2025 年 3 巻 論文ID: 230
The accuracy of thermal analysis is important when conducting satellite thermal design, and it is greatly affected by the accuracy of the thermal model. Thermal models have many parameters, such as thermal conductance and surface optical properties. For conventional medium and large satellites, these parameters are generally calibrated based on thermal vacuum test results. After that, thermal analysis is performed using the thermal model under multiple conditions to guarantee that the temperature of each component is kept within the allowable temperature range with appropriate margins. This process was used for the thermal design of the two 6U CubeSats, SPHERE-1 EYE and ONGLAISAT, both of which share a common bus system. However, nanosatellites have different characteristics from medium and large satellites, such as stronger thermal coupling between components due to their small size. We evaluated the accuracy of these two nanosatellite thermal models by comparing on-orbit temperature data with analytical predictions, and we verified that the conventional thermal design process is also effective for nanosatellites. Our findings indicate that these thermal models, calibrated from thermal vacuum test data, could predict on-orbit temperatures to within 5 degrees Celsius for most components. Additionally, comparing the analytical and on-orbit temperatures for SPHERE-1 EYE revealed that there was little temperature margin on the high-temperature side of the AOBC. To address this, we implemented an additional heat path, which is discussed in detail.
