In 1960, the USA’s space agency NASA launched a balloon-shaped satellite, Echo-1 (photo, below). It took up an orbit comparatively close to Earth, about 1600 kilometers up. Once in position, it grew to a diameter of 30 meters (100 feet), by inflating its own balloon made of a plastic material called Mylar. The Mylar had a reflective coating of aluminum. Radio signals beamed from Earth to Echo-1 bounced off the Satellite’s surface and could be received on the Earth far from the original transmission.
NASA’s Echo-1 successfully transmitted voice, music and pictures between the USA and Europe, but in 1968 it disappeared from the sky.
Project Echo (Wikipedia)