TOULOUSE, France — Thales Alenia Space will be prime contractor for Europe’s Euclid satellite to study dark-energy sources starting in 2020 under a contract announced June 27 with the European Space Agency (ESA).

Valued at 322.5 million euros ($426 million), the contract calls for Thales Alenia Space to incorporate into its program management the observing instrument and its 1.2-meter-diameter mirror. The instrument is being built by Astrium Satellites under a separate ESA contract valued at 72.5 million euros.

Thales Alenia Space said it would select the rest of the Euclid industrial team by 2014.

All told, Euclid is expected to cost ESA and its individual member states — plus NASA, which is making a $40 million in-kind contribution — slightly more than 1 billion euros.

Peter B. de Selding was the Paris Bureau Chief for SpaceNews.