Image-based autonomous navigation of Hayabusa2 using artificial landmarks: The design and brief in-flight results of the first landing on asteroid Ryugu

Hayabusa2 is an asteroid sample return mission carried out by the Japan Aerospace Exploration Agency. The spacecraft was launched in 2014 and arrived at the target asteroid Ryugu on June 27, 2018. During the 1.5-year proximity phase, several critical operations (including two landing/sampling operations) were successfully performed. They were based on autonomous image-based descent and landing techniques. This paper describes an image-based autonomous navigation scheme of the Hayabusa2 mission using artificial landmarks named target markers (TMs). Its basic algorithm, and the in-flight results of the first touchdown and its rehearsal, are shown.