Deep Impact Navigation System Performance.

Deep Impact successfully met its primary mission objective on 4 July 2005 when the smart impactor guided itself into the path of Comet 9P/Tempel 1. The mother flyby spacecraft then observed and recorded the breathtaking collision and subsequent plume development. Ground-based navigators targeted the prerelease trajectory using optical navigation image planning and data analysis, trajectory correction maneuver design and evaluation, and orbit determination using both radiometric and optical data. In-flight improvements to the Tempel 1 ephemeris were also a critical part of the overall navigation design and operations success. The achieved navigation accuracy established a new standard for comet encounters, and this difficult task taught several important lessons. This definitive Work provides a mission overview, summarizes the navigation requirements, compares the achieved navigation performance with a baseline design that reflects in-flight updates, and identifies operational procedures that may benefit future comet-bound navigators. [ABSTRACT FROM AUTHOR]