Related Clues:

• Letters of assent
• "Nifty!"
• 'Pretty amazing!'
• Fine, slangily
• Copacetic
• Fine, to NASA
• Running perfectly
• NASA 'thumbs up'
• 'Sweet!'
• Old-fashioned ''Super!''
• All right
• ''Awesome!''
• "Cool!"
• ''Peachy keen!''
• "So cool!"