I'm spending the week with my father, who turns 90 in a few weeks. He was in the cold war Air Force, and is a consummate engineer who worked on SAGE, the Saturn V Guidance system, Skylab, and a lot of other lesser known projects.

He worked through a lot of transitions in technology - through analog to hybrid to digital simulations, including simulations of the Rocketdyne F-1 engine.

This is the electric motor project that he made in shop class at the age of 11 or 12, which sparked his journey.