Development of Improved Performance, Low Toxic Hypergolic Fuel for Replacing Monomethylhydrazine

Monomethylhydrazine (MMH) is a widely employed fuel in hypergolic, bipropellant systems. Negative aspects of this fuel are its high toxicity and carcinogenic effects. Although gelling of fuel has solved many technical problems, its toxicity and carcinogenic nature is still a major concern. The task of developing a replacement fuel for MMH is constrained to those compounds that maintain or improve all performance characteristics, dovetail into existing infrastructure, while reducing the toxicity and health risks. The proposed work aims at modeling-guided design and development of replacements for MMH. This strategy will significantly reduce the time and cost for development of new hypergolic fuels by predicting their chemical and physical properties at the earliest stage of development. In Phase I, high fidelity molecular-modeling techniques will be applied to identify candidates for MMH replacement by computing their density, vapor pressure, heat of formation, specific and density impulse. The Phase I option program will focus on prediction of toxicity, freezing point and ignition delay time. At the end of Phase I, at least three candidate fuels will be selected for further consideration based on their chemical and physical properties. In Phase II, the selected candidates will be synthesized or purchased, if available, and tested in both liquid and gelled form to examine their performance in small-scale rocket engines under consideration at Northrop Grumman, Aerojet and Orbitec.