Meteorite damage to Webb:

https://www.livescience.com/james-webb-space-telescope-micrometeoroid-picture

The impact made visible damage but did not ruin the scope.

They say in the article they expect, on average, about one impact per month! Outstanding engineering to plan for most of that. I hope the Webb works well for a long time. But, in space, every day could be the last!

I don't see it lasting very long.

Isn't that 2 hits already?

@beowulf said
I don't see it lasting very long.

Isn't that 2 hits already?

@Liljo

Ya I don't see it lasting 3 years...
No repairs? Can they move it if they wanted to?

@sonhouse

When you were doing your NASA thing was their guys like me who were pessimistic and came up with the worst case scenarios?

I imagine science needs scientists like that right? 🤔

@beowulf said
I don't see it lasting very long.

Isn't that 2 hits already?

@Beowulf
That is part of the discipline of space science, to think of the worst thing that can happen and try to engineer the probes to be able to survive such hits, usually in the form of redundant circuitry. In the case of an optical telescope exposed like Webb, the only redundancy is the number of mirrors, in this case 18 separate hexagonal shaped mirrors so if a big one hits and destroys a whole segment, the useability is reduced a bit, like maybe 6% if a whole segment is lost so there is that.
I looked closely at the damage of the one bad segment and it is pretty bad, maybe 1/4th useless so that would be an overall loss of maybe one percent.
Like I said, Hubble is much better protected against strikes directly on the mirror since it is hidden inside the big tube but Webb has no such protection so it will be a race against time as to how long Webb will do it's job. BTW, the damage is bigger than just the impact because of the debris field around the impact itself, dust gets spread out over the mirror and that alone reduces the useability so it is a bit worse than just the impact point.

There will be a judgement call for the next big space scope I'm sure, maybe including some kind of shroud protecting the mirrors from all but straight in shots of space pellets. As it stands now, a microthingy can hit the mirror from near 180 degrees but Hubble has that down to maybe 5 degrees it would have to come in to actually damage the mirror so that will be taken into account for the next one.
Which is probably already in the planning stages.
Latest news shows huge decrease in the weight of Xray telescopes, the word was one of them at something like 600 kg per meter of X ray deflectors and now down to 60 or so Kg for the same scope. There is also work done by Israeli scientists working to develop a kind of blow up mirror which could mean a 100 meter scope in space and that would outdo Webb by a significant margin.

@sonhouse

In NASCAR they have windshields that have 7 layers and they tear a layer off so the one underneath is crystal clear.

Just an idea for a future scope/mirror in space.
I'm sure space rocks hit at such a velocity that it wouldn't stop any damages though 🤔

@Beowulf
Plus the tiny problem there is nobody there to tear off the latest layer.....

@sonhouse said
@Beowulf
Plus the tiny problem there is nobody there to tear off the latest layer.....

@Beowulf
Little R2D2 deal, could work. How about a laser system detecting incoming flecks of sand or whatever and zapping it before it gets close?
One more practical way would be to have a thin mylar kind of sheet in front of the mirror, but that could introduce optical aberrations so it might be it would have to be like a giant Hubble with a tube some size larger than the mirrors to protect it.
I wonder if there has been any reports of the Hubble mirror getting whacked by micrometiors?