A term of art is a word or phrase whose use or meaning is specific to a particular field of endeavor. In this case apparently historians mean something specifi

A term of art is a word or phrase whose use or meaning is specific to a particular field of endeavor. In this case apparently historians mean something specific when they say "space" and there's a bunch of scholarship on it. I wasn't interested enough to dig too deeply, especially since googling it just brings up a bunch of stuff on the history of outer space exploration.