There's a Problem with Webb's MIRI Instrument
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- Опубліковано 1 чер 2024
- There is a problem with Webb's MIRI Instrument. The Mid-Infrared Instrument (MIRI) aboard the James Webb Space Telescope appears to have had an anomaly where one of its Dichroic/Grating wheels reported excessive friction.
00:00 Introduction
01:01 Severity of the Anomaly
02:24 How MIRI Works
03:50 The part on MIRI that is stuck
05:44 Thank you Patrons (and Leo interrupts)
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Erratum: I misspelled "dichroic" as "dichoric". That's what I get for not double checking :(
You're human. We love your work! That's all there is to it. ❤️😎
Well, I was just about to mention that!
Not everywhere though, so no big deal ;)
Could have blamed the cat.
It's good to know a bit of greek (and latin) when you work with science. It's the same "chromos" as in "monochrome", "chromosphere" and... Chrome. Di-chroic - double-coloured.
Good to hear from someone with experience in this area. The first thing that came to my mind was the CME's suspected of causing reaction wheel failures in other spacecraft. Time will tell.
I forgot about that! There's been some big ones recently, too. I'll have to check if they went L2's way...
Yeah, I was also thinking about the issues some mission's reaction wheels had. But, its so early in JWST's lifetime.
nah, when china manufacturers opened back up, everyone and their dogs got defective junk
@@MrPaxio looool. You can get good parts from china and bad parts from china. What your referring to is the lack of quality control. This isn't a Chinese specific issue my man. Not sure how everyone can quite grasp that.
And recently supply in a lot of industries is outpaced by demand so there's more pressure to do less rigorous QC to try and produce enough to make demand.
Oh no! Watching now....
Ok, bummer there is a problem, but that was perfectly presented in my opinion. Short, sweet, to the point and how adamant you are about, it's a problem, there is a process, let's just give them time and we will tackle it one step at a time. 👍🤓
I really hope it is fixable problem .
We came to become so attached to this wonderful machine and excited with its potential.
Thank you for a direct, clear, and dispassionate explanation of what hopefully is a glitch that will be corrected and learned from.
I can't begin the imagine the level of reasoning and engineering that requires the light to bounce around so many times within MIRI. Christian, you're great at explaining complex things, maybe you can do a video about why the light reflects off so many mirrors in MIRI.
Check out the company ASML which makes the advanced lithography instruments in the world based in the Netherlands. Now they are doing ultraviolet lithography. The do the same complex rerouting of light in their instruments.
I'll give it a shot - but I will ignore the very large number of flat mirrors which are used to fold a very long optical path (which gives high magnification and fine detail) into a compact instrument.
0:31
The input beam from the telescope is fed into the MIRI instrument and most of it is directed into the imager.
0:36
A group of curved and flat mirrors changes the f/number of the beam from the telescope to match the requirements of the medium-resolution spectrograph (MRS).
0:38
A tilted flat mirror diverts the beam into the spectrograph. A small image of the primary mirror is formed on the flat mirror (eighteen hexagons and one missing in the middle). Where the missing hexagon would be there is a hole and this is used (as needed) to introduce a uniform light through the entire spectrograph for calibration. Rather than keep switching the calibration light on and off (which would eventually burn out the filament) it is kept running and a tilting mirror directs the beam through the hole. This is one of only three mechanisms in the MRS. When the calibration light is not needed it is directed into one of the many light traps in the MRS. They are not all shown in this animation - it's already cluttered enough ...
0:40
The incoming light is split into four channels by wavelength. Sets of three filters reflect selectively longer wavelengths. The filters are carried on two rotatable drums which allow different parts of the wavelength range to be examined. Three consecutive observations are needed to cover the whole wavelength range.
0:48
An image of the sky (in a specific wavelength range) is produced on the image slicing mirror. This is a crucial feature of the MRS - it slices the image of the sky into short strips and then
0:51
projects them as a single long strip which is equivalent to the slit at the entrance of a conventional spectrograph. In this way, a larger object ( a nebula, say ) can be analysed in a single observation and best use is made both of detector real estate and available observing time.
0:57
The four channels of sliced, stacked light are then re-imaged (again as the image on the primary mirror) onto diffraction gratings which spread out the light to form a spectrum. The diffraction grating is a flat mirror which has very fine grooves cut into it - it acts in much the same way as the pits in a CD can form a spectrum. The gratings are mounted on the underside of double-ended motors which also rotate the dichroic barrels. In this way, the dichroics and gratings can never get out of synch with each other.
