Communications Satellite, Echo 1

Launched in 1960, Echo 1 was designed to explore the new field of communications via space. Its design was remarkably simple: Essentially a large balloon, measuring 30 meters (100 feet) across, the satellite provided a reflective surface in space. Radio signals directed at Echo from one location on Earth "bounced" to another. By the time Echo 2 was launched in 1964, other types of communications satellites had proven superior, and researchers used the Echos primarily for scientific experiments.