Potential of ADN-based Ionic Liquid Propellant for Spacecraft Propulsion

As an alternative to hydrazine, ammonium dinitramide-based ionic liquid propellant (ADN-based ILP)was developed. It is mixture of the solid powders: ammonium dinitramide, monomethylamine nitrate, and Urea. It has a feature to be able to adjust the performance of monopropellant by change of the compositions because the constituents have different role: oxidizer, fuel, and freezing point depressant. By adjusting the components, it has high specific impulse and fuel rich and low freezing point comparing to hydrazine. The basic combustion characteristics of ADN-based ILP wereinvestigated in the strand burner tests forapplication to thruster. The self-sustainable combustion,the linear burning rates,and the flame temperatureswere shown in the results. The features of the ADN-based ILP were discussed on the basis of the results. As a problem of the thruster application, the ignition in vacuum was also discussed.