Vanguard was a beautiful piece of mobile sculpture, four sleek stages of rocket stretching toward the sky. But it was a terrible spacecraft. It was meant to be the American entry in a competition to launch a satellite into orbit around Earth as part of the International Geophysical Year (IGY), the first scientific effort aimed at developing a big picture of the way our planet works as a whole. But the Vanguard rockets that President Eisenhower chose to use over Wernher von Braun's existing Redstone rockets were too complex and unreliable. They were never successfully tested and ultimately blew up on December 6, 1957, in Washington's panicked attempt to match the Soviets' Sputnik achievement and launch a satellite.
Luckily, the ever-resourceful rocket wizard Wernher von Braun had a different rocket and payload standing by. He knew the Vanguard combination would never make it into space, and, as a "plan B," he had prepared his Jupiter C rocket to launch a satellite called Explorer I .
Even though Explorer I was not the first or even the second satellite in space, its instruments were far more sophisticated than those on the Soviets' pioneering Sputnik. The payload was equipped with an instrument designed by James Van Allen to detect radiation belts around the Earth. Although most Americans didn't understand the scientific significance of the Van Allen Radiation Belts, they did see that the "little grapefruits," as Soviet Premier Nikita Khrushchev liked to call the U.S. satellites, could out-perform their Russian counterparts. Thanks to von Braun, America began to close the gap in the competition for superiority in space.
