taber MacCallum, Jane Poynter, Sally Silverstone, Mark Van Thillo, Roy Walford, and Bernd Zabel—not only had to grow their own food but also had to recycle the water they drank and produce the oxygen they breathed. They were responsible for the health of all the other plant and animal species inside the sealed structure. They had to maintain all the complex apparatus that kept Biosphere 2 functioning. The combined scientific knowledge of these versatile, idealistic biospherians represented much of what humans had learned through centuries of observation and experimentation.

Many U.S. astronauts and Soviet cosmonauts had spent long periods in outer space, but they had always taken their food, water, and air along with them. Consequently, the amount of time that these early space explorers could survive away from Earth was strictly limited. Biosphere 2 was designed to prove that humans could exist indefinitely without access to the resources of the mother planet.

Planned to last for one hundred years, the Biosphere 2 structure looked like a gigantic, futuristic greenhouse. It contained a small ocean complete with machinery to create waves, a twenty-thousand-square-foot agricultural area, a tiny rain forest, a savanna, and a desert. The interior also housed machinery and computers to monitor everything that went on inside Biosphere 2, including the regulation of temperature, humidity, artificial tides, and artificial seasons.

Journalists covering the crew’s experiment called the structure a modern Noah’s ark because it held so many different animals, birds, fish, insects, and microbes. It also contained numerous species of plant life to provide food, a pleasant ambience, and the oxygen that was vital to human and animal inhabitants. Altogether, the initial experiment included more than thirty-eight hundred species of interdependent plant and animal life.

The $150 million project was conceived by the Institute of Ecotechnics Institute of Ecotechnics in London and implemented by Space Biospheres Ventures Space Biospheres Ventures with funding from Texas billionaire Edward Perry Bass. During the two-year experiment, the crew met with problems that would have been disastrous if they had occurred in outer space. The experiment, however, taught scientists many valuable lessons. It also demonstrated that human beings could live comfortably and harmoniously in a human-made, self-sufficient ecosystem.

The biospherians reported the inevitable personality conflicts but agreed that they managed to cooperate because of their emotional stake in the success of the mission. They were not entirely isolated from the world: Biosphere 2 became an instant tourist attraction, and many people came to observe the day-to-day operations of the crew through the structure’s triangular windows. The crew members also kept in contact with the outside world through telephone calls, e-mail, and closed-circuit television.

The most serious problem involved oxygen. The integrity of the sealed environment had to be broken when it became apparent that the trees and plants were not producing enough oxygen to support the human occupants. By January, 1992, a few months into the crew’s planned two-year stay, the oxygen content had diminished to about 15 percent from the desired 21 percent of the interior atmosphere. The oxygen content was equivalent to that of air at an altitude of 13,400 feet, and the biospherians were suffering from fatigue, headaches, and sleep disorders.

As the oxygen content fell, the carbon dioxide content rose to ten times its normal concentration in the outside air. This had bizarre effects on the plant life and narcotizing effects on the human crew. It was discovered that the soil inside the biosphere was absorbing more oxygen than had been anticipated, and it became necessary to pump in oxygen to save the experiment.

Another unforeseen event attracted much attention. One crew member had to be taken out of Biosphere 2 because she needed emergency surgery on a wounded finger. When she returned, she brought some supplies with her, and the press speculated that the giant terrarium was not as self-sufficient as had been claimed. Such incidents received wide media coverage, but the project directors reiterated that they had never expected perfection in this first model and that finding the flaws in their design was precisely the purpose of the experiment.

The biospherians produced about 80 percent of the food they needed but suffered crop failures because of unanticipated depredations by mites and other insects. One of the major complaints of the crew members when they emerged from Biosphere 2 was that they had been chronically hungry. Some of them lost as much as 18 percent of their body weight. They reported that their efficiency had been undermined by the fact that they had been obsessed with food that was simply not available in their austere living conditions.

The promoters of Biosphere 2 claimed that overall the experiment had been a great success in spite of its surprises and disappointments. They immediately set to work correcting the problems that had been encountered and recruiting a new crew of biospherians for a second experiment in prolonged isolation; that experiment, however, conducted in 1994, lasted only six months.


Biosphere 2 attracted nationwide attention because of its futuristic design and because the human drama lived by the crew members for two years within the self-sustaining environment fascinated observers. Reporters, scientists, and tourists traveled to southern Arizona from all over the world to see it. The structure’s thousands of windows allowed spectators to view almost everything going on inside. All this public exposure made Biosphere 2 an excellent tool for generating interest in ecological concerns as well as in the potential for human space travel.

