[HN Gopher] The $11B Webb telescope aims to probe the early univ...
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The $11B Webb telescope aims to probe the early universe
Author : infodocket
Score : 205 points
Date : 2021-12-08 18:31 UTC (4 hours ago)
(HTM) web link (www.nature.com)
(TXT) w3m dump (www.nature.com)
| chasil wrote:
| Quick! Take it back to the lab and put one of these on it!
|
| https://www.cam.ac.uk/research/news/colour-changing-magnifyi...
| malfist wrote:
| I now you're probably being factious, but the mirror on the
| telescope is already specifically designed for seeing long
| wavelength to near infrared spectrum.
| cryptoz wrote:
| I have started to wonder, will it ever be possible to 'see' the
| big bang? How close can we get to measuring that far back? From
| what I've seen JWST will be able to peer back to just a few
| hundred million years after the big bang. What are the limit to
| seeing even further back? Is it a matter of telescope size, will
| an even larger telescope by definition be able to see even
| further back? What is the limit?
| gadnuk wrote:
| Unfortunately, we cannot, or will not be able to see the Big
| Bang. The simple reason is, it's just beyond our reach.
|
| For the first few hundred thousand years, the universe was
| opaque.
|
| This link goes into a good amount of detail about the first
| light in the universe:
|
| https://phys.org/news/2016-11-universe.html
|
| We might be able to see a bit closer to the events after the
| Big Bang with a more powerful telescope in the future, but I
| don't think we can ever be able to actually "see" the Big Bang.
| cryptoz wrote:
| Fantastic link, thanks for that. Got me even more excited for
| JWST!
| chana_masala wrote:
| $11B is actually not very much for what this is. Good deal!
| bumby wrote:
| I think the JWST is managed as part of NASA's Space Science
| Directorate. That directorate gets a little less than $8B of
| the agency's roughly $23B budget. You'd have to look at the
| breakdown by year, but 10-15% of the annual directorate budget
| is substantial but not absurd given the project.
| credit_guy wrote:
| Why is that? If the pricetag was, for example $25 BN, would you
| say that would have been too expensive? Where do you draw the
| line? Or no price is too high for this telescope?
| whatroot8 wrote:
| Money is a completely abstract thing and at this point says
| nothing about the material economics. It's used to manage
| agency.
|
| Essentially we allowed people $11 billion in human agency to
| occur for scientific reasons.
|
| Sorry we didn't put more of it into cars and video games, but
| your economy surely benefited from people doing the real
| economic exchange this required.
|
| Personally I'd love to put it into designer drugs we can use
| to let me hallucinate a reality where miserly bean countering
| control freaks don't exist, since we're all going to die
| anyway and entropy will erode the universe.
|
| Excepting rules against violence and careless end of the
| species, why all the rules?
| pradn wrote:
| When US gov expenditures are like $4 trillion yearly, $11
| billion for an era-defining, cutting-edge space telescope
| built over 10-15 years does not seem much at all.
| smachiz wrote:
| 1996 cutting edge
| guerrilla wrote:
| Is there something better in production going into space
| right now? No, because this is literally cutting the edge
| right now.
| podgaj wrote:
| Yet we can't house the homeless.
| [deleted]
| spaetzleesser wrote:
| But then people complain about ITER costing 25 billion
| although its possible impact in the world is much bigger.
| credit_guy wrote:
| My question still stands: would $25 BN be too much? $100
| BN? Why is $11 BN a good deal? Would any price be a good
| deal for an "era-defining" project?
|
| In the '90's there was this huge Manhattan-like project,
| called "The Human Genome Project" [1]. The pricetag was
| about $3 BN. It took more than a decade. Then out of
| nowhere a startup appeared, and sequenced the human genome
| ten times faster and ten times cheaper (and fully with
| private funds). Nowadays, of course, we can sequence
| someone's genome for literally cents.
|
| The JWT project started before SpaceX was a thing. Right
| now it looks quite likely that in less than one year we'll
| have a launch vehicle that will be able to put 100 tons in
| orbit in one shot, and for cheap. All the complexity of the
| folding involved with JWT would become unnecessary with
| Starship. If someone were to start right now a JWT project,
| there's a realistic chance they'll finish it in a tenth of
| the time and a tenth of the cost, just like Celera did. We
| would get the same scientific results, but maybe one or two
| years later.
|
| So, now, am I allowed to ask again: why exactly was the $11
| BN a good deal?
|
| [1] https://en.wikipedia.org/wiki/Human_Genome_Project
|
| [2] https://en.wikipedia.org/wiki/Celera_Corporation
| jacoblambda wrote:
| 20-30B would have been about what I had estimated given
| the complexity involved for this project. I think 11B
| spread over 2 decades and some change was a pretty good
| deal comparatively.
|
| Now I think that hindsight being what it is, if we had
| known that Starship was in the pipeline and this would be
| launching right when Starship is getting into production
| (considering JWST started development in the mid 90s), I
| would have said that we should be designing a
| cheaper/simpler telescope that uses this larger launch
| package.
|
| But that's all hindsight. For what the JWST actually
| accomplishes, it's an engineering marvel and given what
| we knew when it was being designed, I think NASA and the
| associated committees did an excellent job making it as
| cheap and large as it is.
|
| Now if we were to take what was learned from the JWST (a
| lot of innovative work on beryllium mirror design and
| segmented telescope design was done on this project) and
| were to design a new telescope today using modern
| technology, modern materials knowledge, and a launch
| vehicle like the Starship, I'd suppose we could make an
| equivalent telescope for 25% or less of the JWST's cost.
| Unfortunately however by the time this would be feasible,
| the majority of that money had already long since been
| spent using existing technology and techniques. This
| hypothetical cheaper telescope would also likely not be
| ready for launch if started in say 2015 until 2025 or so
| when the Starship would be considered safe enough for
| such a high value mission.
|
| TLDR: It was a good value for the era in which it was
| designed and built. It is limited by what NASA knew when
| they designed it. And if it was to be built today, it
| wouldn't launch for at least a decade after the design
| would start and you'd undoubtedly be able to make a
| similar statement about said design from "now-era" vs a
| hypothetical better value proposition from "future-era".
| Knowing what we knew at the time it was worth it and to
| wait indefinitely for the optimal time to start a design
| will always be a race of better vs perfect.
| credit_guy wrote:
| > For what the JWST actually accomplishes, it's an
| engineering marvel
|
| Sure, but so are the Event Horizon Telescope (which cost
| less than $100 MM) and LIGO (cost about $1 BN). And those
| were truly revolutionary, and they hold a lot of promise
| for more scientific results down the road. At any given
| moment the scientific world has lots of ideas, some are
| truly ingenious, and some are just bigger-is-better
| iterations of older ideas. The really ingenious ones tend
| to be cheaper, if for no other reason than they can't get
| huge amounts of funding given they are not proven yet.
| The bigger-is-better ideas get eye popping dollars, and
| the public opinion is always positive. Just like it
| happens with Hollywood sequels.
