(April 2004) Saftís Lithium-ion batteries are the first to be operated in a geostationary earth orbit (GEO). Saft was the pioneer supplier of this battery to W3Aís prime contractor EADS Astrium. The March 16th launch of Eutelsatís W3A by a Proton rocket was the beginning of a new system in GEO satellite power.
Previous satellites have used Nickel-hydrogen batteries, but this is the first time a GEO satellite will benefit from the lower-weight, smaller-volume Lithium-ion batteries.
As GEO satellites fly in an orbit 36,000 km (about 21,000) miles above the Earth, launch weight and mass are critical factors. By reducing battery weight and space on EADS Astriumís Eurostar E3000 platform, the Lithium-ion batteries enable Eutelsat to add more revenue-gathering transponders to the payload.
W3Aís battery is made of Saftís Lithium-ion VES 140 cells. These batteries, as the payload itself, are designed to perform throughout the 15-year service lifetime of the satellite. Like other satellites, the W3A will use its batteries only when it is hidden from the Sun by the Earth. The rest of the time, it will rely on solar panels