Speaker
Description
CHEOPS (Characterizing ExOPlanet Satellite) is the first small class ESA mission dedicated to characterizing exoplanets known to be orbiting nearby bright stars. CHEOPS telescope allows for high precision observations using the transient method, enabling the scientific community to determine the planets’ size and density accurately and to derive their structure and composition. CHEOPS is in a dawn-dusk Sun-synchronous orbit at an altitude of 700 km.
CHEOPS Mission Operations Center is located at Instituto Nacional de Técnica Aeroespacial in Torrejón de Ardoz, Spain, from which full operations since launch until decommissioning phases are held. End-of-life operations will be executed from this center in order to assure a safe reentry while complying with ESA space debris mitigation standards.
CHEOPS was initially designed to comply with ESA’s disposal policy by decreasing the perigee to an altitude of 490 km in order to re-enter within 25 years. During the preparation activities for the Mission Extension Operations Review held in late 2021, the assessment of the fuel budget, taking into account the collision avoidance and orbit maintenance maneuvers required for the extended period, showed high margin in the remaining fuel for disposal operations.
Consequently, a new detailed disposal plan was proposed to decrease the orbit altitude and further reduce the re-entry time below the initial approach. For the new strategy, the fuel budget and AOCS constraints determined feasible to lower the orbit down to a circular one with an altitude of 350 km, diminishing the re-entry to approximately five months. Crossing of critical orbits, such as the ISS orbit, was considered when designing the new strategy.
In the light of the above, a shortening in the time required for the re-entry, along with the reduced space debris population in such low orbits, will imply a risk reduction of both collision and fragmentation. The new strategy contributes to a more sustainable space environment by avoiding additional space debris generation.
