Dr. Ralph Lorenz is a planetary scientist on the Principal Professional Staff of the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, MD, USA. He was a member of the Cassini Radar team, and helped to develop the Huygens Surface Science Package. He has played a major role in the definition of a range of US and European Titan mission concepts, from airships and hot-air balloons, through airplanes, landers and even a submarine. Thomson–Reuters Sciencewatch in 2011 named Ralph Lorenz as one of the world's top planetary scientists by impact. He is currently working on a design study adopted by NASA for a quadcopter probe named 'Dragonfly', designed to explore Titan.