7 ms·

There _are_ incremental improvements, in the form of 5 gamma ray, 6 x-ray, 5 UV, and 4 visible satellites. Actually, there are more than that since Hubble went

by Cacti 9y ago

There _are_ incremental improvements, in the form of 5 gamma ray, 6 x-ray, 5 UV, and 4 visible satellites. Actually, there are more than that since Hubble went up. Unfortunately there are real physical limits to visible light telescopes, and there are not many ways to get around them without drastically increasing the size of the lens/mirrors, and drastic increases in size and weight are not something that plays well with our space capabilities. I know it seems ridiculous from the outside, but do you really think thousands and thousands of astronomers, physicists, etc., wouldn't be exploring every single possible way to improve visible light telescopes? That the idea of "incremental improvement" never occurred to anyone? They are using the current approach because it is the only approach, at least for the time being. Perhaps in 10, 20, 30 years we'll be able to launch hundreds of smaller telescopes that can achiever a higher effective resolution, but, again, it's pretty damned hard.

lutorm 9y ago
All true. On the other hand, the current JWST is way less capable, and way, way more expensive, than what was initially planned. I think there's a very legitimate argument to be made that maybe, with hindsight, it would have been better not to put all that money into the very large bucket that it's ended up being. It seems the way this goes is "we don't have money for more than one mission, so we have to make it count." But now you only have one mission, so you have to make really sure it doesn't fail, and the cost starts running away. Also, after JWST started, NASA has pretty much completely changed their strategy away from grand missions into many smaller ones with the "faster, better, cheaper" motto.
- TeMPOraL 9y ago
  > It seems the way this goes is "we don't have money for more than one mission, so we have to make it count." But now you only have one mission, so you have to make really sure it doesn't fail, and the cost starts running away. This is recognized by NASA - in particular, I've recently seen one report[0] with a diagram explicitly mentioning this problem. It was called "The Tyranny of Space Transportation Costs", and depicts a spiral with nodes like "High Launch and Space Transport Costs" -> "Infrequent Launch" -> "Inability to Service" -> "Over Engineering" -> "Cost Growth" -> "Need for Extreme Reliability" -> "Higher Launch Costs" -> ... That's one of the reasons NASA is interested in in-orbit mining & manufacturing - to enable rapid iteration on future missions. That seems to also be the reason why they've outsourced LEO transportation to private companies. -- [0] - "Stepping Stones: Economic Analysis of Space Transportation Supplied From NEO Resources". Found it on HN some time ago. https://www.nasa.gov/sites/default/files/atoms/files/eso_final_report.pdf https://www.nasa.gov/sites/default/files/atoms/files/eso_fin... (warning: 140-ish MB); the diagram in question is on page 9.
- gammarator 9y ago
  "Faster, better, cheaper" has not been NASA strategy since the 90's (i.e., pre-JWST). The resulting failures were judged by the public as intolerable. https://en.m.wikipedia.org/wiki/Daniel_Goldin https://en.m.wikipedia.org/wiki/Daniel_Goldin There are indeed very successful missions at smaller scales than Hubble/Chandra/JWST, but they are by necessity less powerful and more specialized. There are regular calls for a "balanced program" of large and small programs, but those run into the astropolitical reality that large missions have more "constituents" in science, government, and industry.
grondilu 9y ago
I want to believe there are very smart people studying these "strategic" issues, with mathematical models and stuff. That is : beyond the technical aspects, the implementation strategies, science return/cost ratios and whatnot. NASA used to be good at implementing incremental approaches to projects, weren't they? I mean isn't the Apollo program a perfect example of it? If they seem less incremental in their approach to space observatories, I assume they have good reasons. Am I being naive?
- lutorm 9y ago
  Am I being naive? I think so. The Space Shuttle was not incremental at all, it was supposed to be a great leap forward. I think calling Apollo incremental is also a stretch. They build a rocket that's still the largest the world has ever seen and flew it twice before putting people on it a year later.
  - TeMPOraL 9y ago
    I'd say Apollo was pretty incremental. Hell, it was very much "move fast and break things", given how many things they designed and tested in the 12 years between Sputnik and the first Moon landing.
    - provost 9y ago
      Yes, it was very incremental. They even sent the orbiter around the moon on a mission before even attempting to land. And there were a number of other tests (manned and unmanned), and even ones without an official Apollo designation. More info: https://nssdc.gsfc.nasa.gov/planetary/lunar/apollo.html https://nssdc.gsfc.nasa.gov/planetary/lunar/apollo.html
      - LifeLiverTransp 9y ago
        Sorry, but Apollo was a clash of german waterfall with american move fast and breaking things. https://en.wikipedia.org/wiki/Wernher_von_Braun#NASA_career https://en.wikipedia.org/wiki/Wernher_von_Braun#NASA_career I assume to have those two directions as two camps in your company, fighting each other generates the most optimal result. If you fail, the cautious camp wins and carefull analysis and slow methodic itteration become stronger. If you win, the move fast team takes over and pushes towards new exploration data and scaling up towards new problem areas.
LifeLiverTransp 9y ago
Could the lens be made in situ from distilled, frozzen again moon-ice and a mirror be crafted from foil? Im sure, this would not be optically optimal, but given good enough camera software, learning about the physical flaws of the system, these flaws could be filtered out?
- jballanc 9y ago
  There's a much simpler plan for a moon-based telescope: ship a big vat of mercury to the moon and spin it. The centrifugal force would curve the mercury perfectly and elemental mercury is a really good mirror on its own.
  - LifeLiverTransp 9y ago
    I found this- but no mention of mercury. https://www.space.com/5628-nasa-envisions-huge-lunar-telescope.html https://www.space.com/5628-nasa-envisions-huge-lunar-telesco... Diffrent solution entirely- dont build a mirror- build a fragment, and rotate it with a counterweight along a axis?
  - gammarator 9y ago
    There was one in Canada: https://en.m.wikipedia.org/wiki/Large_Zenith_Telescope https://en.m.wikipedia.org/wiki/Large_Zenith_Telescope
    - LifeLiverTransp 9y ago
      Now, if you had a perfect simulation of fluid dynamics of mercury- you could use piezo-pumps and image correcting software to angle it partially and compose a image at a angle. Actually- if you do know the fluid dynamics of mecury in openspace, and how to push it where you want it- you can do the same thing up there. Screw my rotor idea, all you need is a way to influence quecksilber in space, push it and take a series of images - that is recomposed into one giant hiRes picture. So, one needs a strong magnetic field to push the mercury into shape, a closed tube, able to withstand that magnetic force and a shielded camera. Or you spin the tube, while applying the magnetic force, thus getting the mercury to collect at the side. Also the mirror would be selfrepairing.. Wow, this would be how much weigth? Anyone with a engineering degree and a calculator nearby?

