Mainstream proposes to develop a vapor compression (VC) thermal management system suitable for long duration lunar equatorial missions. Because the high lunar surface temperatures during daytime operation exceed the maximum allowable temperature for most electronics, an active lifting cycle is needed rather than typical spacecraft thermal control strategies such as passive thermal links or mechanical pumped loops. The objective of Phase I is to design and demonstrate the key enabling technologies needed to produce a fully functioning VC heat pump prototype. The most significant technological innovation needed to achieve a highly reliable lunar VC heat pump is the improvement of microgravity compressor technology. The main focus of Phase I of this program is to adapt our microgravity refrigerant compressor technology for operation at the extreme environmental conditions of lunar equatorial missions. Our approach leverages our experience with spaceflight-proven microgravity compressors and advanced heat exchanger design. In Phase I, we will design, fabricate and test these key technologies for lunar lander thermal management.
NASA has identified a need for improved thermal management systems in the equatorial lunar environment, where surface temperatures can vary between ‑183°C and 100°C. Mainstream’s compressor technology has potential to benefit any space-based system in extreme environments. Increasing the rejection temperature through a lifting cycle can reduce radiator size and weight. Other applications include manned lunar habitat climate control, food preservation freezers, low lunar orbit missions, and Venus exploration missions.
Potential non-space applications include high energy laser cooling systems and industrial high temperature heat pumps. Few manufacturers supply high temperature heat pumps with sink temperatures over 100°C with one main barrier to entry being lack of available low-GWP, high-temperature refrigerants. Mainstream’s compressor has the potential to penetrate these markets.