In spite of the problems encountered by the eight biospherians, their courage, self-sacrifice, and ingenuity led to many important findings. Most significant, they demonstrated that it would be possible, with further study and experimentation, for scientists and engineers to build space colonies in which human beings could live indefinitely. The crew was made up of both men and women partly to draw attention to the fact that future space voyagers would perhaps be producing, rearing, and educating new generations of humans while in space.

Not only science-fiction writers but also scientists, engineers, architects, psychologists, sociologists, philosophers, and other serious-minded authorities have written about the future colonization of space by humans. The designers of Biosphere 2 had much theoretical material on which to draw when they undertook the daring task of turning fantasy and theory into reality. Biosphere 2 also modeled what cities of the future might be like, not only orbiting in outer space or attached to inhospitable planets but also on Earth itself. The creators of this project demonstrated that humans have the power to create healthier, more beautiful, and more life-supporting environments to replace polluted, congested, overcrowded, and unsightly cities. The Biosphere 2 experiment suggested that investment in space colonization could lead to vast improvements in the quality of life on Earth as well.

Biosphere 2 became a a lucrative tourist attraction in Arizona, an arid state that depends on tourism to support its economy. Men, women, and children who know little about science could see in Biosphere 2 tangible evidence that space colonization is not merely a theme of science fiction; rather, it is on the verge of becoming reality. The educational value of the Biosphere 2 experiment was perhaps its greatest contribution.

The creative men and women involved in the project claimed that they had demonstrated the feasibility of “terraforming” Mars—that is, providing another entire planet with an Earthlike atmosphere. They anticipated the development of island ecosystems all around the world that would be used to study and preserve rare and endangered species of plants while serving as laboratories, educational institutions, and tourist attractions.

The futuristic Biosphere 2 structure standing in the middle of the barren desert like a human outpost on a distant planet was the subject of newspaper and magazine articles as Space Biospheres Ventures continued to improve on the original design. In 1995, management of Biosphere 2 was given to Columbia University, and college classes were held there into the early twenty-first century. The property was put up for sale in 2005 and was purchased in 2006 by Fairfield Homes for the development of a planned community. Biosphere 2[Biosphere two] Environmental awareness

Further Reading
  • citation-type="booksimple"

    xlink:type="simple">Allen, John. Biosphere 2: The Human Experiment. New York: Penguin Books, 1991. Provides one of the most thorough descriptions of the Biosphere 2 program available. Copiously illustrated with both color and black-and-white photographs showing the interior and exterior of the structure, the people involved, and major botanical, zoological, and technological features.
  • citation-type="booksimple"

    xlink:type="simple">Lovelock, James. Gaia: A New Look at Life on Earth. 1979. Reprint. New York: Oxford University Press, 2000. Scientific and philosophical work has become a classic in the modern ecology movement. Argues that the earth functions as a single organism that has created humans as an inseparable part of itself.
  • citation-type="booksimple"

    xlink:type="simple">Maranto, Gina. “Earth’s First Visitors to Mars.” Discover 8 (May, 1987): 28-43. Offers a complete description of the Biosphere 2 project and presents the project as a prelude to the colonization of Mars. Discusses the technical aspects of achieving a balance of plant and animal life within the closed environment. Includes many color illustrations and diagrams.
  • citation-type="booksimple"

    xlink:type="simple">O’Neill, Gerard K. The High Frontier: Human Colonies in Space. 3d ed. Burlington, Ont.: Apogee Books, 2000. Professor of physics at Princeton University and leading space-colony authority presents a detailed account of the feasibility of building space colonies that would have controlled climates and artificial gravity and be fueled by solar power. Features many illustrations.
  • citation-type="booksimple"

    xlink:type="simple">Poynter, Jane. The Human Experiment: Two Years and Twenty Minutes Inside Biosphere 2. New York: Thunder’s Mouth Press, 2006. Interesting insider’s account by a crew member details what life was like in Biosphere 2. Includes photographs, bibliography, and index.
  • citation-type="booksimple"

    xlink:type="simple">Walford, Roy L. Beyond the 120-Year Diet: How to Double Your Vital Years. Rev. ed. New York: Four Walls Eight Windows, 2000. Senior nutritionist of the Biosphere 2 crew offers his ideas on achieving health and longevity through proper food consumption. Crew members tried many of Walford’s ideas during their two-year seclusion.

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