James van Allen was born on September 7, 1914 in Mount Pleasant, Iowa. His father was a lawyer and ran a small law office in Mount Pleasant. His mother was a teacher and taught in one-room school houses near Eddyville, Iowa. Their parents had taught them the older traditions of pioneer living in the 1800's, and so hard work, frugality and a devotion to education were very strongly enforced on a daily basis. Every night after dinner, his father would read to James and his three brothers from magazines like National Geographic and The Atlantic Monthly. His chores included raising a flock of chickens, splitting wood, planting and maintaining a large vegitable garden, and doing several hours of homework each day.
Young James was especially fond of magazines such as Popular Mechanics and Popular Science. He enjoyed building motors, radios, and electrical generators that threw foot-long bolts of lightning across the room. His favorite suubjects in school were wood working, latin and of course math and science. He graduated from Mount Pleasant High School in June 1931 and was the class Valedictorian. There was never any question that he and his three brothers would be expected to go to college and 'amount to something'. James attended Iowa Weslyan College as an undergraduate, and then following family tradition went on to Iowa University for graduate school and received his PhD in Physics in 1939.
During the war years, he worked on the development of proximity fuses for bombs and other armaments used in World War II. These fuses would ignite the bomb once they got close to something made out of metal. In July 1942 he was commissioned as a Sheriff in Montgomery County Maryland so that he could carry a loaded gun for security measures, while working at the Applied Physics Laboratory at Johns Hopkins University. After the war, he returned to basic research at Johns Hopkins University. He was encouraged to develop high altitude research programs using the newly-captured German, V-2 rockets. After being away from pure scientific research for so many years, he was eager to tackle problems having to do with cosmic rays, the ionosphere and upper atmosphere. He even helped design a new kind of rocket called the Aerobee, which became the work horse of upper atmosphere research and data collection. Between 1946 and 1951, 48 V-2s and 30 Aerobees had been launched by American physicists under the direction of van Allen and his collaborator Ernst Krause at the Naval Research Laboratory.
By 1950, it became very clear to van Allen that the Applied Research Laboratory where he was working, was becoming less interested in academic-style research. So he accepted a new job at the University of Iowa as the head of the Department of Physics. After many years living far from home, he was now returning to his childhood surroundings and family. Soon, he was back into launching small rockets to study the upper atmosphere and cosmic rays at altitudes of 250,000 feet. The rockets were first carried to 50,000 feet by balloon, and then launched to altitudes of 250,000 feet ( 48 miles). They called them rocket-balloons or just 'Rockoons'. The rockets carried a single 'Geiger Counter' tube and telementry equipment to measure the intensity of cosmic rays as they passed through the tube and registered a 'click'.
In 1956 he submitted a proposal to the National Science Foundation to continue his rockoon program by using the newest satellites now being planned for launch to reach altudes of hundreds of miles. This would be a tremendous opportunity to investigate the origins of cosmic rays, and the mysterious 'auroral primary radiation' which no one had so-far been able to discover. His proposal was accepted for funding and the Iowa cosmic ray experiment was slotted for construction and launch on the next available satellite.
On January 31, 1958 the Jupiter C rocket was launched and carried the Explorer 1 satellite and as soon as it reached altitudes of several hundred miles, the Geiger counter began to register the frantic clicking of thousands of particles passing through the satellite every minute. As van Allen remarked in surprise 'space is radioactive!' Aditional satellites such as Explorer III and IV confirmed this discovery. The Pioneer I and III satellites were launched late in 1958, carried radiation detectors with them on their unsuccessful trips to the Moon, but the data showed just how the 'van allen belts' were shaped in space.
For more information about his background, visit his What is a Space Scientist which is his autobiographical essay at the University of Iowa.