LUNAR OXYGEN - ECONOMIC BENEFIT FOR TRANSPORTATION SYSTEMS AND IN-SITU PRODUCTION BY FLUORINATION

The use of oxygen produced on the Moon-called ''MOONLOX''-is considere d as a propellant component for a reusable Earth-Moon transportation s ystem consisting of an aeroassisted orbital transfer vehicle and a lun ar bus for lunar descent/ascent. Conditions for economic benefit are d iscussed and the processing concept of a lunar oxygen plant based on f luorination is presented. It is shown that the necessary mass of suppl y from Earth for MOONLOX-production is an important parameter, which m ay not be neglected due to its strong influence on the economy. In the ideal case where no supplies from Earth are required a reduction of u p to 50% in masses to be launched into low Earth orbit can be obtained for a typical lunar mission with use of MOONLOX compared to a referen ce scenario with Earth-derived propellant. Mass-saving decreases, howe ver, significantly with increasing supply from Earth until a critical supply-rate is reached-measured in percentage of MOONLOX-mass produced and consumed-beyond which mass-saving and thus economically promising lunar oxygen production is no longer possible. This critical supply-r ate depends on the scenario for MOONLOX-utilization and is much larger in the case of in situ use of MOONLOX on the lunar surface, e.g. as a scent propellant for the lunar bus, than in the case of export for com plete refuelling of both space vehicles. The latter scenario therefore requires significantly more autonomy for MOONLOX-production. The redu ction of masses to be transported into low Earth orbit and correspondi ng MOONLOX-consumption define for given specific Earth-to-LEG transpor tation costs an upper limit on MOONLOX-production costs beyond which e conomic benefit is not possible. Depending on the MOONLOX-utilization strategy this upper limit varies between 3000 and 55000 $/kg for curre nt Earth-to-LEG transportation costs.