| adgjlsfhk1 wrote:
| From link 2: "However, a significant portion of the human
| genome had already been sequenced when Celera entered the
| field, and thus Celera did not incur any costs with
| obtaining the existing data, which was freely available
| to the public from GenBank". The reason Celera was able
| to finish the project cheap was because public funding
| had already done the first 90%.
| wolverine876 wrote:
| > If someone were to start right now a JWT project,
| there's a realistic chance they'll finish it in a tenth
| of the time and a tenth of the cost
|
| What is your basis for saying that 90% of the cost and
| time was due to folding mirrors? That sounds like the
| easy part - it's mechanical, and satellites have been
| unfolding in orbit for a long time.
| trasz wrote:
| Never mind government expenditures as a whole; $11 billion
| is less than a single aircraft carrier.
| gvv wrote:
| For those complaining about the spending: some countries spent
| TRILLIONS on war and and nation building. It's developments like
| these we should be focusing our energy and intelect.
| cogman10 wrote:
| $11 billion for a 10 year mission is peanuts in modern
| government operating expenses. It's not even $11 billion for 10
| years, but already spent money over something like 15 years.
|
| So, roughly $11 billion over 25 years. Something that many
| nations could afford.
| justajot wrote:
| Just for reference, the total U.S. Department of Defense budget
| for 2021 was $705 billion.
|
| https://en.wikipedia.org/wiki/Military_budget_of_the_United_...
| deltree7 wrote:
| or you can let a country have multiple billionaires so that
| they can fund these projects with their own money and compete
| within themselves, take more risks and compress the timelines
| of frontier-conquering and innovation.
|
| But, we want a large bureaucratic organization (by design),
| extremely risk-averse(by design), extremely slow(by design),
| having only one shots (by design) to do this for us
| systemvoltage wrote:
| This is a poor argument and poor reasoning. This way, instead
| of improving, we continue to regress ("Look there! They're
| doing it too!" argument). We should be halving expense on all
| fronts while demanding the same output - whether it's military
| or space spending. Look at ISRO's budget, high efficiency is
| key.
|
| Just because DoD budget is $750b, doesn't mean that we should
| have a free pass to waste money. I'd like to see DoD spending
| cut in half while holding vendors accountable. Same with space
| industry.
|
| Another way to think about this if it helps is for $11b, we
| should have gotten more done. Imagine James Webb Telescope + 5
| more projects for the same $11b. Wouldn't that be awesome?
| gifnamething wrote:
| That's barely enough for a negative revenue electric vehicle
| startup these days
| kdmccormick wrote:
| I think GP's parent is a fair argument against criticisms
| that start and end at "$11B is a lot of money!". It is valid
| to point out that $11B pales in comparison to the US's
| defense budget as a means of providing context for how big
| these really big numbers are.
|
| If someone were to point to specific ways in which the
| project wasted money, that'd be different. But I haven't seen
| such detailed criticisms.
|
| Nobody is arguing that wasting money is a good thing.
| panick21_ wrote:
| While true, its also a huge problem when contractors promise
| something for 2B$ and then it costs 10-15B$ without the
| contractors suffering any consequences. What stops them from
| doing that for every single contract?
|
| There is a reason recently NASA has started to focus on Fixed
| Price contracts.
|
| We need a shift to more missions, building these things more
| often and more on price. Putting absurd amount of money into 1
| mission compared to 20 missions for 500M$ likely doesn't make
| sense.
|
| The Webb telescope has been so long in development that lots of
| subsystems could have evolved considerably since then.
| bregma wrote:
| But I'm sure this project will have many technological spinoffs
| that could, with only a little additional funding, be used
| either to kill a lot of people or to generate personal wealth
| for at least a few select individuals (and those are not
| mutually exclusive). It's a bargain at twice the price.
| yboris wrote:
| With $11B why can't we funnel all that money into _fusion_
| research? Feels like a bigger payoff than anything this could
| bring :/
| cogman10 wrote:
| Good news, since the JWST started the US alone has pushed in
| $7.087 billion dollars into fusion research [1]
|
| By the time it finishes it's mission we're likely to have
| exceeded that $11 billion budget in fusion research.
|
| Unfortunately, I don't think fusion is something simply solved
| by more money.
|
| [1] http://large.stanford.edu/courses/2021/ph241/margraf1/
| afroboy wrote:
| Shouldn't you say that about the US military budget that goes
| over 7OO billion dollar each year?
| pixelpoet wrote:
| Aside: those alphabetical O's you used instead of zeros are
| super jarring!
| m3kw9 wrote:
| There will be annoying people saying - we have world hunger now,
| and you are spending 11b to looking at the universe 10b years
| ago???
| podgaj wrote:
| That would be me. If it is annoying to care about the suffering
| of those less fortunate so be it.
|
| https://endhomelessness.org/homelessness-in-america/homeless...
|
| In January 2020, there were 580,466 people experiencing
| homelessness in America. Most were individuals (70 percent),
| and the rest were people living in families with children. They
| lived in every state and territory, and they reflected the
| diversity of our country.
|
| That $11B would give about $18000 to all of those people. At
| $1000 a monthly rent that would house them for nearly two years
| and would most likely help them to stabilize their lives. Plus
| it would pump more money into the economy.
|
| You will never find the end of the universe, or know why it
| began. And if you do find out, what is the purpose? Will it
| help you love another human being more? No, you will invent
| something else you need to discover.
| jcun4128 wrote:
| I just hope these donations make it to the people, I donate
| to things like this (now including this one) and hope it
| makes a difference.
| kortex wrote:
| We're not yeeting $11B USD into a Lagrange halo orbit. It's
| funding STEM jobs.
|
| Yes we should have UBI but like, that doesn't meant we can't
| do science at the same time. Maybe look to the MIC to cut
| first.
| podgaj wrote:
| Who gets STEM jobs? The already wealthy kids of wealthy
| parents.
|
| Yes, cut the MIC budget, but this is part of that budget,
| kind of, since "Northrop Grumman Fully Assembles NASA's
| James Webb Space Telescope"
|
| https://militarycouncil.ca.gov/2019/09/19/northrop-
| grumman-f...
| jazzyjackson wrote:
| it is hard for me to respond to this sentiment, it's so
| dismissive of an entire industry
|
| even giving credence to this hypothesis that STEM is a
| rich kids' sport, should we let the talent go to waste
| and give rich kids nothing to work on?
|
| I suppose you would say we should apply everyone's
| intelligence to solving the bureaucratic problem of how
| california spends its welfare budget, but it may surprise
| you that that does not inspire passion in many young
| people. Space exploration does, and if we have an economy
| where certain kids get private tutors their whole lives
| so they someday build telescopes that literally take
| photographs of the edge of the universe, I think that's
| something we can celebrate even if it doesn't solve
| literally every problem.
| BitwiseFool wrote:
| >"Who gets STEM jobs? The already wealthy kids of wealthy
| parents."
|
| I believe this is cynically reductive. I worked with
| plenty of first-generation college students when we
| studied engineering. All were on scholarships. I think we
| should be weary of associating STEM with privilege.
