Watch the full replay of the launch coverage of ESA's billion-star surveyor Gaia. Liftoff occurred at 09:12UT/10:12CET on 19 December and the successful deployment of Gaia's sunshield was confirmed approximately 90 minutes later. Gaia is now on its way to L2, where it will study the characteristics of 1 billion stars to create the most precise 3D map of our home galaxy, the Milky Way.