空间光学遥感器变形镜消热结构设计

Athermal Design for Space Telescope Deformable Mirror

摘要: 空间光学遥感器用变形镜可以校正光学系统像差，具有广泛的应用前景。由于空间光学遥感器所处空间环境恶劣，并需经受发射冲击振动等力学环境，因此空间光学遥感器变形镜需满足微重力变形，热环境变化，冲击振动等方面要求；同时，由于变形镜促动器较多，结构非静定，由于变形镜各部分材料线胀系数(CTE)不匹配，在热环境变化条件下热变形严重。本文研究了促动器数量为25，口径为Φ200 mm的空间光学遥感器变形镜，提出了一种消热柔性结构取代原有殷钢材料的柔性结构，通过同材料过渡和柔性结构消除不同材料间热胀影响，并对该结构进行优化设计。设计结果表明该设计在温度变化±8℃工况下，镜面变形PV/RMS为47.26 nm/9.31 nm面形提高约17.8%，柔性结构质量减少约58.5%。微重力变形PV/RMS为20.56 nm/3.50 nm，满足微重力变形要求；一阶频率为1832 Hz，动态性能满足设计要求。消热结构工艺合理，满足空间变形镜设计要求。

Abstract: Space deformable mirror is widely used in compensating system wavefront error for space tele-scope. Space telescope resides harsh environment in space, and needs survive launch environment. Space deformable mirror is structurally non-kinematic. Thermal stress caused by thermal environ-ment may cause unacceptable figure error for optics due to material mismatch in CTE. A new ather-mal structure is proposed by flex transition for a Φ200 mm space deformable mirror with 19 actua-tors. Optimization design is performed. Final design shows the figure error PV/RMS 47.26 nm/9.31 nm for thermal environment change of ±8˚C, the figure error PV/RMS 20.56 nm/3.50 nm for gravity, and first mode 1832 Hz for dynamic performance. Athermal design meets design specification well.