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.
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.
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.)
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.
"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?
"...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."
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.
Thank you so much for both of those links. Absolutely fascinating - especially the Smarter Every Day channel which I wasn’t aware of. Excited to watch more of it.
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.
$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 $11 billion over 25 years. Something that many nations could afford.
While true, its also a huge problem when contractors promise something for 2B$ 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.
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.
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?
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
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.
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.
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.
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...
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.
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."
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?
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.
The CMB shows the universe at the point where its density became low enough that photons could move around freely. That's the furthest point that we can "see" if you required "seeing" to have to do with electromagnetic radiation.
But there are other types of radiation that penetrate dense matter better: neutrinos and gravity waves. Right now it's "holy shit I saw one" for both kinds, so we're a long way off from doing any kind of imaging in those media. But if we ever manage detectors large enough and sensitive enough, we should be able to take "pictures" of the universe when it was even younger than when the CMB was released.
Dense enough matter will stop neutrinos, so that signal will be further back, but not the bang itself. So far as we know, nothing stops gravity--so that signal ought to be... interesting.
(Or at least, that's what Lee Smolin says in his book: Time Reborn)
Shout out to the good folks of Delta, Utah, some of whom work in the Beryllium mines nearby. My car broke down there once and I learned that Beryllium is a vital component in the JWST because it doesn't expand or contract as the sun warms it.
I also learned that I actually broke down inside another telescope:
The Telescope Array project is a collaboration between universities and institutions in the United States, Japan, Korea, Russia, and Belgium. The experiment is designed to observe air showers induced by cosmic rays with extremely high energy. It does this using a combination of ground array and air-fluorescence techniques...The Telescope Array observes cosmic rays with energies greater than 1018eV. The surface array samples events over 300 square miles of desert.
I'm a big fan of prediction markets, where people wager their own money on clear yes/no propositions, and you get a payoff if you buy shares on the winning side. It's a great way to tap the "wisdom of the crowd," even if you don't put up your own money.
Which brings me to the JWST. I'd love to know how likely it is that this amazing (and amazingly complex) tool actually succeeds in its goals. There's no way I could figure it out myself; I'd have to take someone else's word for it. Unless... there is a prediction market somewhere betting on whether the JWST will succeed, so I can piggyback on others' research and self-interest. I haven't been able to find one though. (Perhaps people think betting "against" success is too macabre.)
Anyone want to throw out a likelihood of success? (My WAG: 70%.)
I hope if Webb will be successfully operating, we'll get significant progress in the question of the life origin. Abiogenesis is predetermined and common.
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?
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?
That article is from 2007 but it still had the docking ring as of 2013. Can't find any recent ones that confirm if it will still have the docking ring at launch.
But I don't think we have the capability as of now to actually service it in case something goes wrong. But given how technology is advancing, maybe we can when JWST reaches EOL in 10 years.
I've honestly not been as excited (in astronomy-terms I mean :D) about science as I am about the James Webb telescope. I can't wait to see what it shows
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.
[+] [-] gadnuk|4 years ago|reply
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|4 years ago|reply
$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.
[+] [-] ashika|4 years ago|reply
[+] [-] inglor_cz|4 years ago|reply
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.)
[+] [-] robbiewxyz|4 years ago|reply
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.
[+] [-] belter|4 years ago|reply
"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...
[+] [-] sophacles|4 years ago|reply
[+] [-] chasd00|4 years ago|reply
[+] [-] peter303|4 years ago|reply
The shuttle was decommissioned after the primary Webb design was done. What would have known the launch options at the time it was ready?
[+] [-] callumprentice|4 years ago|reply
[+] [-] gvv|4 years ago|reply
[+] [-] cogman10|4 years ago|reply
So, roughly $11 billion over 25 years. Something that many nations could afford.
[+] [-] panick21_|4 years ago|reply
There is a reason recently NASA has started to focus on Fixed Price contracts.
We need a shift to more missions, building these things more often and more on price. Putting absurd amount of money into 1 mission compared to 20 missions for 500M$ likely doesn't make sense.
The Webb telescope has been so long in development that lots of subsystems could have evolved considerably since then.
