271–280 of 301 posts
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Exactly correct. And Labeyrie has a design in place for the exact type of fleet I'm talking about.
Do you have a link to the design? I'm assuming it's a radio telescope?
Labeyrie has also proposed a fleet in L2 and on the Moon.
If the JWST survives launch but has a subsequent mechanical problem that prevents it deploying properly (and it’s the kind of problem that would have been fixable on Hubble, using a shuttle mission) would it be feasible to mount a robotic rescue mission to chase it down and remote-hands it back to life? For less than the cost of just launching another JWST?
The trouble with robotic repair missions is that it could work pretty well if you knew 100% exactly what was wrong, and exactly what else might go wrong while applying the fix for whatever went wrong. The more potential unknowns, the harder it is. It's much harder to make a robot with enough general flexibility that it could probably handle diagnosing and repairing an unknown issue, or handle something going wrong wh…
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It’s the telescope of Theseus, though.
Because some component bays designed to be swapped out were swapped out? Far as I know they haven’t replaced the 2.4m main mirror or the housing, you know, the “ship”
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It’s the telescope of Theseus, though.
Sort of. The broken optics famously got fixed in the first HST shuttle mission, and there have been other replacements over time. A lot of it is the same, though. And of course, the HST is in LEO, which means it is reachable with current rocket tech, which the James Webb, being situated at L2 won't be. But that's not to say you could not have a large platform at L2 (or another Lagrange point) that could be serviced b…
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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… but the refilling craft doesn’t exist. and webb timescales make that sound impossible
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
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Exactly correct. And Labeyrie has a design in place for the exact type of fleet I'm talking about.
Do you have a link to the design? I'm assuming it's a radio telescope?
For additional background, there are already optical interferometry telescopes in use, see VLTI by the European Southern Observatory (Chile, shared facility with the four VLT telescopes and some smaller telescopes).
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> Instead of building one huge short life-span spacecraft Short life-span? How long has the Hubble been up there?
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
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The challenges in building a mirror that size is enormous and take years. It is not only fairing size that is limiting
why not build the mirror in space? I bet microgravity could help with some of the challenges of building one.
Also I don't know if there actual benefits in doing mirror construction in low gravity
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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
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?
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 and 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.
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Ugh, I can't deal with Systems Engineering. It's a whole lot of gobbledygook before getting to the crux of the problem. A software engineering analogue would be FizzBuzz Enterprise Edition https://github.com/EnterpriseQualityCoding/FizzBuzzEnterpris...
I can understand not liking how bureaucratically onerous it is, but we don't really have a choice. It's imperfect but it's the only way we've found to manage highly complex large scale engineering projects. You certainly aren't going to build something like JWT with a just YOLO agile process unless you're literally willing to fail like 50 times before you get one right (aka the USSR approach to rockets). The upside i…
I agree to an extent, but there's also a risk of simulation breeding a false sense of security even when simulations are conducted well. The investigation of the CST-100 "anomalous" test flight had 21 findings related to software simulations and testing, some related to lack of fidelity. Not that fidelity wasn't possible, but it has some overtones of the Ariane 5 software issue in that there was a lack of integration testing within the different software components.