Organization
School of Engineering Professor
Title
Professor
External link
SAKAMOTO HIRAKU
News & Topics
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JAXAの「革新的衛星技術実証4号機」に膜面展開アンテナ技術の実証衛星が選定 オリガミ膜展開式リフレクトアレーアンテナを宇宙実証
2023/03/16
Languages： Japanese
要点-膜面展開アンテナ技術の宇宙実証が「革新的衛星技術実証4号機」の実証テーマ（キューブサット）に選定-折り紙技術により畳める2層展開膜にアンテナ素子を貼付した、軽量・高収納率な展開アレーアンテナを軌道上実証-小型・超小型衛星への大面積アンテナ搭載を可能に
Research Areas
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Frontier Technology (Aerospace Engineering, Marine and Maritime Engineering) / Aerospace engineering
Papers
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Thermal Evaluation of Flexible Graphite-Based Deployable Structures for Phased Array Antennas
Delburg P. Mitchao, Hayashi Hiroki, Narukiyo Yasuto, Atsushi Shirane, Hiraku Sakamoto, Yasushi Nishikawa
AIAA SCITECH 2025 Forum 2025.1
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Thermal and Mechanical Design of Thin-Film Solar Arrays on Textile Origami Deployable Structures
So Yeon Suk, Atsuki Ochi, So Tanaka, Delburg P. Mitchao, Mitsuhiko Yasuhara, Takashi Tomura, Hiraku Sakamoto, Osamu Mori, Hiroyuki Toyota, Yu Miyazawa, Shusaku Kanaya, Masanori Matsushita, Tamotsu Horiuchi, Ryota Takabe, Yuko Hisada, Rie Tokuda, Kenta Noguchi
AIAA SCITECH 2025 Forum 2025.1
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ハンズオンを用いたシステムズエンジニアリング教育の提案と実践
山崎政彦, 坂本啓, 嶋津恵子
日本工学教育協会論文 22 - 29 2024.12
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宇宙展開式の二層膜アレーアンテナ構造の試作と評価
安原光彦, 越智淳伎, 黒川晴希, 鈴木皓大, Suk So Yeon, 戸村崇, 坂本啓
第68回宇宙科学技術連合講演会 ( 1O10 ) 2024.11
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発電・アンテナ機能を有する軽量膜展開構造物HELIOS-Rの開発と運用準備状況
松下将典, 中川雄登, 大木春仁, 鶴谷柊朔, 高尾勇輝, 杉原アフマッド清志, 森治, 楠本哲也, 渡邊秋人, 堀利行, 伊藤裕明, 佐藤泰貴, 宮崎康行, 奥泉信克, 大月幸穂, 中川果帆, 米田大晟, 芝田朋世, 鳥阪綾子, 粂颯太, 越智淳伎, 坂本啓, 白根篤史, 岡田健一, 仙場淳彦, 青野郁也, 天川海音, 石戸大智, 清水隆貴, 河原寛奈
第68回宇宙科学技術連合講演会 ( 1L18 ) 2024.11
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「宇宙テキスタイル展開構造材料の原子状酸素耐性に関する研究
田中創, 坂本啓, 赤坂大樹, 杉原アフマッド清志, 森治, 松下将典, 渡邊秋人
第68回宇宙科学技術連合講演会 ( 4N05 ) 2024.11
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重力傾斜安定キューブサットへの残留磁気の影響評価と対策
豊田晃大, 粂颯太, 木谷洸一, 越智淳伎, 濟藤颯真, 安原光彦, Suk So Yeon, 坂本啓
第68回宇宙科学技術連合講演会 ( 3N12 ) 2024.11
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膜面展開アレーアンテナの軌道上でのカメラ画像からの形状推定
木谷洸一, 坂本啓
第68回宇宙科学技術連合講演会 ( 3N17 ) 2024.11
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擾乱トルクの影響低減を目指した片翼ソーラーセイルの姿勢運動解析
粂颯太, 坂本啓, 高尾勇輝
第68回宇宙科学技術連合講演会 ( 4I09 ) 2024.11
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「UNISECアカデミー」を通じた超小型衛星技術の集約と展開
坂本啓, 北澤幸人, 川島レイ, 田中里美, 趙孟佑, 桒原聡文, 山﨑政彦, 佐原宏典
第68回宇宙科学技術連合講演会 ( 4L03 ) 2024.11
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折り紙構造による展開リフレクトアレーアンテナ実証機OrigamiSat-2の開発進捗
濟藤颯真, 坂本啓, 戸村崇, 白根篤史, 岡田健一, 中山弦, 黒川晴希, 越智淳伎, 木谷洸一, 豊田晃大, Suk So Yeon, 安原光彦, 鈴木皓大, 前田陸, 粂颯太, 櫻井亮輔, 青見紘起, 岸本皐汰, 白木嵩, 船引廉人, 駒場啄舞, 田中創, 菊池洸成, 張博与, 指村智彦, 森谷元喜, Mitchao P. Delburg
第68回宇宙科学技術連合講演会 ( 2L04 ) 2024.11
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反射位相制御可能な宇宙用膜展開式リフレクトアレーアンテナの設計・解析
越智淳伎, 戸村崇, 坂本啓
第68回宇宙科学技術連合講演会 ( 1O09 ) 2024.11
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Takumi Ohashi, Futo Noda, Takashi Tomura, Ampan Laosunthara, Koudai Suzuki, Yuno Tanaka, Maki Kishimoto, Rie Seto, Hiraku Sakamoto, Gia Khanh Tran, Atsushi Shirane
2024 23rd International Symposium on Communications and Information Technologies (ISCIT) 152 - 157 2024.9
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Development of Multifunctional Lightweight Membrane Structure for Antennas and Power Generation on Small Satellites
