SBIR-STTR Award

Many of NASAs high priority missions in the next decade are located in extreme environments with low, inconsistent or no sunlight. In these cases, NASA has traditionally used RTGs. However, RTGs are inefficient (<8%), with specific powers of just 2.7 W/kg. Complicating issues is the scarcity of GPHS units due to a long drought of plutonium production. Even with a restart in production, this necessitates judicious use of remaining GPHS units. ExoTerra’s proposed advanced micro Brayton energy converter operates a pair of units off a single GPHS. The units are 40% efficient, enabling 100 W of electrical power and a >40 W/kg specific power. The system uses advances in manufacturing techniques to enable high efficiency heat transfer among components and miniaturize the Brayton Cycle components. By using a pair of units, we balance inertias across the spacecraft to maintain control. The proposed Phase I effort completes system design of the micro Brayton unit. We then fabricate a compressor unit to demonstrate the advanced manufacturing techniques. We perform a demonstration test to measure the performance against predictions and feed into Phase II development. Potential NASA Applications (Limit 1500 characters, approximately 150 words) Provides power for NASA missions in areas with limited sunlight, including the search for water at the lunar poles, performing ISRU or supporting a lunar outpost during the 2 week lunar night, or Europa exploration. The system can fit into microsatellite scale missions – including pending commercial lunar payload services vehicles. It can also supply power to microsatellite class nuclear electric propulsion systems for outer planet missions with microsatellites. This increases affordability though reduced launch costs. Potential Non-NASA Applications (Limit 1500 characters, approximately 150 words) Remote Military power supplies Micro UAVs