Revisiting Biosphere 2

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Biosphere 2

This week Diane and I have a friend visiting from back east. As locals generally do when guests visit, we used this visit as an excuse to go sightseeing at local attractions that we somehow never got the time to visit on our own.

So on Tuesday we drove north to take a tour of Biosphere 2, what has been called “a giant space-age ark in the middle of the desert.” The idea, as sold heavily to the public when it was built in the late 1980s and early 1990s, was that eight people would try to live in a closed system for two years, demonstrating the technology needed to both build colonies on other worlds as well as protect the environment here on Earth.

The system wasn’t really closed however (power came from outside), and during the first two year mission it seemed they were somewhat lax about keeping the system closed.

One Biospherian accidentally cut off the tip of her finger and left for medical care. When she returned, she carried in two duffle bags of supplies to the supposedly self-sustaining environment (which presumably would not have been feasible on, say, Mars).

There were also financial issues, as mentioned by our tour guide and confirmed by news stories. Its backer, Texas oil man Edward Bass, spent somewhere between $150 to $200 million. It seems however that the managers running Biosphere 2 didn’t keep good books, and when Bass asked for an accounting they couldn’t provide it. Instead, they attempted to sabotage the project’s second mission.

First, Texas billionaire Edward Bass, principal financial backer of the money-losing project, obtained a federal court order April 1 placing the enterprise in receivership and removing his senior management team, including John Allen, the co-founder who first dreamed up the project with Bass at a Santa Fe commune in the 1970s.

Then Abigail Alling and Mark Van Thillo, two of the original eight “Biospherians” who spent two years in the structure, sneaked into the complex before dawn April 4. They opened doors and broke glass seals, letting outside air into the dome.

…In court documents seeking to dissolve his partnership with Decisions Team Inc., the company created to manage the Biosphere, Bass accuses the company of refusing to cooperate in a planned restructuring of the project. Audits also raised questions about expenditures, unexplained budget shortfalls and possible misuse of company credit cards. The ousted directors deny any wrongdoing and accuse Bass of Texas-size egotism in throwing his weight and money around.

The result of these legal battles, along with the overselling of the project initially, resulted in its research having a generally bad scientific reputation. Because of this I as a science journalist had generally been very skeptical of the project, and paid it little mind.

The tour changed my mind somewhat. It is clear that the project’s initial creators handled things poorly, and even allowed misuse of funds. It is also clear that this project was never aimed at demonstrating a entirely closed system, and they should have been honest about that from the beginning.

Biosphere 2's ocean

Nonetheless, I found myself impressed by much of what they did do. For example, on the right is an image of the small “ocean” they created within the facility. While not a perfect duplication (such things are impossible), it impressed me with its scale of success.

More importantly, they clearly tried to make the biological portion of Biosphere 2 as closed as possible. For this reason, during the first mission, the oxygen levels in the facility dropped over time much more than expected, caused first by far cloudier weather than expected (resulting in less plant growth), and second by an unexpected absorption of oxygen by the curing concrete in the building. Both of these issues involved engineering miscalculations, but such mistakes are part of the development of all new technology. You can’t think of everything, and so you do experiments to find out what you failed to account for.

They also attempted and generally succeeded in providing the bulk of the eight person crew’s food supply for two years from within the facilities gardens and small collection of animals. The project was criticized for starting out with a stockpile of food, but this seems completely reasonable for any project like this. Overall, they focused on growing and eating their own food, and it appears they did so. That the supplies they created were not sufficient, causing everyone to lose weight during the entire two year mission, should not be seen as a failure. Once again, this should be seen as a good data point for redesigning such facilities in the future.

Furthermore, Biosphere 2 has from the start provided a good controlled facility for studying how plant life in different environments interacts with changing conditions. For example, in the tropical rain forest section, they have been able to study how the plant life reacts when drought occurs and when temperatures change. Since the end of the initial project this research has gone on, and has produced some good science.

South Lung in Biosphere 2

Their engineering effort to maintain this very gigantic closed atmosphere was also impressive. They knew the atmosphere would need to expand and contract during the 24-hour day/night cycle, so to provide for that change they built two buildings, dubbed the West Lung and the South Lung, within which the ceilings were an expandable membrane. The image on the left looks up at that membrane. As the interior atmosphere of Biosphere 2 expanded the ceiling would rise. When the atmosphere contracted the membrane ceiling would drop. During the tour we could actually see this happen as we exited one lung. With the room’s door open the multi-ton membrane ceiling could be seen visibly dropping, a drop that ceased as soon as the door to the building was shut. (I should add that the drop was never dangerous, but slow but quite steady and noticeable.)

