Mechanical circuits could be a low performance replacement for electronics in environments where the latter fail, e.g. because of high temperatures or radiation.
I think I remember something about an idea for a mechanical communications system for a Venus lander that worked by wheels that increased or decreased radar reflections so data could be read from orbit by bouncing a radar signal off it.
I think I remember something about an idea for a mechanical communications system for a Venus lander that worked by wheels that increased or decreased radar reflections so data could be read from orbit by bouncing a radar signal off it.
Maybe combine stuff like this?
Edit: adding link: https://www.theengineer.co.uk/mechanical-rover-explore-venus... .