The United States launched its first satellite in January 1958. Explorer 1 carried several scientific instruments to measure the radiation and cosmic ray levels in orbit. As it flew around and around, scientists noted the radiation varied based on altitude and location over the earth. Dr. James Van Allen determined there was a “belt” of charged particles trapped by the Earth’s magnetic field. While the original satellite burned up over the Pacific Ocean in 1970, a group of engineering students and scientists at Montana State University at Bozeman were inspired to build a new version of Explorer 1.
The new satellite – called Explorer 1 Prime – is not an exact replica, but contains a similar suite of instruments designed to do the same functions. Both satellites gave their designers serious engineering challenges to overcome. Explorer 1 was over six feet tall, but it was only six inches wide and the scientific payload could weigh no more than thirty pounds. Dr. Van Allen relied on state-of-the-art transistor technology to reduce the size of his equipment. Explorer 1 Prime is about the size of a softball and weighs 90 percent less than its forebear. Luckily, engineers were able to employ 21st century miniaturized electronics for the components and use solar cells instead of heavy batteries for power.
NASA picked Explorer 1 Prime as its first cubesat mission. However, it has waited more than two years for the chance to “hitch a ride” on a rocket carrying a larger – dedicated – payload. This week – if all goes well – it will roar into space from the Vanderberg Air Force Base in California, a guest of NASA’s Glory satellite. Explorer 1 Prime will study the Van Allen belts like its namesake and have the chance to relive history thanks to a Geiger tube donated to the program by Dr. Van Allen himself. And like its namesake, Explorer 1 prime relives history as it follows into orbit a miniature replica of Sputnik 1.