Lightweight High Spatial Frequency Active Mirror Using E Beam Control

NASA?s Structure and Evolution of the Universe program outlines several missions, such as Terrestrial Planet Finder (TPF) and the Space Interferometry Mission (SIM), that will require the construction and deployment of arrays of telescopes, each potentially 100 to 1000m in diameter, dictating areal densities less than 1kg/m2. Gossamer optics can meet this challenge of affordable, large, lightweight optics. However, due to the difficulties inherent in deploying large scale, thin optics, Gossamer optical systems will require significant technological advances in active wavefront correction. A breakthrough in density, complexity reduction, reliability, and reduced cost per actuator is required for Gossamer systems corrected with adaptive optics. The revolutionary Adaptive Tertiary concept proposed here involves the use of modules, single units of active ceramic with integral electrodes that contain an array of actuator posts with spacings ranging from 1mm to 5mm. The segmented deformable mirror, with up to 349 mirror actuators at 2.5mm spacing in each hexagonal segment, will allow not only the individual correction of errors in any section of the primary optic, but potentially allows a simpler, lighter and less expensive primary to be employed.