Gaia: Organisation and challenges for the data processing

TL;DR

Gaia is a space mission by ESA aiming to map the sky with unprecedented precision, involving complex data processing organized by a European consortium to handle vast telemetry data and produce high-accuracy astrometric and photometric results.

Contribution

This paper details the organization and challenges of Gaia's large-scale data processing system, highlighting its innovative collaborative approach and complex iterative algorithms.

Findings

Successful organization of a large consortium for Gaia data processing

Handling of 100 TB telemetry data over 5 years

Achievement of microarcsecond astrometric accuracy

Abstract

Gaia is an ambitious space astrometry mission of ESA with a main objective to map the sky in astrometry and photometry down to a magnitude 20 by the end of the next decade. While the mission is built and operated by ESA and an industrial consortium, the data processing is entrusted to a consortium formed by the scientific community, which was formed in 2006 and formally selected by ESA one year later. The satellite will downlink around 100 TB of raw telemetry data over a mission duration of 5 years from which a very complex iterative processing will lead to the final science output: astrometry with a final accuracy of a few tens of microarcseconds, epoch photometry in wide and narrow bands, radial velocity and spectra for the stars brighter than 17 mag. We discuss the general principles and main difficulties of this very large data processing and present the organisation of the European Consortium responsible for its design and implementation.