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Man, I really want this telescope to succeed its mission, but I just can't get over how complex its deployment procedure is. I am extremely pessimistic about it

Man, I really want this telescope to succeed its mission, but I just can't get over how complex its deployment procedure is. I am extremely pessimistic about it actually managing to deploy as planned.

d33 7y ago
Could you elaborate on the complexity, comparing it to other complex science projects that succeeded? I'm a layman, curious if this is actually riskier than what humanity has done so far.
- robotixonic 7y ago
  I'm a layman too, and just watched this https://youtu.be/bTxLAGchWnA https://youtu.be/bTxLAGchWnA to better understand the complexity.
- enceladus_ice 7y ago
  I think a big amount of the complexity comes from the folded up sunshield. I remember it had torn during a test deployment last year. Here is a quick animation showing the whole deployment process: https://www.youtube.com/watch?v=vpVz3UrSsE4 https://www.youtube.com/watch?v=vpVz3UrSsE4
  - nullwasamistake 7y ago
    If it tears bad it's technically possible to send up a shield that floats near the telescope. There were some plans for that way back during the design phase if I remember right. Still wouldn't be cheap or easy
    - mikepurvis 7y ago
      It looks from the renders like the telescope has solar panels, antennas, etc on the sun/earth-side of the shield. Wouldn't sending a standalone shield screw that up as it would shade them?
      - nullwasamistake 7y ago
        Probably, although you could shape the shield not to. It's still far more complex than just attaching the thing right to the telescope. And glancing starlight leaking in between the shield and the telescope could be a big problem. I looked it up, the original proposal was actually to use a mobile shield to occlude far away stars for direct planet imaging. I think a similar approach could "fix" JWT but let's hope we never get there
- bumby 7y ago
  For one, I think it has an astronomically (ha) high number of single-points-of-failure. A quick Google search reported 344.
  - mikepurvis 7y ago
    One imagines that for every single point of failure they've got some kind of plan for how to still derive scientific value while operating it in a degraded state, similar to how Hubble was able to take pictures before service mission 1 and COSTAR.
- FrojoS 7y ago
  This video explains it very well. https://www.youtube.com/watch?v=k8yRDrl76d0 https://www.youtube.com/watch?v=k8yRDrl76d0 Half way through the video, I understood why it's so expensive and risky. On the other hand, Apollo 11 had many 'firsts' that couldn't be tested before the actual mission and it worked out 'first shot'. Of course there were some problems and Apollo 13 showed that the odd's where not too good.
  - eafkuor 7y ago
    Wow, this video is mindblowing.
  - NikolaeVarius 7y ago
    Huge difference is that Apollo had highly trained human beings on board to fix things that could not be planned for. There were also 10 previous missions to Apollo 11 to work out the kinks, with one failing with loss of life. JW is not designed to be fixed or fail, nor are there training runs. It HAS to work first shot.
    - petschge 7y ago
      Regarding the 10 missions before Apollo 11: It's a little more complicated. Apollo 1 is the name that was given to honor the astronauts who died in the pad accident. Apollo 2 and 3 didn't exists. But a whole bunch of other tests did exist testing Saturn 5 before we got to the unmanned Apollo 4, 5 and 6 tests. And starting with Apollo 7 humans were included. See https://en.wikipedia.org/wiki/List_of_Apollo_missions https://en.wikipedia.org/wiki/List_of_Apollo_missions for details.
      - NikolaeVarius 7y ago
        I probably should have known this. I've read alot on Apollo, but never really internalized some of these facts.
        TheOtherHobbes 7y ago
- deleted 7y ago
  [deleted]
knd775 7y ago
And this isn't like hubble, where we could (and did) send up a space shuttle to fix an issue after launch. Really scary.
- Klathmon 7y ago
  To be a bit more specific, we can't send something up to fix this because it's magnitudes further away from the earth than Hubble is. JWT will be ~1.5 million km away from earth, in a special orbit around a spot called the "L2 Lagrange point". It's located there so that it can kind of hide in the earth's shadow at pretty much all times and keep all the nearby "bright" things behind the heat shield. For comparison, the Hubble is ~600km away from the surface orbiting the Earth, and the Moon is a little under 400,000km away from the earth. JWT will be almost 4x further away than even the moon.
  - escapecharacter 7y ago
    I mean, the giddy idiot in me just gets excited about the urgent need for a human L2 mission to fix it.
    - lostmyoldone 7y ago
      Likewise. My train of thought goes like "So what if it fails? There's a lot of money sunk into that! Well, maybe someone would actually decide it's worth going to the L2 to fix it, wouldn't that be cool!!" So yeah, not the only idiot...
