Expanded Set of Criteria for Life Support Comparative Assessment

Currently the primary evaluation scheme for comparison of life support systems is Equivalent System Mass (ESM). ESM can be used to identify the most efficient or least costly-to-launch option when selecting a solution from a group of system alternatives. ESM specifically addresses and quantifies the resources required to deploy a system, including: mass, volume, power, cooling required, and crew time. ESM provides a framework for the weighted aggregation of these various categories to one number for easy comparison. However, ESM only address certain aspects of the overall system. In order to expand the set of characteristics used for comparative evaluations, a set of categories were developed to supplement ESM criteria. These additional categories and processes, termed Life Support Multidimensional Assessment Criteria (LSMAC), are used to augment traditional ESM comparison methods for evaluation and comparison of life support systems. Specifically, LSMAC addresses the following additional evaluation criteria: risk analysis, radiation, technology readiness level, manufacturing cost, human factors, reliability, maintainability, and un-crewed operations. The LSMAC framework defines each of these criteria, provides system scoring guidelines, and allows methods with which to compile a weighted aggregate score that considers all criteria. It is important to note that ESM is a criteria within the LSMAC framework and is given significant consideration. LSMAC analysis provides a more inclusive and robust picture of any one system while retaining the useful comparative power that ESM provides. The LSMAC assessment methodology could be used to aid technology evaluations of alternatives for future planned missions beyond Low-Earth Orbit (LEO), such as a cis-lunar Gateway or Mars Transport. This work is supported by NASA Advanced Exploration Systems, Human Exploration and Operations Mission Directorate.