Decomposition Characterization and Optimization for Monopropulsion Systems for Spacecraft

This program seeks to develop a means of initiating a repeatable, reliable exothermic decomposition of USAF developed high performance Hydroxyl Ammonium Nitrate (HAN) based monopropellants, over a range of demanding mission duty cycles with short delaytimes and predictable performance over long storage times. Catalysts do not have the high temperature or oxidation resistance required by these USAF developed HAN based monopropellants to support the program objectives. However, these materials should besusceptible to initiation, or self-sustained energy release, when present in sufficient quantities and exposed to stimuli such as heat, shock, friction, chemical incompatibility, or electrostatic discharge. Under the proposed program, METSS proposes toconduct a study to develop an initiator/sensitizer for HAN based monopropellants by exploiting the exothermic decomposition properties of the amine nitrates. Furthermore, METSS will demonstrate that the formulations synthesized under this program willdecompose HAN at concentrations of 2-5%. Chemicals dispersed with the fuel will react with one another or the fuel over a nozzle structural surface generating heat from the reaction sufficient to either start or speed up the monopropellant decompositionreaction. The chemical initiator composition will be selected for specific characteristics: high thermal stability, fast response, sustained thermal output, and high short-term peak energy. Specifically, the work will emphasize the pre-existingtechnologies of azo polymer initiators and the reduction of nitrate by an added reducing agent, and recent developments that can convert nitrate in water into environmentally benign gaseous nitrogen. METSS believes that high activity, low cost initiatorscan be developed using this approach that will decompose the HAN fuel. This project will demonstrate a complete, cost effective technology. In addition to military interests, there is a wide range of commercial uses for HAN, ranging from pharmaceuticalproducts to re-processing nuclear fuels. A versatile chemical, HAN can also be used as an oxidizer or reducing agent in applications such as photographic developing, semiconductor manufacturing and as a high performance fuel additive, propellant or gasgenerator for mining, boring and other operations. The use of existing commercially available processing equipment and the existing commercial market make the transition of this methodology into the commercial environment technically and financiallyfeasible.