Mock Mars missions or Mars analog missions typically construct terrestrial habitats on Earth and conduct mock missions, taking steps to solve some of the problems that could be faced for one on Mars.[69] An example of this was the original mission of Biosphere 2, which was meant to test closed ecological systems to support and maintain human life in outer space.[70] Biosphere 2 tested several people living in closed loop biological system, with several biological areas in support including rainforest, savannah, ocean, desert, marsh, agriculture, and in an area in support of a living space.[71]