Developing Mars lander software

[Xinok]

On Wednesday, 19 February 2014 at 00:16:03 UTC, Tolga Cakiroglu 
wrote:
>
> TL;DR the link though, how are they detecting that a CPU fails? 
> An information must be passes outside of CPU to do this. The 
> only solution comes to my mind is that main CPU changes a 
> variable on an external memory at every step, and back up CPU 
> checks it continuously to catch a failure immediately. But this 
> would require about 50% of CPU's power already.
>
> While thinking about this kind of back up systems, knowing and 
> reading that some people are really doing is really great.
>

I'm assuming this has something to do with it:
https://en.wikipedia.org/wiki/Heartbeat_%28computing%29

In clustered servers, the active node sends a continuous signal 
indicating it's still alive. This signal is referred to as a 
heartbeat. There's a standby node waiting to take over should it 
stop receiving this signal.