      - GlenTheMachine 7y ago
        We would probably do this robotically.
        ethbro 7y ago
        "What do we do when the robotic satellite fails?" "Send another robot!"
gnu8 7y ago
I have read in other discussions that the contractor has great confidence in the deployment of the sun shield because of their experience with similar systems on classified satellites. I think as long as the launch is successful there won’t be any problems with the mission.
- CydeWeys 7y ago
  I really hope this is true, but there must still be something different, because there's been years of delay caused by the solar shade not deploying properly.
- ttul 7y ago
  Indeed. The NRO - rumor has it - has been launching satellites to observe the earth in the infrared for years..
  - petschge 7y ago
    Since you are looking at a warm planet you will never get your camera down to 7 K nor do you need to as all sources are close by and bright compared to the astronomical targets for JWST. So the shielding issue is somewhat different. Having Earth, Moon and Sun in the same direction so you can block all of them with a single heat shield is actually one of the reasons why JWST is going to the L2 Lagrange point.
- CyanBird 7y ago
  This is a good take, I like it, the US has deployed tons of spy satellites, and if they think the sail/shield+Mirrors will deploy well because they have used it in spy satellites before then I'll believe it
batbomb 7y ago
Normally they name telescopes once they are on orbit and working, because they don’t want to put a name on something and have it fail. The joke with JWST is that it’s not allowed to fail.
jvanderbot 7y ago
I have great faith in it. The "deployables" crowd knows their stuff and all eyes are on them right now.
teraflop 7y ago
That's what I thought about Curiosity's skycrane, and that ended up working out pretty well. Yes, it's complicated, but I'm willing to accept that my intuitions about whether something is too complicated are wrong when we're talking about something that actual rocket scientist have spent millions of hours planning.
- NikolaeVarius 7y ago
  I don't recall ever saying it was too complicated. I only indicated extremely complex, which it is. Millions of man hours have been lost to bad units. Rocket scientists are human.
  - warent 7y ago
    I'm not sure why you're splitting hairs on this. GP is merely addressing your "extreme pessimism" but now for whatever reason you're either arguing semantics or showing some kind of cognitive dissonance.
- falcrist 7y ago
  I can't let go of my intuition that complex deployment procedures carry an inherent additional risk to the mission. Now, maybe that additional risk is less than the risk of doing it a different way, but that just means the mission is particularly risky. That appears to be the case with the JWST in any case. Space is hard. We've failed many times. It seems rational to be concerned in this case.
  - Gravityloss 7y ago
    You can retire risk and accelerate progress by launching more smaller missions and accepting that some of them fail. The public must be enlightened enough to understand that occasional failure ia a much faster and better and even cheaper path to success.
    - petschge 7y ago
      The science done by a bunch of smaller IR telescope is different from what you can do with JWST. (Basically you are reducing resolution but get better time coverage of transients.)
neurostimulant 7y ago
For a project this magnitude, I think they should build a spare telescope or two to account for launch failures. Or is it not how the space industry operates?
- java-man 7y ago
  exactly my sentiment! why not build two, given the fact that most of the budget is likely to be R&D costs.
  - rbanffy 7y ago
    Manufacture, certification and launch are still quite expensive. You'd easily run a couple extra billions building a fleet. Having said that, I'd be delighted to have a fleet of them.
- deleted 7y ago
  [deleted]
- Rebelgecko 7y ago
  The costs don't scale quite as well as you'd expect. Actually building, testing, and transporting the thing is really expensive. If you build 2, it's still a lot of expensive bespoke parts. Maybe if you build dozens the economies of scale start to pay off
topspin 7y ago
Yes, the deployment looks like a lengthy and risky operation. But the risks don't end there. The Northrop Grumman cryocooler has been a major problem for JWST, requiring years of development and rework. If it fails then some of the most crucial instruments are useless.
- mturmon 7y ago
  This is a good comment. The deployment is eye catching, but the cryocooler was the high technical risk item.
baq 7y ago
A more complicated process has worked multiple times in orbit already, look up the Orion program and Mentor sats. https://en.m.wikipedia.org/wiki/Orion_(satellite) https://en.m.wikipedia.org/wiki/Orion_(satellite)
kpU8efre7r 7y ago
I'm incredibly nervous as well. If a second telescope had to be built for whatever reason would it take as long and cost as much as the first? Or is all the cost and time due to R+D?

