• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.40 no.2
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• pp.178-183
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• 2012

To simulate space thermal environment in thermal vacuum test, direct or in-direct heater has been applied on the radiator. Both of them, direct heater attached on the radiator and indirect heater with a distance from the radiator, simulate the heat fluxes from the Sun radiation, the Earth IR and Albedo. They also supply the heat fluxes to the radiator of spacecraft to achieve the target temperature according to thermal test conditions. In general, indirect heater is used when the heater is not allowed to attach on the radiator directly due to constraints of coating property or contamination. For in-direct heater design, it is needed to estimate the heat power to make the extreme test conditions and minimize the interference with heat exchange of radiator and shroud. In this study, optimized thermal design of in-direct heater is proposed and investigated by commercial S/W SINDA. The effective values of design factors are also derived.

• Proceedings of the KSME Conference
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• 2003.11a
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• pp.216-221
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• 2003

A thermal vacuum chamber is mainly used to simulate thermal environments of a test satellite in satellite orbits in which daily temperature variations range from 80K to above 400K depending on solar radiation under the vacuum below $10^{-4}$ torr. The test facility is quite complex and consists of expensive parts. So any modification of control software is discouraged in fear of unexpected system failure. The purpose of this study is to develop a realtime dynamics model of the thermal vacuum chamber in view of controller design and simulate its electrical inputs and outputs for interface with a PLC (programmable logic controller). A PLC program that was used in the thermal vacuum chamber is applied to the realtime simulator. The realized simulator dynamics is found to be quite similar to that of the thermal vacuum chamber and serve to an appropriate plant to verify the control performance of a programmed PLC.