EADS Astrium signs Gala contract

Interavia Business & Technology, Summer, 2006

EADS Astrium has signed a contract with the European Space Agency (ESA) to develop and build the satellite for the Global Astrometric Interferometer for Astrophysics (Gala) mission. Gaia will create an extraordinarily precise 3-D map of the Galaxy, mapping and recording more than one billion stars over a five-year period. The satellite, worth 317 million [euro], is due to be launched in 2011.

The Gaia mission will investigate the composition, formation and evolution of our Galaxy. Gaia will be placed in orbit at the point of Lagrange L2--a point of stability 1.5 million kilometres from Earth in line with the Sun. Gaia's measurement accuracy is so great that if it were on the Moon, it could measure the thumbnail of a person on Earth.

The spacecraft will use the global astronomy concept successfully demonstrated on its predecessor HIPPARCOS, also built by EADS Astrium, which successfully mapped 100,000 stars in 1989. Gaia will be equipped with a latest-generation payload integrating the most sensitive telescope ever made. The telescope will have the largest focal plane ever constructed--with 106 charged coupled devices (CCD) featuring almost 1 gigapixels. This cutting-edge technology draws on EADS Astrium's experience on silicon carbide (SIC) telescopes, used on Herschel and Aladin as well as on three recent Earth observation satellites (Formosat, THEOS and Alsat 2). All of EADS Astrium's sites across Europe are contributing to this major programme.

EADS Astrium in the UK will design and develop the electrical service module which includes the central data management system, and electrical power control and distribution system on the spacecraft* The company will also be responsible for the AOCS (Altitude Orbit Control System), and TT&C (Telemetry, Tracking and Command) functionalities. The design and development of the Payload Data Handling System (PDHS) and system software will also be carried out in the UK.

EADS Astrium in Germany will be responsible for the mechanical, thermal and propulsion systems on the spacecraft. These will include two major elements: the 10 metre diameter deployable sunshield which will keep temperature fluctuations of the sensitive optical systems to a minimum, and the innovative micro-propulsion system which will maintain the spacecraft's position without disturbing the optical system during flight.

EADS Astrium in France will be in charge of overall development of the satellite as well as the design, development and integration of the payload and software design.