Connections can be missed. If it happens, you work with Airtran to get to your destination asap.
That said, I don't think there will be any issues. As soon as you get off the plane, immediately check the departures board to know what gate your connection is taking off from. Then head to that gate. Don't stop for a bathroom break or food. Only do that once you are at the new gate.
I always track my flights as the dates approach. I get a general idea of what gates they are using so I have a mental picture in my head. ATL is large, but the people mover is very efficient. It looks close to walk, but the train is always faster.
Unless your first flight is very late, you will be fine. I had a 37 minute connection in DFW last year. My plane was 20 min late and I had to RUN to my next flight, but I made it.
Duds