Design and implementation of the integrated thermal control system for Chang'E-5 lunar module

Aiming at the thermal control challenges of the Chang'E-5 lunar module, which is a complex of lunar lander and lunar ascent vehicle, a design method was proposed based on optimized management of energy. An integrated and autonomous thermal management system for robotic lunar spacecraft was designed including a single-phase fluid loop, water sublimator and high temperature thermal protection shield. The single-phase fluid loop driven by a miniature pump served as the thermal bus to collect heat. The water sublimator was applied as a supplementary heat sink of panel radiators to dissipate heat load on the lunar surface. The lightweight thermal protection shield was applied to protect the equipment in confined space from high temperature plume of big-powered engine during powered descent and ascending. The combination heat sink of fixed panel radiators and water sublimator was managed to meet different heat dissipation requirements of the Chang'E-5 lunar module. The flight data showed that the proposed thermal control system achieved excellent performance. The electronic equipment onboard the Chang'E -5 lunar module was kept between -7.7 degrees C to 39.6 degrees C during the mission profile. An optimized goal was achieved that there was zero thermal power compensation for the electronic equipment, while the ratio of thermal load peak-to-trough was as high as 7:1. At the same time, an inter-layer heat transfer model of the heat shield was verified with a temperature difference of less than 3 degrees C between the prediction result and flight data.