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Totally naive question here - can all this not be done automatically? It seems to me as if this is a largely manual process, and that's why it's going to take 3

Totally naive question here - can all this not be done automatically? It seems to me as if this is a largely manual process, and that's why it's going to take 3 months, no?

dylan604 5y ago
if you automated it, then what are all of these people going to do? all you automation people wanting to take away the jobs of all these people! this is why unions exist! ;-)
- BurningFrog 5y ago
  That may be overly cynical. But what I always think when a NASA control room erupts in joy after a landing, is that those people just learned they have a job for years.
  - mikepurvis 5y ago
    I don't think that's really the case, is it? Usually there's a handoff between the flight/EDL team and the surface operations team.
    - BurningFrog 5y ago
      That sounds like it's probably true. I have to make an orderly retreat to my next cynical line: everyone in that room is aware that their reaction wis filmed and will be shown across the world.
      - dylan604 5y ago
        You're just a right fun chap, aren't you? Your team spent years researching something that had never been done before. Survived many rounds of "should we just cancel this project", continued to be funded after coming in no where near your proposed budget, delay after delay, to finally see the thing lift off. You wouldn't have the slightest bit of non-robotic emotion for yourself and fellow team members? Hope I never have to work with someone as dull as that.
        BurningFrog 5y ago
        My guess is this conversation doesn't show either of us at our most charming best. Cheers!
  - dylan604 5y ago
    >That may be overly cynical. If you're a developer that has automated something that does something faster/cheaper/more accurately than a person and haven't had this thrown at you, then you're missing out! It's like a rite of passage. No cynicism intended. Hence the ;-)
bluquark 5y ago
It has to be for the same reason that creating a one-off prototype of a new plastic widget involves a much more manual process than a scaled-up assembly line. This is the first time this process will be performed on a real James Webb in space, and between each calibration step, they'll need to verify the results are as modeled in theory and adjust or reiterate if not.
- deleted 5y ago
  [deleted]
iam-TJ 5y ago
Generally automation is applied to repetitive procedures with well understood bounds. In this case all but the fine-phasing and possibly FOV alignment are one-off operations during commissioning. The pre-launch simulations may not match the actual behaviour and results of the telescope so it makes sense to perform each step under engineer/scientist control and be able to spend time studying the data and possibly improving the process along the way and revisiting earlier steps and/or segments.
jvanderbot 5y ago
I guess you imagine the control room is joy-sticking / flipping each individual switch? The processes are automatically executed, but are check-pointed rather than run end-to-end. This is to make sure partial failures can be detected. Building the self-sensing and error-recovery logic to support a "level 5" automated unfolding is wasteful of taxpayer money when a few folks can just take a little longer to do it stepwise -- with much less development, hardware, and software cost overall.
- thunderrabbit 5y ago
  > Building the self-sensing and error-recovery logic to support a "level 5" automated unfolding is wasteful Very true, especially if they tried to do all that the first time. In a way, this stepwise deployment is a test run for a future version that can do it a little bit more automated.
  - willis936 5y ago
    I've worked on a bespoke science experiment not too dissimilar to JWST (though much cheaper). These types of machines never resemble anything like mass produced parts. All of the tooling is custom made for one shot. The next machine will be the same story. What we take forward to the next machine are the lessons learned and technology developed.
Animats 5y ago
The Keck telescope, which is a ground-based telescope with 36 actively aligned mirrors, is aligned automatically twice a second.[1] The original control system used a VAXstation II, but they've probably upgrade by now. The Keck has a tougher alignment problem - gravity warps the mirrors as the telescope is pointed, so they're constantly making corrections. The Webb telescope is 10 light-seconds out, so manual adjustment will be really slow. NASA is being very cautious. It can't be serviced, and the US will probably never launch another one. [1] https://www.osti.gov/biblio/6240189-alignment-calibration-keck-telescope-segmented-primary-mirror https://www.osti.gov/biblio/6240189-alignment-calibration-ke...
- dtgriscom 5y ago
  Clarification; 5 light seconds from Earth, but 10 light second round-trip.
pengaru 5y ago
Pretty sure I read this phase takes so long because the initial alignment is done using the same extremely precise, slow-moving actuators as are used for focusing observations, on a per-mirror basis. It's not because it's a manual process, it's because they opted for simplicity in the actuators department rather than having another coarse+fast mode in the physical mechanism, or redundant mechanisms.
sbierwagen 5y ago
I would guess it's semiautomatic-- lots of humans squinting at interference patterns, guessing at an adjustment, then waiting 24 hours to get data back. Also note that JWST still hasn't cooled down to temp yet! Temps here: https://www.jwst.nasa.gov/content/webbLaunch/whereIsWebb.html https://www.jwst.nasa.gov/content/webbLaunch/whereIsWebb.htm... Mirror is supposed to be at ~50K, and it isn't there yet. (And the instruments are still at 100K+, a month after the sunshield deployed, and you sure aren't doing anything until the actual cameras are cold!) Every time you run an alignment motor you heat up a mirror segment a little bit, so you do want to run coarse alignment early, then gradually converge on fine alignment as the whole structure approaches design temp. Remember, JWST is weird. Hubble was one big piece of (warm) glass. Multisegment telescopes down on Earth can be nailed to a hundred ton support structure, but JWST is comparatively big and floppy, since the frame had to be light enough to launch into space. (Every kilogram of mirror support structure is another kilogram of propellant lost, and once all the fuel is gone you don't have an observatory anymore...) Something like that is just going to inherently take a while to calibrate.
- stavros 5y ago
  Wait, how is it still warm? I guess vacuum is a much better insulator than I thought, does it just take way too long to radiate heat?
  - citizenpaul 5y ago
    The vaccume of space us too hot for the jwt. It actualky has a cooling system to get it colder than space is. I guess it takes time to get that cold.
    - stavros 5y ago
      Oh huh, really? That's very interesting, thanks.
    - adhesive_wombat 5y ago
      The temperature of deep space is 2.7K due to the cosmic microwave background. JWST's cold side is going to be about 40K, so it's substantially warmer than that. I'm not sure how much of that heat is coming through the sunshield and how much is heat from the equipment.

