CHEOPS Automated Operations

Abstract

CHEOPS (CHaracterising ExOPlanet Satellite) is ESA’s first S-class mission dedicated to study already-known exoplanets. It performs high-precision observations of bright stars to determine exoplanets size using the transit method. S-class missions are designed to be implemented quickly and on a small budget, having an impact on every aspect of the mission, such as the spacecraft or the ground segment design. CHEOPS ground segment is mainly divided into the Mission Operations Centre, responsible for the control and operations of the satellite,the ground stations used for communication with the satellite, both hosted by the Instituto Nacional de Técnica Aeroespacial in Madrid, and the Science Operations Centre located in Geneva. CHEOPS was launched in December 2019 into a sun-synchronous orbit at a height of 700 km with a Local Time of Ascending Node at 6:00 a.m. As a result of the orbit design and the ground stations’ location, there are between four to six short passes per day outside of regular working hours. Therefore, operations automation was considered from the very beginning of the project to reduce costs. The initial automation requirements called for the automation of passes where the Activity Plan was not uplinked to the satellite, and the automatic notification to the operators in the event of anomalies. Operators analysed the numerous activities that could be automated considering the automation capabilities of the Mission Control System and the Flight Dynamics System, and the initial requirements were already exceeded before the launch such that most of the routine activities were fully automated. During the commissioning phase, once the automatic uplink was verified, the automatic Activity Plan uplink was introduced. This was a significant breakthrough because routine passes no longer required manual intervention. Operators need to be present during passes only in order to respond in the event of non-routine activities or emergencies in the control centre or in the satellite. All in all, automated operations have shown to be reliable and useful for operators to efficiently control CHEOPS. Additionally, operators can concentrate on the analysis of the results and other activities that require a deeper understanding of the different subsystems by letting the automation system handle the repetitive tasks