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The James Webb Space Telescope has passed the final mission analysis review

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Re: The James Webb Space Telescope has passed the final mission analysis review

#31

Post by bronson »

0xF57A wrote: post #23

I was watching a presentation given by the MGT project manager at cal tech and he mentioned that the MGT has a lower diffraction limit than the JWST. I think “diffraction limit” was the term he used, I don’t remember. The idea was that the images are supposed to be sharper. I was very confused about that. Why build JWST if MGT is going to maker cleaner images?

MGT is limited to the light that filters through the atmosphere. JWST will be tuned to longer wavelengths (redshifted older objects) that can only be seen in cold space.

Re: The James Webb Space Telescope has passed the final mission analysis review

#32

Post by jcims »

0xF57A wrote: post #23

I was watching a presentation given by the MGT project manager at cal tech and he mentioned that the MGT has a lower diffraction limit than the JWST. I think “diffraction limit” was the term he used, I don’t remember. The idea was that the images are supposed to be sharper. I was very confused about that. Why build JWST if MGT is going to maker cleaner images?

I'm just a rube but in general there are two issues:

1 - the atmosphere distorts and filters out a lot of light in various wavelengths. MGT likely has better resolution, but only for light that reaches it.

2 - JWST is primarily for infrared. Given blackbody radiation of the equipment itself can create a bunch of noise there, it's important to keep the equipment as cool as possible.

Re: The James Webb Space Telescope has passed the final mission analysis review

#34

Post by omgwtfbyobbq »

tomschlick wrote: post #11
tectonic wrote: post #3

Such an exciting, and high stakes, and dramatically late and over-budget mission.

Government red tape and contracting at its finest Edit: Downvotes with no comments as to why... This thing is 24 years in development and 20x over budget. If thats not a failure of government contracting, budgeting, etc then idk what is: https://en.wikipedia.org/wiki/James_Webb_Space_Telescope#Cos... - Obviously the platform will be cool once they get it launched, but until then its just a money pit.

I think you're getting downvoted because what you're saying doesn't match up with the wiki article you linked.

The original estimate was for $1.6 billion, in I'm guessing the 90s, and the estimate had been updated to $5 billion by the time it was formally confirmed for construction.

> The telescope was originally estimated to cost US$1.6 billion,[102] but the cost estimate grew throughout the early development and had reached about US$5 billion by the time the mission was formally confirmed for construction start in 2008.

So yes, it has been over budget, but by 2x-3x, not 20x, and that isn't adjusted for inflation.

Also, everything is just a money pit until it's launched/finished/etc.

Re: The James Webb Space Telescope has passed the final mission analysis review

#35

Post by bongoman37 »

0xF57A wrote: post #23

I was watching a presentation given by the MGT project manager at cal tech and he mentioned that the MGT has a lower diffraction limit than the JWST. I think “diffraction limit” was the term he used, I don’t remember. The idea was that the images are supposed to be sharper. I was very confused about that. Why build JWST if MGT is going to maker cleaner images?

Many wavelengths of light are simply blocked by the Earth's atmosphere. If you want to see them you have to go above the atmosphere.

Re: The James Webb Space Telescope has passed the final mission analysis review

#36

Post by marcusverus »

OrvalWintermute wrote: post #16
slownews45 wrote: post #4

Does anyone remember the initial proposals for this. The cost was supposed to be $500M. At most something like $1B. Given this is standard govt contracting - I'm sure it's come out much higher.

Even 5B for a novel, and uniquely powerful observation platform would be a bargain! When you are engineering a unit of 1 pushing the boundaries of science, with multiple conflicting constraints, funded by a variety of self-interested stakeholders, and are forced to do commercial production, rather than govt production, even when it is most cost effective, it isn't like you are heading towards lowest cost, technically…

It's easy to throw these big numbers around, but do you ever stop to consider the actual cost? Let's do some back-of-the envelope calculations to help us consider the human cost of a 5B telescope.

The Median US household income is ~68,000/year[0] The Average income tax paid by someone in the 50-75K income range is $4,600/year.[1] The average working career is probably around 40 years.

5,000,000,000 / 4,600 / 40 = 27,173

To fund a $5B project, 27,173 people (more, actually, since this is household data) could have worked for their entire working lives, with every dime of federal income tax being spent on that one project!

I agree that the JWST is a worthwhile project, but let's not pretend that it's a bargain.

[0]https://www.census.gov/library/publications/2020/demo/p60-27... [1]https://www.fool.com/taxes/how-much-does-the-average-america...

