- Spacebus
Infobox_Spacecraft
Name = Spacebus
Caption = Spacebus 4000C3 (AMC 12)
Organization =Thales Alenia Space
Major_Contractors =
Mission_Type = A platform forCommunication satellite ingeostationary orbit62 orders, 47 launched
Launch = Since1985
Launch_Vehicle = All types of commercial launch vehicles
Mission_Duration = up to 15 years
Mass = from 1.1 ton to more than 5 tons
Power = up to 16 kW
Orbital_elements =Spacebus is the name given to a family of geostationary telecommunications satellites developed starting in the 1980s by
Aerospatiale , nowThales Alenia Space , in itsCannes Mandelieu Space Center .They can be equipped with different payloads, but they are most often used as
communications satellite s. Their typicalorbit aroundEarth isgeostationary .History
During that period,
Aerospatiale was allied with the German companyMesserschmitt (MBB) for the manufacture of satellites, among which was the Franco-German Symphonie program. After an in-house brainstorming within the two firms, it wasGuy Lebègue , an engineer in the marketing department of Aerospatiale/Satellites, who invented the Spacebus name, with reference to the aeronautic programAirbus . The name is trademarked.A franco-German Spacebus agreement was signed, on December 9, 1983 between Henri Martre, Aerospatiale's CEO and Hans Vogels, the MBB's President. The
trademark was registered.The Spacebus name becomes a product. Many dozens of them were built and sold on the export market, bringing a lot of curencies to the countries of the participating firms, increasing their
Balance of trade as regard of the price of a Spacebus, close to the AirbusA 320 price.A number follows the name representing the weight class of the satellites. 1000 for the metric ton, 2000, etc.
The name Spacebus was also given to satellites which were being manufactured while the trademark was being registered, although they have a different architecture (but "not the Symphonie satellites" which had already been launched several years before, and "are not therefore in the Spacebus family".
* Spacebus100for the first generation "Arabsat" satellites
* Spacebus 300 for the direct television satellites in the Franco-German program, and the SwedishTele-X program.Architecture
A
satellite is generally composed of two sections: the payload, which is specific to the mission (telecommunications, Earth observation, navigation, science, etc.) and the platform (or service module) which provides the payload with all the necessary functions.The idea was to develop a generic platform able to adapt itself to various future missions and to the evolutions in the capacity of
launch vehicle s in order to reduce manufacturing costs and if possible to create a series effect.And in fact, more than sixty Spacebuses have been built, since the SB1000 Arabsat satellites in the one-ton class in 1981 up to the SB4000, weighing more than four tons, of the years 2000.
The architecture of the platform is based on:
* A modular design with separate U-shaped payload module, allowing parallel integration between Aerospatiale for the Service Module and a telecom equipment manufacturer for the Communication Payload, followed by the final mating, and test in the Cannes Space Center.
* A central tube incomposite material made of acomposite honeycomb andcarbon fibre sandwich, acting as the satellite’s spinal column, interfacing with the launcher, housing twofuel tanks. Several panels are attached to it caring equipment for servicing. Also attached are three panels carrying the telecommunications payload equipment, two of which (in honeycomb sandwich with aluminium sides to let calories pass through) will act asthermal radiator s allowing the heat generated by the payload to dissipate into the cold of space byradiation . At the beginning, these elements were produced in the Les Mureaux centre of Aerospatiale. After the separation of its satellite activity, the space centre in Cannes Mandelieu took over the manufacture of these elements in composite materials, and in particular, the production of the all the plane structures. The central tube, requiring very special tooling remained in Les Mureaux, which had becomeEADS . A second source isSAAB in Sweden.* A thermal control system necessitating very sophisticated computation programs and technologies which were developed in Cannes: dissipating radiators, super insulation, electric heaters,
heat pipe s.
* Rigidsolar cell s arrays, with various combinations of panels depending on the electrical power requirements
* An electric architecture developed by ETCA in Belgium, with batteries of evolving technology from Nickel-Hydrogen toLithium-Ion .
* Chemical propulsion based on bi-propellant technology developed by MBB in Germany. Theelectric propulsion was also studied, developed and introduced for two satellites: Stentor and Astra-1K, both of which were unfortunately lost during launch.
* A three-axis attitude and orbit control system developed initially by MBB.
