Deformable primary mirror for a space telescope

A 4-m aperture deformable primary mirror has been designed with the mirror and its supports integrated into a single structure. The integrated active mirror's minimal weight makes it desirable for a space telescope as well as a terrestrial application. Utilizing displacement actuators instead of force actuators, the active controls at the mirror's surface include normal position control and slope control in both the radial and tangential directions at each of forty control points. Influence functions for each of the controls are nearly independent, reducing the complexity of the control system. Experiments with breadboard models verify the structural concept and the techniques used in the finite element method of computer structural analysis. This paper describes the results of finite element analyses.