Lessons Learned from Biosphere 2: When Viewed as a Ground Simulation/Analog for Long Duration Human Space Exploration and Settlement

President Bush's recent announcement of the Exploration Initiative dictates manned bases on the Moon and eventually Mars. A ground swell of credible privately funded space projects is also reaffirming the notion that was for a time taken for granted but in recent years has seemed further and further from being realized - that humans will live permanently in space. A human mission to Mars, or a base on the Moon or Mars is a lengthier more complex mission than any space endeavor undertaken to date. Simulation Based Acquisition is a fundamental part of preparing for such a mission. Ground simulations provide a relevant, analogous environment for testing technologies and learning how to manage complex, long duration missions, while addressing inherent mission risks. Multiphase human missions and settlements with limited opportunities for immediate return to Earth should a problem occur, require high fidelity, end-to-end, full mission duration tests in order to evaluate a system's ability to sustain the crew for the entire mission and return them safely to Earth. Moreover, abort scenarios are essentially precluded in many mission scenarios though certain risks may only become evident late in the mission. Aging and compounding effects cannot be simulated through accelerated tests for all aspects of the mission. Until such high fidelity long duration simulations are available, and in order to help prepare those simulations and mission designs, it is important to extract as many lessons as possible from analogous environments. Biosphere 2 is a three-acre materially closed ecological system that supported eight crewmembers with food, air and water in a sunlight driven bioregenerative system for two years. It was designed for research applicable to environmental management on Earth and the development of human life support for space. Although the two-year mission of Biosphere 2 was completed ten years ago, it is quite possibly the best analog for a long duration space mission that has been conducted and warrants reexamination in light of NASA's new direction. A brief overview of the two-year Biosphere 2 mission is presented, followed by select data and lessons learned that are applicable to the design and operation of a long duration human space mission, settlement or test bed. These lessons include technical, programmatic, and psychological issues.