Anon-catalytic pyrotechnic ignition system was developed for advanced green monopropellant systems operating with hydroxylammonium nitrate (HAN)-based monopropellant AF-M315E. This technology will provide increased performance and new operating regimes for future NASA missions that employ green propulsion systems. The non-catalytic ignition system is a critical component for future high-thrust, in-space rocket engines that utilize AF-M315E, offering longer thruster life and faster startup than catalytic engines. This work demonstrated the pyrotechnic ignition system in proof-of-concept hot-fire tests showing AF-M315E combustion in a workhorse thruster in a laboratory environment.

Technology development for green monopropellant thrusters has focused on small engines in the 0.2 to 5 lbf (≈0.9 to 22 N) thrust range, resulting in a gap in the development of larger-thrust-class green thrusters used for delta-V maneuvers. Additionally, state-of-the-art engines using AF-M315E monopropellant use catalysts to initiate reaction of the propellant. In these engines, the catalyst or associated components, such as catalyst bed plates, is a life-limiting component(s), making thruster life difficult to predict.

The non-catalytic ignition system consists of a directed pyrotechnic charge that delivers hot burning gas to the center of the AF-M315E monopropellant spray to initiate combustion. The pyrotechnic charge will instantaneously heat the cold propellant beyond its auto-decomposition temperature and provide nano-sized reactive particles to promote propellant combustion. Liquid propellant is delivered into the combustion chamber via a traditional injection configuration, and then combusted by the pyrotechnic charge. After initial actuation of the pyrotechnic charge, combustion continues as AF-M315E is injected into the combustion chamber.

The pyrotechnic ignition system technology can enable development of higher-thrust in-space rocket engines in the thrust range of 25 to 100 lbf (≈111 to 445 N), with longer usable lives and lower power consumption than traditional engine designs, and will be capable of immediate use for critical emergency maneuvers. This technology will enable the infusion of green propulsion technology into a wider range of NASA satellite platforms including geostationary science satellites, interplanetary exploration satellites, and cargo resupply vehicles. This technology is also suited for end-of-life satellite de-orbit functions due to their long-duration, high-thrust requirements.

This work was done by Stephanie Sawhill, Gautam Shah, Keith Krasnowski, and Randy Hoskins of Systima Technologies for Glenn Research Center. NASA is seeking partners to further develop this technology through joint cooperative research and development. For more information about this technology and to explore opportunities, please contact here. LEW-19273-1