Self-Sustainable Life Support System Trade Study for Lunar Farming

The primary factors to be considered for a life support system design for long-term space habitation are mission location, mission duration, and crew size. When taking into account transportation costs and supply difficulty, a regenerative life support system and an in situ resource utilization (ISRU) system are the most important systems for long-term habitation in space and on planets. Equivalent System Mass (ESM) has been used for regenerative life support system trade studies considering biomass production (food), in other words, the degree of recycling suitable fir long term missions, such as lunar and Mars missions, by NASA over the past 20 years. Therefore, we have developed a trade study tool for designing a regenerative life support system to be able to compare different systems. In this paper, a lunar farm design for six crewmembers was introduced to conduct a life support trade study on an open system, a semi-closed system, and a closed system that were designed with the tool; it indicated that it takes more than 10 years to achieve a lower cost closed system, compared to a semi-closed system.