Advantages of the use of lunar and Mars propellant production

The use of nonterrestrial resources is discussed in the context of facilitating the transport of space-vehicle propellant to be used for lunar and/or Mars missions. A cost-benefit analysis is conducted to determine the feasibility and efficiency of developing propellant-production facilities in space for future mission support. The analysis suggests that after 2-3 years a break-even point is possible for return-on-investment mass, and technological hurdles are described that include systems for automation, mining, and processing.