Cryogenic Monopropellant for Advanced Rocket Propulsion

All rocket propellant power derives from the reaction of a fuel and oxidizer. Accordingly, all liquid rockets, and especially all cryogenic liquid rockets, have two complete fuel systems. One set each of containment tanks, pumps, instrumentation, and so on. Solid rockets, on the other hand, have only one fuel system, so to speak. The solid rocket motor contains the fuel and oxidizer in a rubber-like base. The fuel is called a monopropellant, since it is not necessary to mix the two components. It is interesting to speculate on how things could be different if we had access to a cryogenic monopropellant. Perhaps we could combine some of the best features of solid rockets and liquid rockets. For instance, we could have the fuel system simplicity of a solid rocket combined with the ISP and variable thrust of a liquid rocket. Accordingly, we have developed a new cryogenic monopropellant which is made by adding a hydrocarbon fuel such as methane to liquid oxygen. We will show how liquid oxygen may also be combined with a hydrocarbon fuel, such a methane, under controlled pressures and temperatures such that a single phase, totally miscible, liquid cryogenic monopropellant propellant is provided. Under the conditions described, the liquid oxygen/methane propellant is a single phase totally miscible liquid solution.