High Capacity Multi-Stage Scroll Compressor for Mars Atmosphere Acquisition

The proposed innovation supports technologies for In Situ Resource Utilization (ISRU) processes by collecting and pressurizing gasses from the Mars atmosphere for eventual oxygen production by use of Solid Oxide Electrolysis (SOXE). There are several ways to capture and pressurize CO2, including freezing at cryogenic temperatures, mechanical compression, and absorption. Completed studies on each approach, have generally favored cryogenic temperature and mechanical compression solutions. Recently, mechanical compression has gained momentum through the Mars Oxygen ISRU Experiment (MOXIE), which utilizes an Air Squared compressor for mechanical compression of CO2. If this approach is pursued further for a larger system, there are still several questions concerning reliability over 10,000 hours of autonomous operation in Mars environment and scalability. Air Squared plans on addressing these issues as part of Phase II.The proposed innovation is a Martian Atmosphere Scroll Compressor (MASC). Dealing with the low pressures of the Martian atmosphere, the MASC functions like a vacuum pump utilizing Air Squared scroll compressor technology. During Phase I, Air Squared tested several orbiting and spinning scroll prototypes on CO2 at a wide range of discharge pressures and superior efficiencywas demonstrated with lower discharge pressures. Parallel efforts by NASA-JPL on MOXIE, showed no performance degradation of the SOXE at reduced pressures down to 4.4 PSIA. Additionally, reducing the cathode pressure provides more margin against starting to electrolyze CO. For this reason, Air Squared has decided to focus exclusively on collection-only in an attempt to concentrate efforts on a lightweight and efficient MASC, supporting oxygen generation. The following proposed Phase II work will further develop both a spinning and orbiting scroll MASC for providing 2.7 kg/hr of CO2 at discharge pressures between 4.4 and 15 PSIA.