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webb needs to use thrusters to stay in position. there’s 5 years worth of fuel onboard they did design the fuel in a way that potentially could be refilled… bu

webb needs to use thrusters to stay in position. there’s 5 years worth of fuel onboard they did design the fuel in a way that potentially could be refilled… but the refilling craft doesn’t exist. and webb timescales make that sound impossible

Taniwha 5y ago
And it's at L2 so not that easy to get to
- prox 5y ago
  I take Starship could, and should be operational in some form by then.
  - Cthulhu_ 5y ago
    Question is whether it'll be financially / commercially viable. I think that greatly depends on how much data the telescope gathers or whether it needs more time. Also keep in mind that the Hubble got multiple upgrades over its lifespan, which will be much more difficult with the Webb - is it feasible to do spacewalks that far out? Has any astronaut ever done a spacewalk outside of Earth orbit?
    - LargoLasskhyfv 5y ago
      Are you referring to the protection by Earths magnetic field? If so, would it matter much, given we (allegedly) shot humans in not more than slightly pressurized tin cans to the moon multiple times? And they survived.
    - prox 5y ago
      Yeah, if it has done it set out to do, then we don’t need to. Also depends how much of a moon presence we have in five years. Launching from the moon might make it feasible for sure, considering the billions the JWST has cost!
arp242 5y ago
According to the NASA website there is fuel for 10 years, and the five years is just the "minimal" mission time for which it's tested. https://jwst.nasa.gov/content/about/faqs/faq.html#howlong https://jwst.nasa.gov/content/about/faqs/faq.html#howlong
- Gustomaximus 5y ago
  Question if anyone knows: ~9.5 years any reason to not push it out of orbit into space and continue to get signals back for years longer as it floats off? Like the voyagers?
  - arp242 5y ago
    To push it out in to space like Voyager requires a lot of thrust, so I bet that's the reason. As far as I can find, it's kept in the L2 point mainly for temperature reasons. Not an expert, but this is what I gathered from https://space.stackexchange.com/q/23238/13952 https://space.stackexchange.com/q/23238/13952 and https://space.stackexchange.com/q/38408/13952 https://space.stackexchange.com/q/38408/13952 From what I can tell I don't think that it's very uncommon that these things are designed for 5-10 year missions and that everything else is just a nice bonus. I don't think anyone expected Hubble to survive as long as it did for example, and even the Voyager program was originally designed to be finished in the 80s and I don't think anyone expected it would last this long either.
  - thereddaikon 5y ago
    JWST isn't a probe like Voyager. It's job isn't to go to other worlds and see what's there. Its a space observatory. It does exactly the same job a telescope on earth would do, just in space. The reason why is to avoid light pollution and the interference from earth's atmosphere. So that fuel isn't used for going places, its for aiming the telescope and keeping it steady. Once the fuel is gone it can no longer control where its pointing. If you cant aim a telescope then its useless.
    - dreamcompiler 5y ago
      You can aim it with reaction gyros which rotate the telescope and require only electricity. What you cannot do with electricity is translate the telescope along a vector to compensate for orbital decay and keep it on station. That's what fuel is for.
findalex 5y ago
When you consider how long this thing was in development/production, 5 years doesn't seem very long.

Taniwha 5y ago

And it's at L2 so not that easy to get to

prox 5y ago
I take Starship could, and should be operational in some form by then.
- Cthulhu_ 5y ago
  Question is whether it'll be financially / commercially viable. I think that greatly depends on how much data the telescope gathers or whether it needs more time. Also keep in mind that the Hubble got multiple upgrades over its lifespan, which will be much more difficult with the Webb - is it feasible to do spacewalks that far out? Has any astronaut ever done a spacewalk outside of Earth orbit?
  - LargoLasskhyfv 5y ago
    Are you referring to the protection by Earths magnetic field? If so, would it matter much, given we (allegedly) shot humans in not more than slightly pressurized tin cans to the moon multiple times? And they survived.
  - prox 5y ago
    Yeah, if it has done it set out to do, then we don’t need to. Also depends how much of a moon presence we have in five years. Launching from the moon might make it feasible for sure, considering the billions the JWST has cost!

arp242 5y ago

According to the NASA website there is fuel for 10 years, and the five years is just the "minimal" mission time for which it's tested. https://jwst.nasa.gov/content/about/faqs/faq.html#howlong https://jwst.nasa.gov/content/about/faqs/faq.html#howlong

Gustomaximus 5y ago
Question if anyone knows: ~9.5 years any reason to not push it out of orbit into space and continue to get signals back for years longer as it floats off? Like the voyagers?
- arp242 5y ago
  To push it out in to space like Voyager requires a lot of thrust, so I bet that's the reason. As far as I can find, it's kept in the L2 point mainly for temperature reasons. Not an expert, but this is what I gathered from https://space.stackexchange.com/q/23238/13952 https://space.stackexchange.com/q/23238/13952 and https://space.stackexchange.com/q/38408/13952 https://space.stackexchange.com/q/38408/13952 From what I can tell I don't think that it's very uncommon that these things are designed for 5-10 year missions and that everything else is just a nice bonus. I don't think anyone expected Hubble to survive as long as it did for example, and even the Voyager program was originally designed to be finished in the 80s and I don't think anyone expected it would last this long either.
- thereddaikon 5y ago
  JWST isn't a probe like Voyager. It's job isn't to go to other worlds and see what's there. Its a space observatory. It does exactly the same job a telescope on earth would do, just in space. The reason why is to avoid light pollution and the interference from earth's atmosphere. So that fuel isn't used for going places, its for aiming the telescope and keeping it steady. Once the fuel is gone it can no longer control where its pointing. If you cant aim a telescope then its useless.
  - dreamcompiler 5y ago
    You can aim it with reaction gyros which rotate the telescope and require only electricity. What you cannot do with electricity is translate the telescope along a vector to compensate for orbital decay and keep it on station. That's what fuel is for.

findalex 5y ago

When you consider how long this thing was in development/production, 5 years doesn't seem very long.