First Human Testing of the Orion Atmosphere Revitalization Technology

A system of amine-based carbon dioxide (CO₂) and water vapor sorbent in pressure-swing regenerable beds has been developed by Hamilton Sundstrand and is baselined for the Orion Atmosphere Revitalization System (ARS). In two previous years at this conference, reports were presented on extensive Johnson Space Center (JSC) testing of the technology, which was performed in a representative environment with simulated human metabolic loads. The next step in developmental testing at JSC was to use real human loads in the spring of 2008. This first instance of human testing of a new Orion ARS technology included several cases run in a sealed Orion-equivalent free volume and three cases using emergency breathing masks connected directly to the ARS loop, Significant test results presented in this paper include a comparison between the standard metabolic rates for CO₂ and water vapor production published in Orion requirements documents and metabolic rate ranges observed with the human test subjects. Qualitative assessments of the tolerability of various process flow rates and closed-loop pressure-cycling while using the emergency masks are also included. Recommended modifications to the Orion ARS design and operation conclude the paper.