Dynamic Simulation Study on the Effect of Airtightness on the Sensitivity of Air Composition Monitoring in SPACE FOODSPHERE

In 2021, the Ministry of Agriculture, Forestry, and Fisheries selected the SPACE FOODSPHERE Association as the contractor for a Japanese government-led strategic project called “Development of a Highly Resource-Recycling Food System That Supports Long-Term Stays on the Moon, etc.” In the same year, the writers of this paper, SPACE FOODSPHERE Association members, launched a conceptual design study of a ground-based test facility comprising a crop/microalgae/meat cultivation area, a habitation area, a resource recycling facility, and an environmental control area. In the ground test facility, it is important to measure changes in gas composition as accurately as possible over a long period, but the results will differ greatly if gas leaks out of the facility or flows into it from outside. Therefore, using dynamic simulation, this study analyzed the effects of a change in gas composition in the facility over a span of one year. The results of various specified leakage ratios were compared to determine the airtightness performance required for the experimental threshold. The results identify the relationship between air tightness and the air composition and capacity of the environmental control life support system as well as that between air tightness and the accumulation rate of trace components.