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By | June 6, 2001

      Does the French space agency CNES aim to supplant the ESA in developing new communications satellite technologies? Earlier this year, CNES evolved a plan (TCS-21, Technology for Communications by Satellite) which has since secured funding to the tune of E30 million until 2003; around half of this has been earmarked for TCS-21 itself, and the remainder for validation tests.

      According to Didier Leboulch of CNES’s Radiocomunications Delegation, the agency sees its initial objective as the development of a ‘large platform’ for satcoms – bigger that Astrium’s Eurostar 3000 model already in work for Inmarsat I-4 and Intelsat-X. What CNES has in mind is a platform with a launch mass greater than seven tonnes, developing over 25kW of electrical power. Such a satellite might have a construction price-tag of E200 million and cost E33 million a year to operate, with the industry’s contribution being between 15 and 50 per cent.

      But CNES does not advocate building a big satellite just for its own sake; size is clearly important for carrying the payloads that will soon be needed. TCS-21 envisages a satellite with a simultaneous capacity of five Gigabits per second. This may fall well short of the ‘Third Generation’ of Internet satellites prophesied for 30 years’ time by Takashi Iida and Yoshiaki Suzuki of Japan’s Communications Laboratory at the AIAA Toulouse Conference in April. Indeed, they would weigh “several hundred tonnes” and have capacities of “500Gbps to 5 Terabits per second.” But it’s a start, being roughly five times the throughput of most existing satellites.

      But clearly, plenty of work is needed on payloads if these data rates are to be maintained and satellites are to hold their own against terrestrial fibre and wireless. Providing these seems to be more the role of ESA, judging from the views of Claudio Mastracci, ESA’s director of Applications Programmes (which include telecoms as well as Earth observation). He believes that while “full support” will be offered to CNES in developing these large platforms, Alcatel and Astrium may have already signed an agreement for joint development of a ‘common platform’, much as Stentor, CNES’ technology demonstrator, was developed. Stentor is now set to be launched this coming December.

      Clearly, the two companies will be working closely together in the future. Leboulch could even see them merging eventually, a prospect he views with equanimity despite the reduction in competition it would entail. The only alternative could be one or other (or both) merging with US partners, though this could pose security problems with military orders. Italy’s Alenia Spazio believes Leboulch, “doesn’t want to build large platforms.”

      Where ESA could contribute is in giving support to on-board equipment suppliers. These might be largely separate departments of the same two companies, though ESA has to be aware of its obligations towards smaller companies and those in smaller member-states.

      ESA is now developing its proposals, via a Joint Task Force, for the next Ministerial-level Council meeting, to be held in Edinburgh this coming November. At the last ‘Ministerial’ in Brussels in May 1999, ESA requested E370 million for telecoms programmes (including Galileo initial funding) and got E300 million approved. This time around, Mastracci will be requesting between E1.6 and 2.0 billion, to last until end-2006. His argument for an increase of this size is that telecoms technology provides the strategic infrastructure for all services.

      One item that will have to move towards a flight demonstration, if it is not to be rendered obsolete by US service introductions (Spaceway, Astronlink), is theARTES-3 programme. According to Pietro lo Galbo, head of telecoms at ESTEC, this could fly by 2003-04.

      ARTES-3, ESA’s multimedia programme, has been primarily concerned with two Ka-band GEO systems, EuroSkyWay (Alenia) and WEST Early Bird (Astrium). Both are ‘regenerative’ systems, in that the uplink signal is demodulated on-board and stripped of its noise, switched at IF or baseband, and then re-modulated for down-linking. In this it differs radically from transparent or ‘bent-pipe’ systems. Also, both are multi-spotbeam systems. It is considered that one or both may move from lab tests to an in-orbit demonstration by 2006 or earlier; Mastracci mentioned the possibility of flying a ‘reduced’ EuroSkyWay.

      Apart from ARTES-3, ESA is likely to give attention to the satellite component of UMTS (otherwise 3G cellular systems), though Mastracci is still uncertain that satellites could play a useful role in bringing service to remote areas which it would not be economical to equip terrestrially. He must remember the quicker-than-expected build-out of 2G cellular services which – among other things – sank Iridium.

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