Ariane, a European Meccano set

28 september 2009
Just as Airbus has managed to bring the aircraft manufacturers of four and later six countries to work together in the aviation industry, Ariane has done the same with the space industries of initially 10 and later 12 countries. For the last five years, the industrial prime contractor for Ariane, Astrium Space Transportation, has been conducting an ‘industrial symphony’ whose finale is in Kourou, French Guiana.

Largely inherited from an industrial share-out defined on the basis of the financial contributions made by the twelve states participating in the Ariane programme (Austria, Belgium, Denmark, France, Germany, Ireland, Italy, the Netherlands, Norway, Spain, Sweden and Switzerland), production of the Ariane 5 ECA launcher is spread between some 20 main sites across Europe and in French Guiana.

Main cryogenic stage (EPC)

Integration of the Ariane 5 ECA main cryogenic stage (EPC) during the campaign for Flight 171 in Kourou in March 2006. (© ESA – CNES – Arianespace)
Integration of the Ariane 5 ECA main cryogenic stage (EPC) during the campaign for Flight 171 in Kourou in March 2006. (© ESA – CNES – Arianespace)
The main body structure of the launcher takes shape at Les Mureaux near Paris, where Cryospace (an Astrium Space Transportation–Air Liquide company) manufactures the EPC (main cryogenic stage) tank. The tank is then transferred to the Astrium Space Transportation launcher integration facility, also at Les Mureaux, where it is assembled with the front skirt built by MT Aerospace in Augsburg (Germany). The front skirt transmits the thrust generated by the solid propellant boosters to the launcher. The tank is also integrated with the conical thrust frame built by Dutch Space, an Astrium subsidiary, in Leiden (the Netherlands). The Vulcain 2 engine delivered from the Snecma site in Vernon (France) is assembled with the thrust frame and comprises a combustion chamber built by Astrium Space Transportation in Ottobrunn. Its thrust frame also houses the GAM engine actuation unit built by Sabca in Brussels (Belgium). The complete stage is then taken by barge to the French port of Le Havre for shipment to French Guiana.

Main cryogenic stage A (ESC-A) and VEB

Cryospace also manufactures the liquid hydrogen tank for the ESC-A at Les Mureaux, while Air Liquide constructs the liquid oxygen tank at its Sassenage (France) site. The two tanks are transferred to Astrium Space Transportation in Bremen, northern Germany, where they are integrated with the thrust frame built by Dutch Space in Leiden. The thrust frame is prepared by Astrium Space Transportation in Bremen, and is then fitted with the Snecma HM-7 engine in Vernon, where the industrial organisation is similar to that for the Vulcain engine, and a combustion chamber supplied by Astrium in Ottobrunn. An upper stage comprising the Aestus engine developed by Astrium in Ottobrunn near Munich in Germany is used for the ES/ATV variant.

The ESC-A is mated with the Vehicle Equipment Bay (VEB), also integrated in Bremen based on a structure manufactured by EADS CASA Espacio in Madrid (Spain). The VEB houses the on-board computer, the latter containing the launcher flight software programme enabling the launcher to do everything for itself immediately after ignition takes place, namely trajectory calculation, management of the launcher stages to achieve the orbits targeted and indeed provision of a launcher reconfiguration capability should certain items of equipment fail. VEB components come from Denmark, Spain, France and Sweden. The ensuing composite structure is also shipped out to French Guiana by sea.

1/Mounting the ESC-A stage (Flight 172 campaign) in Kourou in July 2006. (© ESA – CNES – Arianespace)
2/ Fitting the Vehicle Equipment Bay on the ESC-A stage (Flight 172 campaign) in July 2006 in Kourou. (© ESA – CNES – Arianespace)
3/ Roll-out of a solid propellant booster to the Launcher Integration Building (BIL) in June 2006 (Flight 172 campaign) in Kourou. (© ESA – CNES – Arianespace)

Solid propellant boosters (EAP)

The cylindrical segments constituting the body of the EAPs are machined by MT Aerospace in Augsburg (Germany). They are assembled in three sections. The two largest sections are transferred to French Guiana and the smallest to Italy, to receive their thermal protection and solid propellant loads at the Regulus Guiana Propellant Plant (UPG) in Kourou and Avio in Colleferro (Italy) respectively. When the three sections have been combined and assembled in the Booster Integration Building (BIP) in Kourou, under the responsibility of Europropulsion, they are integrated with a nozzle supplied by Snecma Propulsion Solide in Haillan (France), thus forming the solid rocket motor (MPS). The MPS is fitted with front and aft skirts, and a nozzle actuation unit built by Sabca in Brussels. The EAP is then inspected by Astrium Space Transportation and transferred by rail to the Booster Storage Building (BSE) to await the start of the launch campaign.

Launch campaign

Executed under the responsibility of Astrium Space Transportation since launcher L527*, the launch campaign starts in the Launcher Integration Building (BIL), where the EPC main stage is suspended over the mobile launch table. This is followed shortly by transfer of two EAP boosters to the table. The EPC is then lowered onto the anchor clamps, which are manufactured by Kongsberg in Norway, and located in the EAP skirts. The ESC-A stage and the VEB are then erected on the top of the launcher. Following test and inspection of the mechanical, electrical and fluid interfaces, together with all system aspects, the launcher is delivered to Arianespace in the Final Assembly Building (BAF). This is where the launcher receives its payload(s). The payloads are integrated in an upper composite comprising a fairing manufactured by Oerlikon Contraves in Zurich (Switzerland) and payload adaptors as required, manufactured in Madrid by EADS CASA Espacio or in Gothenburg (Sweden) by RUAG Aerospace, and a SYLDA 5 structure manufactured by Astrium Space Transportation in Les Mureaux in the case of a dual launch.

The role of Astrium Space Transportation does not stop there. The launcher still requires something else to accomplish its mission. This is the flight software programme prepared in Les Mureaux. Members of the teams, all with comprehensive knowledge of the system, analyse the specific requirements of the mission concerned, and also telemetry data from previous launches so that, flight by flight, the operational performance and reliability of Ariane can be further improved.

Flight 171 campaign in April 2006: the launcher is almost ready to leave the BIL for transfer to the BAF. (© ESA – CNES – Arianespace)

Each of the above-mentioned contractors and sub-contractors calls in turn on the skills and expertise of specialist suppliers for their components, sub-systems, materials, services and infrastructures. It would therefore be foolhardy to suggest that this covers all the people who are working all over Europe on the incredible adventure that is the Ariane programme.

The role of Astrium Space Transportation, as sole prime contractor, and through its mechanical, aerodynamic, electrical and avionics studies of the entire programme, is to make sure that these individual contributions, industrial contracts, components, systems and sub-systems, from all over Europe, are perfectly assembled to result in a technically coherent whole. Just like the conductor of an orchestra, making sure that each individual plays his or her part in mutual harmony, Astrium Space Transportation ensures that each flight is performed like a symphony; eminently complex, precise and harmonious.

* The first Ariane 5 ECA heavy-lift launcher of the PA production batch (L527) lifted off into the sky above French Guiana on 11 March 2006 for the successful launch of the Spainsat and Hot Bird 7A satellites. This was the first Ariane 5 launcher to be built and flown with Astrium acting as sole prime contractor for Arianespace

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