Orbit Determination and Gravity Estimation Results of KAGUYA: from Nominal Observation Phase to Extended Mission Phase

SELENE (Kaguya) is Japan’s first large lunar explorer that aims to obtain the scientific data to investigate the origin and the evolution of the Moon and to acquire engineering techniques for the future Moon exploration and utilization. The nominal observation phase finished at the end of October 2008, and the extended mission phase started from the beginning of November 2008. In order to perform the additional scientific observation, the Kaguya spacecraft had been put into several sets of different orbits compare to the nominal observation phase. According to the current plan, Kaguya will make a controlled impact with the lunar surface in June 2009. The paper describe the results of the orbit determination of Kaguya from the nominal mission phase to the extended mission phase and the lunar impact analysis for Kaguya. The present status of lunar gravity field estimation results is also described.