Tuesday Telescope: Is the James Webb Space Telescope worth $10 billion?

The rings are real, and they're spectacular.

See full article...

 

[JohnDeL]

This sort of post-hoc bemoaning of opportunity cost is flawed logic.

Dude. Many of us were calling for the JWST to be cancelled when it had merely quadrupled in cost because we knew that it was costing us opportunities.

Say instead that the JWST is or is not worth the money and time on its own merits, and that one lesson we have learned for next time is to mind costs more closely and divide resources more broadly.

Fine.

Since we already had (and continue to have) IR missions in space, the JWST is not worth the money spent on it.

 

[Echohead2]

$10bil is less than 0.2% of the federal budget. If that is spread out over multiple years it is less than 0.1%. If over 10 years it would be like if you made $100k it would be $16/year.

 

[archtop]

No. No it is NOT. You all are missing the point.

For $10B, NASA could have built and flown 10 probe-level space telescopes, each sensitive to different wavelengths. Each more rapidly pointable and able to take science data on Targets of Opportunity, providing irreplaceable data for time-sensitive targets throughout the universe, each one hitting different wavelengths on different targets.

The resulting science would DWARF what the one lone JWST observatory provides. The lost opportunity costs are immense. JWST is so over-subscribed that it sets records for the number of science proposals received; if we had 10 smaller observatories, the number of scientists that would be supported would be substantially more. (yes, I realize that would likely just mean more science for the MAGAts to cut right now. but that's a different issue.)

And, even worse, the fiasco that JWST gave NASA helped the MAGAts undermine faith in government over the past decade as the Observatory went well over 10x its original (admittedly farcical) cost estimate and quadrupled its schedule. While smaller scientific missions have come in closer and closer to on-budget and on-schedule (all the way up to Roman, which is perhaps the first flagship mission to be on budget and on schedule!) but that is ignored. For years now, no politician or NASA Administrator has been able to say that "We are proud of what Goddard and NASA have accomplished" without ALSO saying "despite the immense cost and schedule overruns of JWST, of course."

It's almost as if it's a bad thing to go into a mission with the Principle Investigator, Dr. John Mather, repeatedly saying "It'll cost what it costs." John, I love you so much. But even before the dang Trump administration, Goddard was being punished badly for that overrun.

(lightly edited for more clarity; I think I need to go back to English class, this is hard to read...)

The downside of this approach is that all 10 smaller, less expensive telescopes would have worse resolution -- so would not be looking as deeply into the early universe.

 

[ranthog]

What mattered was that the JWST team promised Congress that the mission could be done in five years and for $0.5 billion and once Congress approved it, continued to overpromise the results and understate the costs. The other teams were more honest about the costs and so were told they could go after the JWST.


No argument there. The other pressure on NASA's science budget was the continuing cost overruns on human spaceflight (specifically the SLS and Orion) which kept taking bites out of science.

Given that the uncrewed portion of the budget is a very separate allocation, I don't think you can as easily claim that if NASA had spent less on the crewed program that it would have led more to the uncrewed programs. Especially given Republican hostilities towards certain types of science (Earth Science).



JWST did survive its project being rebooted after the initial failure of the project.

I don't think that JWST was more or less dishonest than anyone else. When you have a project that advances the state of the art as much as JWST did, there are a lot of risks that you don't know how hard it will be to do. They didn't understand how hard the heat shield would be.

The types of delays from this and from failures from the vendor to handle quality control led to major expenses. I think the late in the process failures of the vendor cost billions on their own.

It is easy to look at these things with hindsight being 20/20 and say that they should have known. There is a reason why most of NASA has only a handful of projects as ambitious as the JWST.

 

[hob_g]

Beautiful. I am really liking this Tuesday telescope

 

[TreeCatKnight]

You almost made me spill my coffee with that Seinfeld reference, well done!

But in a stunning reversal of
Betteridge's classic law of headlines, the answer is a resounding "yes", it was worth every penny. Science always is, and in the grand scheme of government expenditure it amounts to pennies on the dollar anyway.