| cogman10 wrote:
| Is the US government known for being generous with STEM
| pay? I was of the impression that most people take a pay
| cut working for the gov.
|
| Now defense contractors, that's where the big bucks are.
| SonicScrub wrote:
| If you give one person $1000 per month, you can improve that
| person's life with next to zero external consequences. If an
| organization gives half a million people $1000 per month, the
| external macro economic impacts must be considered. Societal
| quality of life improvement is not as simple as in the
| single-person example. You can't scale one up one to the
| other and expect the individual result to similarly scale.
|
| If you doubt this true, consider the fact that the US
| Government currently spends upwards of $1 Trillion /year on
| welfare programs per year. That is money specifically
| dedicated to poverty elimination and/or management. An amount
| that makes the James Web 0.44 billion /year over 25 years
| look like a rounding error. By your numbers, that $1 Trillion
| could be used to give each of the ~0.5 million homeless
| around $1.7 million per year. If it's this simple, why hasn't
| it been done? Is your assumption about how poverty
| elimination is as simple as throwing money perhaps incorrect?
| What do you know that the US Federal government doesn't?
|
| FYI emotional appeals about how a telescope can't help us
| love each other will do you no favours here. Likewise with
| implications that you are the only one who cares about
| homelessness, or that one cannot care about both homelessness
| and space exploration at the same time.
| kataklasm wrote:
| > That $11B would give about $18000 to all of those people.
| At $1000 a monthly rent that would house them for nearly two
| years [...].
|
| Let's not change algebra to fit our conclusions, shall we?
|
| I really don't understand how people are getting angry at
| $11B in space exploration funding. Consider the following:
|
| a. Go through some of the cutting-edge technologies humankind
| has at its disposal nowadays (yes, yes, the kids starving in
| Africa do not, but that's an entire new tangent) and have a
| look at how they were invented. Chances are a lot of them
| originate in space exploration or space experiments. Modern
| navigation systems that power basically any systems you can
| think off that you use everyday. The high-tech tracking
| systems making sure the laser scalpel during LASIK eye
| surgery doesn't destroy your sight but rather restores it?
| Yea that was developed from a program that developed
| automated docking and rendezvous laser tracking systems for
| space dockings.
|
| b. Can't you think of many more money sinks that would
| deserve to get defunded before thinking of space exploration?
| How about you start with the US Military? Last year the US
| spent over $750B on defense costs, that's over 68x the $11B
| figure quoted for James Webb. Surely we can deduct a billion
| or two here and there? You know what? that'd be double
| positive since you wouldn't create a whole portion of hungry
| humans at the same time since you're not going to war with
| half the world anymore. Stop the stupid fucking military
| complex first, then you can talk about defunding space
| exploration.
| jallen_dot_dev wrote:
| > That $11B would give about $18000 to all of those people.
|
| Unfortunately you can't just live inside a pile of cash. The
| problems surrounding homelessness are slightly more
| complicated than you are letting on, and "we spent the money
| to buy a telescope instead" is not one of them.
| dahfizz wrote:
| We already spend over a trillion dollars a year on various
| welfare programs[1]. Throwing more money at social issues
| will not help.
|
| > Plus it would pump more money into the economy.
|
| It would "pump" money straight into the pockets of landlords.
| Its not like the money spent on JWT was shredded...
|
| [1] https://www.budget.senate.gov/imo/media/doc/CRS%20Report%
| 20-...
| [deleted]
| imglorp wrote:
| Explicitly ordering our priorities is probably a good
| conversation to have; better to have it in the open than hidden
| in a pork bill somewhere.
|
| We should also talk about fossil fuel subsidies ~5T/yr (!),
| infra $1.2T (one time), defense at $768B/yr, etc etc.
|
| https://e360.yale.edu/digest/fossil-fuels-received-5-9-trill...
| trasz wrote:
| 11 billion is less than a single aircraft carrier, of which US
| has already built several. There are better things to cut
| funding to than a one of a kind telescope.
| FiberBundle wrote:
| Given that this will be at a distance of more than a million
| miles from earth, I would assume that missions to repair the
| telescope are likely not an option. So how long is jwst expected
| to live? Is it extremely unlikely to collide with any objects at
| such a distance from earth?
| josho wrote:
| What exactly are we hoping to learn from the telescope? I
| understand that it will allow us to see farther than ever before,
| and that is exciting. But, there must be a list of hypotheses
| that astronomers are planning to test. None of the
| videos/articles I've found actually speak to the specific
| discoveries we are hoping to make. Is it simply that the science
| is so advanced that it's out of reach for a layman?
| doctoboggan wrote:
| What I am most excited for is the experiments using this scope
| to analyse the atmospheres of exoplanets. The goal is to look
| for signs of like like high quantities of methane.
| digitcatphd wrote:
| Splendid
|
| It is destined for a point in space 1.5 million kilometres from
| Earth -- too far away for astronauts to visit and fix the
| telescope if something goes wrong. Hubble required an after-
| launch repair in 1993, when astronauts used the space shuttle to
| get to the Earth-orbiting observatory and install corrective
| optics for its primary mirror, which had been improperly ground.
| gadnuk wrote:
| The whole Hubble mirror fiasco was fascinating. The before and
| after images of the galaxy M100 in the following link outlines
| the extent of the error:
|
| https://www.nasa.gov/content/hubbles-mirror-flaw
|
| One may assume that maybe the error was simply too big and
| that's why the aberration. Here's the root cause and the
| magnitude of the error would be dismissed as nothing by most
| people on this planet but ultimately turned out to be huge!
|
| "Ultimately the problem was traced to miscalibrated equipment
| during the mirror's manufacture. The result was a mirror with
| an aberration one-50th the thickness of a human hair, in the
| grinding of the mirror."
| a9h74j wrote:
| That's huge. Everyday profile accuracy can be spoken of in
| "quarter wavelength"-like terms.
| gadnuk wrote:
| The deployment sequence that takes approx 30 days is terrifying
| but also probably one of the most complex things we would ever
| achieve if successful.
|
| Have been waiting for this since I was a teenager. Can't believe
| we are almost there (launch on Dec 22).
|
| Here's a short 2 min video of that deployment sequence if anyone
| wants to be fascinated:
| https://www.youtube.com/watch?v=RzGLKQ7_KZQ
|
| Also a short interview with Dr. John Mather (could listen to him
| all day) if anyone wants to know how the telescope works:
| https://www.youtube.com/watch?v=4P8fKd0IVOs
| kortex wrote:
| How does one even _begin_ to engineer tests for such a sequence
| of events? Yeah you can test each step individually, but then
| you have all the integration effects. How do you know you have
| enough coverage?
|
| $10B buys a lot of QA and I'm sure they try to engineer
| everything with the right margins, but it's still an
| unfathomable amount of state space.
|
| Are there techniques to stay sane and manage risk without just
| throwing money at it? I feel like that kind of knowledge could
| be useful for software test development.
