An unprecedented endeavor to plot the largest, most precise three-dimensional map of the Milky Way galaxy is set for liftoff early tomorrow morning from the Spaceport following today’s go-ahead for Arianespace’s medium-lift Soyuz mission with the European Gaia spacecraft.
This sixth launch of the Russian-built workhorse from French Guiana will deploy the European Space Agency’s (ESA) billion-star mapper during a fast-paced Soyuz mission profile of just under 42 minutes. It will place Gaia on a trajectory toward an orbit around the Sun at a distance of 1.5 million kilometers beyond Earth, operating from a location known as the L2 Lagrangian point.
Gaia has an estimated liftoff mass of 2,034 kg. and was produced for ESA by the Astrium space division of EADS. During its 5.5-year design lifetime, the spacecraft will observe each of its target stars approximately 70 times, precisely charting their positions, distances, movements and changes in brightness.
Discoveries of new celestial objects – such as extra-solar planets and brown dwarfs – are expected in the hundreds of thousands, along with similar numbers of asteroids within the Solar System. Other goals are the study of some 500,000 distant quasars, as well as stringent new tests of Albert Einstein’s General Theory of Relativity.
Gaia contains two optical telescopes that operate with three science instruments to precisely determine the location of stars and their velocities, and to split their light into a spectrum for analysis. Using Gaia’s slow spinning motion, the telescopes sweep across the entire celestial sphere, enabling the spacecraft’s detectors to repeatedly measure the position of each celestial object – detecting changes in motion through space.
Arianespace’s mission with Gaia is designated Flight VS06 in the company’s launcher family numbering system, and uses the Soyuz ST launcher version with a Fregat upper stage. The European star-mapping spacecraft will be the 25th scientific payload lofted by Arianespace.
