Crossword Puzzle Hits the stratosphere

Clue: Hits the stratosphere

Hits theaters (OPENS with 5 letters)
1969 #3 hit ... and a hint to this puzzle's theme (TIMEOFTHESEASON with 15 letters)
W. W. II theater in Asia (CBI with 3 letters)
The beginning of each theme entry is one (ONION with 5 letters)
TheyÂ’re inseparable, sang Sinatra (LOVEANDMARRIAGE with 15 letters)
Hits too high on the backboard (OVERSHOOTS with 10 letters)
Therapy fad (EST with 3 letters)
ID theft datum (SSN with 3 letters)
Levels, as a theatre, say (RASES with 5 letters)
Theater reservation (SEAT with 4 letters)