The CHEOPS Mission

Abstract

The CHaracterising ExOPlanet Satellite (CHEOPS) is a mission jointly led by Switzerland and ESA which was selected in October 2012 as the first small-class mission in the ESA Science Programme. CHEOPS will be the first space observatory dedicated to search for transits of exoplanets by means of ultrahigh precision photometry on bright stars already known to host planets. The CHEOPS telescope will have access to more than 70% of the sky, which will provide the unique capability of determining accurate radii for planets for which the mass has already been estimated from ground-based spectroscopic surveys. This, in turn, will allow a first order characterisation of the planets' internal structure (i.e. the determination of the mean density, which provides direct insights into its composition). CHEOPS will also provide precise radii for new planets discovered by the next generation of ground-and space-based transits surveys. CHEOPS launch is expected by March/April 2019, and its nominal lifetime is 3.5 years with the possibility of an extension of 1.5 years.