Re: The James Webb Space Telescope has passed the final mission analysis review

#37

Post by tomschlick »

omgwtfbyobbq wrote: post #34
tomschlick wrote: post #11

Earlier quoted context omitted.

Government red tape and contracting at its finest Edit: Downvotes with no comments as to why... This thing is 24 years in development and 20x over budget. If thats not a failure of government contracting, budgeting, etc then idk what is: https://en.wikipedia.org/wiki/James_Webb_Space_Telescope#Cos... - Obviously the platform will be cool once they get it launched, but until then its just a money pit.

I think you're getting downvoted because what you're saying doesn't match up with the wiki article you linked. The original estimate was for $1.6 billion, in I'm guessing the 90s, and the estimate had been updated to $5 billion by the time it was formally confirmed for construction. > The telescope was originally estimated to cost US$1.6 billion,[102] but the cost estimate grew throughout the early development and ha…

According to the budget table, when the project started in 1997, the budget plan was 500 million. Today its close to 10 billion.

Re: The James Webb Space Telescope has passed the final mission analysis review

#38

Post by Lammy »

systemvoltage wrote: post #14
tomschlick wrote: post #11

Earlier quoted context omitted.

Government red tape and contracting at its finest Edit: Downvotes with no comments as to why... This thing is 24 years in development and 20x over budget. If thats not a failure of government contracting, budgeting, etc then idk what is: https://en.wikipedia.org/wiki/James_Webb_Space_Telescope#Cos... - Obviously the platform will be cool once they get it launched, but until then its just a money pit.

Another way to put it is that it’s a jobs program. Edit: what’s with the downvotes? I would like to understand what the disagreement is here. Any gov program can be split up into two parts. One, the actual cost as dictated by the market economy, and second, the additional costs for delays, bureaucracy, etc which usually tends to be multiples of the actual costs. This money goes into paying salaries without actually m…

I would say "PR program" more than jobs program. NASA is the public face of the DoD/NRO spy satellite tech. Most of them are just looking back toward Earth at you and I instead of looking out into space. Compare to these programs which had over 4x the budget of JWST in 2004: https://en.wikipedia.org/wiki/Key_Hole

e: For example, KH-11 shares parts with the Hubble Space Telescope: https://en.wikipedia.org/wiki/KH-11_Kennen

'KH-11s are believed to resemble the Hubble Space Telescope in size and shape, as the satellites were shipped in similar containers. Their length is believed to be 19.5 meters, with a diameter of up to 3 meters.[5][23] A NASA history of the Hubble,[24] in discussing the reasons for switching from a 3-meter main mirror to a 2.4-meter design, states: "In addition, changing to a 2.4-meter mirror would lessen fabrication costs by using manufacturing technologies developed for military spy satellites.'

Notice how that says KH-11s, plural.

Re: The James Webb Space Telescope has passed the final mission analysis review

#39

Post by guerrilla »

omgwtfbyobbq wrote: post #34
tomschlick wrote: post #11

Earlier quoted context omitted.

Government red tape and contracting at its finest Edit: Downvotes with no comments as to why... This thing is 24 years in development and 20x over budget. If thats not a failure of government contracting, budgeting, etc then idk what is: https://en.wikipedia.org/wiki/James_Webb_Space_Telescope#Cos... - Obviously the platform will be cool once they get it launched, but until then its just a money pit.

I think you're getting downvoted because what you're saying doesn't match up with the wiki article you linked. The original estimate was for $1.6 billion, in I'm guessing the 90s, and the estimate had been updated to $5 billion by the time it was formally confirmed for construction. > The telescope was originally estimated to cost US$1.6 billion,[102] but the cost estimate grew throughout the early development and ha…

Adjusted for inflation it'd be about $2.5 billion this year. So it's almost exactly 2x.

Re: The James Webb Space Telescope has passed the final mission analysis review

#40

Post by gamblor956 »

tomschlick wrote: post #11
tectonic wrote: post #3

Such an exciting, and high stakes, and dramatically late and over-budget mission.

Government red tape and contracting at its finest Edit: Downvotes with no comments as to why... This thing is 24 years in development and 20x over budget. If thats not a failure of government contracting, budgeting, etc then idk what is: https://en.wikipedia.org/wiki/James_Webb_Space_Telescope#Cos... - Obviously the platform will be cool once they get it launched, but until then its just a money pit.

The original budget was a guess. They didn't know how much the telescope would cost because the required technology didn't actually exist at the start of the budgeting process 24 years ago.

Now that technology does exist, and it turns out it's quite expensive, which drove most of the cost increases. However, since then the budget increases have generally paced with inflation.

Source: your citation.

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