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Each ascent vehicle returning from the lunar surface with a crew vehicle will require several tons of fuel. Most architecture studies of lunar exploration vehicles use liquid oxygen for fuel, either for LOX/LH2 or LOX/methane. Utilization of oxygen generated on the lunar surface saves mass launched from Earth, with a multiplication factor on the order of 4-5, e.g. production and utilization of 4 tons of lunar oxygen for the ascent vehicle saves 16-20 tons of initial mass in low Earth orbit (IMLEO). The paper discusses ongoing MSFC activity on oxygen production by hydrogen reduction of Ilmenite. Specifically the important project milestone is to develop the Technology Readiness Level for the generation of lunar oxygen for propellant production from 3 to 5. The paper will provide an overview of the processes for Oxygen Generation, Complete Systems Architecture for a pilot lunar plant, experimental apparatus development and initial experimental results, and future directions.

Space-based materials processing R&D is examined. It is proposed that the Space Station's Microgravity and Materials Processing Facility will be utilized by academic, government, and commercial customers. Users requirements for materials processing in space are discussed. Consideration is given to the time allocation of the facility, charges to users, and the property rights of the users.

An assessment is made of a manned space station operating with sufficiently high power demands to require a multihundred kilowatt range electrical power system. The nuclear reactor is a competitor for supplying this power level. Load levels were selected at 150kWe and 300kWe. Interactions among the reactor electrical power system, the manned space station, the space transportation system, and the mission were evaluated. The reactor shield and the conversion equipment were assumed to be in different positions with respect to the station; on board, tethered, and on a free flyer platform. Mission analyses showed that the free flyer concept resulted in unacceptable costs and technical problems. The tethered reactor providing power to an electrolyzer for regenerative fuel cells on the space station, results in a minimum weight shield and can be designed to release the reactor power section so that it moves to a high altitude orbit where the decay period is at least 300 years. Placing the reactor on the station, on a structural boom is an attractive design, but heavier than the long tethered reactor design because of the shield weight for manned activity near the reactor.