by Cacti 9y ago

lutorm 9y ago

All true. On the other hand, the current JWST is way less capable, and way, way more expensive, than what was initially planned. I think there's a very legitimate argument to be made that maybe, with hindsight, it would have been better not to put all that money into the very large bucket that it's ended up being. It seems the way this goes is "we don't have money for more than one mission, so we have to make it count." But now you only have one mission, so you have to make really sure it doesn't fail, and the cost starts running away. Also, after JWST started, NASA has pretty much completely changed their strategy away from grand missions into many smaller ones with the "faster, better, cheaper" motto.

TeMPOraL 9y ago
> It seems the way this goes is "we don't have money for more than one mission, so we have to make it count." But now you only have one mission, so you have to make really sure it doesn't fail, and the cost starts running away. This is recognized by NASA - in particular, I've recently seen one report[0] with a diagram explicitly mentioning this problem. It was called "The Tyranny of Space Transportation Costs", and depicts a spiral with nodes like "High Launch and Space Transport Costs" -> "Infrequent Launch" -> "Inability to Service" -> "Over Engineering" -> "Cost Growth" -> "Need for Extreme Reliability" -> "Higher Launch Costs" -> ... That's one of the reasons NASA is interested in in-orbit mining & manufacturing - to enable rapid iteration on future missions. That seems to also be the reason why they've outsourced LEO transportation to private companies. -- [0] - "Stepping Stones: Economic Analysis of Space Transportation Supplied From NEO Resources". Found it on HN some time ago. https://www.nasa.gov/sites/default/files/atoms/files/eso_final_report.pdf https://www.nasa.gov/sites/default/files/atoms/files/eso_fin... (warning: 140-ish MB); the diagram in question is on page 9.
gammarator 9y ago
"Faster, better, cheaper" has not been NASA strategy since the 90's (i.e., pre-JWST). The resulting failures were judged by the public as intolerable. https://en.m.wikipedia.org/wiki/Daniel_Goldin https://en.m.wikipedia.org/wiki/Daniel_Goldin There are indeed very successful missions at smaller scales than Hubble/Chandra/JWST, but they are by necessity less powerful and more specialized. There are regular calls for a "balanced program" of large and small programs, but those run into the astropolitical reality that large missions have more "constituents" in science, government, and industry.