Yuto Nakagawa, Masanori Matsushita, Yuki Takao, Ahmed Kiyoshi Sugihara, Osamu Morihimura, Masahiro Fujita, Hiroaki Yoneda, Shun Yasuda, Tomoyo Shibata, Toshiyuki, Tetsuya Kusumoto, Haruhito Ohki, Kaho Nakagawa, Shusaku Tsuruya, Yukiho Ohtsuki, Sho NisHori, Hiroaki Ito, Akihito Watanabe, Sota Kume, Atsuki Ochi, Sora Kanamaru, Motoki Moritani, Hiraku Sakamoto, Atsushi Shirane, Kenichi OkadaTechnology, Ayako Torisaka, Tokyo Metropolitan UniversityFollow, Nobukatsu Okuizumi, Yasutaka Satou, Yasuyuki Miyazaki, Atsuhiko Senba
Small Satellite Conference 2024.8
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Power Supply and RF Signal Routing Architecture Design for Ultralight Deployable Ka-Band Active Phased-Array Transceivers
Hiroki Hayashi, Yasuto Narukiyo, Delburg Mitchao, Yuki Takeda, Sene Kato, So Yeon Suk, Hiraku Sakamoto, Dongwon You, Kenichi Okada, Atsushi Shirane
Small Satellite Conference 2024.8
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Radiation-Tolerant Ka-Band Deployable Phased-Array Transceiver for Low-Earth Orbit Small Satellite Constellation
Yasuto Narukiyo, Xi Fu, Dongwon You, Sena Kato, Takashi Tomura, Hiraku Sakamoto, Kenichi Okada, Atsushi Shirane
Small Satellite Conference 2024.8
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Takaomi Chubachi, Hiroshi Furuya, Hiraku Sakamoto
AIAA Journal 62 ( 7 ) 2401 - 2413 2024.7
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Design and Evaluation of Deployable Perovskite Solar Arrays Aboard Small Spacecraft
So Yeon Suk, Motoki Moritani, Hiraku Sakamoto, Tamotsu Horiuchi, Ryota Takabe, Yuko Hisada, Rie Tokuda, Osamu Mori, Hiroyuki Toyota, Yu Miyazawa, Masanori Matsushita, Kazuki Nagai, Atsuki Ochi, Delburg Mitchao, Yuki Takeda, Mitsuhiko Yasuhara, Soma Saito, Takashi Tomura
ASME 2024 Aerospace Structures, Structural Dynamics, and Materials Conference 2024.4
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Thermal Control of Array Antenna Transmitters Attached on Space Membrane Structures Reviewed
Yuki TAKEDA, Shinji TAKEDA, Shuhei KOIKE, Kenichiro SAWADA, Masahiro FUJITA, Yuta TAKAHASHI, Motoki MORITANI, Yunosuke SAITO, Haruki HAGIWARA, Shinya TAMURA, Kazuki NAGAI, Sora KANAMARU, Dongwon YOU, Atsushi SHIRANE, Delburg MITCHAO, Masanori MATSUSHITA, Ahmed Kiyoshi SUGIHARA, Yuki TAKAO, Chihiro HATAKEYAMA, Hiraku SAKAMOTO
Journal of Evolving Space Activities 2 1 - 13 2024.4
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Stretchable-Substrate-Impregnated Fabric: Deployable Reflectarray Antennas for CubeSats Reviewed
Masato Machida, Takashi Tomura, Hiraku Sakamoto, Tomohiro Fukao
IEEE Access 12 58562 - 58572 2024.4
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Space Demonstration of Two-layer Deployable Membrane Reflectarray Antenna with Popup Book Mechanism
Hiraku Sakamoto, Takashi Tomura, Atsuki Ochi, Kazuki Nagai, Motoki Moritani, Gen Nakayama, Taichi Oshino
AIAA SCITECH 2024 Forum 2024.1
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Highly Thermal Conductive Deployable Membrane for Large Ka-band Active Phased Array Antenna
Delburg P. Mitchao, Yuki Takeda, So Yeon Suk, Dongwon You, Atsushi Shirane, Hiraku Sakamoto, Yasushi Nishikawa, Masae Yano, Saki Abe
AIAA SCITECH 2024 Forum 2024.1
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Thermo-mechanical Evaluation of Multilayer Graphite Sheet Structures for Space Deployable Antennas
