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Well the obvious question is how much cheaper would space telescopes be if they mass produced and launched a standard design instead of one-offs? What if they

Well the obvious question is how much cheaper would space telescopes be if they mass produced and launched a standard design instead of one-offs? What if they took the JWST design ($10 billion in development costs!) and made 10 or 100 more copies? How much would each additional copy cost to build and launch?

privong 7y ago
> What if they took the JWST design ($10 billion in development costs!) and made 10 or 100 more copies? How much would each additional copy cost to build and launch? There's presumably a way to estimate that. But you'd also want to ask if it's even useful to have 10 or 100 copies of JWST? Even if the unit cost is lower, the total program cost would still be greater than the $10b for one. The astronomical community is probably not large enough to fully utilize 10 JWSTs, let alone 100. I'm sure we could come up with enough observations to keep them all busy, but there isn't enough person-power to analyze and interpret all that data. So if one has money to build 10 JWST's, a likely better use of that money would be to build one or two and spend the rest of the money hiring people (graduate students, postdocs, faculty) to do science with the data. Or just build one JWST and use the money for a second to build something else that pushes capability in other areas (e.g., the "Origins Space Telescope" far-infrared mission concept, or the Lynx X-ray telescope concept). I suspect that would be better for how much new science you can do per dollar spent.
chongli 7y ago
I think the answer to that is “not very much.” Telescopes use a lot of highly specialized parts made of rare and expensive materials. They use a lot of gold for various components and the mirrors are made of gold or platinum. The tolerances in the fabrication of the mirrors are EXTREMELY tight in order to reduce aberrations as much as possible. This sort of high precision manufacturing with exotic materials simply doesn’t scale.
- denton-scratch 7y ago
  "EXTREMELY tight" Telescope mirrors need to be polished to an accuracy of a quarter-wavelength of whatever radiation you want to capture - so for an optical telescope, that's a quarter-wavelength of visible light. Any greater precision than that is spurious, and won't get you better imaging. Less precision than that == bad mirror. The techniques for polishing and testing small mirrors (up to say 12") are amusingly low-tech, almost steampunk. You can get to 1/4 wavelength of visible light with a homemade grinding/polishing rig, and a homemade optical bench that consists of little more than a jig to hold the mirror, a lamp and a couple of razor blades. I'm sure the challenges in building accurate 30m optical mirrors are massively bigger, not least because very big mirrors warp under their own weight. But I imagine the principles are just the same. Incidentally, I had no idea people were building 30m ground-based optical telescopes; that's just insane. I mean, my house is only 8m high.

privong 7y ago

> What if they took the JWST design ($10 billion in development costs!) and made 10 or 100 more copies? How much would each additional copy cost to build and launch? There's presumably a way to estimate that. But you'd also want to ask if it's even useful to have 10 or 100 copies of JWST? Even if the unit cost is lower, the total program cost would still be greater than the $10b for one. The astronomical community is probably not large enough to fully utilize 10 JWSTs, let alone 100. I'm sure we could come up with enough observations to keep them all busy, but there isn't enough person-power to analyze and interpret all that data. So if one has money to build 10 JWST's, a likely better use of that money would be to build one or two and spend the rest of the money hiring people (graduate students, postdocs, faculty) to do science with the data. Or just build one JWST and use the money for a second to build something else that pushes capability in other areas (e.g., the "Origins Space Telescope" far-infrared mission concept, or the Lynx X-ray telescope concept). I suspect that would be better for how much new science you can do per dollar spent.

chongli 7y ago

I think the answer to that is “not very much.” Telescopes use a lot of highly specialized parts made of rare and expensive materials. They use a lot of gold for various components and the mirrors are made of gold or platinum. The tolerances in the fabrication of the mirrors are EXTREMELY tight in order to reduce aberrations as much as possible. This sort of high precision manufacturing with exotic materials simply doesn’t scale.

denton-scratch 7y ago
"EXTREMELY tight" Telescope mirrors need to be polished to an accuracy of a quarter-wavelength of whatever radiation you want to capture - so for an optical telescope, that's a quarter-wavelength of visible light. Any greater precision than that is spurious, and won't get you better imaging. Less precision than that == bad mirror. The techniques for polishing and testing small mirrors (up to say 12") are amusingly low-tech, almost steampunk. You can get to 1/4 wavelength of visible light with a homemade grinding/polishing rig, and a homemade optical bench that consists of little more than a jig to hold the mirror, a lamp and a couple of razor blades. I'm sure the challenges in building accurate 30m optical mirrors are massively bigger, not least because very big mirrors warp under their own weight. But I imagine the principles are just the same. Incidentally, I had no idea people were building 30m ground-based optical telescopes; that's just insane. I mean, my house is only 8m high.