* Various mechanisms for opening solar arrays and antennas developed and built in Cannes.The Versions
The Spacebus evolution towards heavier satellites followed the capacity of launchers from
Ariane 1 toAriane 5 . But it should be noted that Spacebuses have always been designed to adapt to all available launchers on the commercial market: not only the various versions of Ariane, but alsoThor Delta ,Atlas rocket , Soyuz,Proton ,Long March and even exceptionally for launch by theSpace Shuttle Discovery for one of the Arabsat satellites launched on theSTS-51-G mission. These versions will be declined in the following charts. The tables show the “end of mission” meaning the end of operational use; after which, the satellite is often uncontrolled, perhaps slightly de-orbited (a manoeuvre strongly recommended by the satellite operator), and will drift for eternity, its “end of life” not signifying very much. Please also note that certain satellites have changed operators, either before launch or during their orbital life. They can even in this case change their orbital position.pacebus 100
(Arabsat), with 2 KW of electrical power. Later on during the programme, the name "Spacebus 1000" may be used, to allow more easy comparison with the "Spacebus 2000" satellites.
;Launchers
* Two were launched by Ariane in itsAriane 3 andAriane 4 versions
* Arabsat-1B was launched by theSpace Shuttle ,STS-51-G mission to whichPatrick Baudry was participating. It needs an additional rocket motor to transfer the satellite between theLow Earth orbit of the Shuttle to thegeosynchronous transfer orbit : PAM-D.Spacebus 3000
In the advent of
Ariane 5 launches the Spacebus 3000 appears with masses between 2 and 6 metric tons and electrical power supply of 5 to 16 KW. It is declined into several versions profiting from the ever larger payload fairings.In 1991 the cooperation was further extended with the creation of "Satellite Alliance" which brought in three partners: Alcatel Espace,
Alenia andSpace Systems/Loral .Spacebus 3000A
First version developed for the second generation for
Arabsat . It was adopted by two new customers:
* for the Thaicom 5
* and the satellite Sinosat-1. The customer is EuraSpace, a common 50/50 subsidiary between DASA and China Aerospace Corporation (CASC).;Launchers
* Always Ariane 4
* A first launch with Ariane 5: Thaïcom 5.
* A new launcher is used for Sinosat: the ChineseLong March Rocket .Spacebus 3000B3S
. A single satellite in this class: Astra 1K. At the time it was this biggest commercial communications satellite ever built with an electric power supply of 13 kW. Unfortunately it was lost at launch due to a failure of the Proton rocket.
Spacebus 4000C1
For the C1, the height is 4 meters and the electrical power supply is 8.5 kW.
.
A new type of launcher is used:
Zenit rocket on the mobile launch base on the equator,Sea Launch .Spacebus 4000C4
With a height of 5.5 meters, this family can receive 16 kW of solar arrays.
.
;Launchers
* Two will be launched by Zenith from Sea Launch
* Ciel 2 will be launched by Proton managed byInternational Launch Services .Express-4000
On December 6, 2007,
Thales Alenia Space and the Russian companyNPO PM , inKrasnoyarsk , signed [Thales Alenia Space and NPO-PM to finalize an industrial cooperation agreement, Cannes, December 6, 2007, [http://www.thalesonline.com/space/Press-Room/Press-Release-search-all/Press-Release-search-result/Press-Release-Article.html?link=6e0d1819-5c02-3426-4123-41507c545457:central&locale=EN-gb&Title=Thales+Alenia+Space+and+NPO-PM+to+finalize+an+industrial+cooperation+agreement&dis=1 www.thalesonline.com/space/Press-Room] ] an industrial agreement for the development of a powerful multimission platform, named Express-4000, based on the Spacebus 4000 architecture.Express-4000 is a platform for direct injection (GSO) in geostationary orbit, compatible with the
Proton rocket launcher, built, integrated in Krasnoïarsk and sale by NPO PM. On-board will be installed a telecommunications payload build by Thales Alenia Space.Synthesis as September 9, 2008
* Ordered: 65
* Delivered: 54
* Under construction: 11
* Launched with success: 50
* Lost during launch: 4;Launchers used
* "Ariane 4": 21
* "Ariane 5": 12
* "Atlas": 6
* "Ariane 1 à 3": 4
* "Proton": 4
* "Long March": 4
* "Delta": 1
* "Zenith": 1
* "Shuttle": 1Records
* February 2, 1985: launch of Arabsat-1A, First
Arab League communication satellite, a Spacebus 100
* October 28, 1988: launch of TDF-1, First EuropeanDirect broadcast satellite , a Spacebus 300
* October 28, 1998: launch of GE-5, First European communication satellite saled toUnited States , a Spacebus 2000.
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