低轨卫星在轨运行热环境条件下,不能有效释放热应力的反射镜面将产生热变形,镜面法向偏转可达百μrad量级;经其反射的光束将产生较大的指向偏差,严重影响空地激光通信链路的系统性能.对空地激光通信星上端机目前常用的压板法镜体固定方式进行的分析表明:镜体释放热应力后的法向角度偏差可减小近3个数量级,对由于热变形带来的光束指向偏差能进行很好地抑制,减轻对系统性能的影响.

When a low-orbit satellite moves under thermal condition, the normal line of the antenna mirror surface turns due to antenna mirror thermal distortion. The turn magnitude order is 100 μrad when the thermal tension is not released,so the beam transferred has a large deflect and the performance of the space-to-ground laser communication links will suffer seriously. Applying limited element analysis to analyze reasonable application of pressing-plate method shows that normal angle deviation of mirror body after the thermal tension being released can be 3 order magnitude smaller, and the beam direction deviation caused by thermal distortion can be well retarded.