NASA are still Americans. I'm not arguing about metric or imperial being better.

Parent claims genetic inferiority for not grasping metric, NASA does, so they are excluded in the first place.

Same with "military" time.

NASA didn’t begin to standardize on metric until 1990. Far after Voyager was developed and launched.

NASA already used metric internally for the moon landings

https://ukma.org.uk/why-metric/myths/metric-internationally/...

And I doubt that calculations for the voyager mission where done in imperial. The output and for contractors yes, but internally it's metric.