Is it possible to make an electronic system, where every sub-system is duplicated and absolutely nothing is a single point of failure and if a failure (or multiple failures) occurs the system itself will seamlessly route around it?
Back in the 80s I worked with Stratus fault tolerant computers, their party trick was to be able to hot-swap the microprocessor boards, memory or hard discs seamlessly without interruption for the end user. But even this system wasn't quite as good as the adverts - both the clock and the motherboard were single point of failure.
At the simplest level, I've build devices that will choose which of two batteries to connect to (based on state of charge) but even with a simple set-up like this the relay becomes a single point of failure.
I've also worked with microprocessor based systems that would connect to three different GPS feeds and take a 'vote' on the most plausible position if one of the three disagreed with the others. But even with this, the voting system and bus it communicated over was a single point of failure.
Is a possible to build a multi-function system (example - drone autopilots, missile control systems, nuclear reactor safety systems) where every system and sub-system is fully redundant and any internal system failure is seamlessly routed around?
I'll freely admit this is a follow-up to my previous question about space probes. The consensus answer seemed to be that (in the case of Voyager) reliability was ensured by using one-of-everything and making sure that each component was maximum quality and 100% reliable.
It occurs to me that an alternative approach is three-of-everything, and some mechanism to to ensure that if one-of-the-three becomes faulty it gets ignored.