Navigation and Orbit Estimation for New Horizons' Arrokoth Flyby: Overview, Results and Lessons Learned
Weaver, Harold A.; Kavelaars, J. J.; Gwyn, Stephen D. J.; Spencer, John R.; Buie, Marc W.; Porter, Simon B.; Alan Stern, S.; Olkin, Catherine B.; Stanbridge, Dale R.; Nelson, Derek S.; Pelletier, Frederic J.; Bauman, Jeremy A.; Fischetti, Joel T.; Guo, Yanping; Holdridge, Mark E.; Lessac-Chenen, Erik J.; Pelgrift, John Y.; Rogers, Gabe D.; Salinas, Michael J.; Williams, Bobby G.; Williams, Kenneth E.
United States, Canada
Abstract
The New Horizons mission performed a successful flyby of Arrokoth, a distant Kuiper-Belt Object, on January 1, 2019, representing the farthest planetary encounter to date. The navigation strategy and performance required to deliver the spacecraft to the desired flyby target were driven by a number of challenges including those related to Arrokoth's viewing angle and relatively recent discovery in June 2014. These and other challenges required the New Horizons science and navigation teams to devise a strategy in close collaboration that would substantially reduce the flyby navigation errors. Earth-based astrometry and occultation measurements of Arrokoth were collected and used to estimate Arrokoth's orbit and its associated uncertainties, which were in turn used to inform and reduce navigation approach and flyby uncertainties. The New Horizons navigation effort used these a priori orbits along with radio metric and optical navigation measurements to first predict the navigation performance in support of the flyby design, and then estimate New Horizons' trajectory, maneuvers and other filter state parameters during navigation operations. An overview of the Arrokoth orbit estimation and navigation strategy and predicted performance, as well as the operational results from the initial target search campaign in 2004 through Arrokoth's successful flyby in 2019 are presented, along with the principal challenges and most important lessons learned along the way.