Each balloon is provided with a tracking device, which transmits the position, altitude, speed and direction of each balloon back to race control. The trackers use the Inmarsat D+ tracking service, which allows short bursts of data to be sent from the balloon to the tracking providers. Gordon Bennett 2010 is pleased to be working with Satpro, who for many years have provided tracking services to the competition.
The tracker consists of a satellite transceiver, and a pair of batteries, which give at least four days' worth of power. A message is sent every few minutes detailing the balloon's situation. Each "packet" of data takes two seconds to be sent to the satellite. The message is forwarded to Inmarsat's ground stations and thence to Satpro HQ. Finally, a message is sent to the GB2010 servers, enabling us to bring you extremely up-to-date positional information for each team.
The tracker itself is inside a padded bag which is attached to the balloon's rigging. It is placed far enough away from the balloon's hydrogen so as not to present a risk, and it must have the clearest possible view of the sky to work effectively. The bag prevents the batteries and transceiver from getting too cold, which would affect the capacity of the batteries.
Tampering with the trackers, for example to disguise any airspace infringements or to prevent other teams from gleaning useful tactical information, will result in disqualification from the race.
Click here to see the tracks from the 2009 Coupe Aéronautique Gordon Bennett.