Novel Segregated Solid Propulsion System with Separately Stored Fuel and Oxidizer

The development and experimentation of a solid propulsion concept consisting of separate hydrogen-rich solid propellant and solid oxidizer grains is presented. This system consists of an extremely fuel-rich solid propellant, which, once ignited, undergoes a self-sustaining decomposition to release fuel-rich product gases, which are particularly rich in hydrogen gas. These relatively high-temperature gases subsequently react with a solid oxidizer grain stored downstream. Progress in high-nitrogen materials has allowed for the synthesis of fuel-rich compounds that can store significant amounts of hydrogen, with little or no bound oxygen. With these new developments in propellant chemistry, a unique segregated propulsion system has been developed, creating an all-solid propulsion system that combusts analogously to a reverse hybrid rocket system. Because of the physical separation of fuel and oxidizer, a higher level of safety is achieved which concurrently allows for the utilization of higher energy ingredients without the penalty of higher sensitivity. Theoretical performance calculations and experimental data have shown the potential for this system to compete with existing composite rocket propellants while having significant benefits in terms of safety, toxicity, and mission space. This paper presents a detailed overview of the conception, development, and testing of this propulsion system.