1:06
For each channel, a set of three curved mirrors then produces an image of the spectrum on the detector array. There are only two detectors so the images from two channels are aligned side by side on a single detector array. The detectors are 1024 x 1024 arrays of Arsenic-doped Silicon pixels, each of which is 25 micrometres square.
Not near as complicated but just look at a modern camera lens, I'm an amateur Wildlife Photographer and when I see a blueprint of some of my lenses it makes me wonder how they focus correctly much less last for many years..Some of them will have 20+ elements ( groups of glass ) in them that all have a specific job like correcting for sharpness and chromatic aberrations etc etc...And like I said earlier they do it flawlessly for years in sub zero conditions to extreme heat and humidity..
Humans have made some amazing things. It's a shame we can't figure out how to keep from putting bullets in each other to resolve a conflict...And I'm not anti gun by no means I'm referring to war
I was a bit bummed to hear about MIRI having an issue but the cat made me feel a lot better 😁
Best of luck, to the command team!
JWST is amazing!
Hello Mr. Ready, i'm Simon from Denmark. I broke asf, so i can't donate on patreon, but i had to share my appreciation somehow. Your videos are some of my favorite astronomy videos on UA-cam.
Specially since Webb launched, you've been fast and efficient on sharing the news with the rest of us anytime something important comes up. And i appreciate it really really really much Mr Ready! :)
Please include Leo in your future videos 🙏🏾 He's adorable!
What a great explanation with awesome graphics. So well done for all of us that don't live and breath this stuff and just have a curious interest. Thanks.
Leo is the best anomaly that has ever appeared on your channel. You can show us glimpses of him any time. Hopefully every episode from now on.
Meow and happy cosmological exploration!
Awww Leo❤
He was mad I put him on camera, but he was walking on my keyboard!
judging from "dichoric" being misspelled in like 10 different places, i'm actually impressed that it means you've annotated them all yourself. i thought you're just using a pre-annotated footage from somewhere.
Another banger video. Straight to the point and amazing with the visuals and explanation. 10/10, would watch again
Thanks!
Heard about this but the other reports fell short in conveying exactly what was going on. I must thank you for this very clear and concise update. The visuals incorporating diagrams with animation were extremely helpful as well.
Great explanation, and great on not sensationalizing it for hits.
woah you worked on the hubble telescope and other spacecrafts?? that's awesome dude!!
This is so complex. Thank you for the excellent explanation.
Man that optical system is insane
Excellent channel, clear and informative, thanks for your time.
The presentation of this video is outstanding. Making very complex topics understandable!
Thank you kindly!
Fingers crossed that the control team at STScI resolves this issue soon! Thank you for this wonderful explanation.
Truly impressive machinery, even more sophisticated than the best Swiss watch. Fingers crossed this thing gets fixed and produce some good science!
Excellent graphics supporting your narrative.
Great video and explanation. Super cool to undersand how MIRI works!
Excellent,informative vid…….Cheers Christian.
Great explanation and I feel much better, ty! We have been so spoiled and charmed by Hubble and JWST, they've truly been miraculous, but at least it's not a spacecraft wide issue and I have hope from the excellent troubleshooting that has been done, say, on Hubble's last issue. And other workarounds. Even if JWST stopped today, god forbid, the new science we have is amazing. But losing MIRI would be seriously disappointing. Thinking positively!
110% w/ ya!
Totally disagree. I want my money back.
A very tractable explanation. Thank you.
Glad it helped!
This channel is so wonderful
2:43 What is described as the spectrometer is simply the intermediate deck (a glorified spacer). The MRS is faintly visible below the deck.
"Webb" and "problem" are not allowed to be in the same sentence post launch!
Nooo.. I hope they can get it figured out. It's the most important scientific instrument of our generation and maybe ever. It would be a shame for it to be a terminal issue
Life is terminal and in the future all of Webbs knowledge will be lost to the sands of time.
@@suspicionofdeceit that's a very eloquent way to put it, but what I meant was that I hope it's not going down so soon
@@suspicionofdeceit Aren't you just a ray of sunshine.