| jdiez17 wrote:
| There's no real silver bullet other than applying the systems
| engineering process diligently. You start by writing down
| your user requirements (what the system needs to _deliver_ ),
| and you follow the thread of figuring out that "to do X, this
| subsystem has to provide conditions A, B, C..." recursively,
| in a breadth-first search. The level of detail codified in
| these functional, performance and interface requirements
| depends on the level of assurance you need.
|
| Then, you need to _validate_ that each requirement is met by
| your system. This can be done by test, analysis
| (mathematically proving some property), review of design, or
| inspection. It 's true that you can't fully validate most
| space systems on Earth, because we can't simulate all
| environmental conditions simultaneously. That's why you
| ideally you want each requirement to be validated by two
| methods.
|
| When you find anomalies due to integration effects, it's
| usually because your interface requirements are not specified
| well enough ;)
| ausbah wrote:
| this level of rigor always makes me snicker at the
| engineering in "software engineering"
| jl6 wrote:
| This is how you are supposed to build software too.
| danielheath wrote:
| Who supposed that?
|
| Broken software can be fixed cheaply after the fact.
| Yeah, it's cheaper if you find the bugs earlier but it
| shouldn't come as any surprise that pre-validation is
| more extensive in systems that are expensive to change.
| s1artibartfast wrote:
| There are lots of different types of software.
|
| There are phone note apps and control systems for jets
| and artificial hearts
| russtrotter wrote:
| Fair point, but the software that eventually ends up in
| flying space hardware has usually been put to a similar
| test.
| markus_zhang wrote:
| You can probably snicker at most engineering in "X
| engineering".
| thelittleone wrote:
| Likewise... I was pretty impressed with myself in the 90s
| as a young guy passing the Microsoft Certified Systems
| Engineer exam.
|
| "According to Encyclopedia Britannica, the first recorded
| 'engineer' was Imhotep. He happened to be the builder of
| the Step Pyramid at Saqqarah, Egypt." [link]
|
| I look forward to drinking ale with Imhotep (and NASA JW
| Space Telescope engineers) in the great heavenly hall of
| engineers.
|
| https://interestingengineering.com/the-origin-of-the-
| word-en...
| wumpus wrote:
| One of the best talks I've heard recently was by an
| early-20s engineer talking about safety-critical software
| for trains.
|
| Yes, it's very different from most software engineering.
| No need to snicker, just do the appropriate thing for
| your situation.
| peterburkimsher wrote:
| I agree, it's a recursive search! Translated into software
| testing:
|
| _" level of detail codified in functional, performance and
| interface requirements"_
|
| functions, usage frequency, APIs.
|
| _" usually because your interface requirements are not
| specified well enough"_
|
| It's probably a bug in the API.
|
| https://martinfowler.com/bliki/TwoHardThings.html
|
| _" There are only two hard things in Computer Science:
| cache invalidation, naming things, and off-by-one errors"_
|
| https://en.wikipedia.org/wiki/Ctags
|
| Suggestion: use ctags to list all functions, variable names
| in your code. Look for ambiguity (e.g. variable name "i").
| Look at neighbouring code. Zoom in and out. A small bug in
| the most-used code is actually more serious than a big bug
| in code that rarely gets used.
|
| "How long can you work on making a routine task before
| you're spending more time than you save?"
|
| https://xkcd.com/1205/
| zppln wrote:
| Is any of the systems documentation for any NASA project
| publicly available? As someone who spends a considerable
| amount of time sifting through systems documentation where
| the process hasn't been applied so diligently, I've always
| wanted to read a NASA SSDD or similar.
| wolverine876 wrote:
| Simple:
|
| NASA Systems Engineering Handbook
| https://ntrs.nasa.gov/citations/20170001761
|
| That's the 2017 version; maybe there's a later one. IIRC,
| it's an abridged from _NASA Expanded Guidance for SE_ , but
| my link to that is broken.
| qwertyuiop_ wrote:
| Wait no Agile ?
| wolverine876 wrote:
| Did you read it all? ;)
| peterburkimsher wrote:
| You gave the answer! Integration tests. And they work
| recursively, with a Kalman filter to approximate even in
| noisy conditions.
|
| _" USL was inspired by Hamilton's recognition of patterns or
| categories of errors occurring during Apollo software
| development. Errors at the interfaces between subsystem
| boundaries accounted for the majority of errors and were
| often the most subtle and most difficult to find. Each
| interface error was placed into a category identifying the
| means to prevent it by way of system definition. This process
| led to a set of six axioms, forming the basis for a
| mathematical constructive logical theory of control for
| designing systems that would eliminate entire classes of
| errors just by the way a system is defined.[3][4]"_
|
| https://en.wikipedia.org/wiki/Universal_Systems_Language
|
| There's a diagram of rules on the USL Wikipedia page. The
| rules show triangle feedback loops with a parent, left, right
| child. Those are like generations of a Sierpinski triangle.
| Every part is trying to serve the Good Cause that it's
| working for, and love its neighbour.
|
| https://en.wikipedia.org/wiki/Minimal_realization
|
| _" any state-space model that is both controllable and
| observable and has the same input-output behaviour as the
| transfer function is said to be a minimal realization of the
| transfer function The realization is called "minimal" because
| it describes the system with the minimum number of states."_
|
| https://en.wikipedia.org/wiki/Optimal_control
|
| _" the problem of driving the output to a desired nonzero
| level can be solved after the zero output one is."_
|
| An electronic analogy: find GND, then solve for 1.
|
| _A common solution strategy in many optimal control problems
| is to solve for the costate (sometimes called the shadow
| price) A shadow price is a monetary value assigned to
| currently unknowable or difficult-to-calculate costs in the
| absence of correct market prices. It is based on the
| willingness to pay principle - the most accurate measure of
| the value of a good or service is what people are willing to
| give up in order to get it. The costate summarizes in one
| number the marginal value of expanding or contracting the
| state variable next turn._
|
| Each part looks ahead 1 generation, chooses left or right.
|
| https://en.wikipedia.org/wiki/Kalman_decomposition
|
| _convert a representation of any linear time-invariant (LTI)
| control system to a form in which the system can be
| decomposed into a standard form which makes clear the
| observable and controllable components of the system_
|
| Take a big problem, break it down, look for I/O ports. Or in
| software test development: layers of abstraction. A
| suggestion: only add a layer of abstraction when it's too big
| to fit on the screen at once. Use tools like code folding,
| tree views.
|
| https://en.wikipedia.org/wiki/Optimal_control
|
| Optimise for time? When we're in a hurry we break things.
| Another suggestion: aim to minimise entropy, maximise
| connectedness.
|
| Thank you for asking a good question, and thank you for
| reading! Let's go and tidy up this world together, in
| software and hardware.
| smarx007 wrote:
| I would start with https://en.m.wikipedia.org/wiki/V-Model.
| System designs of everything in automotive, aerospace etc are
| based on a V model.
| Nicksil wrote:
| https://en.wikipedia.org/wiki/V-Model
| double0jimb0 wrote:
| Systems Engineering is the discipline that oversees this.
