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Even longer for it to actually power up and start "working." Really excited for it, but feel like something akin to this hubble issue happening with the JW wou

Even longer for it to actually power up and start "working." Really excited for it, but feel like something akin to this hubble issue happening with the JW would be disastrous.

bduerst 5y ago
What's the timeline to being fully operational?
- chowells 5y ago
  Roughly 6 months after launch for all systems to cool to operational temperature.
  - airstrike 5y ago
    More like JFCT
mzkply 5y ago
It'll be a Starship mission with astronauts to go work on it at L2 in 2023/4 then.
- Miraste 5y ago
  Unfortunately, even if we do develop the capability to get astronauts out there, the Webb is constructed with a lot of adhesive and layered components and is basically impossible to service in space.
  - XorNot 5y ago
    I think the best we could hope for is maybe being able to drill into the liquid helium tank and refill it - which is the ultimate determinate of its useful lifetime (that and propellant, but I'm led to believe the liquid helium will run out first). Probably a moot point though: by the time we can get people out to do such an operation, I suspect a reduction in launch costs might lead to a much cheaper space telescope you could just drop off instead.
    - onetwentythree 5y ago
      There is no consumable liquid helium. Past space telescopes have used consumable coolant, but JWST has a closed refrigeration system to cool the one instrument that requires active cooling. If all goes as planned, the limiting factor is propellant. And the propellant tanks have the ports for on-orbit refueling, in case there is ever a desire to develop a robotic servicing mission for the task.
      - XorNot 5y ago
        Huh...seems like this was misreported in a bunch of places, but you're right. It is in fact closed loop on cooling.
sam-2727 5y ago
And not just disastrous for James Webb, disastrous for the possibility of future funding of space missions in the near future. Congress would be much more hesitant to fund anything as large as the James Webb in the future if it failed.
- JaimeThompson 5y ago
  Not if China starts funding such things as many in the US Congress would not want China to have more advanced assets in orbit and would authorize funding to make it work.
- tgsovlerkhgsel 5y ago
  How much of the cost is the R&D vs. actual construction and launch? (In other words, how expensive would be fixing an issue and trying again actually be?)
  - wongarsu 5y ago
    It's hard to say, but for the JWST the design and R&D seems to have been the easier part [1]. In general it's uncommon to build a replacement satellite after an issue. Either you make a backup from the start, or you start over after failure. Making a one-off component often isn't all that much simpler just because you've already done it once a decade ago (and some parts of the JWST should be about a decade old by now). And if you commit to doing that all over again, might as well update the entire design to new capabilities and requirements. 1: https://space.stackexchange.com/questions/48902/are-there-any-estimates-for-cost-of-manufacturing-second-if-first-jwst-fails https://space.stackexchange.com/questions/48902/are-there-an...

Even longer for it to actually power up and start "working." Really excited for it, but feel like something akin to this hubble issue happening with the JW would be disastrous.

bduerst 5y ago

What's the timeline to being fully operational?

chowells 5y ago
Roughly 6 months after launch for all systems to cool to operational temperature.
- airstrike 5y ago
  More like JFCT

mzkply 5y ago

It'll be a Starship mission with astronauts to go work on it at L2 in 2023/4 then.

Miraste 5y ago
Unfortunately, even if we do develop the capability to get astronauts out there, the Webb is constructed with a lot of adhesive and layered components and is basically impossible to service in space.
- XorNot 5y ago
  I think the best we could hope for is maybe being able to drill into the liquid helium tank and refill it - which is the ultimate determinate of its useful lifetime (that and propellant, but I'm led to believe the liquid helium will run out first). Probably a moot point though: by the time we can get people out to do such an operation, I suspect a reduction in launch costs might lead to a much cheaper space telescope you could just drop off instead.
  - onetwentythree 5y ago
    There is no consumable liquid helium. Past space telescopes have used consumable coolant, but JWST has a closed refrigeration system to cool the one instrument that requires active cooling. If all goes as planned, the limiting factor is propellant. And the propellant tanks have the ports for on-orbit refueling, in case there is ever a desire to develop a robotic servicing mission for the task.
    - XorNot 5y ago
      Huh...seems like this was misreported in a bunch of places, but you're right. It is in fact closed loop on cooling.

sam-2727 5y ago

And not just disastrous for James Webb, disastrous for the possibility of future funding of space missions in the near future. Congress would be much more hesitant to fund anything as large as the James Webb in the future if it failed.

JaimeThompson 5y ago
Not if China starts funding such things as many in the US Congress would not want China to have more advanced assets in orbit and would authorize funding to make it work.
tgsovlerkhgsel 5y ago
How much of the cost is the R&D vs. actual construction and launch? (In other words, how expensive would be fixing an issue and trying again actually be?)
- wongarsu 5y ago
  It's hard to say, but for the JWST the design and R&D seems to have been the easier part [1]. In general it's uncommon to build a replacement satellite after an issue. Either you make a backup from the start, or you start over after failure. Making a one-off component often isn't all that much simpler just because you've already done it once a decade ago (and some parts of the JWST should be about a decade old by now). And if you commit to doing that all over again, might as well update the entire design to new capabilities and requirements. 1: https://space.stackexchange.com/questions/48902/are-there-any-estimates-for-cost-of-manufacturing-second-if-first-jwst-fails https://space.stackexchange.com/questions/48902/are-there-an...