Gaia spacecraft launched to map 'a billion stars'
19 December 2013 Last updated at 19:16 GMT
The world's most powerful camera has been launched from French Guiana into space on a five year voyage to map the stars in our galaxy.
The Gaia probe will travel more than 90 million miles away from Earth with the job of mapping the precise positions and distances of more than a billion stars.
Pallab Ghosh reports.