@W Never going to happen
@@ElderberryThee3rd But he is right tho.
Hopefully it can get resolved fairly quickly!
Thank you again for your clear explanations of the workings and problems with Webb’s instruments. All your videos on the topic are 10/10.
Cheers
CHRISTIAN!!!! Wow, I guess things happen. I'm confident that this will be corrected post haste, and we can can continue with science!!!
Here’s hoping!
So if worse comes to worse, they might have to pick one setting for the mid-resolution spectrometer and live with it for the next 20 years? Or they might have a limited number of opportunities to change it in the future, like the region coding on a DVD player...
Sounds like some metal on metal vacuum welding happening in the rotating parts. It might carry on working okay with gradually increasing friction, or it might seize completely, which would greatly degrade the instrument. But it should still be possible to obtain some useful spectral measurements even if locked in one position.
Hey ! You aren't just going to sneak that Stealie in the background past your fellow Heads :) Cool explanation re: the JWST issues - hope they can figure things out and implement a work-around, if necessary...
That's the main experiment, it what it's all about,we got to have the infrared, it's vital.
I sympathize with Webb. I also have occasional problems with my Mrs.
If there is some kind of mechanical problem with that rotator wheel assembly, what can actually be done about it? Does the MIRI have some way to actually move things around in an off-axis kind of way? I can see how you could maybe just keep rotating it to test the bearings, or spread lubricants and such, but I can't think of much past that.
i didnt know you had experience troubleshooting actual space hardware. you should make some cool story videos about firsthand experience doing that. i'm sure you can find something in your career Scott-Manley-style that every nerd would find exciting.
When using a bigger hammer just doesn't seem practical. It is amazing that they can "fix" something this far from earth. Hopefully they figure it out and can continue to do everything this telescope was designed to do. We all no a service call is way out at least for a few decades if ever.
Your experience with this type of work really shows; I like your easy-to-understand descriptions. I also share in your feline-induced anomalies!
Is it possible to rotate it backwards??? Maybe changing direction could help the gear ⚙️ ratio get back to a less strained position? I'm not sure. I'm curious and hope they can get this working out.
This is the most heartbreaking news for me that we are not going to see any images from MIRI.. I hope they somehow solve this problem as soon as possible.. I am depressed after hearing this... MIRI is the instrument that is winning hearts since july..
Good news then. This shouldn't affect MIRI's imaging at all. This affects only mid-resolution spectroscopy. That would be a significant loss of scientific data, but the pretty pictures will continue unimpeded.
@@mal2ksc
A picture is worth a thousand words but a spectrum is worth a thousand pictures.
Actually it's 1024 - but who's counting.
Very worrying news. Miri is among the most important instrument. Thanks for the indepth explanation. I do not understand why they let JWST make pictures of Mars or Jupiter instead doing the much more important ultra deep field astronomy, looking for the first galaxies and stars, planets after the big bang.(as they promised JWST would do)
The most stunning thing about the JWST to me is how NASA made no plan for repairs that can't be done remotely, especially after the experience with the Hubble telescope. I less than a year we have lost a mirror and now potentially this key function, Hubble has had 5 repair and enhancement missions in the time it has been in space.
I’m sure they thought about it a lot but remember everything costs weight and that reduces possible performance elsewhere. It might not be at all practical to make it “repairable” remotely
@@mduckernz -- I was not pushing the remote-repair as the issue, the issue is we don't have a way to send people to repair or upgrade it, so if anything happens that we can't repair remotely then we are stuck and could end up with a 10 billion dollar rock.
With starship launch capability, a reasonable cost unmanned repair/upgrade mission to JWST will be possible in 2 or 3 years.
Wow, I didn't know worked on hubble. I'd love to hear more about that.
The JWST will one day have a major break - just like happened with the Hubble several times. Plans should start being made ASAP to use a SpaceX Starship for a rescue mission. It will be the only option available.
Unfortunately, JWST lacks the provisions for being serviced in space. Hubble has handles and easily accessible fasteners to make the job a lot more practical. I use the present tense because it's still technically possible to perform more servicing missions on Hubble, so long as a vehicle exists to get there -- like Starship, perhaps. And since we don't have another comparable optical band telescope in orbit, we really should be looking to keep Hubble going as long as possible.
In other words, it won't work for Webb, but it might still work for another Hubble service.
Hi Leo!