grondilu 9y ago

I want to believe there are very smart people studying these "strategic" issues, with mathematical models and stuff. That is : beyond the technical aspects, the implementation strategies, science return/cost ratios and whatnot. NASA used to be good at implementing incremental approaches to projects, weren't they? I mean isn't the Apollo program a perfect example of it? If they seem less incremental in their approach to space observatories, I assume they have good reasons. Am I being naive?

lutorm 9y ago
Am I being naive? I think so. The Space Shuttle was not incremental at all, it was supposed to be a great leap forward. I think calling Apollo incremental is also a stretch. They build a rocket that's still the largest the world has ever seen and flew it twice before putting people on it a year later.
- TeMPOraL 9y ago
  I'd say Apollo was pretty incremental. Hell, it was very much "move fast and break things", given how many things they designed and tested in the 12 years between Sputnik and the first Moon landing.
  - provost 9y ago
    Yes, it was very incremental. They even sent the orbiter around the moon on a mission before even attempting to land. And there were a number of other tests (manned and unmanned), and even ones without an official Apollo designation. More info: https://nssdc.gsfc.nasa.gov/planetary/lunar/apollo.html https://nssdc.gsfc.nasa.gov/planetary/lunar/apollo.html
    - LifeLiverTransp 9y ago
      Sorry, but Apollo was a clash of german waterfall with american move fast and breaking things. https://en.wikipedia.org/wiki/Wernher_von_Braun#NASA_career https://en.wikipedia.org/wiki/Wernher_von_Braun#NASA_career I assume to have those two directions as two camps in your company, fighting each other generates the most optimal result. If you fail, the cautious camp wins and carefull analysis and slow methodic itteration become stronger. If you win, the move fast team takes over and pushes towards new exploration data and scaling up towards new problem areas.

LifeLiverTransp 9y ago

Could the lens be made in situ from distilled, frozzen again moon-ice and a mirror be crafted from foil? Im sure, this would not be optically optimal, but given good enough camera software, learning about the physical flaws of the system, these flaws could be filtered out?

jballanc 9y ago
There's a much simpler plan for a moon-based telescope: ship a big vat of mercury to the moon and spin it. The centrifugal force would curve the mercury perfectly and elemental mercury is a really good mirror on its own.
- LifeLiverTransp 9y ago
  I found this- but no mention of mercury. https://www.space.com/5628-nasa-envisions-huge-lunar-telescope.html https://www.space.com/5628-nasa-envisions-huge-lunar-telesco... Diffrent solution entirely- dont build a mirror- build a fragment, and rotate it with a counterweight along a axis?
- gammarator 9y ago
  There was one in Canada: https://en.m.wikipedia.org/wiki/Large_Zenith_Telescope https://en.m.wikipedia.org/wiki/Large_Zenith_Telescope
  - LifeLiverTransp 9y ago
    Now, if you had a perfect simulation of fluid dynamics of mercury- you could use piezo-pumps and image correcting software to angle it partially and compose a image at a angle. Actually- if you do know the fluid dynamics of mecury in openspace, and how to push it where you want it- you can do the same thing up there. Screw my rotor idea, all you need is a way to influence quecksilber in space, push it and take a series of images - that is recomposed into one giant hiRes picture. So, one needs a strong magnetic field to push the mercury into shape, a closed tube, able to withstand that magnetic force and a shielded camera. Or you spin the tube, while applying the magnetic force, thus getting the mercury to collect at the side. Also the mirror would be selfrepairing.. Wow, this would be how much weigth? Anyone with a engineering degree and a calculator nearby?