> I'm not even sure if "radiation-hardening" electronics [...] is even that much
> of an important thing any more. A single transistor (or track) inside a chip
> is a million times smaller than in the late 80s, and would presumably so be
> subjected to much less inducted current when exposed to a powerful EM flux.

Shrinking process node decreases vulnerability to total-ionizing-dose radiation but increases vulnerability to other kinds of radiation effects like single-event upset or single-event latchup. Thus, radiation hardening is still a necessary thing for space microelectronics and probably always will be. The specific hardening methods have changed over time with the ever-shrinking process nodes, though.

https://en.wikipedia.org/wiki/Radiation_hardening#Digital_damage:_SEE