The First U.S. Satellite
Explorer 1 in pre-launch configuration atop its rocket. Courtesy Marshall Space Flight Center.
Sixty years ago January 31, the U.S. sent its first successful satellite launch skyward. Onboard was the Explorer 1 spacecraft, which was created as part of the country’s participation in the International Geophysical Year. That was a time of scientific exploration of Earth, its magnetic field, and other properties. Explorer 1 carried a cosmic ray experiment, designed and built by James Van Allen and his team (and for whom the Van Allen Radiation Belts are named). It sent back some tantalizing data, which spurred scientists to do further work with later Explorer satellites. The biggest discovery it made was the Van Allen radiation belts, a zone of trapped radiation high above Earth’s surface. The spacecraft also counted “hits” from cosmic dust in near-Earth space.
The Explorer 1 launch wasn’t the first satellite. That honor goes to the Soviet Sputnik launch a few months earlier, on October 4, 1957. While the U.S.’s satellite had been long-planned, the Soviet launch was a surprise. They, too, had been planning for a while, but they managed to get up there first.
Both launches were, in a sense, ...