Thermal design and flight validation of the chang’e-4 relay satellite

Abstract

The Chang’e-4 relay satellite operates in the HALO orbit at the Earth-Moon Lagrange L2 point, which can provide relay communication to the lander and the rover operating on the lunar far side to maintain their contacts with the earth and is a key link of the Chang’e-4 exploration mission. Unlike most LEO (Low Earth Orbit) satellites, the outer space environment of the Chang’e-4 relay satellite is much harsher. The Chang’e-4 relay satellite must suffer from a torrid environment that faces direct sunlight or direct exposure to 4K deep cold space in a shadow zone which may last longer than 6 hours. The Chang’e-4 relay satellite must ensure the operation and temperature control of instruments and equipment during the shadow zone with a limited battery level. This proposes high demands on the TCD (Thermal Control Design). The entire satellite resources were reasonably used for integrated TCD with limited battery level and limited weight. According to the working mode of the Chang’e-4 relay satellite and its torrid environment, its TCD was completed successfully, and on-orbit test data conformed to the expected results and theoretical calculation. TCD of the Chang’e-4 relay satellite has worked normally since the day that the Chang’e-4 relay satellite was launched into space.