Totally naive question here - can all this not be done automatically? It seems to me as if this is a largely manual process, and that's why it's going to take 3 months, no?

dylan604 5y ago

if you automated it, then what are all of these people going to do? all you automation people wanting to take away the jobs of all these people! this is why unions exist! ;-)

BurningFrog 5y ago
That may be overly cynical. But what I always think when a NASA control room erupts in joy after a landing, is that those people just learned they have a job for years.
- mikepurvis 5y ago
  I don't think that's really the case, is it? Usually there's a handoff between the flight/EDL team and the surface operations team.
  - BurningFrog 5y ago
    That sounds like it's probably true. I have to make an orderly retreat to my next cynical line: everyone in that room is aware that their reaction wis filmed and will be shown across the world.
    - dylan604 5y ago
      You're just a right fun chap, aren't you? Your team spent years researching something that had never been done before. Survived many rounds of "should we just cancel this project", continued to be funded after coming in no where near your proposed budget, delay after delay, to finally see the thing lift off. You wouldn't have the slightest bit of non-robotic emotion for yourself and fellow team members? Hope I never have to work with someone as dull as that.
      - BurningFrog 5y ago
        My guess is this conversation doesn't show either of us at our most charming best. Cheers!
- dylan604 5y ago
  >That may be overly cynical. If you're a developer that has automated something that does something faster/cheaper/more accurately than a person and haven't had this thrown at you, then you're missing out! It's like a rite of passage. No cynicism intended. Hence the ;-)

bluquark 5y ago

It has to be for the same reason that creating a one-off prototype of a new plastic widget involves a much more manual process than a scaled-up assembly line. This is the first time this process will be performed on a real James Webb in space, and between each calibration step, they'll need to verify the results are as modeled in theory and adjust or reiterate if not.

