Obviously this anecdote is decades out-of-date, but my first boss’ PhD thesis is for an automatic small-airplane guidance system. I mean: as long as your plane

Obviously this anecdote is decades out-of-date, but my first boss’ PhD thesis is for an automatic small-airplane guidance system. I mean: as long as your plane was on a high speed ballistic arc and needed a guidance system that only ran for about 25 minutes. The guidance system used mercury & fluidic switches, in case the small aircraft encountered a constant barrage of extremely large EMPs.