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Aviation History
1983
1983 - 0053.PDF
The Tele X should achieve semi- operational status as a direct-broadcast TV and data com munications satellite in 1988. The fully operational follow- on, Nordsat or Nordcom, is likely to be based on Tele X Tele X: first of a family Sweden's Tele X data communications and direct-broadcast TV satellite, due for an Ariane launch in June 1986, is set to provide the baseline for a fully operational satellite network for the Nordic countries. Norway and Finland are expected to join the Swedish Space Corporation (SSC) in the Tele X programme early this year, and the SSC hopes that Iceland and Denmark will take part in an ambitious follow-on, likely to be called Nordsat or Nordcom. A go-ahead decision for this is expected in spring 1984. Satellites present the Nordic Govern ments with a relatively low-cost, practical opportunity to increase cultural ties with each other, as well as to inject high tech nology into industry. The nations have already agreed to increase the exchange of TV and radio broadcasting, with the ulti mate intention that each home will receive all Nordic TV stations—the languages are similar except for Finnish. The terrain and large distances make microwave or cable TV challenging and expensive, while egalitarian policies dictate that city- dwellers should not be placed at an advan tage over those living in settlements in the far north. As a result, Sweden has only two TV stations, and Norway and Iceland one each. Similar considerations apply to busi ness communications. Sweden has a 64 kbit terrestrial data transmission facility, but Norway has none—although there is an Intelsat station for the oil companies. Another incentive is that business travel in Scandinavia can be expensive, time- consuming, and frustrating—especially in the winter. SSC president Fredrik Engstrom reckons that a cable TV chan nel would cost Sweden a hundred times that of a satellite channel. Tele X is experimental, but will be run on a semi-operational basis from early 1988. Service life is designed to be five years, but the SSC hopes to achieve seven years. Two to three years after the Tele X launch will see the launch of the first Nordsat, according to the SSC's plan. The provision of two satellites will mean that they can be declared operational, since if one fails the other can take over—though only Nordsat will cover Iceland. Depending on how long Tele X lasts, a second Nordsat would be launched to take over and provide a fully operational capa bility throughout Scandinavia. Sweden expects to retain about 64 per cent of Tele X funding, with Norway taking up 26 per cent and Finland the remaining 10 per cent. Total cost is esti mated at SKrl250 million (£105 million), of which the satellite itself consumes about half. The countries will use Tele X according to their financial shares. Aerospatiale has been designated prime contractor, and Tele X will be based upon FLIGHT International, 8 January 1983 the bus of the Eurosatellite TV-Sat/ TDF 1 Franco-German direct-broadcast satellite. Aerospatiale will integrate the satellite at Cannes, and is responsible for thermal control and the solar arrays. The other members of Eurosatellite—AEG- Telefunken, MBB, Thomson-CSF, and ETCA—will take part in the programme. Scandinavian industry will receive about half of the Tele X work. Saab- Scania will build the structure, and is re sponsible for the telemetry, tracking and command system, antenna tower, and the on-board computer for the attitude con trol system. LM Ericsson is in charge of the payload, and shares ground-station work with the Norwegian company Elektrisk Bureau. Several other Nor wegian and Finnish companies such as Raufus and Kongsberg Vapenfabrikk are involved in systems work. In return for the Euro-satellite contract, Saab and Ericsson now have about 8 per cent of the TV- Sat/TDF 1 programme between them. Saab is involved in the telemetry, attitude control, and on-board data handling, while Ericsson will work on the antennas and Ku-band receivers. When Tele X studies began in earnest in 1979, it was unclear whether the market for data or TV would emerge first. Sweden thus elected for a mixed mission and Engstrom feels that this philosophy is likely to continue into Nordsat. Two TV channels will be provided in Tele X, along with one reserve and two data channels. Although other communications satellites use a time-distribution multiple access (TDMA) architecture, the SSC has gone for a single carrier per channel (SCPC) concept. In Engstrom's view—shared by Ericsson—TDMA uses the spectrum efficiently but is very com plex, and can be regarded as an aerial data-bus. Engstrom says that SCPC results in smaller terminals which cost about £20,000, and is less likely to over flow. The data rate is moderate at 64 kbit/sec for the low-cost terminal, but a larger terminal will handle up to 2 Mbits/sec. This translates to about a printed page a second. An operational Nordsat is likely to beam three or four TV channels to eastern Scandinavia, and one or two to Iceland and Greenland. Home receivers will cost about $500. Two SCPC data- communications channels will also be supplied. Tele X is taking the lion's share of Sweden's annual £40 million space bud get, but Engstrom points out that Nordsat will be commercial, hence outside the space budget. Even if Nordsat as such does not come about as planned, there will still be a requirement for some kind of Tele X follow-on, so the future for Sweden's space industry looks secure. New company to process satellite data Scandinavian Satellite Image Corporation (SSIC) is a new commercial venture set up by the Swedish Space Corporation (SSC) to receive and process data from remote- sensing satellites. The SSC's Esrange ground station at Kiruna in northern Sweden already receives data from satellites such as Landsat, and the for mation of SSIC signifies Sweden's intent to stay in the potentially lucrative satellite data-handling business. France's Spot Image Corporation has a 9 per cent share in SSIC, which will perform Spot processing work in support of Toulouse. Kiruna could become the main receiving station because, at its high latitude, Spot will be seen on each orbit. The SSC's McDonnell Detweiler image analysis system is already in use at Solna, near Stockholm. Domestic activity includes preparing turbidity maps of lakes to assess the degree of acid in the rainfall—a major environmental problem in Scandinavia, which receives the "fall-out" of industrial effluents from the rest of Europe. Forest mapping is also im portant because forest owners often fell large areas covertly to avoid high taxation on freshly cut wood. Saudi Arabia is already a major customer for SSC processing—studies of sea depths around a projected port, and a geological map of the Red Sea coast are among the activities. 69
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