James Van Allen
The Illustrious Legacy of University of Iowa Professor and Astrophysicist James Van Allen
BY ABIGAIL FOERSTNER
Astrophysicist and space pioneer James Van Allen (1914-2006), often called the father of space science, was a remarkably influential 20th century scientist. The University of Iowa professor monitored 24 space missions, including Explorer I in 1958, the first successful U.S. satellite, and Pioneer 10 and Pioneer 11 in the 1970s, missions that surveyed Jupiter and Saturn.
In a new biography released by the University of Iowa Press this month, author Abigail Foerstner charts Van Allen’s eventful life, from his Iowa childhood to an illustrious career in space science. This excerpt is the introduction from James Van Allen: The First 8 Billion Miles.
Pioneer 10 and Voyager 1 raced toward opposite ends of the solar system, each on a path to find its edge. The vastness of space separated James Van Allen’s cosmic ray detectors on Pioneer and Don Gurnett’s radio receiver on Voyager while the offices of the two physicists stood only a few doors apart at the University of Iowa. Pioneer 10 fell silent after sending home a final faint signal on January 22, 2003, from nearly 8 billion miles away. The last streams of data from his detectors told Van Allen that the probes were getting close to the intermediate boundary of the solar system, a zone called the termination shock where the solar wind and galactic cosmic rays crash and begin to mix. Physicist Norm Ness found this boundary with an instrument on board Voyager in 2005, a momentous discovery in space science.
Van Allen pioneered the field of space science, discovered the earth’s radiation belts, and helped draw a new map of the solar system on his journey across 8 billion miles. His instruments on board more than 200 rockets, satellites, and space probes transmitted data over six decades. Pioneer 10 alone, launched for a 21-month mission in 1972, sent Van Allen more than 30 years of readings that helped us recognize that the boundary of the solar system extended billions of miles past Pluto.
Van Allen’s career crystallizes the entire history of space exploration. He and a group of freewheeling colleagues launched the era of space exploration with captured German V-2 rockets reassembled and launched at White Sands in New Mexico after World War II. Partnering with the U.S. Army, the scientists replaced the warheads of the “vengeance machines” that had terrorized London with scientific instruments little more than a year later. Van Allen helped found and later chaired an informal rocket panel that met monthly to divvy up the V-2s—and later rocket missions—and to provide a forum for the new field of space science. For 12 years, the panel filled a key role that would be taken over by NASA in 1958.
With his detectors on the V-2 rockets, Van Allen pierced “the cosmic ray ceiling of the atmosphere,” as he called it. The rocket had given him the tool to make his first discovery in space. He had found the cosmic ray plateau, the stream of incoming cosmic rays before they began to disintegrate in the earth’s protective atmosphere and splinter into showers of secondary particles. Van Allen now wanted to map the changing intensities of cosmic rays across the globe, a change controlled by the earth’s magnetic field. It was the perfect project when he returned to his alma mater, the State University of Iowa (now the University of Iowa), in 1951, as head of the physics department and developed a rocket program on a shoestring budget.
During the summer of 1952, Van Allen and a cadre of graduate students hitched surplus rockets to navy balloons and launched them from the U.S. Coast Guard Cutter Eastwind as it headed toward the Arctic. Each “rockoon” mission cost less than $2,000 and carried a single Geiger counter to count cosmic rays. The launches went poorly at first until Van Allen heated juice cans in the gondolas of the balloons to keep the rocket igniters warm enough to fire. Finally, with rockets reaching altitudes of more than 60 miles, Van Allen and the students painstakingly recorded cosmic ray levels across journeys to the Arctic and the Antarctic. Each launch filled in a dot on the map. Subsequent trips over the next five summers added more dots and made groundbreaking discoveries about the earth’s magnetic field and the aurorae. Yet a single launch involved government grants, a ship, crew members, Van Allen, graduate students, staff, and a floating laboratory of gear.
Then on January 31, 1958, Van Allen’s cosmic ray detector went into space on board the first American satellite—Explorer I. A satellite could map cosmic ray intensities around the globe—data from more points in a single orbit than all the rockoon missions had covered in six years.
In addition, Van Allen’s instruments on Explorers I and III discovered the earth’s radiation belts, areas in the earth’s magnetic field that trap intense concentrations of electrons and protons. This major scientific discovery with America’s very first satellites had tremendous political impact as hearings got underway in 1958 to create a U.S. space agency. The debate raged during Senator Lyndon Johnson’s Senate hearings on the benefits of a civilian versus a military space agency. Scientists pointed to the instrument on Explorer I as a prime example for the potential of a civilian space agency program. It added another plus to the prevailing sentiment in Congress that resulted in the civilian-controlled National Aeronautics and Space Administration—NASA.
From a scientific standpoint, the discovery spawned a whole new field of physics—magnetospheric physics. The new field helped remap the solar system in coming years, identifying the shape and dramatic influences of the magnetic fields—or lack of them—of Earth and the other planets.
An ongoing debate in history is to what degree movements shape individuals or individuals shape movements. Are individuals the deciding factor in events or do events create roles that any number of people could fill? The discovery of the radiation belts offers a compelling case study for how individuals and events interplay in the drama of human affairs. Van Allen’s discovery of the belts relied on hard scientific know-how as well as quirks of individuality and fate.
America’s first satellite, Explorer I, was an orphaned space mission called upon to rescue American self-esteem in the aftermath of Sputnik. And Van Allen had the only major scientific experiment available to load on board because of a gamble he made. In the first lap of the space race, he recognized that America had bet its money on the wrong rocket to compete against Sputnik. Van Allen prepared his instrument so it could fly on either the official rocket and satellite or on a clandestine satellite project developed on the sidelines by rocket pioneer Wernher von Braun in Huntsville, Alabama, and the Jet Propulsion Laboratory (JPL) in Pasadena, California. Von Braun’s rocket, JPL’s satellite, and Van Allen’s cosmic ray detectors saved the day for American prestige in the face of Sputnik, but Van Allen’s major scientific discovery added significantly to that prestige. Without Van Allen, Explorer I would have gone into space virtually empty-handed. Discovery isn’t just in the data, however. Van Allen and his students had to recognize in unsettling gaps of their Explorers I and III data that the gaps themselves held the secret of the radiation belts. “They told us our instruments had stopped working. We knew better and realized we had encountered a whole new phenomena in space,” Van Allen said.
In the years that followed, Van Allen juggled space missions with administrative duties as head of a university physics department, with a legendary introductory astronomy course he taught, and with membership on dozens of national committees. He mentored 35 students through their Ph.D.s with research often derived from full partnership in his space missions. The graduates shouldered leadership roles in space programs here and abroad. However hectic the schedule, he came home for dinner at 6 p.m. sharp whenever he was in town. James and Abbie Van Allen raised five children—their proudest achievement of all.
Fundamentally, Van Allen’s life encapsulates the drive of the human mind and heart to explore. Curiosity about the stars and the heavens inspired religion, art, and basic astronomy tens of thousands of years before human beings settled in the first villages—or sent the first satellites into space.
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