Control technology test bed for large segmented reflectors

A description is given of an experimental test apparatus for active control of a seven-segment primary reflector (mirror). Segmented reflectors require an active segment-alignment control system to give the reflecting surface the optical performance of a single-piece reflector. The apparatus, called the Advanced Structures/Controls Integrated Experiment, consists of a Cassegrain optical configuration with a 2-m, seven-segment, actively controlled primary mirror supported by a light, flexible truss structure. The testbed is a response to the need for experiments that can simulate the complex dynamic behavior of a large structure and address the myriad problems associated with precision control of optical surfaces. The testbed is described, details of the control and optical measurement systems are presented, and preliminary performance results are reported.<>