Research Of On-Orbit Thermal Distortion Prediction For Antennas In Satellites

As spacecraft orbit around the Earth in space, the location of spacecraft relative to the Sun and the Earth taking changes at any moment. Meantime, the spacecraft will experience various temperatures as it is orbiting the earth because of various reasons such as sunlight radiation, albedo effect, the cold surrounding environment among other sources, and the shadows of itself. High temperature gradient and severe temperature variation in spacecraft will induce spacecraft thermal expansion and thermal deformation. Thermally induced deflections of reflector have much effect on the electric performance of antenna on satellite that has a great limit in surface precision. Obviously, the research of on-orbit temperature and thermal distortion prediction for antennas in satellites is very important.This paper elaborated the work environment the spacecraft works in and all kinds of effects on the spacecraft produced by it. Take one 1.5 meters diameter parabolic antennae as the example. We found all kinds of influences on its temperature by studying its space thermal balance equation, and the main factor that influence on antenna temperature varying with time using software TMG and test project planed with orthogonal test. And based on the computed result, we found the main factor that influence on antenna surface accuracy by the theory of thermal distortion and test and compute using software I-DEAS and orthogonal test.