Airplanes on Mars

Rovers are great, but what better way to cover more territory then by flying around the planet? Apparently scientists and engineers hope to design an airplane to be flown on Mars that could be navigated without a human pilot. This seems to be a difficult task because the Martian atmosphere is so thin, requiring huge wings or an extremely fast takeoff. Yet, if the plane is dropped off by the entering spacecraft and the wings unfolded it could have a short but very controlled flight.