In January 1958, the United States launched Explorer 1, the country’s first satellite, which operated in orbit for nearly months and did not decay enough to re-enter the atmosphere until 1970. As an attempt to reach space first in the Cold War, the Explorer project was a failure, having been edged out the previous autumn by the Soviet Sputnik program. However, Explorer 1 carried more sophisticated instrumentation and lasted longer in orbit; both of these may be taken as signs of success in this early phase of the space race.
Cold War competition to develop better spacecraft, and faster, was not simply about science: the rocket programs offered a chance to show off advances in ballistic missile technology as well as impress observers with apparent technological superiority. As a result, the American space program had suffered a serious setback when the Soviets launched Sputnik 1 and Sputnik 2 in late 1957. That the latter was effectively a failure – its cargo, a dog named Laika, died after heat control mechanisms failed – was small comfort.
As a result, after the two short-lived Sputnik satellites were launched, the Eisenhower administration hastily revived a joint army-navy plan initially codenamed Project Orbiter, based on liberated German rocket scientist Wenher von Braun’s work with modified Redstone ballistic missiles. Initially, Orbiter had been sidelined in favour of the navy’s similar Project Vanguard; however, as Vanguard encountered difficulties (its first rocket failed on the launch pad in December 1957), Project Orbiter was hastily revived, under the new and somewhat more intriguing name “Explorer.”
Explorer 1 was rapidly assembled by a joint team of the Army Ballistic Missile Agency and the Jet Propulsion Laboratory, headed by James van Allen, whose name was lent to the major discovery of the satellite, the radiation belts which circle the Earth and are a result of the planet’s magnetic field. Along with the cosmic ray detector which was used in detecting the Van Allen belts, the satellite also included temperature monitors and micrometeorite impact detectors. Unlike the Soviet probes, which tended to be ball-shaped, Explorer 1 rather resembled a 6-foot-long, 30-pound missile, with four antennae attached along its midsection. Reflecting von Braun’s work, it was launched into orbit on January 31, 1958, aboard a Jupiter-C rocket, a modified variant of the Redstone medium-range ballistic missile.
It was only a short time afterward that the first satellites would begin to use experimental solar power technology. Explorer-1, however, was powered only by its mercury batteries, which lasted for 105 days in orbit. As a result, while the satellite’s relatively high orbit meant that it remained aloft for a surprisingly long time (until 1970), final contact with ground control was in May 1958.
The Explorer program continued beyond this first satellite and was ultimately taken over by America’s fledgling new space agency, NASA, which assigned the name to a large number of subsequent orbital research satellites. Although its immediate successor, Explorer 2, failed during its launch attempt on March 5, 1958, a replacement vehicle, Explorer 3, reached orbit later that same month. In April 2010, Vandenberg Air Force Base plans to commemorate the accomplishments of Explorer 1, 52 years ago, by using an already-scheduled Taurus carrier rocket to launch Explorer-1 Prime, a similar satellite except built with modern spacecraft technology.
