Roger Angel
Roger  Angel
Steward Observatory, University of Arizona
United States of America

Roger Angel trained as a physicist at Oxford University and the California Institute of Technology in the 1960s and, while working at Columbia University in New York, flitted between astrophysics and high-energy physics. He settled on mirror design at the University of Arizona in Tucson and was soon melting down Pyrex dishes in a makeshift backyard kiln to test his ideas on mirror casting.

With telescope mirrors stuck below 6-meters diameter because they were sagging under their own weight, Angel wanted to make them lighter and stronger. His solution was to cast mirrors in a mold filled with hexagonal columns to give the finished mirror a honeycomb of holes in the back, reducing weight by four-fifths and increasing rigidity. In addition, Angel would spin the mold as the glass cooled to give it a curved surface. He also developed a computer-controlled polishing machine with a tool that could change shape as it moved over the surface. Angel has cast 6.5-meter mirrors for the Multi-Mirror Telescope and the two Magellan Telescopes, plus two 8.4-meter mirrors in the Large Binocular Telescope.

They will also be used in the Large Synoptic Survey Telescope and the Giant Magellan Telescope. Angel created the Steward Observatory Mirror Laboratory, and is director of the Center for Astronomical Adaptive Optics. He has won numerous prizes and fellowships, including membership of the U.S. National Academy of Sciences and the U.K. Royal Society.