In space, you can't underdesign
There's no "just tell the engineer to go reboot the thing". There's no "turn it off and back on again". If some little bit fails, it could well be an extraordinarily expensive lump of metal in space, and the next time there might be no appetite to fund the research (or, worse, another country gets there first).
So you design. Then you overdesign. Then you take that up to eleven.
(I'll point you at Pathfinder for another great example)
Biting the hand that feeds IT
