SputnikThe Soviet Union launches the world’s first artificial satellite, the short-lived Sputnik, which transmits a steady signal from orbit that can be tracked by radio. The reaction in the United States is one of alarmed paranoia, since the launch of an orbiting vehicle demonstrates technological capabilities in excess of what is needed to launch missles from the USSR toward American soil. Sputnik’s launch is the Soviet Union’s contribution to the International Geophysical Year, an international scientific event during which the United States has also promised to launch a satellite.