Magnetically-controlled membrane reflector

Abstract

In recent years, the need for lightweight optics has become increasingly important due in part of the high cost/weight ratio when sending payloads into space. One feature of lightweight optics is that they are typically constructed from a material that is not as rigid as the standard glass billet mirrors. This leads to both the need for, and ability to, control the shape of the reflector. Several methods for controlling the shape have been developed, including piezoelectric, electrostatic, and magnetic actuators. In this paper we discuss the development of a novel prototype lightweight magnetically-controlled membrane reflector (MCMR). The reflector substrate was a composite consisting of latex rubber and iron particles spun-cast onto a reflective Mylar membrane. Permanent magnets were used to provide the control force. A novel shielding array allowed for continuously variable control actuation. Experimental results for both magnetic field characterization and the deformation of the surface figure are discussed.