On August 12, 1960, the Echo 1-A Communications Satellite was launched, becoming one of the very first satellites used to send and receive transmissions from Earth.
Unlike modern communications satellite, the Echo satellites could only reflect signals instead of process and re-send them.
This was achieved through the fact that the Echo satellites were a giant balloon of Mylar, measuring 100 feet across.
Due to its reflectivity and size, the Echo 1A was easily visible to the naked eye when it was still in orbit. The satellite lasted nearly 8 years before burning up on re-entry in May of 1968.
A second satellite, Echo 2, was launched in 1964. It burned up in 1969 and was the last of its kind.