The Gaia satellite, carrying the largest digital camera ever flown in space, has completed final preparations and is ready to be shipped to French Guiana for launch later this year.
The ten-metre in diameter flying-saucer-like satellite has a task of creating a 3D map of the Milky Way. It will use its two optical telescopes that will capture the distant stars with unrivalled precision through a billion-pixel digital camera – the largest such device ever flown to space. To secure the best possible coverage of the entire sky, the satellite will constantly revolve around its axis during the mission.
“Gaia will be ESA’s discovery machine,” says Alvaro Giménez, ESA’s Director of Science and Robotic Exploration. “It will tell us what our home galaxy is made of and how it was put together in greater detail than ever before, putting Europe at the forefront of precision astronomy.”
This week, engineers in the Interspace Centre in Toulouse, France, subjected the flight model to testing in an acoustic chamber that simulated the loads the spacecraft will experience during launch.
Gaia’s resistance to vibrations was verified using dedicated shakers simulating swept-sine vibrations along all three axes, similar to those experienced as the rocket takes off.
The satellite’s propulsion system was tested with helium being filled into the pipes under pressure to make sure there are no possible leakages. As the propellants used are highly toxic and corrosive the system's containment is crucial not only for smooth operations but also for safety during pre-launch manipulation.
Gaia will embark on its five-year mission later this year from the European spaceport in Kourou, French Guiana atop a Soyuz rocket. It will be placed into the L2 Lagrangian point some 1.5 million km beyond Earth’s orbit. The L2 point is a unique location for astronomic missions as the gravitational pull of the Sun and the Earth at this point is balanced. As a result of that, the spacecraft stays more or less stable in its position, creating suitable conditions for ongoing observations. This spot was used also for the recently ended mission of ESA's Herschel telescope.