Saft cells ready for launch

The world's first hybrid lithium battery system for launch-flight applications has been developed by Saft as part of a European effort to improve power supply systems in space.

In a collaborative project with the Russian Institute of Space Defence Engineering (RISDE) and Synertech, the French manufacturer is developing and testing the battery for a new generation of light-class launch vehicles in Europe.

Franck Poirier, business development specialist at Saft's Space and Defence division, said: 'We are seeing changes in the way missions will be carried out. There are longer mission times and, relatively often, higher requests for power and energy during each step of the launch. So we came up with a concept based on two space-proven cells, previously used for planetary missions, that combined together and answered those changing requirements.'

The hybrid battery is based on a modular concept using primary lithium cells alongside rechargeable lithium-ion (Li-ion) cells. Saft said that this approach allows the battery to work from -20°C to +70°C, allowing for a longer mission life and extended storage times.

Poirier said: 'The main advantage is ease to the launch-pad operations, particularly when launch delays occur. However, another important benefit is the elimination delays sometimes experienced by primary cells. To overcome this, Li-ion is used first to ensure voltage stability for a short period and then the primary cells take over. This dual process makes the battery fully autonomous so it does not need to connect to an external charging supply.'

The prototype battery is currently undergoing trials and is expected to make its first space flight at end of 2011.

Ellie Zolfagharifard