Characterization of On-Orbit Temperature and Pressure Performance for Hydrazine Propulsion System

To characterize on-orbit temperature and pressure variation of the hydrazine propulsion system, three types of temperature telemetries including the catalyst bed temperature/tank temperature/pipe temperature, and two types of pressure telemetries including tank pressure/pipe pressure were investigated. Results indicate that the catalyst bed temperature of the 5N hydrazine thrusters decline in the first few minutes before going up during the preheating process, and the turning point is related to the separation of the rocket fairing. The decline of the catalyst bed temperature is owing to the heat convection between the thruster and air in the fairing. The pressure fluctuation during thruster firing is in the range of ±0.25 MPa, but pipe pressure rises up apparently with a speed of 0.5 MPa/°C even the pipe temperature rises slightly in the locked pipe. Accordingly, monitoring measures of the temperature and pressure variation should be taken during on-orbit management of the satellite.