TABLE OF CONTENTS Ever since the invention of line-of-sight radios, people have sought to extend the range from transmitter to receiver. Television is a familiar example of the limited range for signal transmission; we are all used to regional broadcasting. For more pressing applications, regional coverage is not sufficient. Military units on land have obstructions and terrain to overcome, while naval forces have to contend with the curvature of the Earth. Aboard ship, UHF radio antennas and blinker lights on a mast can only communicate with another ship that s within approximately 20 miles of it, even if they have good line of sight.
In both cases the road to improvement is finding a way to extend the antennas by raising them higher. Companies began to try new methods such as remotely piloted planes to extend the range of their new mobile communication devices. Among these tactics, one system that has proved highly beneficial is the use of satellites.
After World War II, several projects experimented with using the moon as an extended antenna. The U.S. Army Signal Corps transmitted radar signals to the moon and bounced them back to Earth in 1948 for proof of concept. The idea was to transmit low-power microwave signals into space and then detect their echo back on Earth. The U.S. Navy followed up 1954, successfully transmitting voice messages on microwave carriers to the moon and retrieving them. These early efforts laid the groundwork for the launch of the U.S.S.R. s Sputnik 1 on October 4, 1957, soon followed by...
