Wednesday, December 28. 2005
9:06 - The satellite GIOVE-A has successfully separated from the Fregat and is communicating with SSTL ground control in Guildford, UK.
This initial step was crucial, validating the successful delivery of the satellite payload for the Galileo project. Good communications at this point are essential to complete the set up of the satellite.
Early communications also validated that the orbit is correct, although this will be known with greater precision in the next two weeks.
Now that the satellite has tested OK, the attitude control and communications teams in the busy mission control room are working to power the satellite. The satellite is launched with fully charged batteries, which are currently being used in combination with a small input from the un-deployed solar panels to power communications, heating and other electronic data processing such as control systems.
The batteries only store power for about 2 hours of operation, during which period the solar panels that will power the satellite must be deployed.
There is still work to be done. First, the satellite will measure its position relative to the sun, then it will find fix its position relative to the earth. Once the position is better known, the attitude control system helps orientate the satellite correctly so that communications equipment is Earth-pointing and the solar panels will be Sun-pointing.
The physical orientation of the satellite is carefully adjusted using wheels and butane thrusters on the satellite. Once the orientation is correct, the attitude control system ensures that the satellite is correctly oriented, slowly rotating as the satellite orbits the earth.
Finally, the solar panels will be deployed. This can only take place once the orientation is correct because the solar panels are very delicate and could be damaged if the satellite was still rotating with any speed. Because the solar panels are delicate, deployment is expected to take 10 – 15 minutes after which point the satellite can recharge its batteries and become fully operational.
11:48 - The first solar panel is successfully deployed!