Really enjoying the resurgence of the Daily Tuesday Telescope!

Thanks, I read right over that! Now I almost spit MY coffee out!

 

[Rhutanium]

Astronomy and a Seinfeld reference?! Hell to the yes!

 

[qchronod]

I'm hoping that the next time someone tries to build a space telescope, they'll do the smart thing and do multiple of them at the same time. From everything that I've seen, it always seems like it's the years of testing that runs up the cost so much. If they just built and tested 5 of them to 95% sure it will work, then we'd likely have a lot more working telescopes then waiting till one was at 99.99%

 

[janhec]

American space telescopes seem to have a track record of being able to eventually demonstrate their worth after extremely shaky starts.

which is totally in character.

 

[NinjaNerd56]

Incredible subtitle Eric, well done

FYI…”The Cool Surface”, about 21 minutes in.

They ARE spectacular …

 

[nosmadar2016]

Am I imagining things or does that nebula take the form of the outline of a cylinder? Stunning image!

Nope. Bell Pepper -- I was cutting some up for Salad last night

 

[nosmadar2016]

I guess this article is just fishing for clicks? There's really no content here, and its asking a question where there's no real objective answer.

For anyone who's getting some sort of benefit, it was worth it. If that money would have been spent on fixing a few bridges in Virginia instead (for example), the answer probably depends on whether you live in or near Virginia.

However, the author does not provide any information on where the money would have gone if it didn't go towards the telescope, so how could anyone possibly provide an answer?

Pendantic much?

 

[Frank C.]

Can't AI do it for cheaper?

Why, you want it to make up shit to show you? Random star field image generator.

 

[Frank C.]

A functional space telescope is always a better investment than a space ship full of some combination of oligarchs, celebrities and fascists regarding of the monetary cost

We call them Trump cunts around here.

 

[ScientificMind]

It's not an American space telescope. It is an American/Canadian/European Space Telescope.

Let's not say that in public. If the administration hears about it ... They'll probably rename it to DJTT ...

 

[MacBrave]

NASA needs to be looking more at pictures like this:

 

[jcolbyk]

I admit to being unfairly skeptical of JWST's impact per dollar, and was very down on the chances that it would be usable after launch (given how many steps needed to work correctly to get it into a production configuration).

I think it's also important to put numbers on this:

The entire NSF budget for supporting major observatories was on the order of around $200million/year in the year 2000. While it seems universal that folks agree $10bil was worth what we have with JWST, it's really important to understand how much money is left over for the support of all sorts of other astronomy research and just how much was put into JWST comparatively.

 

[jcolbyk]

It's funny how popular that answer is. Money is just make-believe after all. Though the public debt is real. We're spending more than we have, but who gives a damn? More, more, more. It's your children and your children's children who will end up having to pay for it. You got a nice picture, and it only comes at the price of their future. And yet, every initiative to reduce public spending is met with outrage. Oh well.

This argument is a vast oversimplification of the nature of currency, debt, and how our nation state handles the value of those things. The fact that our debt is in a currency that we control does and should alter assumptions you make about public debt, and there is a mountain of evidence/research/deep thinking around this that demonstrate why it's an oversimplification to equate public debt with the "...price of their future." As much as I distrust and dislike what crypto-currency has become, it's illustrative to consider that any value assigned to those currencies, is money created out of thin air that does not align with the resources used to create them (up until recently), and just how large the money related markets out there have outstripped the "value" that is "real", i.e. bitcoin alone is currently worth $1.705 trillion, and it wasn't $1.7 trillion of electricity that gave it that value.

The accumulation of debt has been weaponized against the voting public and is part of why we're in such a terrible policy situation now, because it means that our existing debt can be used to amplify and accelerate outcomes that are self-serving for acquiring power in a way that will be very difficult to correct in the future.

 

[jcolbyk]

NASA needs to be looking more at pictures like this: View attachment 107657

Imaging/systematics related artifacts? Similar issue to imagery of the sea floors on Earth. There are a hojillion examples of what appear to be straight geometric features that appear because of how the sea floor was imaged (strips scanned via ships moving in straight lines, not that those lines are there on the sea floor).