| They define what tests will be required to validate the thing
| will do what it is supposed to before any hardware is built.
| I don't think there is a good analogy to typical software QA,
| which is usually a "make sure it doesn't break anything that
| already works" type of discipline.
| inglor_cz wrote:
| We _really_ need Starship in operation. It should be able to
| carry much larger objects into space - no need for complicated
| folding and unfolding mechanisms.
|
| Starship could possibly take normal sized heavy equipment to
| other planets, such as heavy earth movers. (Not those with a
| combustion engine, but still useful.)
| jcims wrote:
| The one thing that I think starship has proven is that for
| any major mission that stretches our current launch
| capanilities, it may be worth investigating developing a new
| launch vehicle instead of accommodating the ones we have.
|
| Just think of all the engineering and risk that's going into
| a process that will be used once.
| grishka wrote:
| Not even that -- seeing how cheap Starship launches would be
| per kg of payload (I've seen a figure of $10), we could as
| well build a huge orbital station and _just manufacture and
| /or assemble arbitrarily sized stuff in there or even in
| space_. No atmosphere, and especially pesky oxygen, to deal
| with, no contaminants to keep out, no gravity to fight
| against. I'd imagine that any scientific and fabrication
| processes that need a deep vacuum would also greatly benefit
| from being done on a space station.
| inglor_cz wrote:
| Zero gravity engineering is going to be an interesting
| challenge, and a source of many funny videos. (Possibly
| some less than funny, too.)
|
| I would definitely love to see something like the Space
| Station V from Kubrick's 2001 - A Space Odyssey IRL. AFAIK
| it was almost a quarter of a mile in diameter. This seems
| to be suited for in-orbit fabrication and assembly.
| chasd00 wrote:
| the "fabric" tensioning looks really sketchy to me. i can
| barely get a fitted sheet tensioned correctly on my bed..
| belter wrote:
| Suddenly extremely worried about this:
|
| "James Webb Telescope will run a proprietary JS interpreter by
| a bankrupt company "
|
| https://news.ycombinator.com/item?id=19737663
|
| https://www.researchgate.net/publication/252882358_Event-dri...
|
| "The James Webb Space Telescope (JWST) will use an event-driven
| system architecture to provide efficient and flexible
| operations as initiated by a simplified, high-level ground
| command interface. Event-driven operations is provided through
| the use of an on-board COTS JavaScript engine hosted within the
| payload flight software..."
|
| Edit: Found something ....Is it too late to postpone the
| launch?
|
| https://www.stsci.edu/~idash/pub/dashevsky0607rcsgso.pdf
|
| "...The JWST science operations will be driven by ASCII
| (instead of binary command blocks) on-board scripts, written in
| a customized version of JavaScript. The script interpreter is
| run by the flight software, which is written in C++. The flight
| software operates the spacecraft and the science instruments.
|
| The on-board scripts will autonomously construct and issue
| commands, as well as telemetry requests, in real-time to the
| flight software, to direct the Observatory Subsystems (e.g.,
| Science Instruments, Attitude Control, etc.)...
|
| The flight software will execute the command sent by the
| calling on-board script and return telemetry, which will be
| evaluated in real-time by that on-board script. The calling
| script will then send status information to a higher-level on-
| board script, which contains the logic to skip forward in the
| observing plan in response to certain events (see Section
| 4.1)... "
|
| Found it...
|
| "JWST uses an extended version of JavaScript, which was
| developed as a COTS product called Nombas ScriptEase 5.00e.
| ScriptEase provides functionality common to many modern
| software languages and follows the ECMAScript standard."
|
| http://brent-noorda.com/nombas/us/toolkit/index.htm
|
| http://brent-noorda.com/nombas/us/toolkit/isdkdownload.htm
|
| Latest errata from 2004, moving from worried to full panic
| mode...
|
| http://brent-noorda.com/nombas/us/devspace/errata/isdk/index...
| xenadu02 wrote:
| It is common in such commercial agreements to provide source
| code or to escrow source code with a third party service with
| conditions that trigger release of the sources (eg bankruptcy
| or sale to another company that discontinues the product). So
| it is possible they have the full source.
|
| It is also worth considering that the JS engine likely hasn't
| changed much (if at all) in the past 15 years. Its bugs and
| limits are well-known at this point.
|
| It is also an interpreter which makes it slower* but less
| subject to vulnerabilities that impact the host. Honestly
| that's probably the correct choice for a spacecraft where
| reliability and safety is more important than performance.
|
| Don't get me wrong: JavaScript is a big ball of WAT and
| nonsense we've spent way too much effort improving but I
| don't blame them for making the choice so long ago and
| sticking with a known quantity rather than risk introducing
| new problems by changing things.
|
| * I once worked on a project that used IronJS to run JS in
| the .Net runtime. It took advantage of the runtime's JIT but
| was a lot of not terribly optimized F# code. I built a V8
| bridge and was very excited for the increase in perf... but
| it got slower. It turned out most customer-written JS code
| spent most of its time using the API which was backed by C#
| code and that meant lots of bridging. At the time I left they
| were still using IronJS because it was faster for their
| workloads. It taught me the importance of testing your actual
| workload and taking a whole-system approach to perf.
| jazzyjackson wrote:
| it's not running Node 0.10.0 for gods sake, it's an
| interpreter to write jobs that scientists can use for their
| studies - the flight critical stuff is a different stack
| belter wrote:
| You sure about that? From the linked paper ( unfortunately
| behind all kinds of paywalls...)
|
| "The major characteristics of our process are
|
| - 1) coordinated development of the operational scripts and
| the flight software,
|
| - 2) an incremental buildup of the operational
| requirements,
|
| - 3) recurring integrated testing. Our iterative script
| implementation process addresses how to gather requirements
| from a geographically dispersed team, and then how to
| design, build, and test the script software to accommodate
| the changes that are inevitable as flight hardware is built
| and tested.
|
| The concurrent development of the operational scripts and
| the flight software enables early and frequent "test-as-
| you-will-fly" verification, thus reducing the risk of on-
| orbit software problems...."
| jazzyjackson wrote:
| " 3.1. Event-driven Operations
|
| The JWST science operations will be driven by ASCII
| (instead of binary command blocks) on-board scripts,
| written in a customized version of JavaScript. The script
| interpreter is run by the flight software, which is
| written in C++. The flight software operates the
| spacecraft and the science instruments."
|
| and in section 3.5, sounds like javascript just has an
| API to lower level system functions:
|
| " ScriptEase JavaScript allows for a modular design flow,
| where on-board scripts call lower-level scripts that are
| defined as functions."
|
| [0]
| https://www.stsci.edu/~idash/pub/dashevsky0607rcsgso.pdf
| nerdponx wrote:
| I am mostly curious as to how they came to JS as the
| embedded scripting language of choice, as opposed to Lua
| or Scheme or anything else.
| writeslowly wrote:
| It would have had to be an interpreter that was available
| off the shelf when this was being designed (so late 90s
| or early 2000s?) that ran on vxWorks on an old PowerPC
| processor. That could have limited the available choices.
