Consider fabbing chips. Fabs spend an awful lot of time verifying the produced chips. I've seen estimates that verification cost exceeds fabrication cost.
How much of the development cost of JWST 2.0 would be spent on verification? I honestly don't know but I would guess it's high.
Another factor: part of making a production process is predicated on how many you'd build. We had a process for making Saturn-V rockets based on the number of Apollo missions we planned for. If you then up and decide you need 500 Saturn-Vs you might have to go through a whole new process for something that will scale that high.
Yet another factor: the launch vehicle. If you decide to do JWST 2.0 in 10 years, what launch vehicle will you use? The same one might not exist so the new mission will have to be designed for what is available.
And another: materials science changes. We don't make the same materials that we did 50+ years ago for good reasons but those materials are a key part of the design of something like Saturn-V.
So I imagine JWST 2.0 would be cheaper but 90% cheaper? I'm not convinced.
L1: between the Sun and the Earth. The Sun reflecting off the Earth would interfere with instruments.
L3: This is suitable for positioning but impractical because of distance from a communication and perspective.
L4 & L5: these are unsuitable because they're stable. Distance is an issue too. Why are stable Lagrange points unsuitable? Because things tend to collect there. Over the eons a whole bunch of crap has built up there and will continue to do so. That's not what you want when dealing with sensitive instuments.
Now you could say that you could orbit L4 or L5 like JWST orbits L2 and that's true but you still expend energy for stationkeeping. At L2 you spend energy to stay around the L2 point. At L4 and L5 you spend energy to avoid falling into the Lagrange point.
According to [1][2] it's more expensive (in delta-V terms) to get to L4/L5 than L2 but not hugely so.
[1]: https://space.stackexchange.com/questions/27010/how-does-the...
[2]: https://space.stackexchange.com/questions/57463/what-is-the-...
That still leaves the L2s of Venus, Mars, Jupiter etc.
And you can probably fit a few more into Earth L2.
It has an orbit around L2 of roughly 0.8 million km. L2 is about 1.5 million km from Earth. The moon is only 0.36 million km from Earth.
* L1 is between the Earth and Sun, so orienting the sun-shield toward the sun would result in the cold-side being heated by reflected light from the earth. It would also have access to the same patch of sky as at L2 for any given time of year, so there wouldn't be an advantage to having it at L1 as opposed to having a second telescope at L2.
* For L4 and L5, there's a ± 60 degree orbital offset relative to Earth. That gives access to a different part of the sky at any given time, but over the course of 6 months, both locations could access any part of the sky. There's a potential for time-correlation studies, where an observation at L2 and L4 are made at the same time, with the ~150 million km between them serving either as the base of a triangle for parallax measurements or as a known distance for measuring speed of travel between the
That said, I'm not sure how useful those would be. The parallax measurements could be done by ground-based telescopes simply by waiting a few months between measurements, and the speed of travel measurements would primarily provide a measurement of the index of refraction inside the heliosphere.
Overall, I'd guess the biggest scientific bang for the buck would be to load up more telescopes at L2. The proposals for the first 12 months of observations totaled about 48 months of observation time [0], so most of the proposals were rejected. The biggest advancement I can see would be to simply have more telescope time overall.
[0] https://www.stsci.edu/contents/news/jwst/2020/jwst-cycle-1-g...
[1]: https://www.esa.int/Science_Exploration/Space_Science/Hersch...
That's what I supposed.
Even L2 is big. I'm sure you could 10s or 100s of kilometres either side of "L2" and still have the same benefits as Webb has. In fact it you have enough objects there, and cooperate, they could effectively orbit each other.
Not a concern.
First: The Sun/Earth L2 is a big place. JWST's orbit around L2 is substantially larger than the Moon's orbit around Earth, and its orbit moves around in multiple dimensions -- it isn't constrained to a single dimension, like a geosynchronous orbit around Earth is. Even if there were debris in the vicinity, the odds of hitting it would be negligible.
Second: Orbits around L2 are inherently unstable -- it's a "saddle point", not an attractor. JWST has to maneuver a bit to keep itself in orbit, so any debris that ended up around L2 would naturally drift away.
Also, the entire Apollo infrastructure was actually designed for many more launches than occurred, that's why some of that infrastructure is still in use to this day. It's been a few years since I read a biography of Von Braun but I remember him making design decisions for Apollo that anticipated many more launches and manned missions to Mars and Venus in the 1970s with a manned Mars base by the early 80s.
