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N° 34–2007: ESA and Inmarsat sign innovative Alphasat satellite contract

23 November 2007

ESA and Inmarsat Global Ltd announce on Friday 23 November in Paris the formal signature of the contract for Alphasat satellite, one of the world’s largest telecommunications satellites.


The Alphasat programme is a major cooperation between the public and private sectors. With Alphasat, Inmarsat will be the first commercial customer for the Alphabus platform, the new European high-power telecommunications platform jointly developed by Astrium and Thales Alenia Space and initiated by a partnership between ESA and CNES (Centre National d’Etudes Spatiales) as a coordinated European response to the increased market demand for larger telecommunication payloads, for new broadband, broadcasting and mobile communications services.

The Alphabus Alphasat programme represents an expenditure of € 440 million by 16 ESA Member States. Under the development schedule, Alphasat will be available for launch in 2012.

Positioned at 25 degrees East, providing extended coverage to Africa, Europe, the Middle-East and parts of Asia , Alphasat will supplement the existing Inmarsat satellite constellation and offer the opportunity for new and advanced services.

Astrium Satellites is the industrial prime contractor for the development of the satellite, including its advanced L-Band mission, which will augment the successful services already being offered by Inmarsat’s Broadband Global Area Network (BGAN). Key to the implementation of this payload is the advanced Integrated Processor, being developed by Astrium Satellites in the UK, which will provide payload flexibility enabling full coverage reconfiguration and flexible power allocation.

Thanks to this increased efficiency of spectrum use and payload flexibility the Alphasat will further enable robust communications in crisis and disaster emergencies, allowing potential connection of houses, schools and businesses in remote locations and communications links for governments with dispersed populations and improve essential voice and data communications for a wide range of industry sectors such as media, maritime, oil and gas.

For this application, the flexibility of the Alphabus platform design will be demonstrated by implementing a ‘geomobile configuration’ with a 90 degree change to the satellite flight orientation and a large deployable reflector (12 metres in diameter).

In addition to the Inmarsat payload, Alphasat will also carry three ESA-provided Technology Demonstration Payloads (TDPs): an advanced star tracker using active pixel technology, an optical laser terminal for geostationary to low-Earth orbit communication at high data rates, and a dedicated payload for the characterisation of transmission performance in the Q-V band in preparation for possible commercial exploitation of these frequencies. A fourth TDP for space environments and effects Monitoring is also under discussion.

Background Information

Alphabus is a programme initiated by ESA and CNES to combine the technical resources of Astrium and Thales Alenia Space in the development of a Large multipurpose geostationary communications platform which would extend the capabilities of European Telecommunications platforms beyond those currently offered by the existing product lines of Eurostar E3000 and Spacebus 4000.

The Alphabus/Alphasat activities of ESA are implemented within the frame of the element 8 of the ARTES programme which is worth about € 440 million in terms of to-date subscriptions. The following sixteen countries contribute to this programme: Austria, Belgium, Canada, Finland, France, Germany, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom.

For Alphasat this platform is utilised at the lower end of its capabilities, but the Alphabus is capable of supporting missions with more than 8 tonne launch mass and 18 kilowatt payload power.

Whilst being a new platform development, the Alphabus is a careful blend of core technologies resulting from the extensive heritage of the two industrial partners with the inclusion of well proven new technologies where deemed appropriate.

For further information please contact:

Dominique Detain

Communications Manager

Directorate of Telecommunication and navigation ESA

Tel: 33 01 53 69 77 26


For further information:

ESA - Media Relations Service

Tel: +33.(0)1.5369.7299

Fax: +33.(0)1.5369.7690