d33 7y ago

Could you elaborate on the complexity, comparing it to other complex science projects that succeeded? I'm a layman, curious if this is actually riskier than what humanity has done so far.

robotixonic 7y ago
I'm a layman too, and just watched this https://youtu.be/bTxLAGchWnA https://youtu.be/bTxLAGchWnA to better understand the complexity.
enceladus_ice 7y ago
I think a big amount of the complexity comes from the folded up sunshield. I remember it had torn during a test deployment last year. Here is a quick animation showing the whole deployment process: https://www.youtube.com/watch?v=vpVz3UrSsE4 https://www.youtube.com/watch?v=vpVz3UrSsE4
- nullwasamistake 7y ago
  If it tears bad it's technically possible to send up a shield that floats near the telescope. There were some plans for that way back during the design phase if I remember right. Still wouldn't be cheap or easy
  - mikepurvis 7y ago
    It looks from the renders like the telescope has solar panels, antennas, etc on the sun/earth-side of the shield. Wouldn't sending a standalone shield screw that up as it would shade them?
    - nullwasamistake 7y ago
      Probably, although you could shape the shield not to. It's still far more complex than just attaching the thing right to the telescope. And glancing starlight leaking in between the shield and the telescope could be a big problem. I looked it up, the original proposal was actually to use a mobile shield to occlude far away stars for direct planet imaging. I think a similar approach could "fix" JWT but let's hope we never get there
bumby 7y ago
For one, I think it has an astronomically (ha) high number of single-points-of-failure. A quick Google search reported 344.
- mikepurvis 7y ago
  One imagines that for every single point of failure they've got some kind of plan for how to still derive scientific value while operating it in a degraded state, similar to how Hubble was able to take pictures before service mission 1 and COSTAR.
FrojoS 7y ago
This video explains it very well. https://www.youtube.com/watch?v=k8yRDrl76d0 https://www.youtube.com/watch?v=k8yRDrl76d0 Half way through the video, I understood why it's so expensive and risky. On the other hand, Apollo 11 had many 'firsts' that couldn't be tested before the actual mission and it worked out 'first shot'. Of course there were some problems and Apollo 13 showed that the odd's where not too good.
- eafkuor 7y ago
  Wow, this video is mindblowing.
- NikolaeVarius 7y ago
  Huge difference is that Apollo had highly trained human beings on board to fix things that could not be planned for. There were also 10 previous missions to Apollo 11 to work out the kinks, with one failing with loss of life. JW is not designed to be fixed or fail, nor are there training runs. It HAS to work first shot.
  - petschge 7y ago
    Regarding the 10 missions before Apollo 11: It's a little more complicated. Apollo 1 is the name that was given to honor the astronauts who died in the pad accident. Apollo 2 and 3 didn't exists. But a whole bunch of other tests did exist testing Saturn 5 before we got to the unmanned Apollo 4, 5 and 6 tests. And starting with Apollo 7 humans were included. See https://en.wikipedia.org/wiki/List_of_Apollo_missions https://en.wikipedia.org/wiki/List_of_Apollo_missions for details.
    - NikolaeVarius 7y ago
      I probably should have known this. I've read alot on Apollo, but never really internalized some of these facts.
      - TheOtherHobbes 7y ago
deleted 7y ago
[deleted]

knd775 7y ago

And this isn't like hubble, where we could (and did) send up a space shuttle to fix an issue after launch. Really scary.

Klathmon 7y ago
To be a bit more specific, we can't send something up to fix this because it's magnitudes further away from the earth than Hubble is. JWT will be ~1.5 million km away from earth, in a special orbit around a spot called the "L2 Lagrange point". It's located there so that it can kind of hide in the earth's shadow at pretty much all times and keep all the nearby "bright" things behind the heat shield. For comparison, the Hubble is ~600km away from the surface orbiting the Earth, and the Moon is a little under 400,000km away from the earth. JWT will be almost 4x further away than even the moon.
- escapecharacter 7y ago
  I mean, the giddy idiot in me just gets excited about the urgent need for a human L2 mission to fix it.
  - lostmyoldone 7y ago
    Likewise. My train of thought goes like "So what if it fails? There's a lot of money sunk into that! Well, maybe someone would actually decide it's worth going to the L2 to fix it, wouldn't that be cool!!" So yeah, not the only idiot...
    - GlenTheMachine 7y ago
      We would probably do this robotically.
      - ethbro 7y ago
        "What do we do when the robotic satellite fails?" "Send another robot!"

gnu8 7y ago

I have read in other discussions that the contractor has great confidence in the deployment of the sun shield because of their experience with similar systems on classified satellites. I think as long as the launch is successful there won’t be any problems with the mission.

