interestingly enough, there is an incident where a unit conversion cause a spacecraft to crash.
https://en.m.wikipedia.org/wiki/Mars_Climate_Orbiter
NASA specifies that companies who work with NASA should use metric units as a part of the contract. Lockheed produced software that output in imperial units and it caused the orbiter to flame out.
This attitude is exactly WHY the US failed to actually convert back in the 70s