Related Clues:

• "Fat chance!"
• Scrapped, at NASA
• "Impossible!" and the theme of this puzzle
• "No way!"
• "Don't think so"
• 'How could you even ask such a thing?!'
• Not even remotely
• 'Unh-unh'
• "You gotta be kidding!"
• "I don't think so!"
• Adamant denial
• Denial
• Backwoods denial
• Refusal to Jose?
• 'I'd rather not'