James Van Allen

American physicist

• Born: September 7, 1914; Mount Pleasant, Iowa
• Died: August 9, 2006; Iowa City, Iowa

James Van Allen pioneered the use of artificial satellites for Earth studies, applying his expertise to help deploy planetary probes to enhance space exploration and knowledge. His discovery of radiation belts around the Earth initiated the field of magnetospheric physics.

Primary field: Physics

Specialties: Astrophysics; nuclear physics

Early Life

James Alfred Van Allen was born to lawyer Alfred Morris Van Allen and schoolteacher Alma Olney Van Allen in Mount Pleasant, Iowa. He excelled at school, particularly in mathematics and science, and studied Latin and woodworking. Van Allen developed his innate curiosity by reading Popular Science and Popular Mechanics magazines, which encouraged him to construct motors, a crystal radio, and a Tesla coil. Learning about planets, Van Allen became interested in astronomy and space.

After graduating from high school in 1931, Van Allen enrolled in Iowa Wesleyan College as a physics major. He came to admire his future mentor, physics professor Thomas C. Poulter, who urged his pupils to pursue innovative research. Poulter taught Van Allen skills that would prove useful for making scientific instruments, and he later hired Van Allen as an assistant. Supplied with a magnetometer by the Carnegie Institution’s Department of Terrestrial Magnetism (DTM), Van Allen gathered magnetic data for a field survey of Henry County, Iowa. Explorer Richard E. Byrd named Poulter chief scientist for his second Antarctic expedition in the early 1930s, and Van Allen served as Poulter’s aide while he prepared for the project. Van Allen earned his bachelor’s degree in 1935.

Interested in pursuing a scientific career, Van Allen expanded his physics knowledge by pursuing graduate degrees at the University of Iowa in Iowa City. He worked with adviser Edward P. T. Tyndall, earning a master’s degree in 1936, and studied under professor Alexander Ellett as a doctoral student, completing his PhD in 1939.

Life’s Work

Van Allen accepted a position at the DTM as a Carnegie Research Fellow in a nuclear physics laboratory. After World War II began, Van Allen devised radio proximity fuses for the US Navy to use for antiaircraft tactics. Beginning in April 1942, he conducted that work in the new Applied Physics Laboratory (APL) at Johns Hopkins University. In November of that year, Van Allen was commissioned as a lieutenant in the Naval Reserve to serve in the South Pacific as an evaluator of the naval deployment of radio proximity fuses. Van Allen married Abigail Fithian Halsey on October 13, 1945, in Southampton, New York, and they later had three daughters and two sons.

After the war, Van Allen returned to the Applied Physics Laboratory to establish and chair the high-altitude research group. The group used German V-2 rockets to assess cosmic rays and other areas of interest within the upper atmosphere. By 1946, Van Allen oversaw the use of new Aerobee rockets. Early in the 1950s, however, administrative changes at the APL led to a shift in research focus away from high-altitude research.

Tyndall, one of Van Allen’s former advisers, urged him to apply for the position of Physics Department chair at the University of Iowa, a position he filled beginning in January of 1951. At Iowa, Van Allen used balloons to transport instruments aloft to investigate cosmic rays. He created “rockoons,” balloon-rocket devices used to launch instruments to high altitudes above Earth. During the 1950s, Van Allen launched rockoons on several expeditions near Greenland and the North Pole to measure cosmic radiation. During this time, he also served as adviser for a number of students pursuing graduate-level research in this area.

Van Allen served as chair of a satellite instrumentation group during the International Geophysical Year, which extended from July 1957 to December 1958. Aware of military efforts to deploy an artificial satellite, he developed instrumentation compatible with both Navy and Army satellites in development. In October 1957, while on a rockoon expedition in the Pacific, Van Allen heard the signal of the Soviet satellite Sputnik on the radio. After returning from the expedition, Van Allen resumed his work with satellites. Under Van Allen’s direction, a Geiger counter, an instrument used to detect and measure radiation, was placed on the Explorer 1 satellite, which launched on January 31, 1958.

