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James Webb Telescope

Puppycow said:
To be fair though, this was often that case in the past, wasn't it?
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Sure.

Voyager 1 and Voyager 2 were basically identical copies of the same design, right?
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At least close enough.

The difference here, though, is that they could do things with two probes that they could not do with one. A second JWST would provide data faster, but a second one doesn't provide any different capability than the first. Same with Mars probes: you're sampling different parts of the planet, and one probe cannot do that.

Sure, if they are exact copies of each other, you don't need to redesign the second one, but actually building it seems to be what costed most of the money.
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I don't know the breakdown between design and manufacturing. The design component is probably pretty significant, and you don't have to duplicate that. But you don't really get economies of scale for the manufacturing part at two. So with a fixed budget, you're probably better off just making one telescope that's the best you can make rather than two lesser telescopes.
 
Another launch delay

During a press briefing with reporters on Tuesday, the telescope's director for launch services, Beatriz Romero, said that there are a "combination of different factors" to consider when setting a new launch date. These factors include shipment of the telescope, the readiness of the Ariane 5 rocket, and the readiness of the spaceport in South America as well. Romero said she did not expect to identify a new launch date until later this summer or early fall.
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Pixel42 said:
Another launch delay
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Well, at least it doesn't appear to be a major delay. At least, not yet.

Could be as little as a couple of weeks.

Hopefully it will still launch this year.

Also:
Launching and deploying Webb successfully would be a masterful feat—unfurling it in deep space requires 50 major deployments and 178 major release mechanisms. All of these must work, or the instrument will fail.
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This is what makes me worry.
 
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Roboramma said:
I have no idea what you're talking about here. Could you expand?
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Again, 10 billion is now small change for Gate Musk Bezos Zukerberg Buffet Apple etc.

I have no doubt there are plenty of reasons why they will never contribute to this public good.
A good that includes avoiding another Chuxilliub
None of them will wash with me.
 
Samson said:
Again, 10 billion is now small change for Gate Musk Bezos Zukerberg Buffet Apple etc.

I have no doubt there are plenty of reasons why they will never contribute to this public good.
A good that includes avoiding another Chuxilliub
None of them will wash with me.
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10 billion isn't small change to any of them.

JWST isn't cataloguing near earth asteroids (or further out asteroids or comets) so it's not related to "avoiding another Chuxilliub".

You want NASA to build and launch a second JWST, not "Gate Musk Bezos Zukerberg Buffet Apple etc." $10 billion isn't small change for NASA. If you now want to change the subject to how billionaires should engage in science-philanthropy, and particular space-telescope philanthropy, maybe we can have that conversation, but it's not what you were talking about earlier.
 
Two of those billionaires are also working on rockets that show promise of transforming space flight. That's certainly helpful towards dealing with another Chicxulub.
 
Ziggurat said:
The difference here, though, is that they could do things with two probes that they could not do with one. A second JWST would provide data faster, but a second one doesn't provide any different capability than the first. Same with Mars probes: you're sampling different parts of the planet, and one probe cannot do that.
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A thought occurred to me though:

There would probably be more than enough demand from astronomers for telescope time for at least two telescopes like this.

That said, I'd like to see whether the first one works before we consider building a second. Since we still have all the plans, I'm sure we could probably build another one like it in less time and for less money than it took to create the first one, should it prove to be a smashing success. On the other hand, if it belly-flops, it might be better to go back to the drawing boards.

Worst case would be if the mission fails for an unrelated reason, like a rocket explosion. Then we'll never know whether the telescope itself would have worked or not.
 
Puppycow said:
A thought occurred to me though:

There would probably be more than enough demand from astronomers for telescope time for at least two telescopes like this.

That said, I'd like to see whether the first one works before we consider building a second. Since we still have all the plans, I'm sure we could probably build another one like it in less time and for less money than it took to create the first one, should it prove to be a smashing success. On the other hand, if it belly-flops, it might be better to go back to the drawing boards.

