Hayabusa2’s station-keeping operation in the proximity of the asteroid Ryugu
small body mission, station-keeping, guidance, navigation, and control (GNC), optical and radiometric navigation
The Japanese interplanetary probe Hayabusa2 was launched on December 3, 2014 and the probe arrived at the vicinity of asteroid 162173 Ryugu on June 27, 2018. During its 1.4 years of asteroid proximity phase, the probe successfully accomplished numbers of record-breaking achievements including two touchdowns and one artificial cratering experiment, which are highly expected to have secured surface and subsurface samples from the asteroid inside its sample container for the first time in history. The Hayabusa2 spacecraft was designed not to orbit but to hover above the asteroid along the sub-Earth line. This orbital and geometrical configuration allows the spacecraft to utilize its high-gain antennas for telecommunication with the ground station on Earth while pointing its scientific observation and navigation sensors at the asteroid. This paper focuses on the regular station-keeping operation of Hayabusa2, which is called "home position" (HP)-keeping operation. First, together with the spacecraft design, an operation scheme called HP navigation (HPNAV), which includes a daily trajectory control and scientific observations as regular activities, is introduced. Following the description on the guidance, navigation, and control design as well as the framework of optical and radiometric navigation, the results of the HP-keeping operation including trajectory estimation and delta-V planning during the entire asteroid proximity phase are summarized and evaluated as a first report. Consequently, this paper states that the HP-keeping operation in the framework of HPNAV had succeeded without critical incidents, and the number of trajectory control delta-V was planned efficiently throughout the period.
Tsinghua University Press
Yuto Takei, Takanao Saiki, Yukio Yamamoto, Yuya Mimasu, Hiroshi Takeuchi, Hitoshi Ikeda, Naoko Ogawa, Fuyuto Terui, Go Ono, Kent Yoshikawa, Tadateru Takahashi, Hirotaka Sawada, Chikako Hirose, Shota Kikuchi, Atsushi Fujii, Takahiro Iwata, Satoru Nakazawa, Masahiko Hayakawa, Ryudo Tsukizaki, Satoshi Tanaka, Masanori Matsushita, Osamu Mori, Daiki Koda, Takanobu Shimada, Masanobu Ozaki, Masanao Abe, Satoshi Hosoda, Tatsuaki Okada, Hajime Yano, Takaaki Kato, Seiji Yasuda, Kota Matsushima, Tetsuya Masuda, Makoto Yoshikawa, Yuichi Tsuda. Hayabusa2’s station-keeping operation in the proximity of the asteroid Ryugu. Astrodynamics 2020, 4(4): 349-375.