Heat Sink Equivalent Thermal Test Method and Its Application in Low-Orbit Satellites

In order to shorten the length of satellite thermal testing and reduce the cost of satellite development, a new method of satellite thermal testing using a heat sink to simulate space heating flow has been proposed. First, based on the characteristics of low-orbit satellites and the current research of thermal tests, the necessity of studying high-efficiency thermal test methods for satellites is expounded, and the advantages of the heat sink equivalent thermal tests compared to conventional tests are explained. Then, the principle of the heat sink equivalent thermal tests is described, the formula to calculate the heat sink temperature is given, and an error analysis of the formula is conducted. It is found that when the emissivity of the heat sink surface is greater than 0.9 and the ratio of the heat sink’s surface area to the satellite’s is greater than 10, the error of the heat sink equivalent tests should be within 1 °C. Next, the application of the heat sink equivalent thermal test is described using the Jilin−1 GF02F satellite as an example. Finally, the test results and the flight temperature of the GF02F satellite are acquired and analyzed. The results show that the error of the heat sink equivalent thermal test is 0.9 °C, the test time is shortened by one-third compared to traditional thermal tests, and the cost of the thermal test is reduced by more than 70%.