Worst case would be if the mission fails for an unrelated reason, like a rocket explosion. Then we'll never know whether the telescope itself would have worked or not.
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I think we can safely assume that it works. That's not to say that this particular article will be free of any major malfunction. But I doubt the project would have gotten this far if the basic design, the construction, and all the components weren't already known to be sound.

It's not like we're throwing milk and lemon juice into a glass and then we'll decide if it's a tasty beverage and we should pour a few more. This is more like a gin martini, shaken not stirred, but if you shake it one too many times it's undrinkable. So you pour another one and pay more attention to the shaking.
 
Puppycow said:
A thought occurred to me though:

There would probably be more than enough demand from astronomers for telescope time for at least two telescopes like this.
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Sure, but they don't have the budget for two of these. And with the budget they do have, any telescope they could build two of wouldn't be as good. And they'd rather have less time on a better telescope than more time on inferior ones.

ETA: I can see a use case for multiple identical space telescopes, though. With radio astronomy, building multiple telescopes to form a giant array allows you to get vastly better diffraction limits on your signal than you can with a single telescope.
 
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Beelzebuddy said:
I really wish NASA would stop doing this prototype-only stuff. If we can justify designing a single sun-shaded telescope operating at a lagrange point a million kilometers from Earth, why not send three and have a bit of redundancy?
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theprestige said:
I hate to say it, but where investing in redundancy makes sense is in national defense.
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Let's also note that there are multiple redundant systems on board the JWST. And that's generally a better way to achieve redundancy than building two that don't have internal redundancy. It doesn't guard against a launch failure obviously, but it does mean you can swap them in one at a time. Can't do that if the redundancy is spread across two independent instruments.
 
RecoveringYuppy said:
Let's also note that there are multiple redundant systems on board the JWST. And that's generally a better way to achieve redundancy than building two that don't have internal redundancy. It doesn't guard against a launch failure obviously, but it does mean you can swap them in one at a time. Can't do that if the redundancy is spread across two independent instruments.
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Fair enough. Thanks for the added perspective.
 
The reason they don't have the budget for two or three is because it's expensive but not valuable. It isn't curing cancer. It isn't controlling the spread of disease. It isn't providing safety and security. It isn't producing peace and prosperity.

It's being built with the surplus generated by these other, more valuable investments. And there's nothing wrong with that. But let's not imbue it with mystical qualities of value far beyond its practical applications. That would be scientism.

There's nothing wrong with speculative blue-sky investment, but it's the least valuable kind of investment. One JWST would be nice to have. Two or three might be nicer, especially if you're a cutting-edge cosmologist thirsty for scope time. But on our society's list of people who need stuff, such cosmologists and their ten billion dollar tools are probably somewhere near the very bottom.
 
theprestige said:
The reason they don't have the budget for two or three is because it's expensive but not valuable. It isn't curing cancer. It isn't controlling the spread of disease. It isn't providing safety and security. It isn't producing peace and prosperity.

It's being built with the surplus generated by these other, more valuable investments. And there's nothing wrong with that. But let's not imbue it with mystical qualities of value far beyond its practical applications. That would be scientism.

There's nothing wrong with speculative blue-sky investment, but it's the least valuable kind of investment. One JWST would be nice to have. Two or three might be nicer, especially if you're a cutting-edge cosmologist thirsty for scope time. But on our society's list of people who need stuff, such cosmologists and their ten billion dollar tools are probably somewhere near the very bottom.
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Paul Graham would say that each individual company y combinator chooses to invest in is "expensive but not valuable" in your sense, in that they put money in and end up with either failure or very small returns. But that's made up for by the huge successes that come around once in a while. He'll also tell you that he really can't tell the difference between them.

Basic science is to society what startups are to investors. You don't know where any major advances will come from, so most of the money that you put in will lead to no or very small returns of practical value. But the few major successes, which make up less than 1% of the total, more than fund all the rest.

Of course you're also right that aside from practical value that sometimes comes out of basic science, we also get the beauty of learning about the universe for it's own sake. And that may be reason enough for society to invest at the level that we do in things like space telescopes. But practical value does come out of these sorts of things, and we can't predict ahead of time which basic science will turn into valuable applications.
 
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