Assessing information collected from Explorer 1, Van Allen noticed first an absence and then a surge of data and concluded that radiation was affecting the measurements. He later gathered information from instruments on Explorer 3 and 4, determining that two “radiation belts” existed around Earth. On May 1, Van Allen publicly announced his detection of the radiation belts, which were later named in his honor, in a paper at an American Physical Society and National Academy of Sciences meeting. In March 1959, Van Allen published an article describing the radiation belts in Scientific American. Van Allen’s work inspired the field of magnetospheric physics, which intrigued researchers worldwide.

Beginning in 1958, Van Allen chaired a space scientists’ group that supported a piloted lunar landing, but he eventually decided robotic missions were preferable for space exploration because he thought few significant scientific results had been achieved by human space travelers. Van Allen devised instrumentation for the Mariner spacecraft deployed to Venus, and as principal investigator, he developed instruments for Pioneer 10 and Pioneer 11, detecting and surveying radiation belts associated with Jupiter and Saturn in the 1970s. He later supported deploying the Voyager probes, which expanded exploration to the outer planets, and the Galileo craft that orbited Jupiter.

Although Van Allen retired in 1985, he remained active in his department and profession. Mount Pleasant citizens restored Van Allen’s boyhood home during the late 1990s, and he participated in its dedication as a historical site. Van Allen received numerous recognitions for his accomplishments, including the Royal Astronomical Society Gold Medal, the Royal Swedish Academy of Sciences Crafoord Prize, the National Air and Space Museum Trophy, and US National Medal of Science.

On October 9, 2004, the University of Iowa hosted a ninetieth-birthday celebration for Van Allen, who continued to research and evaluate satellite data in his office in Van Allen Hall. Van Allen died on August 9, 2006, in Iowa City. The university sponsored a public memorial and established a scholarship in his honor.

Impact

Van Allen shaped space science as it emerged in the mid-twentieth century. His contributions revealed new information about the universe, providing crucial data that enabled spacecraft to maneuver in the solar system. His work highlighted the potentials of space and influenced students to seek careers in space science. Many of his students and colleagues became prominent NASA investigators and administrators. His opinions also influenced NASA policy, especially the increase in unpiloted space missions during the 1990s. While some historians consider Van Allen’s detection of Earth’s radiation belts to have strengthened the position of the United States in the Cold War space race, his investigations were motivated by scientific curiosity rather than political ambition. He nurtured a sense of scientific community in the United States, and he worked with rocket scientists and other researchers from a variety of countries, sharing insights into advancing science and technology.

Bibliography

Beatty, J. Kelly, Carolyn Collins Petersen, and Andrew Chaikin, eds. The New Solar System. 4th ed. Cambridge: Sky, 1999. Print. Includes a chapter written by Van Allen and astrophysicist Frances Bagenal describing their work with magnetospheres and incorporating examples from throughout Van Allen’s career, including planetary exploration with probes.

Bille, Matt, and Erika Lishock. The First Space Race: Launching the World’s First Satellites. College Station: Texas A&M UP, 2004. Print. Provides biographical details on Van Allen and his research as well as historical context for US and Soviet aerospace research conducted in the 1950s.

Foerstner, Abigail. James Van Allen: The First Eight Billion Miles. Iowa City: U of Iowa P, 2007. Print. Chronicles Van Allen’s scientific curiosity, space research philosophy, and achievements from childhood through his radiation discoveries with satellites and probes.

O’Brien, Brian. “Radiation Belts.” Scientific American 208 (1963): 84–96. Print. Provides a wealth of information about the discovery of the Van Allen radiation belts, including maps of the belts and the shape of the magnetic field.

Van Allen, James A. Origins of Magnetospheric Physics. Iowa City: U of Iowa P, 2004. Print. Offers a detailed account of Van Allen’s research and experiences and includes images from his field notebooks, radiogram and correspondence transcripts, diagrams, and research proposal excerpts.