著者
Eizo NAKAMURA Katsura KOBAYASHI Ryoji TANAKA Tak KUNIHIRO Hiroshi KITAGAWA Christian POTISZIL Tsutomu OTA Chie SAKAGUCHI Masahiro YAMANAKA Dilan M. RATNAYAKE Havishk TRIPATHI Rahul KUMAR Maya-Liliana AVRAMESCU Hidehisa TSUCHIDA Yusuke YACHI Hitoshi MIURA Masanao ABE Ryota FUKAI Shizuho FURUYA Kentaro HATAKEDA Tasuku HAYASHI Yuya HITOMI Kazuya KUMAGAI Akiko MIYAZAKI Aiko NAKATO Masahiro NISHIMURA Tatsuaki OKADA Hiromichi SOEJIMA Seiji SUGITA Ayako SUZUKI Tomohiro USUI Toru YADA Daiki YAMAMOTO Kasumi YOGATA Miwa YOSHITAKE Masahiko ARAKAWA Atsushi FUJII Masahiko HAYAKAWA Naoyuki HIRATA Naru HIRATA Rie HONDA Chikatoshi HONDA Satoshi HOSODA Yu-ichi IIJIMA Hitoshi IKEDA Masateru ISHIGURO Yoshiaki ISHIHARA Takahiro IWATA Kosuke KAWAHARA Shota KIKUCHI Kohei KITAZATO Koji MATSUMOTO Moe MATSUOKA Tatsuhiro MICHIKAMI Yuya MIMASU Akira MIURA Tomokatsu MOROTA Satoru NAKAZAWA Noriyuki NAMIKI Hirotomo NODA Rina NOGUCHI Naoko OGAWA Kazunori OGAWA Chisato OKAMOTO Go ONO Masanobu OZAKI Takanao SAIKI Naoya SAKATANI Hirotaka SAWADA Hiroki SENSHU Yuri SHIMAKI Kei SHIRAI Yuto TAKEI Hiroshi TAKEUCHI Satoshi TANAKA Eri TATSUMI Fuyuto TERUI Ryudo TSUKIZAKI Koji WADA Manabu YAMADA Tetsuya YAMADA Yukio YAMAMOTO Hajime YANO Yasuhiro YOKOTA Keisuke YOSHIHARA Makoto YOSHIKAWA Kent YOSHIKAWA Masaki FUJIMOTO Sei-ichiro WATANABE Yuichi TSUDA
出版者
The Japan Academy
雑誌
Proceedings of the Japan Academy, Series B (ISSN:03862208)
巻号頁・発行日
vol.98, no.6, pp.227-282, 2022-06-10 (Released:2022-06-10)
参考文献数
245
被引用文献数
1

Presented here are the observations and interpretations from a comprehensive analysis of 16 representative particles returned from the C-type asteroid Ryugu by the Hayabusa2 mission. On average Ryugu particles consist of 50% phyllosilicate matrix, 41% porosity and 9% minor phases, including organic matter. The abundances of 70 elements from the particles are in close agreement with those of CI chondrites. Bulk Ryugu particles show higher δ18O, Δ17O, and ε54Cr values than CI chondrites. As such, Ryugu sampled the most primitive and least-thermally processed protosolar nebula reservoirs. Such a finding is consistent with multi-scale H-C-N isotopic compositions that are compatible with an origin for Ryugu organic matter within both the protosolar nebula and the interstellar medium. The analytical data obtained here, suggests that complex soluble organic matter formed during aqueous alteration on the Ryugu progenitor planetesimal (several 10’s of km), <2.6 Myr after CAI formation. Subsequently, the Ryugu progenitor planetesimal was fragmented and evolved into the current asteroid Ryugu through sublimation.
著者
Shota TAKAHASHI Naoko OGAWA Yasuhiro KAWAKATSU
出版者
THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES
雑誌
TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, AEROSPACE TECHNOLOGY JAPAN (ISSN:18840485)
巻号頁・発行日
vol.17, no.3, pp.404-411, 2019 (Released:2019-05-04)
参考文献数
9
被引用文献数
1 1

Failure of the orbit insertion maneuver has a significant impact on the entire mission, for the trajectory of a spacecraft is largely deflected by swing-by. The risk can be reduced by targeting a point on the B-plane where the spacecraft reaches the free-return (FR) trajectory with the target body in the case of insertion failure. The backup orbit must also satisfy conditions suitable for the mission. We investigated the type of orbit insertion that is both robust to failure and reasonable for the mission requirements. We call this method FR ensured orbit insertion. Among various failure modes of the orbit insertion maneuver, we focus on the complete maneuver failure. The impact parameters on the B-plane to achieve the orbit insertion are formulated based on the geometry of velocity vectors at swing-by. The necessary deflection angle αFR at swing-by must be smaller than the possible maximum deflection angle αmax for the target body. When we introduce proper scaling factors, the relation of αmax and αFR is characterized by a single parameter λ. Using polar orbit insertion as an example, maps which show the reachability of FR trajectory after the insertion failure for each approaching condition are presented. The derived maps can be used as a tool to assess the applicability of the method in the mission design. Finally, as an application to practical mission design, we demonstrate the use of FR ensured orbit insertion in JAXA's MMX mission.
著者
Naoko OGAWA Yuichi TSUDA Yuto TAKEI Hiroka INOUE Shota TAKAHASHI Yasuhiro KAWAKATSU
出版者
THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES
雑誌
TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, AEROSPACE TECHNOLOGY JAPAN (ISSN:18840485)
巻号頁・発行日
vol.17, no.3, pp.398-403, 2019 (Released:2019-05-04)
参考文献数
3
被引用文献数
3 4

The Martian Moons eXploration (MMX) mission is now under study by the Japan Aerospace Exploration Agency (JAXA). Its scope includes the world's first landing on one of the Martian moons, collecting samples from the surface, and returning to Earth. This paper describes the orbit design for MMX. Nominal and backup trajectories for launch in 2024 and 2026 are discussed. The Mars orbit insertion (MOI) sequence using 3-impulse maneuvers is introduced. A new scheme, the robust MOI, is also proposed as a contingency to enhance the robustness of the mission sequence. A method to design a robust MOI trajectory and examples are presented.