New HAN-based mixtures for reaction control system and low toxic spacecraft propulsion subsystem: Thermal decomposition and possible thruster applications

HAN-based liquid monopropellant has been studied for its possible substitution of hydrazine toxic component. The onset temperature of decomposition was provided by DTA-TG thermal analysis. Moreover, the effect of 5 M HNO3 and 5 M NH2OH addition on catalytic decomposition was also examined. The major products measured by mass spectrometer were N2, NO, N2O, NO2, H2O and NH3. Otherwise, the burning rates of HAN-based monopropellants were measured from the strand burner videos taken by high speed camera. The effect of methanol addition; as fuel; on the burning rates was demonstrated. On the other hand, HAN-based liquid monopropellant was tested and decomposed in 20 N thruster and different catalysts were compared. Honeycomb catalysts were tested instead Shell 405 catalysts, the obtained data demonstrate the improvement of burning reactions and pressure slopes after HAN-based decomposition.