ESA’s Gaia Galaxy-Mapping Satellite

On December 19, 2013 at 09:12 UTC (1:12 AM PST), a Soyuz ST-B launched from the European Space Agency’s Guiana Space Centre in French Guiana carrying a spacecraft called Gaia. Its five year voyage will not seek out and find new civilizations–but it will boldly go where no man has gone before. Gaia is designed to create a three-dimensional map of our region of the Milky Way galaxy by carefully surveying one billion of its stars. While one billion stars sounds like a lot—and in fact is—it is no more than one percent, and probably less than one percent, of the 100 to 400 billion stars in our galaxy.

Gaia will take up a position at L-2, the Lagrange point 932,000 miles from Earth, on the far side of the moon. It should reach L-2 in about three weeks.

Source SPACE.com: All about our solar system, outer space and exploration