Results of the Telstar System Communication Tests

Since the launch of the Telstar satellite on July 10, 1962, a large number of communications tests have been conducted at the A.T.&T. earth station at Andover, Maine. These tests have consisted of numerous successful transmissions of monochrome and color television signals, two-way telephone signals, and a variety of d a t a signals. In addition, communications test signals of many types have been transmitted. Most of the television and telephone transmission tests have been conducted between the Andover station and the British Post Office (GPO) and French National Center for Telecommunications Studies ( C N E T ) stations. These stations are respectively located at Goonhilly Downs, England and Pleumeur-Bodou, France. In addition, a number of one-way transmissions were made f r o m the Andover station to the Bell Telephone Laboratories station at Holmdel, New Jersey, described in a companion paper. 1 Communications tests, most of which have been made on a loop basis to t h e satellite and back to the Andover station, have included measurements of received carrier power, noise, transmission gain and stability, system linearity, data system errors, absolute delay and Doppler shift. A large a m o u n t of valuable d a t a has already been obtained; and, as this is written, system tests continue. This paper summarizes the more significant communication test results, most of which have been gathered during the period from July to November, 1962. 1561