1958-0001a

As part of the US participation in the International Geophysical Year, NASA and the Jet Propulsion Laboratory launched its first successful satellite, Explorer I following the Soviet Union’s Sputnik I and Sputnik II, into orbit and beginning the Space Race with America’s entry-on this day in 1958. Remaining aloft and functional for some one hundred and eleven days, the payload consisted of various sensors and detectors to measure cosmic radiation and micrometeor impact and was instrumentation array was designed and installed under the direction of astrophysics professor James Van Allen of the University of Iowa. Explorer I discovered the zone of energetic particles enveloping the Earth that forms as a result of solar wind caught and shaped by the planet’s magentosphere and Van Allen’s namesake belts which protect the atmosphere from obliteration by solar flares.