What Went Wrong?

As an attempt to create a balanced and self-sustaining replica of Earths ecosystems, Biosphere II was a miserable (and expensive) failure. Numerous problems plagued the crew almost from the very beginning. Of these, a mysterious loss of oxygen and widespread extinction were the most notable.

Catching Their Breath

Starting when the crew members were first sealed in, Biosphere II experienced a constant and puzzling decline in the percentage of oxygen in the atmosphere. It was initially hoped that the system was merely stabilizing itself, but as time passed it became increasingly clear the something was amiss. Not quite 18 months into the experiment, when oxygen levels dropped to the point where the crew could barely function, the outside managers decided to pump oxygen into the system so theyThey anticipated that some species would not survive, but the eventual extinction rate was much higher than expected. Of the 25 small vertebrates with which the project began, only 6 did not die out by the mission's end. Almost all of the insect species went extinct, including those which had been included for the purpose of pollinating plants. This caused its own problems, since the plants could no longer propagate themselves.

At the same time, some species absolutely thrived in this man-made environment. Crazy ants, cockroaches, and katydids ran rampant, while certain vines (like morning glories) threatened to choke out every other kind of plant. The crew members were forced to put vast amounts of energy into simply maintaining their food crops. Biosphere II could not sustain a balanced