| bumby wrote:
| "They" is likely the contractor. It may be simply a
| choice that allowed them to be lowest bidder
| grumpyprole wrote:
| I'd like to understand how such a pinnacle of human design
| and engineering came to depend on a technology that is,
| putting it politely, certainly not.
| beebmam wrote:
| The fact that a project as profoundly important as the
| James Webb telescope only has a $11 Billion budget is
| staggering to me.
| nickff wrote:
| Well, it started off with a $0.5 BB budget, and was
| supposed to be launched about 14 years ago...
| BatFastard wrote:
| It had a 1.5 billion budget, 9.5 billion in overruns.
| bumby wrote:
| Software assurance within NASA is often a low-priority if
| not just an afterthought. Many project/program managers are
| from the hardware side (e.g., mechanical, electrical, or
| industrial engineers) and don't always give the appropriate
| gravitas to software in terms of its ability to contribute
| to failures.
| wolverine876 wrote:
| What is that based on? And has NASA had many software
| failures? Their missions seem incredibly reliable,
| especially considering how far beyond the bleeding edge
| they operate.
| belter wrote:
| Sounds like somebody at NASA should contact Brent Noorda.
|
| "Nombas,Un-Incorporated" http://brent-
| noorda.com/nombas/us/index.htm
|
| He is in the critical path...
| robbiewxyz wrote:
| From that video it appears the unfolding sequence is set to
| occur prior to the insertion burn into L2.
|
| If the JWST will in fact spend almost a month in earth's orbit,
| does someone have an educated estimate on the magnitude of risk
| posed by space junk to nominal deployment?
|
| Looking at those solar shields I imagine that they could be
| destroyed entirely by even the smallest of debris fragments.
| Same with the mirrors.
|
| Edit: I'm wrong here (thanks @thethirdone). The burn set to
| occur after deployment is the L2 insertion burn and not the
| transfer insertion burn. Most of deployment will occur in the
| transfer orbit en route to L2, far away from earth-orbiting
| debris.
| ProjectArcturis wrote:
| It will orbit and deploy at the point where the Earth's and
| sun's gravity cancel out, which is far beyond most anything
| else, especially space junk.
| thethirdone wrote:
| I interpreted "orbital insertion burn" to mean the
| stabilization into L2 burn. With that interpretation the
| unfolding occurs during its travel to L2 where there is
| little space debris.
| 0x0nyandesu wrote:
| Basically none cause it's outside the typical orbit
| ashika wrote:
| it's wild to me, given all the delays and complexity and risk,
| that the mission length is only 5-10 years max. but even if it
| blows up on the launchpad we've learned a ton, if only about
| the difficulty of manufacturing such devices in the 21st
| century. i am praying it does work, though, and that we get 10
| years of amazing data from it before eagerly deploying a
| replacement.
| cogman10 wrote:
| Is 10 years a hard max (like does it crash into the moon or
| something?) or is it just a projected max timeframe?
|
| I wonder that mostly because we've managed to use a lot of
| our other space equipment well past their their mission
| lengths. I'd be interested if JWST is possibly the same.
| ditn wrote:
| It's a hard limit due needing fuel to maintain its orbit.
| It's in a lagrange point
| (https://en.wikipedia.org/wiki/Lagrange_point) which
| requires occasional orbital corrections.
| edg-l wrote:
| a good video about lagrange points
| https://www.youtube.com/watch?v=Gu4vA2ztgGM
| jacoblambda wrote:
| Well it's not strictly a hard limit but it's currently
| planned to be a hard limit. If SpaceX can pull off even a
| fraction of what they claim with Starship, it's not
| unrealistic to think that it'd be financially viable to
| attempt a refuelling of the JWST.
| ditn wrote:
| That's an event I'd like to see!
| ortusdux wrote:
| IIRC, it was also not designed to be serviceable.
| terramex wrote:
| It has a docking ring for potential service mission.
| Tuna-Fish wrote:
| -ish. They have no firm plans for servicing it, but it
| does have a docking adapter and the fuel/coolant
| connections are designed to be usable in space.
|
| Basically, because there is no reasonable way to service
| something in L2, they can't really plan for it, but it's
| expensive enough that they made sure there is the
| capability if someone in the future would, say, build a
| spaceship that is orbitally refuelable and designed so it
| can take crew that far out.
| mcdonje wrote:
| Yes and no. Fuel is the limiting factor, but it could go
| beyond a decade. See here:
| https://space.stackexchange.com/questions/55309/james-
| webb-t...
| [deleted]
| captn3m0 wrote:
| The limit is propellant in the tank, which needs to be used
| for station-keeping.
|
| 5.5yr is the minimum, 10 sounds probable (stated goal),
| while 20-40yrs is the best guess with expected fuel usage.
|
| https://space.stackexchange.com/questions/55309/james-
| webb-t...
| [deleted]
| gadnuk wrote:
| Unlike Hubble, since JWST will need to be stable and
| orbiting around L2, this is cited as the reason for it
| being a finite mission:
|
| Edit after someone corrected me.
|
| Please refer to this comment:
| https://news.ycombinator.com/item?id=29490291
| jazzyjackson wrote:
| I'm sure one of our manned moon missions can swing by and
| top her off
|
| /kidding
|
| //a little
| reportingsjr wrote:
| The article you linked says absolutely nothing about the
| helium cooling medium.
|
| Three of the four imagers on the telescope are passively
| cooled and will work as long as they don't succumb to
| radiation, diffusion, etc. The fourth one (MIRI) has a
| cryocooler that uses liquid helium, but it will leak out
| very slowly and mechanical wear and electronics lifespan
| is expected to be the limiting factor there. [0, 1]
|
| As stated in other comments, the primary driver of
| lifespan is a combination of how stable the telescope
| orbit is, and the resulting amount of fuel needed to keep
| the telescope in a stable orbit. Depending on how things
| go it has enough fuel for somewhere between 5.5 and 40
| years of operation. Assuming nothing else goes wrong. :)
|
| "Webb is designed to have a mission lifetime of not less
| than 5-1/2 years after launch, with the goal of having a
| lifetime greater than 10 years." [2]
|
| 0: https://jwst.nasa.gov/content/about/innovations/cryoco
| oler.h... 1: https://www.nasa.gov/feature/jpl/how-cold-
| can-you-go-cooler-... 2:
| https://jwst.nasa.gov/content/about/faqs/faq.html
| gadnuk wrote:
| You are right. The source for my statement above is this
| link: https://www.americanscientist.org/article/jwsts-
| limiting-fac...
|
| At the end of the link is the clarification:
|
| Drs. Heng and Winn respond:
|
| As pointed out to us by Drs. Jason Kalirai and Jason
| Tumlinson at the Space Telescope Science Institute
| (STScI), as well as Mr. Sykes, our article misstated the
| reason for the finite lifetime of the upcoming James Webb
| Space Telescope. The mission duration of 5.5 to 10 years
| is not limited by the supply of liquid helium, as we
| stated. Rather, it is limited by the supply of hydrazine
| fuel needed to maintain the spacecraft's orbit.