 

[Casual_Indifference]

Yes, of course it is worth it. And we should already be designing and building the next one.

 

[Zim the Vixen]

This is a really good example of what happens as you converge toward the JWST aperture. This comes from a technical report from 2007: https://www.stsci.edu/files/live/si...al-documents/_documents/JWST-STScI-001157.pdf

View attachment 107644

oh! this makes a lot of sense! thank you, and thanks fur the link!!

 

[Jarron]

Dude. Many of us were calling for the JWST to be cancelled when it had merely quadrupled in cost because we knew that it was costing us opportunities.

Seriously, for as long as I've been involved in the mission (10+ years), you can bet on John coming in here to educate us on its continuing schedule delays ballooning costs.

Fine.

Since we already had (and continue to have) IR missions in space, the JWST is not worth the money spent on it.

I'm sure you're being facetious, but there is absolutely no IR mission that can hold a candle to JWST's capabilities and scientific potential. Solar system science (planets, KBOs, asteroids), exoplanet science (direct imaging and transit spectroscopy), resolved stellar populations in nearby galaxies, the oldest galaxies ever observed (z~14; 13.8 billion years old!). Spitzer IRS was the last instrument even close to JWST MIRI capabilities, and shutdown over in 15 years ago and was an order of magnitude lower spectral resolution. Astronomers are learning so many new things every day with this thing and it still have another decade of life.

 

[Akawe]

This accessment isn't quite correct. First, like with Hubble the majority of the cost was due to the delay and launch being moved back time and time again. It's actual build value+ launch was only one billion. Blame upstair planning and storage cost if you will.
That said, it revoluionizing science since Hubble says it all.

 

[blookoolaid]

JWST was a worth doing. But it really shouldn't have cost 10 billion dollars. Most of the cost overrun was due to project delays and most of the delays were due to the challenges meeting the mission requirements within the mass budget.

NASA should have cut back on instruments to save mass budget as soon as it became clear that they were exceeding their margins. If that meant they couldn't do their primary mission as designed, they needed to redesign the mission or wait for a more capable launcher.

Much as I love what JWST can do I really can't wait for the transition to assembling telescopes in LEO. Most of the challenges and expense of JWST go away if you could ship it in parts to an orbital facility and do the assembly and check outs there prior to sending it to Lagrange point. This will be even more impactful for missions to the outer regions of the solar system. I dream of a near future where deep space probes are cheap enough to build and launch that we have a bunch of orbiters monitoring all the major bodies of our solar system and an array of telescopes looking deeper into the universe than we can currently imagine.

 

[dobrien75]

That is amazing!

 

[JohnDeL]

Given that the uncrewed portion of the budget is a very separate allocation, I don't think you can as easily claim that if NASA had spent less on the crewed program that it would have led more to the uncrewed programs. Especially given Republican hostilities towards certain types of science (Earth Science).

Actually, I can. Here's a direct quote from a 2011 Science article:

The cut to the earth science program at NASA is part of a proposed $16.8 billion budget for NASA as a whole, $1.6 billion below the current year budget. The bill protects funding for human space flight, including a crew vehicle and launch system. "While the Committee supports Earth Science functions, this area has rapidly grown over the past few fiscal years, and the current constrained fiscal environment simply cannot sustain the spending patterns envisioned by NASA in this field," said committee members in a report.


That statement " is very misleading, as it does not take into account the years of neglect and declining budgets for NASA Earth Science during the previous Administration," says Busalacchi. "Coupled with considerably increased costs for access to space," he adds, "this cut, plus the wording to protect specific missions, leaves NASA with very little flexibility to maintain a balanced approach to earth system science."

If you want me to, I can find other examples.

The simple truth is that human space flight has always been protected and cost overruns in that field led directly to budget decreases for science.

I don't think that JWST was more or less dishonest than anyone else. When you have a project that advances the state of the art as much as JWST did, there are a lot of risks that you don't know how hard it will be to do. They didn't understand how hard the heat shield would be.