Thanks Christian for the update. I hope Nasa sorts this little anomaly soon.. If i am not mistaken some these instruments do overlap.👍🤞❤
Lets hope Webb is still under warranty! ;)
...Seriously though, hopefully they can get it fixed remotely soon.
This doesn't sound good to me. They should probably settle on a useful data window, say the middle band, set the wheels there, and make do before it stops moving altogether. The mid-infrared is absolutely critical to deep space observations!
@@MrPaxio why bother typing ?
Keep in mind that only the spectroscopy instrument in MIRI is the issue not the imaging instrument. Also the team has a process for addressing technical issues that arise just as Hubble did. And Hubble often had issues resolved remotely.
Bit of a bummer, sounds like something that would ideally be cycling often while imaging.
I'd be really curious to know the nitty gritty details - is it sticking at a specific point in travel? How bad is it - is the actuator just drawing too much current, or is it jamming or vibrating? How is it actuated, and what do the bearings look like? Seems like a critical element of that instrument - I wonder what kind of contingency plans there are.
Same here. So far, all we have is the press release plus the already available information. I'm sure they'll reveal more info as they learn it though.
From some time I generally became curious about bearings used in space. Things like lubricants would need to work in those temperatures and vacuum (so not sure if they are even used that much).
@@ImieNazwiskoOK Yea agreed, I wouldn't be surprised if there aren't any lubricants. I would imagine there could be specialized sputtered coatings or surface treatments instead.
The extreme high and low temperatures, vibrations during launch - I couldn't imagine any kind of lubricant staying in place... they'd probably find their way all over the shop.
Awesome video mate. Good to hear about this from someone who is a professional. P.S I also have a cat that walks and/or sits on my keyboard.
sounds like nasa needs to go to home depot for a can of WD40 lol . jokes aside i hope they sort the problem out thanks for the update christian great video . cheers mate
Will it still be able to analyze exo planet atmospheres for bio signatures?
Yes.
@@LaunchPadAstronomy Thanks
Dang there is a whole light show going on in there!
Say Hi to Leo 🐈
I won’t be surprised if the rotating wheel problem has to do with damage from unanticipated electrostatic buildup and discharge. This is why rotation wheels used to control direction commonly fail.
Damn. MRS spectroscopy is pretty important stuff. Hope it gets worked out. Stuck wheels could be a ton of things.
Yup it's important and mechanical stuff tends to be hard to fix when it's 1,000,000 miles away. Hopefully it's just a setting that needs an adjustment and not a mechanical problem.
*LEO* is great, was he born in August?
Perhaps he'll visit *Low Earth Orbit* someday?
~ *GDTRFB*
He's a good guy, but he thinks he's a lion. Suffice to say, he doesn't like it when "Samson and Delilah" comes up.
Considering your extensive experience & expertise, was it you that saved Matt Damon with that adorable Hex Dancing Robot (HDR)? If so, is there any news on an even more adorable HDR+? If not, another educational video? Just subscribed. #HitThisGuyInTheLikeButton
high dynamic range
Alternate vide title: Something About Miri
Love it!
Leoooo! ❣️🐱❣️
Is there a duplicate dichroic wheel on earth to test possible fixes on?
Almost certainly there will be at least one flight-spec motor/rotor assembly and probably more than one.
I need a discussion of how a permanent loss of MIRI would impact the overall operation of James Webb. It seems like they are still getting good pictures so it's not clear how it would be limited.
one think you got wrong in this video which id like to point out... Leo didnt get in your way; it was you who was in Leo's... Hes the curious one here...
how can they cure a physical problem at a distance?
rotate the whole thing at 100 RPM and hope for the best ;)
( i dont mean the entire satellite I mean that particular instrument )
BTW I gave you a thumbs up good info
I was just about to correct you but I see your housekeeping routines are working better than JWST's.
Friggin' mechanics. Judging by previous descriptions of problem solutions, most likely is that they have an identical instrument here on earth and will try to run it through the same motions as were performed on the in-space version. I'm guessing the excess friction is coming from a back-emf or similar sensing on the motor. They can also look at the thermal sensors to get an idea of the instrument had uneven temperatures, which can lead to sticking (parts expand and contract with temp, so uneven temps is bad). The guys who do this work are very good, and I am guessing one of the prime rules is to do nothing until everyone agrees on a good theory of what is happening.
