Evolution of Environmental Control and Life Support System Requirements and Assumptions for Future Exploration Missions

NASA programs are maturing technologies and system architectures to enabling future exploration missions to Mars and in cislunar space. The future life support system is one of many technical focal areas. As the core life support system technologies and system matures, developers must make assumptions on the requirements relating to the future flight program. Multiple efforts have begun to define these requirements, including team internal assumptions, planning system integration for early demonstrations, and discussions between international partners to identify areas for future collaboration. For many detailed life support system requirements, existing NASA standards and design handbooks define the performance basis; however, a future vehicle may be constrained in ways that lead to tailoring requirements derived from these standards as well as deriving mission-specific requirements. Other requirements are effectively set by interfaces or operations, and may be different for the same technology depending on whether the hardware is a demonstration system on the International Space Station, or a critical component of a future vehicle. This paper highlights key assumptions relating to life support system requirements and discusses driving scenarios, constraints, and other issues.