Voyager 2 navigation to Uranus

Navigating the upcoming Voyager 2 encounter with Uranus presents unique challenges and opportunities. Uranus will be the most distant planetary encounter carried out to date, with a 2.75 hour delay each way for communication. Furthermore, Voyager 2 is the most sophisticated spacecraft ever used for first encounter with a planetary system. In this paper the special features of the encounter are analyzed from a navigation point of view. First, the most relevant science opportunities are introduced. Then the challenges posed by the Uranian distance and geometry are outlined. The result of a detailed navigation accuracy study is presented. Finally, the unique features of optical navigation at Uranus are shown.