I wonder how often problems happen that the redundancy solves. Is radiation actually flipping bits and at what frequency. Can a sun flare cause all the computers to go haywire.

Not a direct answer but probably as good information as you can get: https://static.googleusercontent.com/media/research.google.c...

Basically, yes, radiation does cause bit flips, more often than you might expect (but still a rare event in the grand scheme of things, but enough to matter).

And radiation in space is much “worse” (in quotes because that word is glossing over a huge number of different problems, both just intensity).

[dead]