Mechatronic Approach towards Lightweight Mirrors with Active Optics for Telescope Systems

摘要

Midsized telescopes currently receive a lot of interest due to their application in free space optical communication and space debris observation. This paper analyzes an active mirror support system of a very thin meniscus with a diameter of 1 m and 25 mm thickness for the application in a lightweight, low-cost telescope. An analytic model for self-weight surface deflection is used to determine the number of concentric continuous support rings and find their radii to sufficiently support the mirror. The obtained radii are used as initial value for a finite element analysis to include shear effects and the presence of a central hole for optical access, enabling further improvement. Following that, a transition from continuous support rings to point supports is made. With a number of 24 support points, a surface RMS error of 10.9 nm can be achieved. Additionally, the requirements for an active support to correct low order aberrations are determined.