Description: Future exploration to the outer reaches of our solar system and beyond will require high-thrust, high specific impulse propulsion systems to reduce transit time. For this reason, missions are being designed that would make use of propulsion systems using cryogenic propellants such as liquid hydrogen (LH2). A promising layout for these systems includes the use of a small electrically-driven pump able to provide a reliable boost to propellant pressure, simplifying the engine cycle and improving reliability and mass. To address this need, Creare proposes to develop a compact, low Net Positive Suction Head (NPSH), electrically-powered LH2 pump capable of operating with saturated liquid at its inlet. NASA mission projections indicate a need for pumping up to 0.6 kg/s LH2 flow with 45 psid head rise. The density of LH2 is relatively low; therefore, the volume flow rate and motor power are appreciable, and providing a substantial head rise requires high operating speeds, driving cavitation concerns. In Phase I, we will prove the feasibility of the cryogenic propellant pump by developing a preliminary design, predicting its overall performance, and demonstrating its key features by testing in simulant cryogenic fluids. In Phase II, we will optimize the pump design, fabricate an integrated pump assembly, demonstrate its steady-state and transient performance at representative conditions, and deliver it to NASA for further performance evaluation.

Benefits: Technology developed in this project will reduce the mass of cryogenic propulsion systems for future interstellar or similar long-range missions, and thus reduce the cost of these missions and increase their frequency. It is directly applicable to nuclear and solar thermal cryogenic propulsion systems. The electrically-driven pump also has application to any system requiring delivery of high-pressure cryogenic fluids, including robotic propellant transfer for satellite servicing, and pumped fluid loops in thermal management systems for spacecraft.The technology also has applications in commercial spacecraft propulsion systems and sounding rockets. The pump technology itself has many other space and terrestrial applications, including circulation pumps for thermal management systems and hybrid-electric aircraft.