Thermal Effects of Aluminum-Copper-Aluminum Clad Material for the Utilization of the Entire Heat Capacity of Microsatellites

Abstract

Microsatellites have smaller masses, sizes, and power resources, and shorter development periods than medium and large satellites. A different thermal design method is required for microsatellites. Utilization of the entire heat capacity of microsatellites for the reduction of temperature fluctuation is a feasible thermal design concept proposed previously. A material with high thermal conductivity and specific heat is preferable. Considering the aforementioned design concept, in this study, the thermal effect of using an aluminum–copper–aluminum clad material with a high conductivity is investigated by comparison with those of aluminum alloys A1050 and A5052, which is generally used in satellites. The microsatellite is 30-cm cubic and has two mass conditions of 10 kg (Case 1) and 30 kg (Case 2) as on-board equipment. The orbit of the microsatellite is a sun-synchronous circular orbit at the altitude of 500 km with the descending node at 11:00 am local time. The microsatellite is Earth-pointing. Thermal analyses and thermal vacuum tests are performed to confirm the temperature history of the microsatellite. The hemispherical emissivity and its temperature dependence of the black aluminum tape used in the experiments are also measured because they were unknown. It is found that the averages of the temperature fluctuation range of the clad material are 1.6 ℃ and 2.8 ℃ smaller than those of A1050 in Case 1 and Case 2, respectively, and 5.2 ℃ and 8.1 ℃ smaller than those of A5052 in Case 1 and Case 2, respectively.