Gaia's ambitious mission is to chart a three-dimensional map of the Milky Way, in process revealing the composition, formation and evolution of our galaxy.
The 2.1b version adds an upgraded engine (RD-0124) with improved performance to the second stage. First launch took place from Plesetsk Cosmodrome Site 43 on 26 July 2008 with a classified military payload. The 2.1b/ST version is sometimes called Soyuz ST-B.
Arianespace SA is a multinational company founded in 1980 as the world's first commercial launch service provider. It undertakes the production, operation, and marketing of the Ariane programme. Their vehicles launch exclusively from French Guiana in South America.INFO WIKI