During the early phases of human Mars exploration, in situ resource utilization (ISRU) will lower costs, expand capabilities, and serve as an enabling technology for establishing permanent colonies. Martian atmospheric resources can be used to provide consumables such as fuel, oxidant, breathable air, and water that are critical for early human missions. Martian atmospheric carbon dioxide and imported hydrogen can be used, for example, as feedstock for the catalytic production of oxygen, methane, methanol, and other propellants and water (Zubrin, 1991, 1996, 1997, 1998, Zubrin, Meyer, McMillen 1998, Meyer 1981).

These processes utilize catalytic reactors containing small amounts of iron, nickel and other suitable catalysts, plus gas selective membranes, electrolysis, and other easily implemented gas separation techniques. Waste carbon monoxide from carbon dioxide reduction processes together with hydrogen can be combined to produce other liquid and gaseous fuels and chemical compounds. Excess heat from an exothermic Sabatier reaction can be diverted to minimize heat requirements in endothermic processes such as the reverse water-gas shift reaction. Thus valuable synergies can be realized by integrating various processes. Oxygen and fuel production processes can be combined so the thermal and material wastes of one process can be utilized by the other thus forming a unique Martian “chemical refinery” that features internal hydrogen recycling and production of a purified carbon monoxide intermediate by-product. Turbines can also be used to recover mechanical energy from high-pressure waste gas and systems can share common hardware and feedstock systems. Thus feedstock, power, heat and mechanical energy are utilized efficiently and conserved in the design of these robust Martian atmospheric refineries whose technologies may also find applications in industrial waste utilization technology on Earth.