A-OK

Excellent. The  term  dates  from  a  specific  incident  in  1961, when the   National  Aeronautics   and   Space  Administration’s   Colonel  “Shorty” Power misunderstood astronaut Alan Shepard’s “OK” for “A-OK,” indicating that  his  suborbital  flight  was  going  well. The  term  caught  on,  along  with other space-flight terms that entered the language about the same time.