Of course, anytime you can pitch something as complicated as science to the masses, then you make a grave contribution to humanity as more "curious minds" gets attracted & involved in it. In the process, more brilliant minds are tapped which in turn may "greatly contribute" to mankind sometime down the road.

*Aside from the popularization of science via his books & films, Carl Sagan was also strongly involved in the space exploration of the 60's. He worked as a consultant in some of NASA's space flights/probes & also worked in labs in determining the composition & atmosphere of the other planets (if they are suitable to life) via the pictures & samples sent back by the probes.