"CLEAN" PROPELLANTS FOR COMMERCIAL APPLICATIONS

Abstract

Trends for solid propellant applications in the Netherlands during the last decade are described, especially focusing on new propellant formulations which are "clean". In 1985 TNO Prins Maurits Laboratory (TNO-PML) became involved in the development of pyrogenic devices for Ariane 5's Vulcain engine HM 60, which developed into a production programme of AN based turbine pump starters and igniters for the European Space Agency (ESA). During the development, it turned out that removing the hydrochloric acid has other advantages, e.g., less smoke in the rocket plume, while AN based formulations show better cook-off behaviour. Another application of "clean" propellant technology is the development of a new "environmentally friendly and human friendly" gas generator composition for an airbag. This composition is based on AN with triaminoguanidine -nitrate (TAGN) or nitroguanidine (NQ) and has the advantage over sodium azide (NaN3) based gas generators that less toxic and corrosive products and much less solid reaction products are formed. In a search for new "clean" high performance propellants, performed for the ESA, Hydrazinium Nitroformate (HNF) based propellants were identified as new interesting formulations, that offer a much higher specific impulse than obtained with conventional composite propellants. Under sponsorship of ESA and the Netherlands Agency for Aerospace Programs a research programme was initiated, aiming at experimentally demonstrating the increased performance of HNF based propellants.