Yuki Takeda, Delburg P. Mitchao, So Yeon Suk, Dongwon You, Atsushi Shirane, Hiraku Sakamoto, Yasushi Nishikawa, Masae Yano, Saki Abe
AIAA SCITECH 2024 Forum 2024.1
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A Ka-Band Deployable Active Phased Array Transmitter Fabricated on 4-Layer Liquid Crystal Polymer Substrate for Small-Satellite Mount
Dongwon You, Xiaolin Wang, Hans Herdian, Xi Fu, Hojun Lee, Michihiro Ide, Carrel Da Gomez, Zheng Li, Jill Mayeda, Daisuke Awaji, Jian Pang, Hiraku Sakamoto, Kenichi Okada, Atsushi Shirane
IEEE Access 11 69522 - 69535 2023
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A Flexible Implementation of Ka-Band Active Phased Array for Satellite Communication
Xiaolin Wang, Dongwon You, Xi Fu, Hojun Lee, Zheng Li, Daisuke Awaji, Jian Pang, Atsushi Shirane, Hiraku Sakamoto, Kenichi Okada
IEEE MTT-S International Microwave Symposium Digest 2022-June 753 - 756 2022
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A Ka-Band 16-Element Deployable Active Phased Array Transmitter for Satellite Communication
Dongwon You, Yuta Takahashi, Shinji Takeda, Motoki Moritani, Haruki Hagiwara, Shuhei Koike, Hojun Lee, Yun Wang, Zheng Li, Jian Pang, Atsushi Shirane, Hiraku Sakamoto, Kenichi Okada
IEEE MTT-S International Microwave Symposium Digest 2021-June 799 - 802 2021.6
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Phase adjustment algorithm for deformation compensation of nonflat reflectarray antenna
Masaki Kato, Hiraku Sakamoto, Takashi Tomura, Masaaki Okuma
2020 International Symposium on Antennas and Propagation, ISAP 2020 495 - 496 2021.1
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Keisuke Omoto, Takashi Tomura, Hiraku Sakamoto
IEEE Access 9 54101 - 54108 2021
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A Flexible Element Antenna for Ka-Band Active Phased Array SATCOM Transceiver
Dongwon You, Daisuke Awaji, Atsushi Shirane, Hiraku Sakamoto, Kenichi Okada
Asia-Pacific Microwave Conference Proceedings, APMC 2020-December 991 - 993 2020.12
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Significance of 3U CubeSat OrigamiSat-1 for space demonstration of multifunctional deployable membrane Reviewed
Kosuke Ikeya, Hiraku Sakamoto, Hiroki Nakanishi, Hiroshi Furuya, Takashi Tomura, Ryoga Ide, Ryo Iijima, Yohei Iwasaki, Keigo Ohno, Keisuke Omoto, Takashi Furuya, Teruaki Hayashi, Masaki Kato, Sae Koide, Madoka Kurosaki, Yuki Nakatsuka, Shigeaki Okuyama, Reo Kashiyama, Junya Nakamura, Wataru Nio, Tsubasa Tsunemitsu, Yutaka Yamazaki, Keisuke Taga, Britta Hohmann, Towa Amamoto, Takaomi Chubachi, Sho Tamura, Hideaki Okada, Akihito Watanabe, Nobuyoshi Kawabata, Toshiyuki Hori, Hiroaki Ito, Takeshi Kuratomi, Yuya Shimoda, Nana Hidaka, Kazuki Watanabe, Ayako Torisaka, Masahiko Yamazaki
Acta Astronautica 173 363 - 377 2020.8
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Experiment and Analysis of Spinning Membrane Deployment Focusing on Shape Imbalance for Solar Sail Reviewed
Kengo SHINTAKU, Saburo MATUNAGA, Go ONO, Hiraku SAKAMOTO, Takeshi SATOH, Osamu MORI, Yoji SHIRASAWA, Nobukatsu OKUIZUMI
TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, AEROSPACE TECHNOLOGY JAPAN 12 ( ists29 ) Pc_55 - Pc_62 2014.8
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Wrapping Experiments of Piecewise Straight Fold Membrane for Large Solar Sail
SATOU Yasutaka, FURUYA Hiroshi, SAKAMOTO Hiraku, SHIRASAWA Yoji, MORI Osamu, OKUIZUMI Nobukatsu, NATORI M. C.
TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, AEROSPACE TECHNOLOGY JAPAN 12 ( 29 ) Pc_49 - Pc_54 2014
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Deployment and steering dynamics of spinning solar sail "IKAROS" Reviewed
Osamu Mori, Yoji Shirasawa, Yasuyuki Miyazaki, Hiraku Sakamoto, Mitsue Hasome, Nobukatsu Okuizumi, Hirotaka Sawada, Hiroshi Furuya, Saburo Matunaga, Michihiro Natori, Yuichi Tsuda, Takanao Saiki, Ryu Funase, Yuya Mimasu, Junichiro Kawaguchi
Journal of Aerospace Engineering, Sciences and Applications 4 ( 4 ) 79 - 96 2012.10
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Small-scale experiments and simulations of centrifugal membrane deployment of solar sail craft "IKAROS" Reviewed
Nobukatsu Okuizumi, Azusa Mura, Saburo Matsunaga, Hiraku Sakamoto, Yoji Shirasawa, Osamu Mori
Collection of Technical Papers - AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference 2011
MISC
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Storability of Space Deployable Textile Membrane Structures with Flexible Electrical Circuits
大野奎悟, 坂本啓, 大熊政明, 岡田健一, 白根篤史, 戸村崇, YOU Dongwon
宇宙太陽発電(Web) 5 18 - 22 2020
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Design and Validation of the 5.8-GHz-band Active Reflectarray that reconfigure nonflat surface
大本圭祐, 坂本啓, 戸村崇, 広川二郎, 大熊政明
宇宙科学技術連合講演会講演集(CD-ROM) 63rd 2019
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Conserving finite element dynamics of gossamer structure and its application to spinning solar sail "IKAROS" Reviewed
Yasuyuki Miyazaki, Yoji Shirasawa, Osamu Mori, Hirotaka Sawada, Nobukatsu Okuizumi, Hiraku Sakamoto, Saburo Matunaga, Horishi Furuya, Michihiro Natori
Collection of Technical Papers - AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference 2011.4
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Mission report on the solar power sail deployment demonstration of IKAROS Reviewed
Hirokata Sawada, Osamu Mori, Nobukatsu Okuizumi, Yoji Shirasawa, Yasuyuki Miyazaki, Michihiro Natori, Saburo Matunaga, Hiroshi Furuya, Hiraku Sakamoto
Collection of Technical Papers - AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference 2011.4
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A spin-up control scheme for contingency deployment of the sailcraft IKAROS Reviewed
Hiraku Sakamoto, Yoji Shirasawa, Daisuke Haraguchi, Hirotaka Sawada, Osamu Mori
Collection of Technical Papers - AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference 2011.4
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Analysis of membrane dynamics using multi-particle model for solar sail demonstrator "IKAROS" Reviewed
Yoji Shirasawa, Osamu Mori, Yasuyuki Miyazaki, Hiraku Sakamoto, Mitsue Hasome, Norizumi Okuizumi, Hirotaka Sawada, Hiroshi Furuya, Saburo Matsunaga, Michihiro Natori, Jun'ichiro Kawaguchi
Collection of Technical Papers - AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference 2011.4
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Design criteria for spin deployment of gossamer structures considering nutation dynamics Reviewed
Daisuke Haraguchi, Hiraku Sakamoto, Yoji Shirasawa, Osamu Mori
AIAA Guidance, Navigation, and Control Conference 2010.8
Research Projects
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Design Methodology Development and Space Demonstration of Innovative Space Origami Structure with Multi-Physics Adaptation
Grant number：24H00358 2024.4 - 2027.3
Japan Society for the Promotion of Science Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (A)
Grant amount：\48750000 （ Direct Cost: \37500000 、 Indirect Cost：\11250000 ）
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宇宙展開・形状可変無線機による災害時と平常時双方で利用可能な通信システムの研究
Grant number：24K00940 2024.4 - 2027.3
日本学術振興会 科学研究費助成事業 基盤研究(B)
白根 篤史, タン ザカン, 坂本 啓
Grant amount：\18590000 （ Direct Cost: \14300000 、 Indirect Cost：\4290000 ）
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超小型衛星用の全方位ビーム走査閉曲面膜展開トランスミットアレーアンテナの創出
Grant number：23K26105 2023.4 - 2026.3
日本学術振興会 科学研究費助成事業 基盤研究(B)
戸村 崇, 坂本 啓, 白根 篤史
Grant amount：\19240000 （ Direct Cost: \14800000 、 Indirect Cost：\4440000 ）
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Model-Based Design Methodology for Globally Optimized System Using "Suriawase"
Grant number：22H01715 2022.4 - 2025.3
Japan Society for the Promotion of Science Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)
Grant amount：\17420000 （ Direct Cost: \13400000 、 Indirect Cost：\4020000 ）
