Gary K. Lund

Magnesium-neutralized propellant

Conventional solid rocket motors, which utilize ammonium perchlorate as the propellant oxidizer, produce hydrochloric acid (HC1) as an exhaust product. A low-acid propellant has been developed which substantially reduces the HCl content of the solid rocket exhaust. The predominant mechanism for HC1 exhaust reduction is a neutralization of the acid by the base magnesium hydroxide which is generated in the exhaust plume from the combustion of magnesium (Mg) fuel. Experimental analysis of the Mg-propellant combustion products has shown that HCl levels of less than 1 % are achievable. The Mg-neutralized propellant exhibits properties that are compatible with the reliability, cost, performance, ballistic, and mechanical properties as well as the safety dictates of an advanced launch system (ALS). Predictions for propellant variability and sensitivity suggest that the Mg-neutralized propellant reliability will compare favorably with the current state-of-the-art hydroxy terminated polybutadiene (HTPB) propellants. The range of ballistic tailorability is broad and the low-volumetric solids loading of the Mg propellant results in outstanding mechanical properties and simple processing. The Mg propellant also exhibits DoD zero cards class 1.3 hazards properties which suggests that no compromise in safety will be encountered relative to current propellants used in large booster applications.