Data Analysis and Correlation for Thermal Balance Test on a Micro-Satellite Model

Abstract

This article deals with the output of a thermal balance test performed on a thermal test model of a micro-satellite and a model correlation between the thermal analysis and the test observations. The test was conducted in a thermal vacuum chamber with the vacuum level higher than 10 − 5 mbar and the surrounding temperature of −85°C. Three test cases, namely, the sun-pointing solar array with part of orbit in eclipse (or Earth's shadow), the payload operation with part of orbit in eclipse, and the extreme worst hot case, were designed and conducted in such a way that the desired orbital environment could be simulated as closely as possible. The temperature data were monitored and sampled at 105 critical points distributed at different locations within the satellite body. These temperature versus time profiles and their agreements with the analytical results obtained using SINDA/G (a special software package for heat transfer analysis in space environment by Network Analysis, Inc.) are discussed. Main observations such as the large temperature gradient across the solar panel thickness and the high temperature in the radio frequency module are presented, and the underlying reasons are discussed. Model correlation for the thermal mathematical model is conducted based on the numerical analysis results and the test observations. The philosophy of model correlation is put forward. Effects of some material and interface parameters on the temperature profiles are studied. It was found that the tuned values of the surface contact conductance were quite less than the nominal values, although the temperatures of the panels are not sensitive to them.