ESA and Inmarsat sign innovative Alphasat satellite contract

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.