Thermal design and analysis of high power star sensors

The requirement for the temperature stability is very high in the star sensors as the high precision needs for the altitude information. Thermal design and analysis thus is important for the high power star sensors and their supporters. CCD, normally with Peltier thermoelectric cooler (PTC), is the most important sensor component in the star sensors, which is also the main heat source in the star sensors suite. The major objective for the thermal design in this paper is to design a radiator to optimize the heat diffusion for CCD and PTC. The structural configuration of star sensors, the heat sources and orbit parameters were firstly introduced in this paper. The influences of the geometrical parameters and coating material characteristics of radiators on the heat diffusion were investigated by heat flux analysis. Carbon–carbon composites were then chosen to improve the thermal conductivity for the sensor supporters by studying the heat transfer path. The design is validated by simulation analysis and experiments on orbit. The satellite data show that the temperatures of three star sensors are from 17.8°C to 19.6°C, while the simulation results are from 18.1°C to 20.1°C. The temperatures of radiator are from 16.1°C to 16.8°C and the corresponding simulation results are from 16.0°C to 16.5°C. The temperature variety of each star sensor is less than 2°C, which satisfies the design objectives.