The satellites which were donated to NASA by the NRO where likely leftover from the abortive Future Imagery Architecture program which was unrelated to Hubble.
Source: just my perspective after 20 years working on space systems.
Case in point: When there are 3 people on a planet that know how to create a specific sensor, and they happen to be NASA civil servants, JPL employees, Professors in Academia, or from a boutique non-profit like Aerospace or Mitre...in many cases the govt will decide to push the fabrication to commercial industry to create it, instead of the elite teams that created the most recent groundbreaking sensor.
This causes huge cost overruns as the commercial teams fumble around [1] and in some cases, even get paid despite dropping a satellite [2]
One of the funny fixes to this for NPP, was assigning a government "hall monitor" experienced in safe satellite testing to oversee test operations, and gig them for every infraction of safety protocols.
[1] https://www.defensedaily.com/npoess-has-more-than-1-billion-...
[2] https://spacenews.com/another-factory-mishap-damages-noaa-n-...
But of course. I meant before that happened, i.e. planning to make some siblings.
basically after the manufacturing, calibration, tuning, assembly, etc. techniques have been perfected to the required degree
plus, it would make sense to try to repeat this a few times always trying to 80-20 it. (I mean intentionally trying to "half-ass" the next iteration. spend less on it than on the previous one, and try to get the best out of that budget - with the same tech of course.)
the big problem is that ... it doesn't make much sense to do this. JWST delivers the data for the science it was intended and ... for the new questions that we'll raise we'll probably need some even more specialized observatory.
Just for fun, buy two IKEA flatpacks for, say, bookshelves. Build one, then the other. I bet you spend half the time building the second, even though you're doing exactly the same thing, by hand.
Reminds me of when in March 2020 I was also told I didn't know what I was talking about when I pointed out how a Covid vaccine could be made available in 6 months rather than the conventional 18 minimum times. The vaccines were available in 7 months.
The airplane I worked on the design of, the Boeing 757, would have cost at least 100 times as much per-plane if it was a one-off design.
It's not clear to me that designing something that needs to be assembled successfully once vs twice vs 10 times doesn't introduce some more cost tradeoffs in itself. Just around tolerances and yield even, how many pieces are required to be made to give one complete set of parts that all work together vs 10 complete sets that all work together. I could see some extra pain and assembly from having to get more permutations of part variances all working together and validated. A while back, at least, a lot of the testing processes for space components were VERY manual so you'd either need to invest more for automation or accept linear costs on all the extra production/verification.
This is partly quibbling over trivial details - I would imagine the savings is closer to 50-75% than 90% - but at a certain point those differences in tens-of-percentage points are lots of billions of dollars.
Here's the real kicker to me: why spend even an extra 10% up-front before even deploying one of them? Why not spend the marginal costs on building an additional unit only if the first fails? Then you can learn from the failure too? And if it works the first time, those billions can be spent elsewhere instead.
You're right that the 757 was meant to be built in bulk, and hence one has to pay attention to tolerances so the parts are interchangeable.
Conventional vaccines are sterilizing, have good safety records, and protection in years, or decades.
This "vaccine" is none of above.
These MRNA "vaccines" required a change in the definition of a vaccine, and have atrocious safety records.
The new Novavax vaccine [1], which is a conventional vaccine, may prove to have much longer effectiveness period, and not require boosters every 3 months. It also took much longer to develop.
[1] https://www.novavax.com/science-technology/recombinant-prote...
It's great that newer, vaccines are being developed. But in the meantime, the Novavax vaccine is not available. I'll take the one that is available. I'm not really interested in dying waiting for the perfect vaccine.
Many vaccines do not provide sterilizing immunity. Just to give one random example: flu vaccines do not provide sterilizing immunity.
> have good safety records
The various SARS-CoV-2 vaccines have very good safety records. They've been administered to billions of people, and the rates of serious side-effects are on the order on one per several hundred thousand - orders of magnitude lower than the rate of serious complications from infection.
> The new Novavax vaccine, which is a conventional vaccine
I don't know how you're defining "conventional" here, but Novavax also uses a new vaccine platform.
I know 2 people with severe adverse events from the vaxx.
Considering how many vaccinations I have received my life due to military service, that is an order of magnitude worse than any vaccination, ever.
