Nitrous Paraffin Hybrid

The Nitrous Oxide Paraffin Hybrid engine (N2OP) is a proposed technology designed to provide small launch vehicles with high specific impulse, indefinitely storable propulsion. In the N2OP engine, the combination of liquid nitrous oxide on solid paraffin as a rocket propellant allows for the development of compact lightweight high performance stages using densely packed propellant tankage. This is because N2O/paraffin hybrids have a very high oxidizer/fuel mixture ratio and because paraffin has a much higher regression rate than typical hybrid hydrocarbon fuels. Propellant slumping can be prevented by molding the paraffin into a 3% by volume graphite sponge matrix. Currently, space launch missions require cryogenic or extremely toxic propellants which are limited in their storage times, reducing their capability for rapid response launch. The much more storable solid propellants have higher cost, and lower performance while still being a large explosive hazard. The N2OP propulsion system also is compatible with ocean temperatures, allowing launch by floating in water. The achievable Isp for this propellant combination using autogenous pressurization is about 235 seconds at sea level and over 310 s in vacuum, making its performance fully adequate to support operation of a safe, fully storable, highly-responsive multi-stage launch vehicle.