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Comment by fortysixdegrees | Hacker News Reader

Although I guess once it's in orbit, and major problems could be sorted out over the following years with manned repair missions, like they did with hubble

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Not really, unfortunately. Webb will be much further from Earth than Hubble is, so as far as I'm aware a human mission to go repair it isn't really considered an option.

https://www.nasa.gov/topics/universe/features/webb-l2.html

If Starship delivers on its deltaV and economic promises, it's at least feasible, although that's a big if. Besides, if you can boost something the mass of the telescope with twice the volume and much less money, why would you bother fixing the one you have?

They've worked on the design for over 20 years AFAICT. Even tho Starship will enable bigger and better telescopes, if there's a repairable problem and it is within reach, would be odd to just bail on JWST when the whole design/build process of the next gen will likely be a very long endeavor.

https://en.wikipedia.org/wiki/James_Webb_Space_Telescope#His...

I think it's fair to say that with lower stakes you can definitely take less time on each telescope. The Webb is a miracle of engineering, but a lot of that miracle goes towards squeezing it into a pretty narrow fairing.

Sure, I'd also expect (as an outsider) that new iterations will be quicker from this new knowledge base and a 9m x 18m rocket payload, I'm just saying if there is a way to fix broken JWST I see no reason to not even try and wait out the next gen. They are not mutually exclusive.

You're better off with a plan along the lines of "launch a less-good-but-still-perfectly-fine new space telescope every couple of years" so that you eventually get good at it, and can afford to make mistakes.

A few hundred million for each launch; heck, the long-term ground support is probably more expensive than the flights and the hardware after a while.

About 10-15 years ago the European Space Agency was advertising that philosophy. IIRC they contrasted perfectionism (or zero risk) and slow learning against smaller experiments and faster learning. There was also some third term contrasted, perhaps that being that all-or-nothing huge projects demand a shift toward zero-risk and slow learning.

> major problems could be sorted out over the following years with manned repair missions, like they did with hubble

Not anytime soon. The Hubble is in low-earth orbit at an altitude of 540 Km, whereas JWST is at the Earth-Sun L2 point at an altitude range of 370 Mm to 1.5 Gm; further than the Moon. No spacecraft capable of carrying humans beyond LEO has been built since the Apollo missions.

Starship and SLS will change the game, but both are still years away from manned flights.

Even then, it's quite possible a human mission beyond LEO to repair the JWST would end up costing more than just building a replacement telescope.

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