Jun 9 2006
Galileo Industries and the European Space Agency (ESA) have selected Saft lithium-ion (Li-ion) battery modules to provide the on-board power for the four satellites that will comprise the IOV (In Orbit Validation) phase of GALILEO, Europe's contribution to the Global Navigation Satellite System (GNSS). The GALILEO Programme is jointly funded by the European Commission and ESA and the project will see Saft's high-energy, flight-proven Li-ion batteries, which are already well established as the first-choice for GEO (Geosynchronous Earth Orbit) communications satellites, breaking new ground in the world's first application of rechargeable Li-ion battery technology for a permanent constellation of MEO (Medium Earth Orbit) satellites.
This latest development follows Saft's successful delivery in May 2005 of the Li-ion battery modules for the GIOVE second pathfinder (technology validation) satellite for the GALILEO programme. This satellite, manufactured by Alcatel Alenia Space on a Proteus LEO platform and due for launch late 2006, will and perform in-orbit testing and characterisation of critical payload elements and the Galileo navigation signal and receivers.
GALILEO is scheduled to be fully operational before the end of the decade, with overall costs estimated at EUR3.7 billion. It is seen as an independent but complementary system to the US GPS and Russia's Glonass. GALILEO is being designed around the needs of civilian users with the objective to make the already existing and future satellite-based navigation systems inter-operational and compatible.
GALILEO will comprise 30 satellites in a 'Walker' constellation, with three orbital planes at 56degrees nominal inclination and an MEO altitude of 23,222 km. Each plane will contain nine operational satellites, equally spaced at 40degrees, plus one inactive spare satellite that can be manoeuvred quickly into position in case of failures. This configuration results in a constellation repeat cycle of 10 days, during which each satellite will have completed 17 revolutions.
The VES180S cells will be manufactured in Saft's industrial factory in Bordeaux, France and integrated into the satellite modules and tested at Saft's facility In Poitiers, France. The qualification and flight model batteries will be delivered to Alcatel Alenia Space, the company responsible for integration of the GALILEO satellite. Saft will deliver the batteries for the four satellites according to a planned schedule between November 2007 and April 2008.
In normal operation, the solar panels on the GALILEO IOV satellites will supply all the power required for the on-board electronic systems. But there will be a minimum of 170 times a year when the panels are 'eclipsed' by the earth, with no direct sunlight for periods of up to 80 minutes. During these periods, the on-board batteries will have to provide around 1.5 kW of power to ensure the satellite's continued, uninterrupted operation, throughout a 12-year mission.
Saft has developed a specialised high energy battery module for the GALILEO IOV project, comprising nine Li-ion battery packs connected in series, each pack comprising three VES180S cells in parallel. The VES180S is a new, up-rated cell derived from the VES140S cells established as the standard for GEO satellite applications. It has a specific energy of 170 Wh/kg, a 25 per cent improvement on the VES140S, providing a significant weight saving and improved payload capacity.
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