JWST was much more dishonest. They said that based on what they had learned from Hubble (which ended up costing $4 billion) they could bring in the new telescope for $0.5 billion.

An honest estimate would have been $4 billion or maybe $3 billion if you are willing to stretch a point. But to claim that a new telescope with multiple experimental design features would cost less than 1/8^th what the previous one had? That's just plain lying.

As for the heat shield, they had an opportunity to test it. In the original plan, they were going to test it, which would have derisked it (or shown it simply wouldn't work) and lowered the overall cost and sped up the timeline. Instead, they removed it as a "cost saving measure".

It is easy to look at these things with hindsight being 20/20

THIS ISN'T HINDSIGHT! At the time it was proposed, other teams were saying that the JWST would cost much more and be much riskier than the team claimed. They were ignored.

 

[GreyGoshawk]

Beautiful photo! And especially stunning in the comparison with the photo from the WISE telescope.

What I am hoping is that someone is working in the background on some way in ten years to top-up the refrigerants on Webb and deliver them safely. (Yes, I know about the danger to the sun-shade. Hence, do it at 'end-of-useful-life'.) Webb is an incredible asset; I would hate to have it decommissioned if it can be 'resuscitated'. Ten years is both a long time and a short time...

 

[Jarron]

JWST was a worth doing. But it really shouldn't have cost 10 billion dollars. Most of the cost overrun was due to project delays and most of the delays were due to the challenges meeting the mission requirements within the mass budget.

NASA should have cut back on instruments to save mass budget as soon as it became clear that they were exceeding their margins. If that meant they couldn't do their primary mission as designed, they needed to redesign the mission or wait for a more capable launcher.

Much as I love what JWST can do I really can't wait for the transition to assembling telescopes in LEO. Most of the challenges and expense of JWST go away if you could ship it in parts to an orbital facility and do the assembly and check outs there prior to sending it to Lagrange point. This will be even more impactful for missions to the outer regions of the solar system. I dream of a near future where deep space probes are cheap enough to build and launch that we have a bunch of orbiters monitoring all the major bodies of our solar system and an array of telescopes looking deeper into the universe than we can currently imagine.

So, first question is, which instruments would you have cut? NIRCam? Not possible since it's the primary imaging instrument and absolutely necessary to align the mirror segments. NIRSpec? This is the primary near-IR spectrograph required to confirm high-redshift galaxies; just impossible to do that science without it. MIRI? Hell no, MIRI has the highest subscription rate because its wavelength range and spectroscopic capabilities are by far the most unique; I can't imagine this mission without MIRI (might even not have been worth it). I guess that leaves NIRISS, which was part of the CSA contribution?

Regardless, the problem you're talking about wasn't going to be solved by cutting instruments. The delay wasn't directly because they were over the mass budget, but because of volume limitations. How do you launch a 6.5-meter telescope in an Ariane-5 fairing? Even if you launched the bare minimum of science instruments, we would have still been in the same position: you still have to fold the mirror and fold the sunshield. Without these two components, the telescope would not have been able to meet its science requirements. The mirror size was necessary for the high-redshift science (you need a light bucket to collect as many photons as possible). The sunshield is necessary to minimize solar thermal radiation and keep the instruments and NIR detectors nice and chilled at their 40K operating temperature under ambient conditions (no cryocooler required). It's really really hard to come up with a design that meets these requirements while fitting in that small volume.

From my perspective, one of the issues with delay was the defense contractors not putting their best people on the project. NASA HQ trusted these professional aerospace companies to do their job and instead focused their administrative watchful eyes on the universities and research institutes to make sure they were on time with the science instruments. In the end, the science instruments were completed and delivered around 2012, while telescope, spacecraft, and sunshield were still all being fiddled with. Once it became apparent how much N-G was missing their milestones (despite claiming to technically have achieved them to get their bonus payouts), then NASA program managers focused all their attention in that direction to push forward the spacecraft assemly. Towards the end, every year of delay was a giant pile of cash, because you had to feed the giant standing army (retain their knowledge and expertise) who were waiting to finish up commissioning after launch.

