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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.)
He put a reflective metal coating on a purchased piece of glass with the proper final curvature.
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.
Technically Lord Rosse (https://en.wikipedia.org/wiki/William_Parsons,_3rd_Earl_of_Rosse) was an amateur, and his telescope was 72 inches.
I read it the same way.
They probably cut the mirror and polished the glass, and then the edge chipped.
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; they apply pressure over the glass to bend it slightly. A chip could have micro-cracks and other damage that would easily spread across the surface. Without the actuators deforming the glass the image won't be as clear, but it would be good enough for a hobby telescope.
Once the glass chipped they likely just stopped the process, so the new owner would need to add the mirror surface on his own.
//TODO: Think of witty sig statement
Here is the scoop on the 70" telescope. Mike Clements purchased a polished but uncoated mirror that is 70" across that was intended for a spy satellite project that was cancelled. A huge uncoated mirror is not a telescope anymore than (car analogy - wait for it...) a V8 engine is a racecar. Building a good performing telescope (collimation tolerances are measured in thousandths of an inch) is a significant task, a huge telescope like this is a major engineering feat. What's more this is a transportable telescope. It is possibly the biggest transportable telescope in the world. This telescope is more powerful than any telescope that existed before 1917 (when the 100" Hooker telescope saw first light).
Successfully silvering the mirror using updated 19th Cedntury mirror coating technology was nifty too.
Second class citizen of the New Gilded Age
Cloudy nights thread and a another news article.
It was silvered with a spray-on solution using a weed sprayer; much too large for the regular vacuum deposition chambers.
-R C
"'Tis great confidence in a friend to tell him your faults, greater to tell him his." --Poor Richard's Almanac
Truely "news for Nerds". Brings back fond memories of building 'scope and staring at the skies with my father.
This man has drive, dedication and the ability to both conceptualise and physically realise his dreams.
Instead of bullshit "surveys" with no-longer-funny "CoboyNeal" options, here's a serious suggestion - how about we instigate the /. annual "Nerd" awards?
Fuck it, this is going way offtopic, but I don't care...categories anyone?
"Charlize Theron NSFW"
I keep clicking on those words, but nothing happens :(
You might owe yourself another slap. It's a reflecting telescope. Grins.
Trying to become famous by taking photos. Visit my homepage please.
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