I was b being sarcastic for humourous purposes. Of course tthey do but i do
wonder if they make the right guesses about which bits fail.

How are the rotary race rings and bearings doing these days?

Brian

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From the Sofa of Brian Gaff Reply address is active
"Jeff Findley" wrote in message
...
In article ,
says...

Have they busted something else, I tell you when these devices are out of
warranty you can never get them serviced economically....

Electronics fail from time to time, which is why spares are already
prepositioned on ISS.

Jeff
--
"the perennial claim that hypersonic airbreathing propulsion would
magically make space launch cheaper is nonsense -- LOX is much cheaper
than advanced airbreathing engines, and so are the tanks to put it in
and the extra thrust to carry it." - Henry Spencer