The Euclid Mission

Euclid is a high precision survey mission under development by the European Space Agency to investigate the properties of Dark Energy and Dark Matter by means of a weak lensing and baryon acoustic oscillations experiments. The technical capabilities of Euclid are such that it also addresses other cosmological and astronomical topics, providing an unprecedented science legacy. The survey mission will carry out an imaging and spectroscopic survey of the entire extragalactic sky (20,000 deg2). Euclid carries a meter class telescope which feeds two instruments: a visible imager (VIS), a near-infrared photometer combined with a medium resolution spectrometer (NISP). The two instruments have identical sized field of views (0.5 deg2) and will operate simultaneously in step-and-stare mode. The nominal mission period is 5 years. We describe the mission, the satellite, and the payload concepts, which we have adopted at the start of the definition phase.