The James Webb Space Telescope has passed the final mission analysis review • Hacker News Board

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

#151

Post by abz10 » Wed, Jul 07, 2021, 10:58 PM UTC

bumby wrote: post #140

abz10 wrote: post #131

Earlier quoted context omitted.

The F-22 was sufficient for threat mitigation. The F-35 raison d'être was cost reduction, after that was exportability which again was supposed to help with cost reduction. Edit; comparing the logic of a 'but for' vs a 'necessary' condition. Was the F-35 necessary for threat mitigation. No. Was it framed as the necessary for cost savings, yes.

> Was the F-35 necessary for threat mitigation. No. Was it framed as the necessary for cost savings, yes. I think we're saying the same thing. The argument is, "Was the F22/F18/Fwhatever/weapon-system necessary for threat mitigation? Yes." With that said, if proponents of the F35 want to frame it as "threat reduction + cost savings" that's how they get the budget approved. But the point stands that without a threat,…

I don’t think it’s a great example of using existential threat for sales, when the whole thing was sold as a cost saving. Pretty much everyone at the time just wanted more F-22s. I was a technical advisor on the project.

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

#152

Post by scrumbledober » Wed, Jul 07, 2021, 11:00 PM UTC

jcims wrote: post #75

lisper wrote: post #9

Earlier quoted context omitted.

I used to work at JPL, and I was there when the sky-crane (the system currently used to land rovers on Mars) was first proposed back in the late 90s. I remember thinking to myself, "That is the craziest idea I have ever heard, there is no way that could possibly work." But it did. Never bet against NASA engineers. Sure, they have the odd high-profile screwup, but on the whole they are shockingly competent.

Do you know if there is any test footage of that anywhere? That's, to me anyway, the second most amazing thing about the sky crane...that I can't find a single frame of it in operation on earth.

would it have had enough thrust to work in earth gravity?

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

#153

Post by OrvalWintermute » Wed, Jul 07, 2021, 11:01 PM UTC

marcusverus wrote: post #36

OrvalWintermute wrote: post #16

Earlier quoted context omitted.

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,…

I think that NASA's budget, unlike many other federal agencies, is actually highly beneficial to US Taxpayers due to the large amount of IP/new inventions generated. Similar to DARPA, there are huge ROI factors that come in from an organization that researches, conducts science and engineering efforts on a massive scale, resulting in technologies that consumers can use economically.

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

NASA's budget is one of the smallest slices of the federal budget, and for that amount we receive a great deal back in benefits.

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

Due to the huge amount of technologies generated, and refined from these large prestige missions, I do not consider them to be a waste of funding.

One great example are the weather satellites generated by the NASA/NOAA partnership, such as GOES-R, and JPSS, and their predecessor missions in GOES & POES, to name a few. While they are very expensive they equip meteorologists with the rich data needed to make accurate observations. These observations directly impact human life, both by guiding evacuation decisions, knowing tornado tracks, and also, farming decisions. This same data is used for supply chain management, and there are a number of other uses for it.

Although many commercial media sources will be happy to provide you a weather feed, they often do not tell you that they have a backend connection to NASA, NESDIS and NWS, in order to provide their own weather data, or data from a research satellite. Or they'll provide you a customized photo which is actually a tailored version of imagery from GOES-*.

Because of the incalculable costs of an earth impacting asteroid, or a Carrington-dwarfing electromagnetic storm https://en.wikipedia.org/wiki/Carrington_Event , outward looking to see more of the cosmos is one of the best things we can do to ensure our survival as a species. The more we look out, the more we are able to prepare for such an event.

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

#154

Post by Pokepokalypse » Wed, Jul 07, 2021, 11:04 PM UTC

abz10 wrote: post #122

bumby wrote: post #120

Earlier quoted context omitted.

Unfortunately, I think it's easier to fund something like the F-35 because it can be framed as a way to avoid an existential threat. It's difficult to do the same with fundamental science

The F-35 was framed as a way to save money.

So was STS (Space Shuttle). . .

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

#155

Post by Pokepokalypse » Wed, Jul 07, 2021, 11:05 PM UTC

Retric wrote: post #138

abz10 wrote: post #131

Earlier quoted context omitted.

