Related Clues:

• Verbal thumbs-up
• "Everything's fine!"
• "Permission granted"
• Word of affirmation
• NASA's "Go"
• Spoken thumbs-up
• Approving answer
• NASA fine?
• Informally, all right
• Common jargon for yes, all right
• There's nothing with the girl to make it 8 across
• Calling Katherine to say it's 18 down
• ''Go ahead''
• Acceptance word
• Perfect for NASA