Thermal Control Design and Validated for MEO Navigation Satellites

In consideration of the configuration design, orbital attitude, and operation mode of the MEO navigation satellite, both passive and active thermal designs including conduction, diffusion, insulation, switch or proportional control and multistage control strategy are used in the satellite thermal system to satisfy the strict temperature requirements. For high-power payloads and phased array antennas, heat pipe networks along with extended radiators are employed; for temperature-sensitive equipment like battery and atomic clock, thermal insulation along with active control are applied. On-orbit fault diagnosis and automatic isolation designs are utilized in the thermal control software to improve the on-orbit autonomous operation capability. The satellite thermal design is validated by the ground thermal balance test and the performance of satellites in orbit. Validation results illustrate that on-board equipment satisfies temperature requirements, and the design margin and temperature trend lines well with expectation.