Active optics for space astronomy.

Discussion of the segmented and deformable active optics approaches underlying some of the modern electrooptical techniques that are to be used in the design of future generations of giant-aperture orbital space telescopes. Combinations of laser interferometry and precise servomechanisms are shown to make possible the solution of such key problems of large monolithic mirrors in orbit as weight, thermal distortion, launchability, and material stability. The applicability of these active optics approaches to future giant-aperture space astronomy systems in the 200-inch to 400-inch diameter range is reviewed.