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Cold War Spoils: Amateur Builds Telescope With 70-Inch Lens
First time accepted submitter 192_kbps writes "Mike Clements, a long-haul trucker from West Jordan, Utah, built the largest amateur telescope ever with a whopping 70 inch primary mirror he purchased at auction. The entire telescope is 35 feet tall, 900 pounds, and he hopes to tour it in parks. As a hand-turned Dobsonian the telescope lacks the photographic capacity and tracking required for professional astronomy but the views must be breathtaking." (Are there other compelling candidates out there for "largest amateur telescope ever"? The 71" scope listed by nitesky.org appears to be dormant.)
I took that to mean they just cancelled the satellite project after casting and polishing the mirror but before silvering it.
Alternatively, the intended use may have involved some classified exotic coating that serves some special purpose and they needed to strip the coating before selling the mirror at auction.
Riiight.. I mean the guy lives in Utah so there are dark skies close enough to him but I'm plagued with air pollution and light pollution in my area and have to go at least 3 hours away to get a decent night of observation. Even then you still have upper atmospheric interference at times whereas the HST doesn't have any of that. The other problem I'd see with a Dobsonian of this size is maneuvering it and hauling it without damaging it. Props too him though for building it though, I wonder how many times he had to go to Home Depot to finish it?
Harrison's Postulate - "For every action there is an equal and opposite criticism"
Taking short exposures and processing them on a computer is the "poor man's adaptive optics". A very powerful technique (if the object is bright enough) is too take a large number (thousands) of short exposures, then sort through them for a "lucky" image - one in which the atmosphere is momentarily stable. Multiple lucky images can be stacked together to get longer exposures. This really is a very powerful technique, not requiring extremely expensive high precision tracking hardware.
Starships were meant to fly, Hands up and touch the sky - Nicky Minaj
Years and years ago, around 1976, I had a tube type TV that went fritz so I took it to an Austin, Tx TV repair shop. The guy took it in the back to work on and while he was doing it I looked around his shop and there were quite a few very nice amateur astronomy photos, Jupiter, Saturn, the Moon and such. I was taking some astronomy classes at UT. When he came out we got talking and he told me he was into astronomy. Now, this shop was a WRECK, much like most TV repair shops I have ever seen. pretty much a dump. He asked me to come in the back to 'See something'. The guy was about 6'6" tall and BIG, and rough looking, and I am NOT, so I declined, but he insisted so I finally went through a maze of old junk, narrow dark halls, and finally got to the back of the store. I was kinda scared. He pointed to something on the ground. It was a round plug of glass on a large wooden palate. My jaw dropped, I asked him if it was what I thought and he confirmed it was a slug for a 6 ft telescope. I believe he said he got it at auction when a Swiss observatory had two made and the first worked out, so he got it cheap. It was unfinished, just a blob of glass, but at the time I'd only seen telescopes in the 36" range and this was huge! He was grinning ear to ear, and I was astounded. I believe his name was Chuck Knesek but I may be wrong or only close. It's been 35+ years. I never saw him again. If anyone knows what happened to him or his slug I'd love to know.
A chip in the glass could be a fatal injury for a spy satellite as the article suggests was the intended use. Such telescopes use active optics to improve image quality;
Why? It's in microgravity and temperature controlled. There's not going to be any sort of variation during operation to make active optics worthwhile. It's certainly not going to be adaptive optics, because you're moving across the atmosphere too rapidly to have any hope of keeping up with localized distortions. The only reason I could see it being useful is it would allow for more lax manufacturing tolerances, since you could fine tune it once you hit orbit.