GEO, GSO and MEO satellites
Saft has extensive experience in working with major prime contractors worldwide, such as Thales Alenia Space, Astrium Satellites, Boeing, Orbital Science Corporation and RNIIKP, to design, develop and manufacture on-board battery solutions for civil and military satellite projects.
A Geosynchronous Earth Orbit (GEO) satellite has an orbital period that synchronizes with the Earth’s speed of rotation. So, for an observer at a fixed location on Earth, a GEO satellite will always return to the same place in the sky at exactly the same time each day.
It is also used in the Geo-Stationary Earth Orbit (GSO) satellite is a special type of GEO, in which the satellite is placed in orbit directly above the Earth’s equator at a precise height, so that it maintains the same position relative to the Earth’s surface.
Middle Earth Orbit (MEO) satellites have orbits ranging from a few hundred miles to a few thousand miles above the earth's surface, with orbital periods ranging from around two to 12 hours. MEO is used mainly for satellite navigation systems such as GPS, Galileo, Glonass and Beidu.
Role of the on-board batteries
Normally, the on-board electronic systems on a GEO, GSO or MEO satellite will rely on solar panels for their electric power. However, the nature of their orbit means that there will be periods when the panels are ‘eclipsed’ by the Earth, receiving no direct sunlight for long periods. During these periods, the on-board batteries have to provide several kilowatts of power to ensure the satellite’s continued, uninterrupted operation, over a service life of 10 to 15 years.
A range of technologies
Saft offers a range of rechargeable battery technologies for satellite operations including:
Li-ion technology advantages
Saft is a world leader in space-proven Li-ion batteries, including the
VES140, VES180 and
VL48E, which offer a number of advantages for GEO, GSO and MEO satellites. These include:
- more power
- increased energy storage
- lower weight
- smaller footprint
- low self-discharge
- superior charging efficiency
Saft was the first battery company to put a Li-ion battery system on a GEO satellite. It has now established a significant flight heritage, with 17 GEO satellites powered by Saft Li-ion batteries in orbit at the end of 2007.