 Working from NASA's Langley Research Center in the mid- to late-1970s, Dr. Soffen was project scientist for the NASA's Viking program of Mars landers, the first successful missions to perform unmanned experiments on the surface of the planet.In that role, he oversaw all scientific investigations conducted by the landers, coordinating the work of more than seventy scientists around the nation.In 1977 he appeared on an episode of the popular television series "In Search Of" entitled "Martians" and he spoke about the Viking's findings up to that time.