Application of Precision Thermal Control Techniques in Taiji-1 satellite

Abstract

In order to detect gravitational waves in space, the Chinese Academy of Sciences has drawn up the Taiji plan. The first step of the Taiji plan is to verify the key techniques of the core payload through the Taiji-1 satellite in low Earth orbit. Because the temperature stability directly affects the measurement accuracy of the interferometer ranging and acceleration, the temperature control index of (<italic>T</italic>± 0.1) K with high precision and high stability is proposed for the Taiji-1 satellite. Based on this requirement, an efficient thermal control scheme was designed. In the scheme, the thermal control from the selection of thermal components to the application of stand-alone equipment was controlled according to high indicators. At the same time, in the process of thermal implementation, in order to ensure the efficiency of the scheme, detailed control was also carried out. The thermal control scheme adopts the constant temperature cage as the design concept, adopts the means of three-stage temperature control, and combines the principle of active and passive. Finally, the high stability index of on-orbit flight temperature control of (<italic>T</italic>±0.005) K is obtained. Through the application research of high precision and high stability technology, it is found that thermal control heating scheme, heat leakage control, single resolution of temperature controller, temperature measuring circuit, control algorithm, control precision, temperature measuring resolution of temperature measuring element are still the important factors that restrict high precision temperature control technology.