If it’s a fixable problem I have complete faith in the people working on it.
And if it's not a fixable problem, I expect they'll figure out the most useful setting to get stuck in and leave it there -- better to have the instrument stuck on one known setting than to have it get stuck with things misaligned so it can't be used at all.
why didn't they include a backup for MIRI ?, or any of the other instruments in case something like this were to happen ?
NIRCam is fully redundant, with an A and B side.
There is always a tradeoff to adding more complexity to an already complex piece of technology. And besides that your question may be premature as this issue only just happened so the team has hardly begun to problem address the matter.
Hubble had problems arise as we which were often dealt with remotely.
Learn some patience. I hear that is a virtue!!
The space available is very small; the triangular dichroic wheel is only 65mm across flats. This precludes the use of a bearing which has an inner race, one set of balls, an intermediate race (grooved on both the inner and outer surfaces), a second set of balls (with more balls) and an outer race.
Hi Christian,Now Your On My Time,lol,Welcome To My World😂Im Sad Hearing This,But If Its Not A Major Issue,Onward We Go,and Look At Possibilities For A Repair,Thank You For The Video,Ha,Ha..Leo😂❤️God Bless and Clear Skies❤️🙏🏻🔭🌏✨
Losing MRS capability on MIRI would be really bad indeed but I'm just gonna wait and see what the resolution is going to be.
I hope you get your spacebar fixed, buddy
What observations are effected by this wavelength and is there another instrument that can cover the bandwidth should this instrument fail completely
2:20
Cats just love to try and help.
next satellite telescope should have a sentient nano-robot that can do minor to major repairs?
Gosh I hope this telescope doesn't continue to experience some of the problems it's had thus far such an expensive endeavor so many of us have waited for so long it would be so tragic if it suddenly quit sending back data altogether the mission only lasted a few months keeping my fingers crossed
off topic. more cat in the videos please
Why are there so incredibly many mirrors for each sensor? What is the reason we need to bounce around the light much?
He specifically says it needs to be split for spectroscopy and the packaging is actually as compact, lightweight, and least complex that it could be.
When you have a telescope that needs different sensors and mechanism to do different types of science and the only light input for all the instrument is the secondary mirror, there has to be a way to split that light up for the needs of the differing instrumentation.
Otherwise you’d be building 4 or more telescopes to do the job of one.
He even breaks down the main science that the telescope is used for In this video.
Want to know more? Go watch other videos on his channel he explains how everything works and why.
Physics isn’t easy, at least not on the level Webb is performing.
If you’re interested check it out seriously. It’s not like they found just send a big space telescope with a single Sony cmos sensor in it and call it a day.
Send the shuttle!
It’s still under warranty, right?
Maybe upload new fixed video with dichroic
It's starting to sound like JWST is going to have a short lifespan.
Yeah, it's hard to know what a firry anomaly will do next.
Sir, make a video on, How NASA's DART mission changed the path of a asteroid.
The scray thougt is this is the beginning of many failures to cone as it is.more and more exposure to the cold deep space. Nice video for us compete novice..
Your feline friend didn't mess up your outro. He made it! (Or she, as the case may be.)
Something is wrong, the telescope shouldn't be seeing aliens everywhere...
wild guess: cold welding.
Pfffff… lets give ‘‘em sometime
This is very saddening. The MERI instrument package is what gives Webb the ability to see the furthest back in time. now its just a slightly better Hubble. I hope the wheel can be unstuck.
Wouldn't it help to have a mini robot to aid in small repairs? Not just on space telescopes but rovers too? Little micro jets, glue guns and cleaning stuff etc.
feel free to design (and build) one
Chuck Norris has already scanned the entire universe(in infrared) with his left eye.
We are everywhere.
Just rotate it backwards and go forward. Maybe some kind of sand stuck in the bearing. Let's crush it!
Roll on the ELT.
So more than likely it's stuck and I can definitely see them not attempting anything without an extremely high possibility of no further error.
If the wheel gets stuck in place impeding any further movement these sensors will be completely useless. As of now part of the censor suite is functioning and will apparently continue to function for the next 20 years.
Since we can't trust the SLS to get us to the moon in an appropriate timely manner maybe we can redirect it for a repair mission???? And is a repair mission for web even possible considering it's construction and location?