The Successful Conclusion of the Dawn Mission: Important Results without a Flashy Title

摘要

Dawn completed its second and final extended mission on 31 October 2018. The spacecraft had been operating in a 35 x 4000 km orbit around dwarf planet Ceres, enabling high resolution observations to the end of the mission. Because of the loss of three of the spacecraft's reaction wheels earlier in the mission, the attitude was controlled exclusively with hydrazine. Thanks to an extensive campaign of hydrazine conservation, the propellant lasted longer than originally anticipated. When it was depleted, the spacecraft was unable to maintain attitude and mission operations concluded. I describe the conclusion of the mission and some of the lessons. Recent advances in the understanding of Ceres enabled by Dawn's data are presented as well.