Those are the ignorant ones.
It isn't quite a "Those who know don't speak and those who speak don't know" situation, but this is just blindingly obvious to anyone who has done any R&D to manufacturing and risk assessment. Heck, even just having a duplicate on the ground to debug could save the mission (since there isn't one, let's hope it doesn't come to that).
On one-off projects of any size, the design, prototyping, testing, & refining the design just overwhelm the cost of fabricating the final parts — and they do it by orders of magnitude. Just for the carbon fiber parts I work in daily, the initial R&D test program for a sizeable (scale of 1 m^2) part might cost $25K, the first mold $12K, the first part sells for $3K, the second part $2K and the fifth part 1.7K. To get to volume production in the 100s, there's probably another dev program & set of molds, and the 300th part out the door might sell at $1200.
Modern cosmology assumes-so, but it need not be true.
Homogeneity has been very well tested out to a redshift of a few by surveys like the Sloan Digital Sky Survey and the Dark Energy Survey, each of which have observed thousands of square degrees of sky (there are about 41k square degrees in total). And as another commenter notes, the CMB (at redshift 1100) is homogeneous (to one part in 10k).
What if 10 were built, each with only a 10% chance of success? What would that have cost? After all, it doesn't need the expense of being man-rated.
There’s physically not enough infrastructure (clean rooms, testing facilities, vacuum chambers, etc…) nor skilled manpower available to NASA to be able to build more than one in parallel, so that would add to the cost significantly.
Nothing?
Of course, the sensible thing to do is to build the test equipment, procedures, train the testers. Then test #1. Then test #2. Then test #3. That's what everybody does.
The cost of the Saturn V rocket was amortized over many launch vehicles, despite a host of new technologies that had to be developed for it, despite much of it being hand-built.
All that adds to the cost of the first mirror, and adds $0 to the second.
I don't think these NASA/JPL guys are quite as dim as you seem to suggest (but you have more info) and they may have done a little cost/benefit analysis before embarking on the project.
BTW, I am not suggesting they are dim. But one can be the finest physicist in the world and not be familiar with cost accounting and manufacturing.
Successful launch and arrival at the observation point? The 6 month setup period before observations can be made?
I contend that success here is a full mission that yields science data over decades of observation. If we cut down the acceptable error rate so we can launch early, how does that impact longevity?
2x — failed to deploy, mission lost
4x — early operation error, 6mo lifetime
3x — lower performance, 3 year lifetime
1x — mission successful, 10 year lifetime
…do we get a better deal building them with larger faults, at a lower cost?
A lot of expense is in developing technologies, assembly tooling, and test rigs — all of which is easier if we don’t need them to be as assured because only 1 in 10 needs to succeed.
No idea. Do you? Genuinely interested, particularly regarding methodology. Not intending at all to be insulting.
My dad told me that Pratt&Whitney made the most reliable aircraft engines by putting them on a test stand and running them at full power until they broke. The engineers would figure out why it failed, redesign the part, stick that on the engine, and continued running them at full power.
It's straightforward, inexpensive, and it works.
Then there's all sorts of complex failures that aren't addressed by single engines: " Prior to this crash, the probability of a simultaneous failure of all three hydraulic systems was considered as low as one in a billion. However, statistical models did not account for the position of the number-two engine, mounted at the tail close to hydraulic lines, nor the results of fragments released in many directions. Since then, aircraft engine designs have focused on keeping shrapnel from puncturing the cowling or ductwork, increasingly utilizing high-strength composite materials to achieve penetration resistance while keeping the weight low"
(I'm not disrespecting P&W- I'm sure they have more tests than just "100% power until it breaks, fix and repeat")
Keep in mind that my former job was designing gearbox parts for the Boeing 757. This included doing the math, and devising a test plan. I've spent a lot of time on "what could go wrong" scenarios in the real world.
Also, when I prepare slides for a coding presentation, the implementation code for a concept gets trimmed way down to what will fit on a slide.
But it seems patently obvious. After all, 10 technologies don't have to be reinvented. No research would need to be redone. No test rigs would need to be redesigned and duplicated. And on and on.
The most bizarre argument against building a duplicate was there wouldn't be anything extra worth looking at. Yet I watched the NOVA episode on the scope last night, and everywhere they look where we thought there was "nothing" turns out to be crammed with 10,000 galaxies and stars.