Some of the project’s design however revealed its showbiz failures. According to our tour guide, the architect they hired wanted to express himself by having the different buildings evoke different past human architectural styles, such as Egyptian and Mayan pyramids and Islamic mosques. To my mind, this decision only increased cost, and likely made the functional engineering more difficult. For example, the triangular struts that form the structure for the greenhouse end up blocking almost half the sunlight. If the architect had been instead focused on the goals of the project instead of creating interesting-looking buildings, he might have conceived a structure that allowed more light in, which in turn might have prevented the drop in oxygen levels when there was less sunlight than expected.

Biosphere 2 survives today because the University of Arizona needed a facility where it could do a controlled agricultural experiment, dubbed the Landscape Evolution Observatory. Unlike the original Biosphere 2 experiment, this project is from the get-go entirely focused on very specific scientific questions.

The experiment consists of three artificial landscapes contained within elaborate steel structures and located inside three adjacent bays within the University of Arizona – Biosphere 2. The landscapes are designed as experimental replicates; each has dimensions of 30-m length, 11-m width, an average slope of 10°, and is filled to a uniform depth of 1 m with crushed basalt rock that was extracted from a volcanic crater in northern Arizona. In their initial state, the landscapes consist of approximately 500 metric tons (more than 1 million pounds) of the crushed rock, which has a loamy sand texture. This initial condition will allow scientists to observe each step in the landscapes’ evolution—from purely mineral and abiotic substrate to living, breathing landscapes that will ultimately support microbial and vascular plant communities

Those observations are made possible by the array of more than 1800 sensors and sampling devices that are installed on, within, or above each landscape. The sensors enable monitoring of water, carbon, and energy cycling processes, and the physical and chemical evolution of the landscape at sub-meter to whole-landscape scales. As the soil, topography, and biological communities evolve to increasingly complex states, scientists will be able to document how those changes affect water, carbon, and energy cycling within the landscape, and between the landscape and the atmosphere.

The money to run this project comes partly from grants, partly from the income provided by paying tourists on tours, and partly from a $30 million gift from Biosphere 2’s original backer, Ed Bass. Despite the facility’s checkered history, it appears that he hasn’t given up on it.

We shall see if that new faith will be rewarded.



  • Kirk

    Bob, did you take their “History Tour” or just the basic “Under the Glass Tour”, and if the former, was it worthwhile?

  • Kirk: We took the history tour, which also includes the “Under the Glass Tour.” I think it was worth it, though of course you always have to recognize that the amount of information you can get on one of these tours is somewhat superficial. The main reason to go is to see the place.

  • Kirk

    Thanks! I’ll consider a visit next time I’m out that way.

  • Mike Borgelt

    Our planet isn’t a closed system either. The power comes from outside

  • Edward

    Nice report, Robert. I learned quite a bit, and I will have to take that tour, if I get to that area. (There are a couple other tours on my list, such as the Titan Missile Museum: )

    This report suggests that there were not clear, specific goals for the original experiment to accomplish. This would explain why it had so many critics, back then. The goals inform the experimenter what to measure and track and whether the experiment failed to accomplish the goal.

    My recollection was that the experiment was to be a closed system, and any violation of that closure would invalidate the experiment. If it was to be mostly closed, then it should have been made clear what could go in or come out (but didn’t have to) and for what reasons, in order to make clear why the experiment was successful rather than a failure. Did the reduced sunlight (something that was necessary to go in) invalidate the experiment? Without a clear plan, no one knows.

    Being lax about keeping the system closed and not keeping good financial accounts suggests to me that they were not serious about the data that they were collecting. That is a lot of time and expense for irreproducible results.

  • Dave


    Your article serves as an important reminder of the difference between actual “science” and zealotry – whoever the zealot, whatever the “object” of ones zealotry might be. Thank you for a wonderful reminder!


  • Scott

    I was interested to hear that the Biosphere2 now has a history option. I’m local as well and have been twice but don’t remember that option (it has been a few years). At the time they seemed to avoid the history unless you asked. If you asked they would talk about it. The first time I went it was a small group and I felt free to pepper the guide with questions and I did and it was fascinating. The second time the group was large and I didn’t feel I could monopolize the conversation. Anyway, I remember thinking both times that they should emphasize the history, maybe even put in some life-size card-board cut-outs of the crew! :-) I’ll have to go again now. I’m guessing that there are probably still (sadly) no crew cut-outs but sounds like the tour is more interesting!

  • Scott: I am not sure you will find the tour that much more interesting. As I mentioned in an earlier comment, the amount of information provided is generally somewhat superficial.

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