Research on mirror lateral support of large astronomical telescope

Mirror support system of astronomical telescope is composed of axial support and lateral support. In traditional telescope, because the contribution of lateral support to surface distortion is less than axial support, there are usually few lateral support methods such as lever counterweight, hydrostatic pressure and steel strap in the past. With increase of diameter to thickness ratio and use of strongly concave mirrors, lateral support is becoming more complicated and important than before. At the same time, application of segmented mirror make it impossible to support periphery of mirror, so, some new schemes have been designed to meet requirement of large segmented-mirror telescope. This paper introduces some classic and recent methods of lateral support for large telescope and gives some results of finite element analysis.