I have found many people saying that a rad-hardened Z80 with ferrite-core memory was used on the Space Shuttle, though I can't find an authoritative source to back that up.
The Shuttle did indeed use core memory for awhile, but in what was basically a repackaged and rad-hardened System/360 (so not Z80-based AFAICT): https://en.wikipedia.org/wiki/IBM_System/4_Pi
