First Launch: 2013-12-19. Last Launch: 2013-12-19. Number: 1 . Gross mass: 2,030 kg (4,470 lb).
European Space Agency Gaia spacecraft to measure the three-dimensional positions and velocities of galactic stars, placed in Lagrangian Point 2. As Gaia rotated, a gigapixel detector array consisting of a complex arrangement of mirrors, CCD's, and photometers measured stellar positions, brightness and color; and Doppler shifts of stars with unprecedented accuracy. The Gaia catalog, when it is available in the 2020's, was expected to put the whole field of astrophysics on a firmer footing. Soyuz ST-B with upper stage Fregat-MT No. 1039 from Kourou-Sinnamary. The Fregat upper stage separated from the Soyuz booster at suborbital velocity. It then made a first burn to a 175 x 175 km parking orbit, then reignited for a 16-minute burn from 09:33 GMT to propel Gaia to a 344 km x 962,690 km x 15.0 deg orbit, on its way to the Sun-Earth L2 point. Gaia fired its own propulsion system of 6 10-N thrusters to raise apogee to around 1.5 million km towards midnight; after a few weeks it entered a Lissajous orbit around the L2 point and began observations. Gaia's data will take years to process and was to result in the best yet catalog of galactic stars.