 

[gavron]

Mr Berger,

Your interview with Butch and Sunni should get you a Pulitzer.

But they won't.

And if you lay your head down on your pillow and wonder if you're making a worthwhile difference, yes, Sir, you are.

Perhaps the upvotes will show that Ars readers enjoy your wordcraft and research. I do.

Ehud
Tucson, Arizona, US

 

[JohnDeL]

I'm sure you're being facetious, but there is absolutely no IR mission that can hold a candle to JWST's capabilities and scientific potential.

Bullshit.

We've had the following space-based IR telescopes:
Name Wavelengths Resolution Collecting Area Lifespan Cost
IRAS 12, 25, 60, 100 μm 3 arcsec-2arcmin 2,019 cm² 10 months ??
Infrared Space Observatory (ISO) 2.4-200 μm 1.5 arcsec-90 arcsec 11,000 cm² 30 months $1 B
Spitzer Space Telescope/SIRTF 3.6–160 μm 1.5 arcsec 5,000 cm² 68 months/197 months $1.3 B
Herschel Space Observatory 55–672 μm 10 arcsec 5,000 cm² 48 months $1.9 B
Wide-field Infrared Survey Explorer/WISE+NEOWISE 3.4, 4.6, 12, 22 μm 6 arcsec 4,800 cm² 36 months/120+ months $0.5 B
JWST 0.6–28.5 μm 0.1 arcsec* 250,000 cm² 60 months $10 B

*Equivalent to the resolution of the Hubble's IR instruments

The only thing that the JWST has going for it is that it is much larger than the other missions, which allows it to see fainter objects and to resolve brighter ones in less time. It covers the same regions in the IR that previous missions have and has the same resolution as the Hubble IR instruments do.

IMO, that isn't worth spending twice what we spent on the Hubble for an instrument that might work 1/3 as long.

Solar system science (planets, KBOs, asteroids),

All examined with previous IR telescopes and with the Hubble.

exoplanet science (direct imaging and transit spectroscopy),

This is indeed new. It is also starting to fail as one of the instruments has developed a glitch.

resolved stellar populations in nearby galaxies,

All examined with previous IR telescopes and with the Hubble.

the oldest galaxies ever observed (z~14; 13.8 billion years old!).

Herschel saw one at z=6.34/12.8 billion years old. So you've spent five times as much for an improvement of ~7%.

 

[MarkW98]

Herschel saw one at z=6.34/12.8 billion years old. So you've spent five times as much for an improvement of ~7%.

(In response to "the oldest galaxies ever observed (z~14; 13.8 billion years old!)."

Well, if you measure time intervals from the moment of the Big Bang rather than from present day, the improvement is a lot more than 7%.

 

[kapix]

You're better than this, Berger.

 

[gavron]

Space is mostly black emptiness - stars make up only 0.4% of the area of the universe.

Imagine if any of that was true.

It's not.

The universe is neither two-dimensional nor a perfection of a 3D projection. Any "percentage" is just a wanker score, a number used by wankers because ... they want a number. You got 0.4%.

There's no source because it's not based on data. An expanding explosive result in 3D doesn't have "the area of the universe" at its component.

Space is mostly black emptiness.

Your racist ideas of what space is like defy all bounds of reason. I'm pretty sure black is the absence of light, and space is the absent of matter, but neither is true of that place we observe with our $10B telescopes.

 

[Jarron]

Bullshit.

We've had the following space-based IR telescopes:
Name Wavelengths Resolution Collecting Area Lifespan Cost
IRAS 12, 25, 60, 100 μm 3 arcsec-2arcmin 2,019 cm² 10 months ??
Infrared Space Observatory (ISO) 2.4-200 μm 1.5 arcsec-90 arcsec 11,000 cm² 30 months $1 B
Spitzer Space Telescope/SIRTF 3.6–160 μm 1.5 arcsec 5,000 cm² 68 months/197 months $1.3 B
Herschel Space Observatory 55–672 μm 10 arcsec 5,000 cm² 48 months $1.9 B
Wide-field Infrared Survey Explorer/WISE+NEOWISE 3.4, 4.6, 12, 22 μm 6 arcsec 4,800 cm² 36 months/120+ months $0.5 B
JWST 0.6–28.5 μm 0.1 arcsec* 250,000 cm² 60 months $10 B

*Equivalent to the resolution of the Hubble's IR instruments

The only thing that the JWST has going for it is that it is much larger than the other missions, which allows it to see fainter objects and to resolve brighter ones in less time. It covers the same regions in the IR that previous missions have and has the same resolution as the Hubble IR instruments do.

