Method of off-loading supporting for large aperture light weighted reflect mirror at optical axis horizontal situation

The precise testing of large aperture light weighted reflecting mirror in gravity environment is a difficult problem at present. In view of the high rate of light weighting and the absolute low stiffness, in this situation, different forms of support have huge impacts on optical test results in gravity environment. In this paper, a solution was suggested that pre-defining of supporting force was achieved through a series of pulley blocks self-adapting to solve large aperture mirror testing in gravity environment. The result of mechanics model analysis shows that the testing of optical axis horizontal can reduce the Rams variation of surface shape effectively, which is caused by gravity in vertical and horizontal state, and the variation less than 0.003 (=632.8 nm). The method can be extended and applied to the design of testing supporting for other large aperture light weighted reflect mirror, and provid; technology foundation for large aperture mirror.