精密热控技术在太极一号卫星上的应用

Application of Precision Thermal Control Techniques in Taiji-1 satellite

为探测空间引力波,中国科学院提出了太极计划,其第一步是通过近地轨道卫星太极一号对核心载荷的关键技术进行验证.由于温度稳定性直接影响干涉仪测距和加速度的测量精度,太极一号卫星提出了(T±0.1)K的高精度、高稳定度温控指标.针对该指标要求设计热控方案,从热组件的选取到单机设备的应用均依照高指标进行控制.为了保证方案实施的有效性,在热设计实现过程中进行了详细的控制.热控方案采用“恒温笼”的设计思路以及三级控温方式,采取主动与被动相结合的原则,实现了在轨飞行(T±0.005)K的高稳定性温控指标.通过对高精度、高稳定度技术的应用研究发现,热控加热方案、漏热控制、控温仪单机的分辨率、测温电路、控制算法、控制精度、测温元件的测温分辨率仍然是制约高精度控温技术的重要因素.

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(T±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(T±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.