Gaia is positioned for its star-mapping launch on an Arianespace Soyuz
The payload “stack” is now taking shape for this month’s Arianespace launch of Gaia – Europe’s billion-star mapper satellite, which is to be lofted by a Soyuz vehicle on December 19 from French Guiana.
As the latest milestone in a now well-established processing flow for Arianespace’s medium-lift Soyuz, Gaia was positioned atop the launcher’s Fregat upper stage during activity in the Spaceport’s S3B preparation building. Fregat is an autonomous, highly flexible upper stage that will perform two separate burns in sending Gaia on its way to an orbit around the Sun at the L2 Lagrangian point.
The next processing step is to encapsulate the Gaia/Fregat combination in a two-piece payload fairing, readying the unit for mating to Soyuz after the vehicle’s rollout from its separate MIK integration building – where the Russian-built launcher was assembled.
Gaia is designed to observe one billion stars in the Milky Way approximately 70 times each during a mission design life of 5.5 years, and has a liftoff mass of 2,030 kg.
Built by Astrium at its Toulouse, France facility, Gaia will be operated by the European Space Agency to provide a representative sample from which properties of the entire galaxy can be measured, ultimately allowing astronomers to determine its origin and evolution.
Gaia will be launched on Arianespace’s sixth Soyuz flight performed from the Spaceport since 2011, where this workhorse launcher is operational alongside the company’s heavy-lift Ariane 5 and lightweight Vega vehicles.