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IR Oscillating Secondary Mirrors
Gordon made 2-inch metal mirrors on a lathe which were used as oscillating secondaries for Frank Low's 12-inch Cass (see "National Air and Space Museum Space Artifacts: Lear Jet Infrared Telescope, picture to right), mounted in place of a window in a souped up NASA Lear Jet, that in an unpressurized cabin would make it up to +50K feet. The source signal from the germanium in liquid helium cooled bolometer ("gold" box in picture) was very weak, and the oscillation of the secondary allowed the source to be seen as AC, the noise DC that would be rejected before massive amplification.
So KAO was coming online and who did he have to work on it? Well, he had me and Eric Lee - two freebie high school students who'd made multiple telescope mirrors. He handed us off to Don Moody's optics shop, and we ground and polished a 9-inch aluminum secondary. It was like kids in a candy store, because we had access to professional polishing equipment and computerized optical testing equipment. No more hand grinding. We had to use an immense amount of force required to move the metal, so we used a grinding machine and very viscous syrupy lap that drooped when you used it. We spent more time fixing up the lap than polishing it, because it kept curling off the machine. We had 20 lb weights pressing down on the machine. It squirted off everywhere.