deleted 5y ago
[deleted]

iam-TJ 5y ago

Generally automation is applied to repetitive procedures with well understood bounds. In this case all but the fine-phasing and possibly FOV alignment are one-off operations during commissioning. The pre-launch simulations may not match the actual behaviour and results of the telescope so it makes sense to perform each step under engineer/scientist control and be able to spend time studying the data and possibly improving the process along the way and revisiting earlier steps and/or segments.

jvanderbot 5y ago

I guess you imagine the control room is joy-sticking / flipping each individual switch? The processes are automatically executed, but are check-pointed rather than run end-to-end. This is to make sure partial failures can be detected. Building the self-sensing and error-recovery logic to support a "level 5" automated unfolding is wasteful of taxpayer money when a few folks can just take a little longer to do it stepwise -- with much less development, hardware, and software cost overall.

thunderrabbit 5y ago
> Building the self-sensing and error-recovery logic to support a "level 5" automated unfolding is wasteful Very true, especially if they tried to do all that the first time. In a way, this stepwise deployment is a test run for a future version that can do it a little bit more automated.
- willis936 5y ago
  I've worked on a bespoke science experiment not too dissimilar to JWST (though much cheaper). These types of machines never resemble anything like mass produced parts. All of the tooling is custom made for one shot. The next machine will be the same story. What we take forward to the next machine are the lessons learned and technology developed.

Animats 5y ago

The Keck telescope, which is a ground-based telescope with 36 actively aligned mirrors, is aligned automatically twice a second.[1] The original control system used a VAXstation II, but they've probably upgrade by now. The Keck has a tougher alignment problem - gravity warps the mirrors as the telescope is pointed, so they're constantly making corrections. The Webb telescope is 10 light-seconds out, so manual adjustment will be really slow. NASA is being very cautious. It can't be serviced, and the US will probably never launch another one. [1] https://www.osti.gov/biblio/6240189-alignment-calibration-keck-telescope-segmented-primary-mirror https://www.osti.gov/biblio/6240189-alignment-calibration-ke...

dtgriscom 5y ago
Clarification; 5 light seconds from Earth, but 10 light second round-trip.

pengaru 5y ago

Pretty sure I read this phase takes so long because the initial alignment is done using the same extremely precise, slow-moving actuators as are used for focusing observations, on a per-mirror basis. It's not because it's a manual process, it's because they opted for simplicity in the actuators department rather than having another coarse+fast mode in the physical mechanism, or redundant mechanisms.

sbierwagen 5y ago

I would guess it's semiautomatic-- lots of humans squinting at interference patterns, guessing at an adjustment, then waiting 24 hours to get data back. Also note that JWST still hasn't cooled down to temp yet! Temps here: https://www.jwst.nasa.gov/content/webbLaunch/whereIsWebb.html https://www.jwst.nasa.gov/content/webbLaunch/whereIsWebb.htm... Mirror is supposed to be at ~50K, and it isn't there yet. (And the instruments are still at 100K+, a month after the sunshield deployed, and you sure aren't doing anything until the actual cameras are cold!) Every time you run an alignment motor you heat up a mirror segment a little bit, so you do want to run coarse alignment early, then gradually converge on fine alignment as the whole structure approaches design temp. Remember, JWST is weird. Hubble was one big piece of (warm) glass. Multisegment telescopes down on Earth can be nailed to a hundred ton support structure, but JWST is comparatively big and floppy, since the frame had to be light enough to launch into space. (Every kilogram of mirror support structure is another kilogram of propellant lost, and once all the fuel is gone you don't have an observatory anymore...) Something like that is just going to inherently take a while to calibrate.

stavros 5y ago
Wait, how is it still warm? I guess vacuum is a much better insulator than I thought, does it just take way too long to radiate heat?
- citizenpaul 5y ago
  The vaccume of space us too hot for the jwt. It actualky has a cooling system to get it colder than space is. I guess it takes time to get that cold.
  - stavros 5y ago
    Oh huh, really? That's very interesting, thanks.
  - adhesive_wombat 5y ago
    The temperature of deep space is 2.7K due to the cosmic microwave background. JWST's cold side is going to be about 40K, so it's substantially warmer than that. I'm not sure how much of that heat is coming through the sunshield and how much is heat from the equipment.