astronomy

Symphonie

Symphonie is a astronomy topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Symphonie rather than just read about it. In short: The Symphonie satellites (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…

Key takeaways

Symphonie belongs to astronomy; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Symphonie to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Symphonie from memory before moving on to harder problems.

Reference excerpt

The Symphonie satellites (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.

1963–1970: Beginnings January 22, 1963: Signing by President Charles de Gaulle and Chancellor Konrad Adenauer of the Élysée Treaty, an agreement for Franco-German cooperation. Start of preliminary studies in France (SAROS project) and in Germany (Olympia project) of communications satellites. June 1967: Both countries sign an intergovernmental convention concerning the launch and exploitation of an experimental telecommunication satellite (Symphonie) and the development and construction of earth stations necessary for control of the satellites. Formation of a Franco-German board of directors and executive committee. The committee is headed by two executive secretaries – one German and the other French. Belgium joins the program. 1967–1968: A Request for Proposals is launched for the Symphonie satellite, which was answered by two Franco-German consortia. The leaders are, respectively, Nord Aviation (which was to become Aérospatiale after merging with Sud Aviation) for the CIFAS consortium (Consortium Industriel Franco-Allemand pour le satellite Symphonie) and Matra Space for the competing consortium. The CIFAS consortium was selected after the evaluation of bids and undertook, according to the terms of the consultation, a rounding-out of the various roles of the French and German firms in charge of electronic technology. 1969: Beginning of a preliminary definition phase of the satellite, and negotiation of the contract and main subcontracts. Establishment of the industrial project team in Les Mureaux (Nord Aviation) and the client-project group in Brétigny-sur-Orge (CNES). Production of mission specifications, satellite specifications and specifications for the control and exploitation segments.

Industrial Organization 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:

Aérospatiale (France) Consortium leader and host of the integrated project team at its centre at Les Mureaux. Structures, and thermal-control subsystems and manufacture of all associated panels, mechanisms, thermal hardware and antenna reflectors (Cannes Space Centre). Manufacture of the cold gas attitude control system, harness and pyrotechnics (Les Mureaux). Integration of mechanical and thermal models (Cannes). Integration of the electrical identification model and the first flight model, Symphonie-A (Les Mureaux).

Messerschmitt-Bölkow-Blohm (MBB) (Germany) Attitude and Orbit Control Subsystem (AOCS) (Ottobrunn, near Munich). Manufacture of the hot-gas (bi-propellant) thruster system (Ottobrunn and Lampoldshausen). Apogee motor (bi-propellant) subsystem (Ottobrunn and Lampoldshausen). Mechanical ground-support equipment for integration and transport. Contribution of electrical test sets. Integration of the qualification prototype and the second flight model, Symphonie-B (Ottobrunn).

Thomson-CSF (France) Super high frequency (SHF)-antenna subsystem for telecommunications payload and VHF-antenna subsystem for the TT&C (Meudon). Manufacture of the TT&C system (Gennevilliers and Vélizy-Villacoublay). Manufacture of equipment for telecommunications transponders, local oscillators and frequency conversion. Electronic test system (EGSE level 1) for ground testing (integration phase and preparation for flight).

Siemens AG (Germany) SHF C-band telecommunications transponder subsystem (Munich). Manufacture of equipment for telecommunications transponders, receiving section and intermediary frequency amplification (Munich). Contribution of electrical test set.

SAT (France) Solar-array subsystem (Paris and Lannion). Manufacture of telemetry encoder (Paris). Contribution to electrical test sets.

AEG-Telefunken (Germany) Regulated electric power supply subsystem (Wedel, near Hamburg). Manufacture of equipment for the telecommunications transponders, transmission section (Backnang – near Stuttgart – and Ulm). Manufacture of SHF modulators and demodulators for onboard telemetry and telecommand. Contribution to electrical test sets.

Other major contributions The six CIFAS companies participated in the integrated project team with detached personnel, headed by Pierre Madon (Aérospatiale). Belgium officially contributed to the project; its industrial presence included the Ateliers de Constructions Electriques de Charleroi (ACEC) and the space division of ETCA, supplier of the DC-DC converters for the electric power supply; and SAIT for the EGSE test computers. French and German equipment manufacturers contributed under contract to the consortium members (notably Sodern, SAFT, Crouzet and Starec in France and Teldix and VFW in Germany). Major test facilities used for the qualification and acceptance tests (space environment simulation): SOPEMEA (a subsidiary of CNES in Toulouse) and IABG in (Ottobrunn). Calibration of telecommunications performance: Centre National d'Etudes des Telecommunications (CNET, in La Turbie).

… excerpt ends here. Continue reading the full article.

Illustrations

Worked examples

Example 1 — a first encounter with Symphonie

Start with the simplest possible case. Write down what Symphonie claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In astronomy, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Symphonie before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Symphonie ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Symphonie

In research: Symphonie appears in astronomy research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Symphonie in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Symphonie is common in secondary-school and first-year university syllabi. It links to neighbouring topics Communications satellites, European space programmes, France–Germany relations, so understanding it makes those chapters shorter.
In everyday life: Look for Symphonie outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Symphonie in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Symphonie means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Symphonie out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Symphonie in simple terms?

Why does Symphonie matter?

Because it connects several astronomy ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Symphonie?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Symphonie.