CydeWeys 7y ago
I really hope this is true, but there must still be something different, because there's been years of delay caused by the solar shade not deploying properly.
ttul 7y ago
Indeed. The NRO - rumor has it - has been launching satellites to observe the earth in the infrared for years..
- petschge 7y ago
  Since you are looking at a warm planet you will never get your camera down to 7 K nor do you need to as all sources are close by and bright compared to the astronomical targets for JWST. So the shielding issue is somewhat different. Having Earth, Moon and Sun in the same direction so you can block all of them with a single heat shield is actually one of the reasons why JWST is going to the L2 Lagrange point.
CyanBird 7y ago
This is a good take, I like it, the US has deployed tons of spy satellites, and if they think the sail/shield+Mirrors will deploy well because they have used it in spy satellites before then I'll believe it

batbomb 7y ago

Normally they name telescopes once they are on orbit and working, because they don’t want to put a name on something and have it fail. The joke with JWST is that it’s not allowed to fail.

jvanderbot 7y ago

I have great faith in it. The "deployables" crowd knows their stuff and all eyes are on them right now.

teraflop 7y ago

That's what I thought about Curiosity's skycrane, and that ended up working out pretty well. Yes, it's complicated, but I'm willing to accept that my intuitions about whether something is too complicated are wrong when we're talking about something that actual rocket scientist have spent millions of hours planning.

NikolaeVarius 7y ago
I don't recall ever saying it was too complicated. I only indicated extremely complex, which it is. Millions of man hours have been lost to bad units. Rocket scientists are human.
- warent 7y ago
  I'm not sure why you're splitting hairs on this. GP is merely addressing your "extreme pessimism" but now for whatever reason you're either arguing semantics or showing some kind of cognitive dissonance.
falcrist 7y ago
I can't let go of my intuition that complex deployment procedures carry an inherent additional risk to the mission. Now, maybe that additional risk is less than the risk of doing it a different way, but that just means the mission is particularly risky. That appears to be the case with the JWST in any case. Space is hard. We've failed many times. It seems rational to be concerned in this case.
- Gravityloss 7y ago
  You can retire risk and accelerate progress by launching more smaller missions and accepting that some of them fail. The public must be enlightened enough to understand that occasional failure ia a much faster and better and even cheaper path to success.
  - petschge 7y ago
    The science done by a bunch of smaller IR telescope is different from what you can do with JWST. (Basically you are reducing resolution but get better time coverage of transients.)

neurostimulant 7y ago

For a project this magnitude, I think they should build a spare telescope or two to account for launch failures. Or is it not how the space industry operates?

java-man 7y ago
exactly my sentiment! why not build two, given the fact that most of the budget is likely to be R&D costs.
- rbanffy 7y ago
  Manufacture, certification and launch are still quite expensive. You'd easily run a couple extra billions building a fleet. Having said that, I'd be delighted to have a fleet of them.
deleted 7y ago
[deleted]
Rebelgecko 7y ago
The costs don't scale quite as well as you'd expect. Actually building, testing, and transporting the thing is really expensive. If you build 2, it's still a lot of expensive bespoke parts. Maybe if you build dozens the economies of scale start to pay off

topspin 7y ago

Yes, the deployment looks like a lengthy and risky operation. But the risks don't end there. The Northrop Grumman cryocooler has been a major problem for JWST, requiring years of development and rework. If it fails then some of the most crucial instruments are useless.

mturmon 7y ago
This is a good comment. The deployment is eye catching, but the cryocooler was the high technical risk item.

baq 7y ago

A more complicated process has worked multiple times in orbit already, look up the Orion program and Mentor sats. https://en.m.wikipedia.org/wiki/Orion_(satellite) https://en.m.wikipedia.org/wiki/Orion_(satellite)

kpU8efre7r 7y ago

I'm incredibly nervous as well. If a second telescope had to be built for whatever reason would it take as long and cost as much as the first? Or is all the cost and time due to R+D?