AF-M315E Advanced Green Propulsion – GPIM and Beyond

Abstract

With the successful launch of the GPIM demonstration mission in June 2019, the long-sought benefits of a low toxicity, high performance green monopropellant AF-M315E propulsion system, offering a 50% greater density-Isp than hydrazine, have become reality. However, ongoing efforts initiated even while the GPIM system delivered in 2015 awaited launch aboard SpaceX’s Falcon Heavy rocket have continued to move the technical state-of-the-art of AF-M315E advanced green monopropellant technology forward. While the GR 1 thruster design flying on the GPIM mission represents a mission-ready green technology statistically capable of meeting the operational requirements of 50% of applications typically performed by conventional hydrazine thrusters in its 1 N thrust class, already demonstrated improvements in catalyst bed life will extend these capabilities to meet the needs of approximately 90% of all such missions in a next-generation “GR 1A” thruster currently in development on the AFRL Advanced AF M315E Monopropellant Engine (AAME) program. Further, a number of design improvements, related to both materials and processes, promise reductions of up to 30% in required preheat power and 50% unit cost. The GR 1A will also benefit from advances in catalyst manufacturing methods successfully undertaken in 2019. Meanwhile, parallel efforts aimed at adapting advanced green monopropellant technology for small microsatellite/CubeSat applications are rapidly approaching completion.