Welcome to FT, rustyjones!
This is frequently asked here. Quick summary of the answers you're likely to get: Very probably not. If you miss any flight, the airline is likely to cancel all of your remaining trip.
Can you have a stopover in Atlanta on this ticket? If so, why not just fly the extra sectors to save the money you want to save, and have your stopover in Atlanta either on the way out or on the way back?