## 3 Control of Thermal Deformation Optimization Strategy
### Orbital Temperature Distribution  
#### 3.1.1 Heat Dissipation Surface Analysis  
The low-orbit communication test satellite weighs 490 kg and has an orbital lifetime of 5 years. It can perform multi-functional technology verification and on-orbit service, including satellite-earth broadband communication, inter-satellite communication, and network working. It is outfitted with a laser and Ka-band microwave inter-satellite chain, a Ka-band satellite-earth link, and an integrated on-satellite processing load. Very strict requirements for the thermal control system are presented by the high power density, several working modes, power consumption variations across modes, and other characteristics. The satellite's external heat flow analysis is necessary in order to calculate the dimensions of the heat dissipation surface in each direction. The angle between the satellite orbit plane and the sunlight vector is known as the \(\beta\)-angle. The exterior heat flow of a satellite at various \(\beta\)-angles varies due to the action of sunlight. The analysis of the time fluctuation of the \(\beta\)-angle of the low-orbit communication test satellites is shown in Figure 4 as the results. The low-orbit communication test satellite's \(\beta\)-angle fluctuates from \(-89^{\circ}\) to \(+88^{\circ}\) and changes by \(1.423^{\circ}\) every 24 h in its near-polar circular orbit. The variation in the \(\beta\)-angle and the amount of external heat flow at various times are both significant. After entering orbit, the satellite + \(Z\)-axis are oriented toward the ground, and the three axes are stable to maintain the load of the phased array antenna pointed at the ground in order to carry out data transmission activities between the satellite and the ground. To accomplish the energy balance of a single circle in any orbit state and working mode if a fixed solar panel is used, a large solar panel area is required. This is not the best design approach for increasing the precision of satellite control in orbit, decreasing the launch weight into orbit, and enhancing the economics. In this project, an A/B dual-axis SADA drive is used to monitor the solar panel's solar capture and ensure that the satellite's energy balance is maintained in a single circle beneath the tiny solar panel area. The solar panel's axis A, which is located close to the satellite bus, is used to regulate the solar panel's continuous rotation along the satellite's \(Y\)-axis (pitch axis) within a \(360^{\circ}\) range. The solar panel development satellite's B axis, which is located adjacent to the solar panel, is used to regulate the precession rotation of the \(X\) axis (rolling axis) within a range of \(42^{\circ}\). The thermal deformation of the solar panel and the coupling of the satellite bus can be disregarded because the A/B axis of the solar panel is connected by thin rods. The mathematical model for thermal deformation simplifies the concept of a solar panel. Yet, the shielding of the solar wing's intricate motion route will affect the heat flow outside the satellite's Y planes, and this influence on the satellite's temperature cannot be disregarded. A simulation model of the satellite's thermal properties was created; each surface was separated into a number of sections, and the heat flow to the satellite's surface was measured, as seen in Figure 5. The heat flow to the exterior of each surface was determined by weighing and averaging the final statistical data, as shown in Figure 6.  
Figure 4: Change of the \(\beta\)-angle in orbit. The infrared heat flow from the Earth that is incident directly on the outside surface of every single board has little change since the satellite has been in a state of orientation to the ground for a long period, as indicated in Table 3. The solar radiation heat flow that is immediately incident on each surface of the satellite changes noticeably under the impact of the \(\beta\)-angle fluctuation.