Applying the Thermal Design Method Based on Overall Heat Capacity to Microsatellites

Microsatellites differ from large and medium satellites in that the former have smaller masses, sizes, power resources, and development periods compared with the latter. Thus, a different thermal design method is required for the microsatellites than those used for large and medium satellites. The thermal design method employed in this work was based on the overall heat capacity of microsatellites and was applied to cubic microsatellites with a side of 50 cm. This design method was used for microsatellite with materials having high thermal conductivity and consisting of a structure with two U-shaped, folded single panels as side panels in order to decrease the temperature change in the microsatellite as it moves on its orbit. The mass of the microsatellite considered in this study was 50 kg and the panels of the microsatellite accounted for less than 20% of the entire mass of the microsatellite. The orbit of the microsatellite model was set to a sun-synchronous, circular orbit at an altitude of 500 km with a descending node at 11:00 am local time. The thermal design method used in this study was verified via thermal analyses and thermal vacuum tests to ensure that the temperature of the microsatellite was within the allowable temperature range of 0–40°C. Based on our verification results, it was found that the temperature of the microsatellite was suitably within the allowable temperature range on all panels except two of the outer panels. Hence, it was concluded that the thermal design method used in this study is applicable to 50-cm-sided cubic microsatellites with components having a narrow allowable temperature range mounted on its inner panels.