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James Webb is fully deployed

nasa.gov

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Re: James Webb is fully deployed

#431

Post by hypertele-Xii »

WalterBright wrote: post #311
hypertele-Xii wrote: post #154

Earlier quoted context omitted.

Doubling the data will also double the processing requirements for that data. The observatory is just the remote part of this operation. The data doesn't do squat unless stored, analyzed and interpreted by expensive professionals on expensive equipment. It's like saying if you're gonna build a chip fab, why not build two while you're at it? Well because the building isn't the operation.

Why do I have to do all the thinking? 1. Grad students and computers are cheap. 2. Crowd source it. Make the data (and the programs that process it) freely available. Let anyone who wants to analyze it - if they find something cool, they can be famous. They'll do it for free. 3. Processing doesn't have to be done in real time. There's no problem with taking 5 years to analyze 1 year of data.

All of the above are already utilized, to varying degrees of success, and lack thereof. I believe in this stuff but let's be real, we're exploding fossil fuel to propel a camera into space. Baby steps for global consciousness.

Re: James Webb is fully deployed

#432

Post by jibalt »

voidfunc wrote: post #419
JohnBooty wrote: post #208

Earlier quoted context omitted.

Great blog post from NASA themselves explaining it: https://blogs.nasa.gov/webb/2022/01/06/why-doesnt-webb-have-... the post is really not very long and I would suggest getting it straight from the horse's mouth, but for those not willing to devote a click here are arguably the most relevant bits! "deployment surveillance cameras would not add significant information of value for engineering teams commanding the spac…

Once again scientists miss the entire point. It is about marketing and making people interested. It makes it easier when you go back five years later and ask for more money if people can see the multi-million dollar toy they paid for.

Yeah, scientists are point-missing dummies who think that the images that telescope will produce are of no value next to images of the telescope unfolding. Far better to have internet randos who surely aren't dummies running things.

Re: James Webb is fully deployed

#433

Post by DisjointedHunt »

I'd like to see the scientific community get more throughput. While the launch of this telescope is great, it cost wayyy more than anyone expected and took far too long.

I hope all the applause doesn't drown out the criticism on the badly run operations and manufacturing capabilities at NASA that contributed to the delays.

Re: James Webb is fully deployed

#434

Post by jibalt »

idealmedtech wrote: post #266
frosted-flakes wrote: post #234

Earlier quoted context omitted.

With Hubbles's highest resolution optics, the JWST will be about one-tenth the size of a pixel.

How can it make out galaxies at billions of light years away, but not a truck sized craft at a few million miles? I haven't done the math myself, so I'm certain one side of that equation is wrong, but that seems hard to believe!

galaxy_width / truck_width = 3 × 10^20

Re: James Webb is fully deployed

#435

Post by WalterBright »

sailingparrot wrote: post #355
WalterBright wrote: post #312

Earlier quoted context omitted.

After reading all these replies, I'm glad Musk never listened to people who said he couldn't make a cheap, reliable rocket that could land on its tail. grump, grump, grump

Your point is completely unfair. Sure if our goal was to mass manufacture a "cheap and reliable JWST" we could, with a lot of money, create an entire assembly line and benefit from economies of scale. And then what? What are we supposed to do with 100s of JWST? It's cool they only cost 200M$ each now, but we don't need them. What we need after JWST is a different telescope with different technologies to answer questi…

Is it unfair?

In Spring 2020, in this forum, the vaccine experts here told me in no uncertain terms that a vaccine would take 18 months to develop. I said it could be done in 6 if all the slack was removed, and things done serially were done concurrently. I was told that was all completely unreasonable and impossible.

6 months later, the vaccine was released.

The JWST has what, 390 single points of failure, and cost $10B. I.e., it cannot afford to fail, so $10B was spent to ensure it would not fail. And it worked! But suppose for $1B one could build a less reliable JWST. They fail like Musk's early rockets, but since they're cheaper the failure is not career ending, and you can iterate the design fixing the things that broke rather than trying to make everything perfect. You wind up in the end spending a lot less money.

BTW, the airplane industry long ago gave up trying to make parts that could not fail. (390 parts that could fail and end the mission is pretty darn risky.) Instead, one makes redundant systems. It is far, far cheaper, and yet more reliable than going for perfection. Yes, it'll be heavier, and that will cost more. It makes airliners heavier, too, and it indeed costs more. But in the end it costs less, much less.

Do I know how to build satellite telescopes? Nope. But I do know how airliners are designed and built. And I know that Musk upended how rockets were designed and built.

As for different technology telescopes, I bet a lot of the telescope could be the same from design to design, just changing the instrument package.

Re: James Webb is fully deployed

#436

Post by jibalt »

ducktective wrote: post #26
dgrin91 wrote: post #23

One of the big numbers that been thrown around is that JWST has 344 single points of failure in its mission. Now that deployment has been completed, is there somewhere that lists how many of those points we have passed?

>344 single points of failure How can a system have more that one single point of failure?

BY the phrase not meaning what you think it means.

https://en.wikipedia.org/wiki/Single_point_of_failure

"A single point of failure (SPOF) is a part of a system that, if it fails, will stop the entire system from working."

Re: James Webb is fully deployed

#437

Post by jibalt »

jes wrote: post #70
ISL wrote: post #27

Earlier quoted context omitted.

If you're in a car being held above the ground by a chain, every single link is a potential single-point of failure.

In a real chain, only one link is actually the weakest, and it is at that link where the chain will break, in the hypothetical you offer.

"only one link is actually the weakest"

Which isn't relevant since (obviously) no one was talking about how many links are the weakest link.

"it is at that link where the chain will break"

Wars have been lost by thinking this way. e.g., D-Day was a successful assault on a strong link.

Re: James Webb is fully deployed

#438

Post by asteroidbelt »

tnle wrote: post #323
asteroidbelt wrote: post #103

No mention of ESA again, looks like it is solely NASA project, which it is not. Shame.

From the article, near the very top: "A joint effort with the European Space Agency (ESA) and Canadian Space Agency, the Webb mission will explore every phase of cosmic history – from within our solar system to the most distant observable galaxies in the early universe."

They changed the link. It pointed to a tweet initially.

Re: James Webb is fully deployed

#439

Post by jibalt »

mabbo wrote: post #33
ducktective wrote: post #26

Earlier quoted context omitted.

>344 single points of failure How can a system have more that one single point of failure?

I think linguistically the term can be hard to parse. If any one of 344 pieces were to fail during deployment, then all of the deployment has failed and the entire $10B was a loss. Consider the engine in your car- how many single pieces of it could fail before the entire engine can't work? The difference with Webb is that most of those points were single actions that had to work once. And we're now at a stage where m…

"A single point of failure (SPOF) is a part of a system that, if it fails, will stop the entire system from working."

>I think linguistically the term can be hard to parse.

Yeah, "solitary" might make more sense ... or "non-redundant". Or "point of single failure".

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