|
| Thanks for the correction, will edit my parent reply.
| ainar-g wrote:
| The Opportunity rover had a planned mission duration of ~93
| Earth days. It went on to serve for ~5,500.
| wolverine876 wrote:
| I wonder how credulous I've been about those estimates.
| Underpromise, overdeliver is an old tool for managing
| expectations. I wonder what NASA really expects for these
| projects.
|
| (The projects are still amazing; I'm not complaining about
| the engineering or performance!)
| sophacles wrote:
| Cool videos thanks. Do you have any handy links to _why_ it
| takes 30 days to unfold everything? I assume there are good
| reasons, but I just can 't imagine what they are.
| gadnuk wrote:
| Here's another video expanding a bit more on that deployment
| sequence: https://www.youtube.com/watch?v=WY9KckPI68Y
|
| The observatory has around 7000 moving parts with complex
| structures for the primary and secondary mirrors and more
| importantly, the sunshield that would be used to keep the
| observatory instruments at a specific low temperature. It
| will take roughly 30 days for Webb to reach the start of its
| orbit at L2.
|
| At the end of 30 days, the telescope should have stabilized
| itself in an orbit around L2. But I would assume it takes
| that many days for deployment and unfolding everything
| because of the sheer number of parts and motions involved
| coupled with things like getting to L2, stabilizing orbit,
| temperature stability and all the checks for the instruments
| on board along with the mirror deployment (since it's not one
| big sheet of mirror).
|
| Here's a link which gives an idea about the logistics
| involved (along with a cool video series of the journey
| embedded): https://hackaday.com/2021/11/02/30-days-of-terror-
| the-logist...
|
| To fathom how complex the sunshield deployment is (and that's
| just a part of the whole sequence), from the link above:
|
| "Full deployment of the sunshield is without a doubt the
| sketchiest part of the whole process. The sunshield consists
| of five separate metalized Kapton sheets, each the size of
| three tennis courts. Each one must be unrolled, extended to
| its full size, tightened, and spaced out vertically for the
| sunshield to do its job. This takes the coordinated action of
| 140 release mechanisms, 70 hinges, eight deployment motors,
| about 400 pullies, and nearly 400 meters of cable to
| accomplish, not to mention the sensors, wiring harnesses, and
| computers to control everything. It'll take the better part
| of two days to complete the sunshield deployment."
|
| The whole thing is just insane.
|
| From this talk by Dr. John Mather:
| https://www.youtube.com/watch?v=2RLGx_wgyAw
|
| Around 1:47 you can see the number of people involved. 3
| space agencies (ESA, NASA, CSA), over 3000 engineers and
| technicians and 100 scientists worldwide.
| sophacles wrote:
| Woah - this thing is really freaking cool. Thanks for all
| this info - I feel equipped to go on a long "nerd out"
| after work today.
| spaetzleesser wrote:
| I think there is a lot of testing done after each step. It
| also may have to do with the cooling.
| cogman10 wrote:
| AFAIK, the equipment is super sensitive as well. They
| likely don't want to proceed to the next stage until they
| are absolutely sure the previous stage happened
| successfully, otherwise they'll risk damaging things which
| will hose the whole mission.
| konschubert wrote:
| I guess every time after you unfold a thing, you want to
| check it behaves as expected and keeps behaving as expected
| before you unfold the next thing.
| smarx007 wrote:
| I think most critical phases you'd want to happen when the
| satellite is in direct contact with the ground stations (they
| probably make extensive use of relay satellites to maximize
| windows of telemetry/payload data transmission, but here we
| are talking about issuing critical command sequences). Those
| windows are not 8 hours long. Further, it apparently takes
| almost 30 days to travel to the L2 Lagrange point and not all
| systems deploy until then.
|
| Edit: nope, I was wrong, it's going to deploy a whole range
| of systems while on the way to the L2.
| https://youtu.be/RzGLKQ7_KZQ
| whiteboardr wrote:
| Here's hoping that "incident" a couple weeks ago will be the only
| one and everything will work out just fine.
|
| This launch and perspective for science has me anxious and
| excited since its inception - and it's been a while.
|
| I will open a bottle of champagne when the first data will be
| sent from L2 with something along the "fully operational" lines.
|
| Godspeed.
| AustinDev wrote:
| I have an acquaintance that's been working on the team for this
| telescope for as long as I've known him ~10 years. He's had so
| many disappointments with the continued delays and issues. I
| hope for his sanity and his research this launch goes
| flawlessly.
| cheschire wrote:
| If someone ever wanted to understand what a space force might
| provide, consider what happens when someone wants to use one of
| the lagrange points for their own purpose, and it's currently
| occupied by someone they don't like.
|
| There's more to what any military force brings, obviously, both
| positive and negative. It's just sometimes when discussing the
| purpose of a military with others, the concept seems a little too
| fuzzy because most resources seem broadly available enough that
| they could easily be shared from a laypersons perspective.
| Lagrange points are very finite.
|
| edit: apparently the area contained within a lagrange point is
| larger than I expected. Negates my point.
| jakeinspace wrote:
| You don't need to reach the exact Lagrange point and reduce
| your velocity relative to it to 0. James Webb will be orbiting
| the Sun-Earth L2 with an apogee of nearly a million miles.
| There is a ridiculous amount of room for craft to orbit L2,
| just like there is to orbit Earth (beyond LEO).
| bdcp wrote:
| Also there are other satellites at L2 already.
|
| https://en.wikipedia.org/wiki/List_of_objects_at_Lagrange_po.
| ..
|
| It's really a none issue
| pohl wrote:
| How would a space force take possession of a lagrage point,
| though, without creating a permanent field of dangerous debris?
| [deleted]
| simcop2387 wrote:
| Only reasonable way at the moment would be some kind of
| satellite capture system that nobody has publicly
| demonstrated.
| m4rtink wrote:
| AFAIK Lagrange points are not fully stable, so any debris
| cloud will likely disperse into the Solar orbit, which is
| kinda big.
| cgriswald wrote:
| None of the ideas in the sibling comments (to my post) will
| work, because they ignore the fact that enemies will employ
| counter-measures which may cause debris to be formed. In the
| extreme case, a nation's military may decide to deny the area
| to anyone rather than lose their own access, intentionally
| creating such a debris field.
| xyzzyz wrote:
| Rendezvous, attach booster, and deorbit, or just fly away?
| ziotom78 wrote:
| You make it look as if one should stay _exactly_ on the
| Lagrangean point to appreciate its benefits.
|
| The reality is that spacecrafts fly on very large orbits around
| these points: the Planck spacecraft followed a 400,000 km-wide
| orbit [1] around the Sun-Earth L2 point, and this is the same
| for many other spacecrafts that have flown around that place.
|
| 400,000 km is ~30 times larger than the Earth's diameter.
| Unless somebody has nasty intentions like e.g. purposefully
| crashing their own spacecraft against some other, there is no
| reason to be worried. There is more space around these points
| than here on Earth.
