CHEOPS Spacecraft Thermal Verification and In-orbit Performance



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50th International Conference on Environmental Systems


CHEOPS - CHaracterising ExOPlanet Satellite - is the first mission dedicated to searching for exoplanetary transits by performing ultra-high precision photometry on bright stars already known to host planets. The mission's main science goals are to measure the bulk density of super-Earths and Neptunes orbiting bright stars and provide suitable targets for future in-depth characterisation studies of exoplanets in these mass and size ranges. Airbus Defence & Space Spain is the prime contractor for CHEOPS spacecraft, whose launch mass, is approximately 280 kg. The satellite design is based on the use of the AS-250 platform, an Airbus product line designed for small and medium size missions operating in Low Earth Orbit. CHEOPS has one instrument � a photometer with a single CCD, operating in the visible/near-infrared wavelength range, that is at the focal plane of an on-axis Ritchey-Chr�tien telescope of 32cm diameter. The main thermal challenge is to keep the detector operating at -40�C, with a stability better than 10 mK during imaging. All platform requirements aim at supporting the functionality of the payload and its ultrahigh photometric precision. The main challenge for the platform thermal architecture is to minimize flux exchanges between the Platform and the Instrument to achieve the stringent requirements for instrument detector temperature and thermal stability. The Platform also has to accommodate several medium to high dissipative electronic units and ensure dedicated heat rejection capacity while minimizing heating power. CHEOPS Spacecraft thermal verification began with the thermal tests of the Instrument Structural and Thermal Model, followed by the Instrument Proto-Flight Model. Once the Instrument was integrated on the Platform, a full Thermal Vacuum / Thermal Balance test was performed at Spacecraft level. CHEOPS was launched on the 18 December 2019 and the early in-orbit thermal performance is presented in this paper.


Romain Peyrou-Lauga, ESA
Ignacio Melendo, AIRBUS Defence and Space
ICES203: Thermal Testing
The 50th International Conference on Environmental Systems was held virtually on 12 July 2021 through 14 July 2021.


Spacecraft, Thermal control, In-orbit performance