This artist's concept of lunar mining operations illustrates the production of liquid oxygen. Ilmenite, a fairly common oxygen rich component of lunar soil, is the material actually being mined here. At center, a robot front-end loader scoops out lunar soil, which is then dumped into sifters, the red containers, at center. There, the soil is sifted, the useable material then dumped into electrostatic separators which further discriminate between useable and unusable material. Material, which cannot be used for this process, is carried away on the tracks seen leading out from the facility where they are dumped for later use in other processes to recover valuable minerals and ores. Back at the facility, material is dumped into a 700 furnace that is heated by using hydrogen as a fuel. This process produces water, from which an electrolysis process is able to produce hydrogen and oxygen. The hydrogen is recycled back into the process, while the oxygen is taken to the yellow buildings where it is converted into a liquid through a super cold cryogenic freezing process. The liquid oxygen is then piped to the modules at center right, transported to the container in the center background, and ultimately shipped to the orbiting way station via the lunar lander at the top background of this photo. At top center is a large berm shelter that houses workers at this site. This concept would have it consist of two discarded Shuttle external tanks, covered with lunar soil, which would provide 2,400 square feet of living space.