**LAUNCH POSTPONED** New launch date targeted Wednesday, 18 December 2019.
Cheops, the Characterising Exoplanet Satellite, is ESA’s first mission dedicated to the study of extrasolar planets, or exoplanets. It will observe bright stars that are already known to host planets, measuring minuscule brightness changes due to the planet’s transit across the star’s disc.
Scheduled for launch at 09:54 CET on 17 December 2019, Cheops will lift off as a secondary passenger, hitching a ride on the Soyuz-Fregat that will deliver the first satellite of the Italian Space Agency’s Cosmo-SkyMed Second Generation constellation into space. The launcher will also carry three ‘CubeSats’, small satellites based on standardised 10 cm cubic units, including ESA’s OPS-SAT, the world’s first free-for-use, in-orbit testbed for new software, applications and techniques in satellite control.
The separation of Cosmo-SkyMed Second Generation from the launcher is expected about 23 minutes after lift-off, whereas Cheops separation is expected about 145 minutes after lift-off, around 12:20 CET, and the CubeSats separation is expected around two hours after that.
Note: This graphic was updated on 18 December 2019.