Van Allen, James (Alfred) (1914-)

US physicist whose instruments aboard the first US satellite Explorer 1 1958 led to the discovery of the Van Allen belts, two zones of intense radiation around the Earth. He pioneered high-altitude research with rockets after World War II. Born in Mount Pleasant, Iowa, Van Allen studied at the University of Iowa. He organized and led scientific expeditions to Peru 1949, the Gulf of Alaska 1950, Greenland 1952 and 1957, and Antarctica 1957 to study cosmic radiation. From 1951 he was professor at Iowa. He participated 1953-54 in Project Matterhorn, which was concerned with the study of controlled thermonuclear reactions, and he was responsible for the instrumentation of the first US satellites. After the end of World War II, Van Allen began utilizing unused German V-2 rockets to measure levels of cosmic radiation in the outer atmosphere, the data being radioed back to Earth. He then conceived of rocket-balloons (rockoons), which began to be used in 1952. They consisted of a small rocket which was lifted by means of a balloon into the stratosphere and then fired off.