Abstract
Larger mirrors are needed to satisfy the requirements of the next generation of UV-Vis space telescopes. Our NASA-NIAC funded project, titled A Precise Extremely large Reflective Telescope Using Reconfigurable Elements (APERTURE), attempts to meet this requirement. The aim of the project is to demonstrate technology that would deploy a large, continuous, high figure accuracy membrane mirror. The figure of the membrane mirror is corrected after deployment using a contiguous coating of a Magnetic Smart Material (MSM) and a magnetic field. The MSM is a magnetostrictive material which is driven by magnetic write head(s) (MWH), locally imposed on the non-reflective side of the membrane mirror. In this proceeding we report the figure accuracy of the MSM coated membrane mirror under various conditions using a Shack-Hartmann surface profiler. The figure accuracy and magnetostrictive performance of the membrane mirror is found to be significantly dependent on ambient temperature fluctuations, the tension load on the membrane, time, magnetic writing head orientation and magnetic field strength. The results and reproducibility of the surface profiling experiments under various conditions are introduced and discussed.
