The<i>Gaia</i>mission

Abstract

Gaia is a cornerstone mission in the science programme of the EuropeanSpace Agency (ESA). The spacecraft construction was approved in 2006, following a study in which the original interferometric concept was changed to a direct-imaging approach. Both the spacecraft and the payload were built by European industry. The involvement of the scientific community focusses on data processing for which the international Gaia Data Processing and Analysis Consortium (DPAC) was selected in 2007. Gaia was launched on 19 December 2013 and arrived at its operating point, the second Lagrange point of the Sun-Earth-Moon system, a few weeks later. The commissioning of the spacecraft and payload was completed on 19 July 2014. The nominal five-year mission started with four weeks of special, ecliptic-pole scanning and subsequently transferred into full-sky scanning mode. We recall the scientific goals of Gaia and give a description of the as-built spacecraft that is currently (mid-2016) being operated to achieve these goals. We pay special attention to the payload module, the performance of which is closely related to the scientific performance of the mission. We provide a summary of the commissioning activities and findings, followed by a description of the routine operational mode. We summarise scientific performance estimates on the basis of in-orbit operations. Several intermediate Gaia data releases are planned and the data can be retrieved from the Gaia Archive, which is available through the Gaia home page.

Keywords

Affiliated Institutions

• Laboratoire d'Astrophysique de Bordeaux FR
• Université Paris Cité FR
• Sorbonne Université FR
• University College London GB
• Institut de Mécanique Céleste et de Calcul des Éphémérides FR
• Technische Universität Dresden DE
• European Space Astronomy Centre ES
• University of Copenhagen DK
• Sorbonne Paris Cité FR
• University of Edinburgh GB
• Centre National de la Recherche Scientifique FR
• Royal Observatory of Belgium BE
• European Space Operations Centre DE
• Observatoire de la Côte d’Azur FR
• Rutherford Appleton Laboratory GB
• Institut d'Astrophysique Spatiale FR
• Osservatorio Astronomico di Padova IT
• Observatoire astronomique de Strasbourg FR
• Universitat de Barcelona ES
• Université de Strasbourg FR
• Université Paris-Saclay FR
• Université Paris Sciences et Lettres FR
• Max Planck Institute for Astronomy DE
• Fund for Scientific Research BE
• KU Leuven BE
• Université de Lille FR
• Centre National d'Études Spatiales FR
• Airbus (France) FR
• University of Liège BE
• Systèmes de Référence Temps-Espace FR
• Université Libre de Bruxelles BE
• University of Cambridge GB
• Galaxies, Etoiles, Physique et Instrumentation FR
• University of Geneva CH
• The Open University GB
• Lund University SE
• European Space Research and Technology Centre NL
• Leiden University NL
• Universidad Pablo de Olavide ES
• Délégation Paris 7 FR
• Osservatorio astronomico di Bologna IT
• Robert Bosch (Germany) DE
• Université de Bordeaux FR
• Osservatorio Astrofisico di Torino IT
• Royal Observatory GB
• Arcetri Astrophysical Observatory IT
• National Observatory of Athens GR
• Heidelberg University DE
• Radboud University Nijmegen NL

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