James Van Allen was known for his belts

A January 2017 article in Popular Mechanics magazine, with the headline “How NASA got Apollo astronauts through the dangerous Van Allen belts”, describes some of the “many difficulties” encountered by the US Apollo space program, which ran from 1961 to 1972.

“The issue of the Van Allen belt and its radioactivity was a particularly serious concern while planning the [Apollo 11 flight to land men on the moon] mission,” it says.

This “deadly radiation of space”, as it was described in a Fox TV special, “Conspiracy Theory: Did we land on the moon?”, which first aired in 2001, was submitted as evidence that the 20 July 1969 moon landing may have been faked.

The Van Allen belts, named for US physicist James Van Allen, are described by Space.com as “giant doughnut-shaped swaths of magnetically trapped, highly energetic charged particles” that surround Earth.

Van Allen discovered these radiation belts in 1958 after the launch of Explorer 1, the first US satellite.

He had been born 44 years earlier, on 7 September 1914, on a farm in Iowa, a landlocked agricultural region in the middle of the US. Naturally, he dreamed of going to sea.

After graduating from his hometown Mount Pleasant High School in 1931, as valedictorian, he decided to join the US Navy.

In 2004, to help celebrate Van Allen’s 90th birthday, fellow space researcher and former NASA chief research scientist George H Ludwig prepared a “biographical sketch” in which he described his friend’s naval experience.

“All went well initially, but when he appeared for his physical examination, he was rejected for three reasons: he had flat feet, his eyesight was somewhat deficient, and he didn’t know how to swim.”

With his navy hopes scuttled, Van Allen entered Iowa Wesleyan College in Mount Pleasant.

In an article in the 1990 Annual Review of Earth and Planetary Sciences, Van Allen describes this phase of his education. He took all the courses offered in physics, chemistry and mathematics, a summer field course in geology, “and the one available course in astronomy … the only formal course in astronomy that I ever took”.

He cites a professor, Thomas Poulter, in physics, as a principal inspiration, noting that he was in the process of preparing for a role as chief scientist on the second Byrd Antarctic Expedition.

“I became a part of those preparations,” Van Allen says. “I helped build a simple seismograph and was entrusted with checking out a field magnetometer on loan from the Department of Terrestrial Magnetism of the Carnegie Institution of Washington, one of the most beautiful instruments that I have ever seen.”

He used the magnetometer to make precise measurements of the geomagnetic field at three random Iowa locations.

In 1935 he entered the University of Iowa and in 1939 earned a PhD with a dissertation titled “Absolute Cross-Section for the Nuclear Disintegration H2 + H2 -> H1 + H3 and Its Dependence on Bombarding Energy”.

Van Allen took on research in fields including cosmic radiation, geomagnetism, atmospheric structure, ionospheric physics, high-altitude photography of the Earth’s surface, and the ultraviolet and X-ray spectra of the Sun.

The years of study came together when NASA launched Explorer I on 31 January 1958, carrying a cosmic-ray measurement instrument designed and built by a team led by Van Allen, which was selected as the principal element of the payload of the first flight of a four-stage Jupiter C rocket.

Van Allen explains in his 1990 article: “Both the vehicle and our instrument worked. The data from the single Geiger-Mueller tube on Explorer I (as the payload was called) yielded the discovery of the radiation belt of the earth – a huge region of space populated by energetic charged particles (principally electrons and protons), trapped within the external geomagnetic field.

“The launch of Explorer III on 26 March 1958, with an augmented version of the Iowa instrument, was successful. The Explorer III data provided massive confirmation of our earlier discovery and clarified many features of the earlier body of data.” 

On 10 August 2006, NASA announced that Van Allen had died the previous day, with NASA administrator Michael Griffin calling him “one of the greatest and most accomplished American space scientists of our time”.

Griffin said few researchers “had such a wide range of expertise in so many scientific disciplines”, adding that “NASA’s path of space exploration is far more advanced today because of Dr Van Allen’s groundbreaking work”.

Along with the 1958 discovery of what are now called Van Allen belts, encircling the Earth, he also is credited with discovery of a new moon of Saturn in 1979, and radiation belts around that planet.