CHEOPS, from CHaracterising ExOPlanets Satellite, or Satellite for the Characterization of Exoplanets, is being developed by the European Space Agency (ESA) and its purpose is thoroughly study known extrasolar planets.
CHEOPS is a Ritchey-Chrétien telescope with a 30 cm aperture and 1.2 m length that, from a synchronous orbit to the sun of 650 × 800 kilometers, you will search orbiting bright stars in our local neighborhood in order to accurately determine their radius.
Finally, the information will help us to find out if they are gaseous or rocky planets. According Kate Isaak, CHEOPS project scientist:
CHEOPS will monitor the optical and infrared light of individual stars and will accurately measure the decrease in the signal during the transit of a planet, when crossing in front of the star, using an ultra-high precision photometer.
Its launch is scheduled for the end of 2018, with an estimated mission duration of three and a half years. Isaak He notes that "the mission is small in size and costs, with a development time that is much shorter than in other ESA scientific missions: six years from the beginning (selection of proposals) until it is ready for launch."