Thermal Design and Verification of Multi-head Very High Accuracy Star Sensor Onboard GF-7 Satellite

According to the mission requirements of high thermal stability of multi-head very high accuracy star senor for GF-7 satellite, the thermal design of multi-head very high accuracy star sensor is accomplished. Firstly, according to the requirements of high thermal stability technical indexes of star sensor that the thermal drift of the optical axis is better than 0.3(″)/℃, the structure and internal thermal design of star sensor are carried out. The thermal control technical indexes of mounting flange and optical lens barrel of star sensor are determined, and the thermal control design scheme of star sensor is formulated according to the orbital parameters and the structural layout of star sensor. Secondly, through the simulation analysis, the thermal stabilities in pitch(around X-axis) direction and yaw(around Y-axis and Y-axis of star sensor are ±0.55″and ±0.16″ respectively. Finally, the on orbit test results show that the temperature of the mounting flange and the optical lens barrel meets the thermal control requirement, and that the optical axis angle between the two multi-head very high accuracy star sensors is within ±1.8″. The thermal design of the star sensor is reasonable and effective, which can provide reference for the thermal design of other spacecraft star sensors.

This article provides a detailed thermal design for a domestically produced multi probe very high-precision star sensor applied to GF-7 satellites with high thermal stability. The simulation analysis and ground thermal test results show that the temperature of the installation flange and optical lens barrel of the star sensor can meet the thermal control index requirements of the star sensor under various working conditions, and the thermal stability index can also meet the task requirements. The results of in orbit testing and verification show that the temperature of the installation flange and optical lens barrel of the star sensor are also within the thermal control index range, and the optical axis angle error of the star sensor is much better than the smallest optical axis angle error of previous star sensors, verifying the rationality and effectiveness of the thermal design of domestic multi probe very high-precision star sensors. The thermal design and verification method in this article can be applied to the thermal design of star sensors, rendezvous and docking sensors, and navigation obstacle avoidance cameras on other spacecraft.