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1974 and 1975 communication satellites From Wikipedia, the free encyclopedia
The Symphonie satellites[1] (2 satellites orbited) were the first communications satellites built by France and Germany (and the first to use three-axis stabilization in geostationary orbit with a bipropellant propulsion system) to provide geostationary orbit injection and station-keeping during their operational lifetime. After the launch of the second flight model, they comprised the first complete telecommunications satellite system (including an on-orbit spare and a dedicated ground control segment). They were the result of a program of formal cooperation between France and Germany.
Within the bilateral (CNES – GfW) French-German contract, and under industrial prime contractorship of the CIFAS consortium (which was a European economic interest grouping under French law) composed of six companies (three French and three German), their responsibilities were as follows:
Symphonie was the forerunner for numerous telecommunications services. Its prohibition on commercial use may have paradoxically induced a larger program for experimentation of space telecommunications than ever before – both in the number of participating countries and diversity of field applications. As an example of the extent of its use, 40 countries participated in links via Symphonie A and B (east-west and north-south) – from Quebec to Argentina, from Finland to Reunion Island and from China to Indonesia. The Symphonie A and B experiments may be divided into two types:
To these types operational experiments may be added, notably for links between metropolitan France and its overseas departments for telephony and television via satellite. From this viewpoint Symphonie was a forerunner of the French national programs Telecom-1 & 2 and TDF 1 & 2, and the German programs TV-SAT and DFS Kopernikus. The wideband transponders, with their operational flexibility, made it possible to test all-access techniques (single or multiple) and modulation: FDMA (frequency sharing), TDMA (time sharing) and SSMA (spread spectrum). Symphonie terrestrial stations with antennas of various diameters from 16 to 2.2 meters (fixed, portable and mobile) contributed to the renown of the programme around the world. + Several demonstrations were:
One opportunity to demonstrate Symphonie's utility in 1978 was not used; it could have been utilized in Kolwezi (the intervention of French troops in Zaire to protect Europeans living in Katanga), if the French chiefs of staff had followed the above-mentioned UN example rather than calling upon logistical support from the United States.
Symphonie's ten years of service have been credited with developing the maturity and reliability of space technology, at a time when telecommunications operators were thinking in terms of cables and ground microwave links. After Intelsat (a pioneer in intercontinental telephony), Symphonie led to the development of regional systems with a number of applications (including tele-distribution, tele-education and reliable radio-electrical access) for use in isolated areas with no ground infrastructure and low population density. The Symphonie program was also a training program; it trained engineers, operators and satellite users, who acquired their expertise through the program and distributed it on the European and international level.
Afterwards, new European programs followed and enabled Europe to attain excellence in the field of space telecommunications. The technical success of this precursor program, the demonstration in orbit of the quality of technology born in Europe and the diverse uses benefiting many countries and communities make Symphonie one of the major bases of Europe's success in space.
On the industrial level, it helped launch Europe into major space programs and spurred an industrial restructuring which transformed national industries into European groups. Most of Symphonie's industrial partners contributed to the genesis of the Spacebus programs, and to commercial applications in space communications and direct-to-home TV broadcasting.
Symphonie was the:
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