During his long, productive career, Van Allen helped develop (1940-42) a proximity fuse for antiaircraft ammunition and subsequently served as a naval gunnery officer in World War II. After the war, he conducted high-altitude research using rockets and balloons, and discovered (1953) the electrons associated with the aurora borealis. Van Allen also was prominent among the scientists who proposed (1950) and organized the international scientific research program that became the International Geophysical Year (1957-58).
Although he supported the development of the U.S. space exploration efforts that culminated in the Apollo space program and moon landings (1969-72), the relative paucity of scientific data reaped by human spaceflight led him to champion the use of space probes and satellites. He subsequently studied the radiation belts of Jupiter and Saturn using data from Pioneer probes and participated in the Galileo mission to Jupiter.