IMO, that isn't worth spending twice what we spent on the Hubble for an instrument that might work 1/3 as long.




All examined with previous IR telescopes and with the Hubble.


This is indeed new. It is also starting to fail as one of the instruments has developed a glitch.



All examined with previous IR telescopes and with the Hubble.


Herschel saw one at z=6.34/12.8 billion years old. So you've spent five times as much for an improvement of ~7%.

I was under the impression you were referring to existing telescopes.

But in any case, I would still rather have JWST right now than a copy of any those. There is absolutely no contest on the combination of sensitivity, spatial and spectral resolution. You're not getting spatially resolved IFU spectroscopy of exoplanet atmospheres on any of those. No other past or present telescope can see Saturn mass planets in other star systems. You're not getting 10ppm transit spectroscopy. Yes, all those telescope revolutionized the science in their time. And JWST is doing much more at larger distances, and higher resolution, and better sensitivity. I literally cannot believe you're scoffing at z~14 galaxies!

This is just a wild response to my excitement about the science that we are doing right now with this amazing telescope. I encourage you to go find someone else's joy to ruin, because I'm not having it, not today, and not in this political climate.

 

[JohnDeL]

I was under the impression you were referring to existing telescopes.

At the time the JWST, several of them were existing telescopes. One still is.

You're not getting spatially resolved IFU spectroscopy of exoplanet atmospheres on any of those.

And that is the only improvement- and it could have been done without the sunshield.

And JWST is doing much more at larger distances, and higher resolution, and better sensitivity. I literally cannot believe you're scoffing at z~14 galaxies!

As noted above, the improvement is incremental at best.

 

[JohnDeL]

Well, if you measure time intervals from the moment of the Big Bang rather than from present day, the improvement is a lot more than 7%.

Except that in order to do that, we’d have to be standing at the Big Bang. We’re not, so the improvement truly is just ~7%.

 

[Jarron]

And that is the only improvement- and it could have been done without the sunshield.

For exoplanet science, the wavelength matters. The unique capability of JWST for this science case is the longer IR wavelengths (>3um) where so many of the important molecular lines reside. High contrast imaging of exoplanets on ground-based telescopes perform much better than JWST at <3um. But because of the sky brightness, it's better to go to space for longer wavelengths. Spatial resolution also matters, so you need a big aperture. Maybe someone had come up with a solution to deploy a 6.5-meter telescope (pre-SpaceX) in space without a sunshield while cooling the optics and structure to a temperature necessary to prevent large thermal emission removing that advantage over the ground. And keep the detectors at cryogenic temperatures. And keep pristine wavefront error stability while changing solar elongation angles hoping that no thermal evolution is going to make ever-so-slight distortions of your mechanical structure.

Name Wavelengths Resolution Collecting Area Lifespan Cost
JWST 0.6–28.5 μm 0.1 arcsec* 250,000 cm2 60 months $10 B

[...]

IMO, that isn't worth spending twice what we spent on the Hubble for an instrument that might work 1/3 as long.

Just a small note: I'm sure you know that JWST science operation started 3 years ago. So, by your calculation here, it's only got another 2 years left of life? I'm confident you know better, though. Sorry, but your responses towards me just wreak of bad-faith engagement.