|
| [1] https://sci.esa.int/web/planck/-/34728-orbit-navigation
| WaxProlix wrote:
| I don't think there's much ambiguity around a military's
| utility in forcefully enclosing the commons, or claiming
| extranational resources at gunpoint. I suspect people who are
| leery of a 'Space Force' have other reasons to feel that way.
| And I'd hope there are other ways of managing the sharing of
| things like Lagrange points than outright violence (though I
| suppose some body must have the capability to employ force or
| else any agreements made would be easily violated, yadda
| yadda).
| cgriswald wrote:
| The United States Air Force started off as a division of the
| United States Army Signal Corps. It didn't become its own
| branch of the military until after 40 years and two world wars.
|
| Lack of a "space force" doesn't mean lack of military
| capability in space.
| samstave wrote:
| Phil Mosby, the guy who did the Webb inspired piece that Nasa
| bought and hung in their library is from Tahoe and good friends
| with my brother... we have one of his pieces hanging in our
| living room, but whats REALLY cool is his astro-calendar (a
| calendar with a whole bunch of space facts and beautiful pics..
| Highly recommend...
|
| https://i.imgur.com/B7aA3Xw.jpg
| sahil50 wrote:
| I expect we'll see more mature galaxies in the distant universe.
|
| This is a glaring problem for the standard model (big bang LCDM)
| right now.
|
| XMM-2599, SPT0418-47, MRG-M2129, all mature galaxies, far away
| TrainedMonkey wrote:
| I wonder how much of the vehicle's final cost is directly
| attributable to the complexity of deployment. I.E. how much
| easier would this be if we had a launch vehicle with a fairing
| capable of fitting fully deployed configuration.
| bregma wrote:
| You would probably make up for the cost savings by building
| something strong enough to withstand the forces of achieving
| Earth escape velocity in a fully deployed configuration, not to
| mention all the increased mass that would be required.
|
| Since it's impossible to do maintenance on this observatory
| while it's in solar orbit, and since launches have strong
| vibrations and forces, it's important that the delicate and
| sensitive equipment be stowed in a way to minimize the effects
| of launch forces and minimizate the requirements for after-
| launch maintenance.
| pirate787 wrote:
| This is exactly the promise of SpaceX Starship.
| jltsiren wrote:
| The Starship is way too small to carry the fully deployed
| James Webb telescope. The sunshield is roughly 20 m x 14 m,
| while the diameter of the Starship is only 9 m.
| m4rtink wrote:
| Still the segments could be biggearand or heavier, possibly
| reducing complexity.
| qwertyuiop_ wrote:
| Didn't they just drop it ?
| dxxvi wrote:
| Why does anybody want to spend $11B on a telescope while it can
| solve world hunger for almost 2 years?
| dang wrote:
| " _Eschew flamebait. Avoid unrelated controversies and generic
| tangents._ "
|
| https://news.ycombinator.com/newsguidelines.html
| selectodude wrote:
| The cost of food is a small fraction of the cost of
| distribution of said food. If you think we can solve world
| hunger for $11bn/yr I have a bridge to sell you.
| TedDoesntTalk wrote:
| They are not mutually exclusive.
| pwned1 wrote:
| I'm assuming this is snark.
| sadfev wrote:
| It's not going up. ESA's incompetence makes sure that this
| telescope doesn't see the light of space.
| [deleted]
| podgaj wrote:
| I wonder how many cheap studio apartments they could build for
| $11B to house the homeless?
|
| People need to probe their hearts instead of probing the
| universe.
|
| Sorry if I spoiled your fun.
| jacoblambda wrote:
| To be entirely honest the answer is probably 0. It is cheap to
| build housing but there is absolutely no political interest in
| it. No amount of money fixes this issue because NIMBYs will do
| everything in their power to block any efforts to meaningfully
| improve housing.
| podgaj wrote:
| No need to build cheap or new housing, plenty of places to
| rent for $600 - $1000 a month. That $11B could house all the
| homeless in the US for two years.
| jacoblambda wrote:
| That doesn't matter. Landlords would under no circumstances
| accept those people as tenants for the same reasons that
| the government renting hotels for the homeless has been so
| unsuccessful in the past. Namely the perception that the
| homeless will destroy their property. This isn't
| necessarily true but all it takes is a handful of bad
| examples and suddenly landlords are sceptical at best if
| not outright refusing.
|
| Homelessness is a symptom of systemic issues, it's not the
| cause. Fixing those systemic issues will cost significantly
| more than 11B annually.
|
| Don't get me wrong, I think we should be making those a
| first priority but scientific projects are not who we
| should be targetting for poor spending. The research this
| project will do and the research that most of these space
| oriented science projects do have the potential to
| significantly shape our understanding not just of space but
| of how the world works which has direct quantifiable
| benefits for industry.
|
| If you want to pick an expenditure to be upset about
| instead, be upset about how much the US spends on the
| military. Alternatively be upset about the inefficiencies
| of the US medical system or the lack of taxes paid by large
| corporations or any of the other inefficiencies and
| failures of the US government and economic environment. Any
| of those could have their efforts redirected towards
| improving the issues that lead to homelessness and wealth
| inequality.
|
| TLDR: Scientific research on average pays back many
| multiples of the original investment and 11B isn't remotely
| close to enough to even impact the root causes of
| homelessness. Pick your battles and focus on actual
| inefficiencies in the US that are worsening the
| homelessness issue or actual opportunities to increase tax
| revenue/reuse actually corrupt/wasteful spending.
| jungturk wrote:
| Without coming off as too obtuse, is your argument that the
| best return we can expect is from investing in basic needs?
|
| Or that for any investment to be moral we must have
| satisfied more primal basic needs?
|
| What if it were the case that investment in basic research
| today alleviates a greater amount of suffering over a
| longer time horizon? What would the moral investment be?
| kortex wrote:
| As dang would say,
|
| > "Eschew flamebait. Avoid unrelated controversies and generic
| tangents."
| SonicScrub wrote:
| The US Federal Government spends ~1 Trillion dollars on various
| welfare programs per year. The James Web Space telescope
| program has costed $11B over 25 years. Or roughly ~0.04% of the
| total amount spent on poverty elimination / management programs
| in the same period. The argument that "space-exploration is too
| expensive, we should eliminate poverty instead" is pure
| nonsense when comparing the scales of the resources applied to
| those two issues. I fail to see how increasing welfare spending
| by 0.04% at the expense of the James Webb program would be in
| any way beneficial.
|
| [1]
| https://www.budget.senate.gov/imo/media/doc/CRS%20Report%20-...
| aaaaaaaaaaab wrote:
| It will be the most expensive fireworks if it explodes on the
| launchpad.
| sadfev wrote:
| This is a perpetually failed project waste tax payer money on
| incompetent scientists and engineers.
|
| #NotAScienceEquipment #wontlaunch
| marricks wrote:
| I'd much rather my tax dollars be spent on 11B failed
| telescopes than failed trillion dollar fighter jets. Or really
| most other defense project to be honest.
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