Research Projects

The space industry has experienced remarkable growth over the past decade, with an increasing number of private companies and startups joining the space race each year. However, the exponential increase in the number of satellite launches is adding more greenhouse gases and other harmful byproducts to our atmosphere, causing further environmental damage. One of the promising propulsion systems that could eliminate these problems is hypergolic hybrid propulsion, where a combination of solid fuel and liquid oxidizer is used. In addition to generating less harmful combustion products, hypergolic hybrid propulsion is also advantageous due to its better control over thrust and the absence of igniters and separate combustion chambers. However, most of the fuels that exhibit hypergolic reactions are based on toxic and corrosive fuming nitric acids and nitrogen tetroxide oxidizers. To avoid such toxic and corrosive oxidizers, green oxidizer hydrogen peroxide (H₂O₂) was evaluated for its hypergolic behavior. However, only rocket-grade hydrogen peroxide (H₂O₂, greater than 90%) exhibited hypergolic reaction with fuels containing hydride, borohydride, amino borane, and transition metal complexes. The major drawbacks of such fuels that restrict their potential application in hybrid rocket motors are poor chemical and thermal stability, difficulty in motor re-ignition, low density, higher metal content (above 15%), and notably low specific impulse. To address these problems, the proposed research aims to develop advanced hypergolic rocket fuels with green oxidizers (H₂O₂, HAN, and AN), which will be chemically and thermally stable and perform better than existing hypergolic fuels. We propose to synthesize a series of monometallic and bimetallic potential hypergolic fuels based on energetic triazole and tetrazole derivatives. The fuels are designed to give ultrafast ignitions with H₂O₂ (90%), oxidizer formulations of H₂O₂ with HAN and ammonium nitrate (AN), and fast ignitions (below 50 ms) with H₂O₂ (80% and 70%). To the best of my knowledge, air stable hypergolic fuel having ignition delay time (IDT) below 50 ms with H₂O₂ (80% or 70%) is not known. IDT below 50 ms is a highly challenging and crucial parameter of a hybrid rocket motor. The incorporation of strained hydrocarbon moieties such as cyclobutane and cyclopropane is expected to improve the enthalpy of formation of our fuels, which in turn will result in higher specific impulse. Moreover, the designed fuels are expected to have good thermostability (about 250 °C) and density (about 1.7 g/cm³) that may allow its application in hybrid rocket motors. We also propose to develop several green oxidizer formulations of H₂O₂ with HAN and AN having better ignitability and lower freezing point than pure H₂O₂; and study their long-term storage stability. The proposed research will yield important data and guidelines for developing futuristic green fuels and oxidizers for hypergolic hybrid rocket motors.