## 3 Control of Thermal Deformation Optimization Strategy
### Multi-Objective Optimization Design  
#### 3.3.1 The Overall Optimized Design Idea  
Through the above simulation calculation, we can see that the angle change between the laser communication load and the star sensor is greatly affected by the thermal deformation of the satellite, so it is necessary to control the thermal deformation of the satellite. The most effective thermal deformation control method is to precisely control the temperature variation range of the whole satellite structure. However, the characteristics of high heat consumption of communication satellites make all the masks of satellite bodies need to be designed as cooling surfaces. This design method can meet the temperature balance of the whole satellite under high-temperature conditions, but the satellite has a variety of different power consumption scenarios, such as automatic standby mode after the main load is out of the range of the monitoring and control station, orbit maintenance mode, etc. The change in internal heat source power and the constant heat dissipation area make it difficult for the satellite to maintain the same temperature environment. At the same time, different external heat flow conditions will also affect the temperature of the satellite. The above reasons cause the temperature distribution of satellite bodies to change greatly. The resources for satellite active temperature control and temperature measurement are limited, and the cost of accurately controlling the temperature change of satellite body structure is high.  
Based on the above analysis, a local accurate thermal deformation control method based on the design of a flexible isolation common physical reference is proposed in this study to reduce the influence of the whole satellite temperature variation on the laser communication load alignment uncertainty region and acquisition time.  
In this method, the star sensor and laser communication are connected and installed through the same physical reference bracket with stable thermal deformation. The support material uses 55% SiC/Al with a large elastic modulus, high thermal conductivity, and a small linear expansion coefficient. A large elastic modulus is beneficial to improve its adaptability to dynamic characteristics and reduce weight. A smaller linear expansion coefficient is conducive to reducing the thermal deformation of the support. High thermal conductivity is conducive to the uniform temperature design of the support, reducing the temperature fluctuation of the support and thus reducing the thermal deformation of the support.  
Secondly, it provides flexible isolation with the satellite bus to reduce the influence of the temperature fluctuation of the whole satellite on the temperature fluctuation of the support and reduce the influence of the thermal deformation of the whole satellite on the  
Figure 12: Calculation results of the maximum thermal deformation of the main structure of the satellite in orbit (**a**) +X, +Y, -Z plane; (**b**) -X, -Y, +Z plane.  
uncertain region of laser communication alignment. The material for flexible isolation is a flexible isolation device made of silicone rubber material commonly used in aerospace to isolate the influence of thermal deformation of the satellite bus on laser and satellite sensitivity. The appearance of the isolation material is shown in Figure 13.  
Finally, satellite load isolation was adopted to narrow the thermal control area, reduce the difficulty of thermal control, accurately control the temperature of the isolated physical reference support, and reduce the influence of the temperature change of the physical reference support.