The 1945 Proposal by Arthur C Clarke
Sir Arthur C. Clarke's most famous prediction on the future is his proposal of geostationary satellite communications published in the Wireless World magazine in 1945. Not considered seriously at the time it became a reality within 20 years with the launching on 1965 April 6th of Intelsat I Early Bird the first commercial geostationary communication satellite.A satellite in an equatorial circular orbit at a distance of approximately 42,164 km from the center of the Earth, i.e., approximately 35,787 km (22,237 miles) above mean sea level has a period equal to the Earth's rotation on its axis (Sidereal Day=23h56m) and would remain geostationary over the same point on the Earth's equator. In 2002 the Clarke Orbit had over 300 satellites.
