Infrared cage thermal balance test of high-power spacecraft heat pipe radiator

To meet the thermal management requirements of high-power spacecraft, a high-efficiency heat pipe radiator is designed, fabricated, and experimentally verified through an infrared (IR) cage thermal balance test. A thermal balance test is conducted to investigate the radiator's thermal balance characteristics under different orbital conditions, pumping flow rates, and external heat flux variations. Multiple infrared heat flux loading schemes are designed to represent steady-state and transient operating conditions. The results indicate that the IR cage can accurately reproduce the on-orbit thermal environment of the radiator. At a beta angle of 0°, the external heat flux exhibits strong periodic variations, while at a beta angle of 83.5°, the heat flux remains stable and evenly distributed. Increasing the pumping flow rate significantly reduces the average radiator temperature and enhances overall heat transport capability. An auxiliary heating power of approximately 390 W is required at a beta angle of 0° and 10% flow to prevent fluid freezing. Multi-step infrared heat flux loading schemes effectively reproduce the transient variations of orbital heat flux. These findings provide essential experimental evidence and technical guidance for the design, ground verification, and in-orbit application of high-power spacecraft heat pipe radiators.