Significant Research Outcomes
Early Biosphere 2 Research
Growing food on Mars, Not a novel idea for Biosphere 2:
The early goals of the project were to design an enclosed facility that could be used by humans to live on other planets, and to demonstrate the inter-connectedness of humans and the environment (Allen 1991). Construction of the main apparatus began in January 1987 and was concluded in September 1991. The first mission (September 1991 to September 1993) in which four men and four women lived inside the totally sealed but, energy rich environment of Biosphere 2 growing all their food and recycling all their air, water and wastes (figure 1 attached). The experiment was an outstanding success in engineering terms but failed as a sustainable planetary ecosystem analog.
The tightly closed structure (leak rate of less than 10% per year) (Dempster 1999) was furnished with an extremely rich organic soil (Leigh et al 1999, Scott 1999). The soil supported rapid growth of the synthetic model ecosystems and crops in Biosphere 2. However, the rich soil was the major factor in causing the experiment to become unsustainable. Soil metabolism was so active, and soil reserves of carbon were so great, that atmospheric composition changed rapidly. Oxygen was absorbed from the air by soil microbes and these released huge amounts of CO2 from the soil back to the air that exceeded the photosynthetic capacity of plants to assimilate it and to regenerate O2. Instead, the excess CO2 was absorbed by the fresh, unsealed concrete of the structure, and O2 levels declined rapidly (Severinghaus et al 1994); O2 make-up was needed (Dempster 1999) if the 8 humans were to survive (figure 2 attached).