I'm not arguing that JWST wasn't expensive; I'm sure it could have been cheaper with better management. I joined the project with the hope and intent to help realize its full potential. Yeah, I wish we weren't beholden to early-2000s technology; I want faster detectors, more onboard storage, a modern coronagraph, active wavefront control, an 8-10 meter monolithic mirror, UV sensitivity. Maybe I'm biased, but there is every reason to believe that what we have is performing well above anyone's expectations and much better than anything we've ever put in space across 1-30um. Even if you doubt my personal and professional experiences, it's hard to ignore the excitement within the scientific community. Just go look at the number of proposals, papers, conferences. I haven't seen the mid-IR exoplanets and disks community this engaged in over a decade. The high redshift datasets are vast and rich with information, and everything that's been published so far is just low hanging fruit. Brown dwarf evolutionary models are trying to keep up with new observations. The gravitational lensing community is doing a lot really cool stuff. Extragalactic SNe groups are now able to spectroscopically probe molecular features in ejecta further into the IR. Work on the water content of T Tauri stars has been stagnant since we lost Spitzer IRS, and MIRI blows that data out of the water (pun intended). It also adds to existing IRS data, confirming some of the little blips we saw and thought were noise were actually high-SNR (but unresolved and blended) emission lines! And these are just the things I've paid attention to. There is just so much amazing. science. being. accomplished. But what do I know...

 

[Outlaw Shark]

For exoplanet science, the wavelength matters. The unique capability of JWST for this science case is the longer IR wavelengths (>3um) where so many of the important molecular lines reside. High contrast imaging of exoplanets on ground-based telescopes perform much better than JWST at <3um. But because of the sky brightness, it's better to go to space for longer wavelengths. Spatial resolution also matters, so you need a big aperture. Maybe someone had come up with a solution to deploy a 6.5-meter telescope (pre-SpaceX) in space without a sunshield while cooling the optics and structure to a temperature necessary to prevent large thermal emission removing that advantage over the ground. And keep the detectors at cryogenic temperatures. And keep pristine wavefront error stability while changing solar elongation angles hoping that no thermal evolution is going to make ever-so-slight distortions of your mechanical structure.

[...]

Just go look at the number of proposals, papers, conferences. I haven't seen the mid-IR exoplanets and disks community this engaged in over a decade. The high redshift datasets are vast and rich with information, and everything that's been published so far is just low hanging fruit. Brown dwarf evolutionary models are trying to keep up with new observations. The gravitational lensing community is doing a lot really cool stuff. Extragalactic SNe groups are now able to spectroscopically probe molecular features in ejecta further into the IR. Work on the water content of T Tauri stars has been stagnant since we lost Spitzer IRS, and MIRI blows that data out of the water (pun intended). It also adds to existing IRS data, confirming some of the little blips we saw and thought were noise were actually high-SNR (but unresolved and blended) emission lines! And these are just the things I've paid attention to. There is just so much amazing. science. being. accomplished. But what do I know...

Thank you for your insider's perspective on this program and sharing what you know. Much appreciated.

 

[JohnDeL]

For exoplanet science, the wavelength matters.

Yes, it does.

Maybe someone had come up with a solution to deploy a 6.5-meter telescope (pre-SpaceX) in space without a sunshield while cooling the optics and structure to a temperature necessary to prevent large thermal emission removing that advantage over the ground.

The most obvious solution is brute force - use more coolant. That reduces the lifetime, but if it cuts the cost to 1/3 who cares if the lifetime is just 1/2?

Just a small note: I'm sure you know that JWST science operation started 3 years ago. So, by your calculation here, it's only got another 2 years left of life? I'm confident you know better, though. Sorry, but your responses towards me just wreak of bad-faith engagement.

If going by what NASA has promised is”bad faith”, then, yes that’s how I‘m arguing.

They hope to get ten years from the JWST, but only promise five.

. Maybe I'm biased, but there is every reason to believe that what we have is performing well above anyone's expectations and much better than anything we've ever put in space across 1-30um.

As noted, it is a very expensive “much better” that had the side effect of delaying or cancelling a lot of other, good and important science.

Just go look at the number of proposals, papers, conferences.

From what I’ve seen, it is about the same as the excitement level with every other mission.

I get your POV. You finally got the toy you’ve been asking for and you are fiercely protective of it. The problem is that in order for you to get it, the other kids had to do without.