Operating Cheops, and the planning of and executing science operations, is divided across many European centres, reflecting the collaborative nature of this mission.
The Consortium science operations centre is located at the University of Geneva, and is responsible for the processing, archiving and distribution of science data. Planning of observations will be carried out there using mission planning software developed in Portugal, and then communicated to the mission operations centre, where commands will be uplinked and data downlinked via ground station antennas at Villafranca and Torrejon (Spain). During the early mission operations, Cheops will make use of the ESA ground station located at Kiruna (Sweden).
Up to 10% of each year will be reserved for activities to monitor the satellite’s performance and fix any problems. Observations of a list of exoplanet targets defined by the Cheops Science Team – scientists associated with the institutes within the Cheops mission Consortium – will account for 80% of the science observing time. The remaining 20% will be available to scientists worldwide, who can apply to use Cheops through the ESA-run Guest Observers Programme. Proposals will be selected by an independent committee based on scientific merit and the applicability of Cheops, thus enabling the community at large to capitalise on the unique capabilities of Cheops. All data will be made public through the Cheops archive after a proprietary period.
First the raw data from the satellite is processed into usable science data by the Consortium. For example, software from Switzerland will be used to ‘unpack’ the data that arrives from the ground station, while France is responsible for the software that automatically processes the raw data, with contributions from Portugal. Processed data will be stored in an archive that is also developed in Portugal, with a backup archive hosted by Italy.
The UK is providing ‘quick look’ software for checking instrument health, while Switzerland has developed software to simulate the behaviour of the instrument in orbit. Sweden has developed software to package data generated by the simulator, which can then be processed in the same way as real spacecraft data and used for testing.