Answer: NOGO

AnswerCrossword Clue
NOGOUnworkable
NOGONot possible.
NOGONot possible: Colloq.
NOGOHopeless attempt: Colloq.
NOGOWithout use: Colloq.
NOGOUseless: Colloq.
NOGOOpposite of A-OK.
NOGOImpossible: Slang.
NOGONix.
NOGOCape Kennedy failure.
NOGOImpossible
NOGOKind of gage
NOGOWords of impossibility.
NOGOCape Kennedy term
NOGONothing doing!
NOGOForget it!
NOGOSpace-shot bust
NOGONix!
NOGO"Not a chance!"
NOGOUseless: Slang
NOGO"Futilitarian" expression
NOGONASA's "not ready"
NOGOOn the fritz
NOGOCanceled by NASA
NOGOThumbs down
NOGODescribing a bad project
NOGONASA postponement
NOGOAborted plan
NOGOSomething scratched
NOGOLike an area that's off-limits
NOGOCanceled, as a space launch
NOGOCancelled rocket launch, e.g.
NOGOInoperative, as a launch
NOGOScratch, at NASA
NOGODud to NASA
NOGOPost-snafu utterance
NOGOOut of order
NOGONot a chance!
NOGOHep turndown
NOGOFailed NASA launch