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What symptoms did the Biospherians experience when oxygen levels fell?
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Biosphere 2
Biosphere 2, located in Oracle, Arizona, U.S., shown in 2008. The facility was originally developed to study survivability and assess whether humans were capable of building and living in self-sustaining colonies in outer space. It was later used as a scientific research facility.
When oxygen levels within the Biosphere 2 facility dropped from approximately 20.9 percent to 14.2 percent during the first mission, the crew members experienced marked lethargy and difficulty breathing. These physical symptoms raised significant concerns regarding the health of the Biospherians and their ability to complete the two-year mission.1