The F-22 was sufficient for threat mitigation. The F-35 raison d'être was cost reduction, after that was exportability which again was supposed to help with cost reduction. Edit; comparing the logic of a 'but for' vs a 'necessary' condition. Was the F-35 necessary for threat mitigation. No. Was it framed as the necessary for cost savings, yes.

Their designed for slightly different roles. The F-35’s R&D looks hard to justify vs simply having more F-22, but the F-35B can do verticals takeoff for example and the F-22 can’t. So, the real question is if the F-35’s should have had fewer versions and thus been more capable in it’s remaining roles.

F-22 theoretically can do a vertical take off as well. (not landing).

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

#156

Post by messe » Wed, Jul 07, 2021, 11:05 PM UTC

imglorp wrote: post #109

geenew wrote: post #57

Earlier quoted context omitted.

It has a docking clamp, though that's for future-proofing. Apparently the initial type of mission envisioned was a crewed Orion vehicle, though I'm sure a wide variety of missions could attach. My guess was that the clamp was mainly for possible future replenishment of consumables, though presumably some sort of robotic-arm-equipped repair mission could attach as well. A crewed mission seems possible, too, assuming o…

Nothing in the current fleet of new capsules have arms or airlocks. There is hope for the robotic refueling type mission though, or at least the kind where a new utility bot attaches to an old satellite and takes over propulsion to extend its life. https://nexis.gsfc.nasa.gov/rrm_refueling_task.html

> Nothing in the current fleet of new capsules have arms or airlocks.

True, but a docking adapter with an airlock that works with starliner and dragon is technically feasible. That said, it would still likely require recertification, as its inclusion would effect abort modes.

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

#157

Post by lazide » Wed, Jul 07, 2021, 11:07 PM UTC

wolverine876 wrote: post #93

JoeAltmaier wrote: post #71

Earlier quoted context omitted.

That's how space travel development works. It doesn't take off; it crashes; it explodes; it fails to land; it works. From then on pretty much, it works.

What is that based on? How do you distinguish launch systems that just don't work well? Everything works in the end? That would make engineering much easier and less stressful!

I’m unaware of any launch system that gets many tries at failures - it either gets what needs to be done relatively quickly or it gets cancelled. The number of tries you get is usually single digits.

Everyone fails a few times at a minimum.

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

#158

Post by justshowpost » Wed, Jul 07, 2021, 11:07 PM UTC

RapidFire wrote: post #147

whatshisface wrote: post #142

Earlier quoted context omitted.

The JWST's mission is to see deep infared, which can pass through interstellar clouds. It will uncover things that have been veiled to us since the beginning of history. It can only be built as a space telescope because the frequency of its intended observations are so low that to a device sensitive to them, air radiates light of blinding intensity.

Thanks for this comment; that's a fascinating bit of information.

But that was just like saying what F-35's mission is to fly high in the skies, sorry.

This sort of proves my point, no one knows which exactly research JWST will do upon deployment, because original mission goals mainly became obsolete.

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

#159

Post by [deleted] » Wed, Jul 07, 2021, 11:10 PM UTC

justshowpost wrote: post #158

RapidFire wrote: post #147

Earlier quoted context omitted.

Thanks for this comment; that's a fascinating bit of information.

But that was just like saying what F-35's mission is to fly high in the skies , sorry. This sort of proves my point, no one knows which exactly research JWST will do upon deployment, because original mission goals mainly became obsolete.

[deleted]

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

#160

Post by 7373737373 » Wed, Jul 07, 2021, 11:10 PM UTC

spaetzleesser wrote: post #139

When I look at project management for the small projects (1-20 people) I am working on I always wonder how projects of such a complexity are managed. It must be freakishly difficult to coordinate all the pieces. The people working on this will also have several stressful months ahead of them. From launch to full deployment so many things can go wrong and there is nothing that can be done when something fails.

I wonder the same for large (especially international) companies, government bureaucracies or other organizations. With thousands of employees and branches in different locations, it must be impossible to get a full understanding of the state of the system.