What happens when this thing breaks? Will they abandon a $10B device in space? Or maybe send a guy to go out to L1 and "turn it off and back on again"? Lol
They'd do what they can from the ground, but it's basically not physically repairable if it's damaged, so it would be software fixes only.
It's too far away for humans; nothing on it is designed as an attachment point; and body heat on the parts on the dark side of the sun shield, let alone engine exhaust, would risk further damage.
A robot might be able to fix something, but that risks being more expensive than building another telescope — I don't know how much of the cost was designing it vs. building it, but a second would probably be cheaper than the first.
> nothing on it is designed as an attachment point
I would be curious to know why they didn't implemented anything like this. I know that no robot, space vehicle or any other technology currently exists that could repair such a spacecraft in L2, but I would like to know whether leaving this door open by adding one or more attachment points would have increased the cost of the telescope too much.
Mass and volume are at a premium on any satellite. Adding attachment points and access panels would have reduced the capacity for scientific instruments. Since NASA has no repair capacity now or even seriously planned for the future, it was pointless to design for serviceability. Building and launching a whole replacement JWST would certainly be cheaper, considering that they have some experience now.
