High-Bandwidth Lightweight Primary Mirror Concept Demonstration

Abstract

A unique approach to achieving high temporal bandwidth control of large active primary mirrors has been conceived and demonstrated experimentally. This high speed control is accomplished via implementation of a lightweight, reactionless facesheet that overcomes the typical mechanical resonance limitations on bandwidth for large primary mirror assemblies. Laboratory testing of a reactionless facesheet breadboard has: . Validated the reactionless principles of self-canceling symmetry of mass motion and stiffness forces . Confirmed the localized influence function of the inherently stiff high density, piezoelectric actuators used to control the mirror surface figure . Confirmed the feasibility of achieving high bandwidth control of large primary mirrors. This paper describes the design, test methods, and results of a concept demonstration and compares test data and predicted response.