Whilst units are sometimes conjoured up to make a good story or headline, I think they do have a place in some circumstances for engaging with, and relating to, the public. Perhaps not the SI Giraffe, but solar system debris measured in London buses might well have a place in popular culture.
Similarly for your space shuttle speed. 22x speed of sound is relatable to a certain generation who knew the Concorde cruised slightly above Mach 2. But I get your sound in space point.
BTW I was present at the British Concorde’s (002) maiden flight from Filton, Bristol, which happens to be 54 years ago today!
