superior solar conjunction, Hayabusa2, Ryugu, hovering satellite, mission operations
In late 2018, the asteroid Ryugu was in the Sun’s shadow during the superior solar conjunction phase. As the Sun-Earth-Ryugu angle decreased to below 3∘, the Hayabusa2 spacecraft experienced 21 days of planned blackout in the Earth-probe communication link. This was the first time a spacecraft had experienced solar conjunction while hovering around a minor body. For the safety of the spacecraft, a low energy transfer trajectory named Ayu was designed in the Hill reference frame to increase its altitude from 20 to 110 km. The trajectory was planned with the newly developed optNEAR tool and validated with real time data. This article shows the results of the conjunction operation, from planning to flight data.
Tsinghua University Press
Stefania Soldini, Hiroshi Takeuchi, Sho Taniguchi, Shota Kikuchi, Yuto Takei, Go Ono, Masaya Nakano, Takafumi Ohnishi, Takanao Saiki, Yuichi Tsuda, Fuyuto Terui, Naoko Ogawa, Yuya Mimasu, Tadateru Takahashi, Atsushi Fujii, Satoru Nakazawa, Kent Yoshikawa, Yusuke Oki, Chikako Hirose, Hirotaka Sawada, Tomohiro Yamaguchi, Makoto Yoshikawa. Hayabusa2's superior solar conjunction mission operations: Planning and post-operation results. Astrodynamics 2020, 4(4): 265-288.