Who keeps track of the launcher once it lifts off?
A launch campaign from Europe's spaceport does not end with liftoff. As the launcher rises into the sky, ground stations scattered along its path take over and check that it remains on track. Computers onboard the launcher transmit data to the ground stations for instant forwarding to Europe’s Spaceport in French Guiana.
The number of ground stations used depends on the type of launcher and the mission itself. For instance, the Galliot ground station, named from the mountain in French Guiana where it is located, tracks the first five minutes of an Ariane-5 launch into geostationary transfer orbit.
Then, a tracking station in Natal on the coast of Brazil takes over for the next 3 minutes, during which the main stage separates and the second stage ignites. The next ground station to follow the track of the Ariane 5 is on Ascension Island, in the middle of the Atlantic Ocean. From here the launcher is tracked for approximately 9 minutes until the satellites are injected into geostationary transfer orbit. There are many other ground stations scattered around the world. They are used to track launchers and also to gather and transmit data from satellites in orbit.
Transportable tracking stations
A new development that commenced in 2000 was the use of a transportable tracking station. These were first used during the first operational flight of an Ariane 5, when it launched ESA’s XMM satellite. This transportable tracking station provides more flexibility.
ESA has a network of ground stations which are run by CNES through a special convention with ESA.
