Design and Optimization of the Flexible Support Structure for Space Mirror

The mirror subassembly is the key component of the space optic remote sensor and the mirror shape is always required to reach high accuracy due to the crucial importance to the system’s imaging quality. However, the mirror shape is usually influenced by gravity, temperature, forced displacement and launch vibrations to distort after leaving earth. The support structure of the subassembly plays an important role to minimize the impact of above factors while the conflict of the mirror’s static accuracy and the subassembly’s dynamic strength needs to be studied. Therefore, based on a Φ 260 mm-aperture mirror subassembly, a whole set of flexible support structures was researched. Combining with the conventional ring-type lateral support structure, a discrete-type flexible mounting scheme was proposed. Materials of the mirror and cell, the micro-stress mounting strategy and parameters of the flexure hinges were established aiming at maintaining high static precision of the mirror under multi-conditions, and the resilient connector was optimized by stress deconcentration and viscoelastic materials damping to obtain adequate dynamic strength margin. Finally, the comprehensive performance of the subassembly was verified eligible by finite element analysis that the mirror surface error RMS was superior to 0.002 λ under objective static conditions with enough safety margin in the harsh vibrations. In conclusion, the flexible support structure brought forward by this article is feasible which has general compatibility for other small-size space mirror.