Gaia

Gaia is an ESA satellite that will create an extraordinarily precise 3D map of more than one billion stars in our Galaxy. After its launch in 2010, Gaia will provide an unprecedented number of new discoveries; hundreds of thousands of new celestial objects like extra-solar planets, brown dwarfs and star-forming nebulae. Dutch technology is essential to this mission.

 

Gaia satellite - artist impression - image: ESAEvery day, on average, it will discover about 100 new asteroids in our solar system, 10 new stars possessing planets, 50 new stars exploding in other galaxies, and 300 new distant quasars. Exo-planets will be detected by measuring the tiny movement of the star, caused by the small gravitation pull of the planet. It is estimated that Gaia will discover about 15,000 new exo-planets during its operational lifetime. Via comprehensive photometric classification, Gaia will also provide detailed physical properties of each star observed: characterizing their luminosity, temperature, gravity, and elemental composition. 

 

Gaia’s massive stellar census will provide the basic observational data to tackle an enormous range of important problems related to the origin, structure, and evolutionary history of our Galaxy. Gaia also offers fascinating technological advances. It requires picometer accuracy in terms of metrology, pushing the bounds of optical standards, especially considering that that accuracy must be maintained even after the inherent mechanical vibrations and forces of launch.
Silicon Carbide polished free form mirrors for Gaia - credit: TNO

 

A unique Silicon Carbide (SiC) core, including an optical bench made entirely of a single piece of SiC developed and created in the Netherlands, is the key to this never-before-seen accuracy. SiC is an extremely beneficial material for spaceflight due to its high stiffness and thermal properties, but it is extremely hard to work with. In fact, Dutch research organisation TNO is the only organisation in Europe that can polish SiC to the required surface error limits.

 

TheNetherlandsand Gaia

 

The Netherlands contributes crucial elements to the Gaia mission. In close cooperation with the Technical University of Eindhoven and with support from the former NIVR and now the Netherlands Space Office, TNO has developed the opto-mechanical assembly for the Basic Angle Monitoring (BAM) system that assures Gaia’s mapping accuracy. TNO also developed the Wave Front Sensor (WFS) that will monitor Gaia’s optical inputs and is responsible for the ground calibration system, Auto-collimating Flat Mirror Assembly (AFMA), that will test the Gaia satellite payload in a large vacuum chamber. Dutch Space contributed innovative data processing technology that will provide more detail and accuracy in images for analysis.