CryoSat-2 - Four Years of Operations

The CryoSat-2 spacecraft is one of the Earth Explorer Opportunity missions of the ESA Living Planet programme. It is operated by the European Space Operations Centre, in Darmstadt. The CryoSat Mission objective, fulfilled by the CryoSat-2 satellite, is to provide global continuous measurements of the ice cover variations on the Polar caps and continental ice sheets plus other areas of land ice, which is being achieved thanks to the use of its multi-mode interferometer radar, SIRAL. Additionally, CryoSat-2 data is being used to support the Oceanography community with respect to the long term sea level monitoring. In April 2014, Cryosat-2 achieved four years of operations, covering six-months of commissioning and the follow on routine operations. Overall, the mission has proven to be very successful and the spacecraft overall performance very reliable. This paper first provides an overview of the CryoSat-2 Ground Segment and the implemented operational concept covering the payload operations planning cycle, automated passes, housekeeping data replay and analysis, followed by an overview of the mission and the in-flight operational status of the Satellite. The remainder of the paper will present details of the main satellite operations carried out in flight, from the post launch anomaly investigation and corrective actions through to routine operations. The routine operations will be described, for example data downlink automation, orbit maintenance manoeuvre execution, Star Tracker operations, debris collision monitoring, platform units maintenance and payload calibrations via Transponder passes. Special operations in support of the mission and also as a consequence of anomalies will be presented, addressing how and why these are executed and the issues encountered. Support to future missions and additional objectives have also resulted in some special operations, and these will be briefly described. The interfaces with the other facilities required to support and enhance the mission will be briefly described. This will include the facilities involved in the planning of routine and special operations, plus how the Flight Operations Segment interfaces with the Processing and Dissemination facilities to provide the data to different users. As conclusions, the need for stable operations to preserve data quality is highlighted and how the evolution of the current operational concepts allows the Cryosat-2 mission to fully support the all of the user communities’ needs.