The 1945 proposal by Arthur C. Clarke for Geostationary Satellite Communications

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.

The first reference to geostationary satellites is Clarke's letter to the editor titled Peacetime Uses for V2 published in the 1945 February issue of Wireless World (page 58).
Arthur Clarke in his Scientific Autobiography Ascent to Orbit published 1984 say that he had forgotten about this letter till he was reminded of it in 1968 by the engineering staff of the Sri Lanka Broadcasting Corporation.

A 150 dpi scanned image of page 58 of an original 1945 Wireless World magazine is linked at http://lakdiva.org/clarke/1945ww/1945ww_feb_058.html

Clarke privately circulated in 1945 May a proposal titled The Space-Station: Its Radio Applications in six typed manuscripts. The top copy of that is now in the National Air and Space Museum, Smithsonian Institution, Washington D.C. It was reprinted in Spaceflight, Vol 10. no 3, March 1968 pp 85-86 and in Ascent to Orbit pp 57-58.

In Ascent to Orbit Clarke says the paper with original title The Future of World Communications was written in late June and submitted to the RAF censor on July 7th. It was sent to Wireless World on August 13th and accepted on September 1st. The editor had changed title to Extra-Terrestrial Relays and published it in the 1945 October issue of Wireless World (pages 305-308).

The 150 dpi scanned images of pages 305-308 of an original 1945 Wireless World magazine is linked below. Note that the last two pages reprinted in Ascent to Orbit have been reformatted omiting an illustration on page 307 which had no Figure number. See link at
http://lakdiva.org/clarke/1945ww/1945ww_oct_305-308.html

See also details of the Wireless World Magazines images
http://lakdiva.org/clarke/1945ww/provenance.html

http://lakdiva.org/clarke/1945ww/

Mike Terry