[+] [-] justajot|4 years ago|reply
https://en.wikipedia.org/wiki/Military_budget_of_the_United_...
[+] [-] bregma|4 years ago|reply
[+] [-] systemvoltage|4 years ago|reply
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?
[+] [-] deltree7|4 years ago|reply
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
[+] [-] whiteboardr|4 years ago|reply
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|4 years ago|reply
[+] [-] TrainedMonkey|4 years ago|reply
[+] [-] bregma|4 years ago|reply
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|4 years ago|reply
[+] [-] samstave|4 years ago|reply
https://i.imgur.com/B7aA3Xw.jpg
[+] [-] digitcatphd|4 years ago|reply
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|4 years ago|reply
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."
[+] [-] panick21_|4 years ago|reply
[+] [-] cryptoz|4 years ago|reply
[+] [-] gadnuk|4 years ago|reply
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.
[+] [-] __MatrixMan__|4 years ago|reply
But there are other types of radiation that penetrate dense matter better: neutrinos and gravity waves. Right now it's "holy shit I saw one" for both kinds, so we're a long way off from doing any kind of imaging in those media. But if we ever manage detectors large enough and sensitive enough, we should be able to take "pictures" of the universe when it was even younger than when the CMB was released.
Dense enough matter will stop neutrinos, so that signal will be further back, but not the bang itself. So far as we know, nothing stops gravity--so that signal ought to be... interesting.
(Or at least, that's what Lee Smolin says in his book: Time Reborn)
[+] [-] mwattsun|4 years ago|reply
Digging Beryllium for James Webb
https://earthobservatory.nasa.gov/images/148574/digging-bery...
I also learned that I actually broke down inside another telescope:
The Telescope Array project is a collaboration between universities and institutions in the United States, Japan, Korea, Russia, and Belgium. The experiment is designed to observe air showers induced by cosmic rays with extremely high energy. It does this using a combination of ground array and air-fluorescence techniques...The Telescope Array observes cosmic rays with energies greater than 1018eV. The surface array samples events over 300 square miles of desert.
http://www.telescopearray.org/
[+] [-] dtgriscom|4 years ago|reply
Which brings me to the JWST. I'd love to know how likely it is that this amazing (and amazingly complex) tool actually succeeds in its goals. There's no way I could figure it out myself; I'd have to take someone else's word for it. Unless... there is a prediction market somewhere betting on whether the JWST will succeed, so I can piggyback on others' research and self-interest. I haven't been able to find one though. (Perhaps people think betting "against" success is too macabre.)
Anyone want to throw out a likelihood of success? (My WAG: 70%.)
[+] [-] unknown|4 years ago|reply
[deleted]
[+] [-] novaRom|4 years ago|reply
[+] [-] josho|4 years ago|reply
[+] [-] 1970-01-01|4 years ago|reply
JWST has been estimated to be 800% - 2000% over budget.
James Webb was also director for the Office of Management and Budget, 1946 – 1949.
[+] [-] FiberBundle|4 years ago|reply
[+] [-] gadnuk|4 years ago|reply
https://www.space.com/3833-nasa-adds-docking-capability-spac...
That article is from 2007 but it still had the docking ring as of 2013. Can't find any recent ones that confirm if it will still have the docking ring at launch.
But I don't think we have the capability as of now to actually service it in case something goes wrong. But given how technology is advancing, maybe we can when JWST reaches EOL in 10 years.
[+] [-] nend|4 years ago|reply
I was surprised to find out, 5-10 years. I was expecting longer.
[+] [-] jordanpg|4 years ago|reply
Those famous Hubble pictures are the defining images of a generation of scientists and dreamers. Are we about to get an update of those?
Or is this mission about the data?
[+] [-] ItsBob|4 years ago|reply
[+] [-] chasil|4 years ago|reply
https://www.cam.ac.uk/research/news/colour-changing-magnifyi...
[+] [-] malfist|4 years ago|reply
[+] [-] aaaaaaaaaaab|4 years ago|reply
[+] [-] qwertyuiop_|4 years ago|reply
[+] [-] chana_masala|4 years ago|reply