Copasetic, also spelled copacetic, copesetic or - less commonly - kopasetic, means very satisfactory or acceptable.

Copasetic is an unusual English language word in that it is one of the few words of seemingly unknown origin that is not considered slang in contemporary usage. It is used almost exclusively in North America, and is said to have been first widely publicized in communications between the astronauts and Mission Control of the Apollo Program in the 1960s

/No, I didn't know either

My mother used it when I was a kid in the 40s and early 50s. I didn't realize it's an unusual word.

The english word 'cope' derives from ancient latin french 'colper', strike a blow. I think it quite possible, that confronted with the english usage of 'to cope', american french speakers would use 'il sait couper' as 'he knows how to cope'. From there, a 'latin' adjectival derivation such as 'copasetic' could be imagined.
I think it is much more likely though, that southern blacks invented this word, using the english root with a latin inflection. They needed to cope, and whatever helps to cope is copasetic.