When two Symphonie satellites were orbited in December 1974 and August 1975, they marked multiple key firsts for European space – and for the participating Airbus predecessor companies. However, there was a “catch,” which was to drive European decisions in space programmes for years to come.
The Symphonie spacecraft resulted from a French/German cooperative agreement signed in 1963 by President Charles de Gaulle and Chancellor Konrad Adenauer. The goal was to build on the countries’ early experience with satellites (including France’s Asterix, lofted in 1965 on the country’s Diamant launcher; Germany's AZUR, orbited in 1969 on an U.S. Scout-B rocket; and the Franco-German DIAL satellite, lofted in 1970 by a Diamant B launcher version).
This high-level agreement set the way for the future, forming the first European communications satellite system. Symphonie-A and Symphonie-B also were the world’s first three-axis stabilised communications satellite in geostationary orbit with a bipropellant propulsion system, meaning the spacecraft were maintained in a fixed orientation: providing a stable platform for relay duties via its antennas aimed at the Earth, and the power-generating solar panels that face toward the Sun.
Among the Airbus predecessor companies involved in Symphonie’s development were France’s Aérospatiale (leader of the industrial consortium, host of the integrated project team at its Les Mureaux centre; and developer/manufacturer of structures and subsystems), and Messerschmitt-B?lkow-Blohm of Germany (attitude, orbit control and thruster systems; along with testing and integration).
The “catch” for Symphonie stemmed from Europe’s inability to orbit these pioneering spacecraft due to the failed multinational launcher programme, called Europa. With Europa’s abandonment, France and Germany turned to the U.S. for launches on Thor Delta 2914 satellite-launch vehicles – but with a restriction from across the Atlantic: any commercial use of Symphonie was forbidden by the U.S. State Department.
Symphonie programme managers and the government officials were convinced this was a clear protectionist measure. The U.S. aerospace industry had not yet applied three-axis stabilisation to its telecommunication satellites – relying on spin stabilisation instead. With a “spinner” satellite, the entire spacecraft rotates around its own vertical axis, like a spinning top. Disadvantages of spin stabilisation include the inability to use large solar arrays to obtaining electrical power from the Sun (therefore requiring significant amounts of battery power), and the need to “despin” a satellite’s antennas, trackers and optical instruments in order to point in the desired direction.
According to Professor Hubert Curien (who headed the French CNES space agency and the European Space Agency, later serving as the French research and technology minister), Symphonie sharpened Europe’s desire to pursue future programmes that ensured European sovereignty in access to space. “It helped give ‘birth’ to many initiatives in the years to come, including the decision to create the Ariane launcher. This avoided having to rely on others to orbit our own satellites; and it encouraged industry and government alike to support French and German national programmes in satellite telecommunications and TV relay.”
The U.S. prohibition on Symphonie’s commercial use – restricting them to experimentation only –helped bring Europe together for a space telecommunications effort larger than ever before in terms of participating countries; and for humanitarian, cultural, educational, technical and scientific experiments that were performed (ultimately involving 40 countries, and employing fixed, portable and mobile ground stations). France also employed the Symphonie spacecraft to validate satellite-based telephony and television links between metropolitan France and its overseas departments – technologies applied in many programmes to come.
There is no question that Symphonie’s legacy goes well beyond the two satellites and their 10-years of loyal in-orbit service. In addition to spurring the communications sector’s evolution from terrestrial cable and microwave links to space-based relay, Symphonie also helped create a cadre of designers, technicians and builders – along with a willing global user community – for European space-based telecommunications services.
As importantly, it spawned an industrial restructuring which transformed national industries into European groupings, helping to create a framework for what is Airbus today.
Among the programmes that followed in Symphonie’s footsteps were the Telecom national spacecraft in France, which provided relay capacity for both civilian and military users – designed and manufactured by Airbus predecessor company Matra. The spacecraft use for Telecom satellites were derived from an earlier program called ECS, in which Matra was a subcontractor to British Aerospace (with this UK activity later to become part of what now is Airbus’ spacecraft production activity).
France and Germany came together for collaboration on direct broadcast satellite systems, with the TDF 1 and 2 relay platforms serving France after launches in 1988 and 1990; and TV-SAT 1 and 2 orbited in 1987 and 1989 for utilisation by Germany – all cooperatively produced by Airbus predecessor companies Aérospatiale and Messerschmitt-Boelkow-Blohm. TDF and TV-SAT were based on Aérospatiale’s Spacebus platform, which evolved into a product line of satellites built for France, Germany and export customers (including the Arabsat telecommunications organisation and Sweden). Responsibility for development and production of the Spacebus series subsequently was passed to another spacecraft manufacturer.
Also included in the Airbus telecommunications heritage are the German national DFS satellites developed as a national system for the German Federal Post Office. Three spacecraft were launched from 1989 through 1992, produced by a German industrial consortium that included Airbus forerunner company MBB-ERNO.
A long-running satellite product line is Eurostar, jointly developed in the mid-1980s by?Matra Marconi Space?with British Aerospace, and now integrated within?the space activities of Airbus. The Eurostar series of high-performance communications satellites is suited to a full range of communications missions – including links with fixed ground stations, mobile services, broadcast and broadband – becoming a benchmark for in-orbit reliability. Airbus has expanded Eurostar in a phased process, increasing the satellite power and propulsion capability and ability to accommodate equipment and antennas – as well as on-orbit lifetime.
Included in the Eurostar series are Skynet spacecraft for the British Ministry of Defence, which helped establish Airbus’ competence in secure communications relay platforms for utilisation by militaries and governments.
Overall, more than 84 Eurostar satellites have been ordered, with the fleet of spacecraft logging well over 600 years of combined operations in orbit. Among the newest versions are the Eurostar E3000, featuring high mission flexibility and enhanced payload accommodation; and Eurostar Neo, with increased efficiency, performance and competitiveness from the cost and manufacturing schedule perspectives. Both the Eurostar E3000 and Eurostar Neo platforms can use the more traditional chemical propulsion systems as well as new-generation electric propulsion – which enables a reduction in the mass of satellites, leading to lower launch costs for a given mission and/or a more capable satellite for a given mass.