Assessment of the Differential Drag Maneuver Operations on the CYGNSS Constellation

The CYGNSS constellation was deployed in December 2016. To optimize the coverage of tropical cyclones, the eight observatories have to be evenly spaced out along the orbit. Since the spacecraft do not have a system of propulsion, differential drag maneuvers have been conducted to control the constellation phasing. However, many constraints have considerably restricted the differential drag operations, particularly during the first months of the mission. The study discusses these constraints and provides an evaluation of the effectiveness of the differential drag maneuvers during the first year of the mission. Future plans for the completion of the constellation phasing are also presented.