GAIA - The largest astronomical discovery machine in history

About the project

For decades people have been trying to explore the universe. With GAIA, a space mission of the European Space Agency ESA was launched in 2013 for the most extensive survey of our galaxy to date.

Gaia ©ESA/ATG medialab; background: ESO/S. Brunier

With the GAIA space telescope, astronomers will be able to take measurements of approximately one percent of all the stars in our Milky Way – an estimated one billion stars – with very high precision. Using these star measurements, researchers will create a three-dimensional map of the Milky Way. This map also contains the positions, distances and movements of the celestial bodies in space. These findings will help scientists to clarify the origin of stars and the development of the Milky Way.

Gaia Linsen ©EADS Astrium SAS, France

Our contribution

To perform such measurements, a highly sensitive camera is required. A spectrometer records the light from the stars and determines whether the stars are moving towards us or away from us. The spectrometer separates light according to color and also prevents spherical aberrations. To achieve this, various optical components are required: a filter, two prisms, two prism lenses and a diffraction grating. All of these optical elements were made of the fused silica Suprasil from Heraeus.

Suprasil is a material with very good optical homogeneity as well as very high transmission (light transmittance) at high radiation exposure in space.

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