Dawn has been in orbit around Ceres since March 2015. In 2016, Dawn completed its prime mission of exploring Vesta and Ceres, and it completed an extended mission at the dwarf planet in 2017. The spacecraft has lost all reaction wheel control, making attitude control dependent on a dwindling supply of hydrazine. Nevertheless, in 2017 the project was approved for a second and final extended mission at Ceres. Starting in April 2018, Dawn used its ion propulsion system to maneuver to two new orbits. These highly elliptical orbits provided hydrazine-efficient opportunities for the acquisition of valuable new data. Now in the second of these orbits, Dawn's lowest altitude is only 9% of the lowest altitude previously in the mission, enabling significant improvements in the spatial resolution of the data. We describe Dawn operations in its second extended mission, the nature of the orbits, and the observation campaigns. We also summarize expectations for the end of the mission.
Dawn's Second and Final Extended Mission: A New Operational Campaign at Ceres
01.10.2018
Preprint
Keine Angabe
Englisch
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