Ballistic deployment of the Hayabusa2 artificial landmarks in the microgravity environment of Ryugu

Shota Kikuchi, Naoko Ogawa, Osamu Mori, Takanao Saiki, Yuto Takei, Fuyuto Terui, Go Ono, Yuya Mimasu, Kent Yoshikawa, Stefaan Van Wal, Hiroshi Takeuchi, Hitoshi Ikeda, Atsushi Fujii, Yuki Takao, Tetsuya Kusumoto, Naru Hirata, Naoyuki Hirata, Kei Shirai, Toru Kouyama, Shingo KamedaManabu Yamada, Satoru Nakazawa, Makoto Yoshikawa, Satoshi Tanaka, Seiji Sugita, Sei ichiro Watanabe, Yuichi Tsuda

Research output: Contribution to journalArticlepeer-review

16 Citations (Scopus)


Hayabusa2 deployed two artificial landmarks called “target markers (TMs)” on the asteroid Ryugu for autonomous landing control. To achieve precise deployment on target landing sites, the TMs were designed to dissipate kinetic energy and released near the asteroid surface (with an altitude of less than 40 m). This study evaluates the performance of the ballistic deployment in the actual microgravity environment by reconstructing the trajectories of the TMs from optical, altimetric, and radiometric data. In addition, based on the reconstructed trajectories, low-velocity impacts of the TMs on the surface of Ryugu are characterized with dynamical parameters, such as dissipated energy and a coefficient of restitution. The physical implications of the impact analysis are discussed in comparison with on-ground experimental data. Furthermore, the gravitational environment is investigated using the reconstructed trajectory data and a shape model of Ryugu, providing information on the local gravity anomaly. Consequently, this paper demonstrates the usefulness of deployable artificial landmarks for small-body landings and further offers insight on surface conditions and internal structures near the Hayabusa2 landing sites where samples of Ryugu were collected.

Original languageEnglish
Article number114220
Publication statusPublished - Apr 2021
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science


Dive into the research topics of 'Ballistic deployment of the Hayabusa2 artificial landmarks in the microgravity environment of Ryugu'. Together they form a unique fingerprint.

Cite this