## 3 Control of Thermal Deformation Optimization Strategy
### Orbital Temperature Distribution
#### 3.1.2 Analysis of Temperature Distribution  
This section uses thermal control design and FEM simulation to determine the temperature field distribution of the satellite, which is then used as the input condition for thermal deformation optimization design. A proven technique for obtaining temperature field distribution is FEM simulation, which is used in the CubeSat design simulation [26; 27]. The influence of the temperature field on the deformation of the satellite structural body under varied working situations must be taken into account given the diversified load of the satellite and the complex task combination. The model's construction and simulation, however, are too challenging. We select the variance between the high and low temperature conditions in orbit as the measurement of the thermal deformation scale to simplify the work requirements. Some working situations have a thermal environment that fluctuates between high and low temperatures. Since linear materials can approximate the thermal expansion coefficient of satellite materials, it can be assumed that the satellite's thermal deformation varies between high-temperature and low-temperature situations. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline  & **+X** & **–X** & **+Y** & **–Y** & **+Z** & **–Z** \\  & **KS-ZA@20 \({}^{\circ}\)C** & **KS-ZA@20 \({}^{\circ}\)C** & **OSR@20 \({}^{\circ}\)C** & **OSR@20 \({}^{\circ}\)C** & **KS-ZA@20 \({}^{\circ}\)C** & **OSR@20 \({}^{\circ}\)C** \\ \hline Minimum average & & & & & & \\ heat dissipation & 285.8 & 285.8 & 275.1 & 274.4 & 173.9 & 298.5 \\ capacity & 285.8 & 285.8 & 275.1 & 274.4 & 173.9 & 298.5 \\ (W/m\({}^{2}\)) & & & & & & \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Average heat dissipation capacity of each surface. Figure 8: The satellite bus’s primary structure. The position of the internal heat source and the external heat flow largely determine the setting of the high and low temperature conditions. The temperature of the satellite will increase as the strength of the internal heat source increases and as the spacecraft's ability to dissipate heat decreases. For now, it is set to a high temperature condition, and the opposite is true for a low temperature condition. Table 6 displays summary data on internal heat source power. The electric pusher module is only initiated in orbit control mode, not business mode, so the influence of electric propulsion is not taken into account when establishing the high and low temperature conditions. Terahertz was utilized as a payload for technical validation and is not activated in business mode; hence, in both hot and low temperature situations, there is no power usage. All on-board equipment, with the exception of terahertz, electric propulsion, and backup equipment, functions at its maximum power consumption under the high temperature condition, which replicates the maximum power consumption of all equipment in the on-orbit business mode. In the low temperature condition, the load on the satellite is shut down, the equipment of the satellite bus maintains the lowest energy consumption state, and the laser communication load is turned on to carry out the intersatellite alignment capture. In this condition, heating belts should be used for temperature compensation to keep the temperature of the equipment on the satellite higher than the lower limit of its temperature requirement, so as to ensure the safety of the satellite. According to statistics, the power consumption of the satellite is 2039.2 W under high temperature conditions and 887.6 W under low temperature conditions. As can be seen from Table 6, the Ka-band phased array antenna, as the main load of the whole satellite, has high power consumption. When three phased array antennas work at the same time, the heat dissipation capacity of the antenna mounting surface is insufficient to meet the heat dissipation requirements of phased array antennas. Phased array antennas are easy to overheat when working in high temperatures.