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Model-Based Design Methodology for Globally Optimized System Using "Suriawase"
Grant number：23K22984 2022.4 - 2025.3
Japan Society for the Promotion of Science Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)
Grant amount：\17420000 （ Direct Cost: \13400000 、 Indirect Cost：\4020000 ）
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Flexible Phased Array for Directional Wireless Communication
Grant number：20H00236 2020.4 - 2024.3
Japan Society for the Promotion of Science Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (A) Grant-in-Aid for Scientific Research (A)
Kenichi Okada
Grant amount：\44070000 （ Direct Cost: \33900000 、 Indirect Cost：\10170000 ）
This project aims to enable millimeter-wave band phased-array antennas, which are conventionally placed on planar surfaces, to be placed on non-planar surfaces as well. The objective is to reveal a method for estimating the position of each antenna on a non-planar surface and realize a compensation of beam pattern. A CMOS integrated circuit that enables beamforming with high-precision phase and amplitude control and measurement of the coupling between antennas is fabricated, and the effectiveness of the proposed method is evaluated. Even for a bent phased-array antenna, an improvement of 10 dB in EIRP is achieved by using the proposed method.
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Research on in-space demonstration of ultra-lightweight deployable Origami array antenna
Grant number：20H00281 2020.4 - 2024.3
Japan Society for the Promotion of Science Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (A) Grant-in-Aid for Scientific Research (A)
Grant amount：\46280000 （ Direct Cost: \35600000 、 Indirect Cost：\10680000 ）
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Creation of reflectarray antenna systems with ultra-high gain, compact storage, and large deployability
Grant number：20H02146 2020.4 - 2023.3
Japan Society for the Promotion of Science Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)
Takashi Tomura
Grant amount：\17810000 （ Direct Cost: \13700000 、 Indirect Cost：\4110000 ）
The following three research projects were undertaken with the aim of creating a reflectarray antenna system with ultra-high gain, compact size, and large deployment capability. (1) In non-flat compensation technology, we found a reflective element structure that can be realized using rigid and flexible substrates, and evaluated a reflective array antenna prototype to demonstrate its effectiveness. (2) For reflection elements that satisfy the fold pattern, we determined the conditions for the fold pattern width and array period, and found element shapes that do not cross the fold line at any element position. (3) By integrating the above technologies, we designed an ultra-high gain, compact, and large deployable reflector array antenna system that can be installed on the nano-satellite OrigamiSat-2.
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Construction of design and verification methodology for large deployable space structures through development of CubeSat demonstrator
Grant number：17H03477 2017.4 - 2020.3
Japan Society for the Promotion of Science Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)
Sakamoto Hiraku
Grant amount：\16900000 （ Direct Cost: \13000000 、 Indirect Cost：\3900000 ）
Space deployable membrane structures are expected to realize innovative space applications; however, their designs and fabrications are difficult to be verified on the ground. As a result, structural designs tend to be conservative and massive. To this end, this study develops a new lightweight membrane structure to be tested on orbit. A 3U CubeSat (nano-satellite) is developed and launched to space. Through the development, design/verification strategies for space membrane structures are constructed.
Specifically, the three insights are obtained. First, the new designs and ground test methods were practically developed. Second, the experimental results were used to derive design methodology for larger membrane space structures. Third, designs for solar power generation satellites and membrane array antennas were proposed though the knowledge obtained through the CubeSat development. -
Grant number：26249131 2014.4 - 2018.3
Japan Society for the Promotion of Science Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (A) Grant-in-Aid for Scientific Research (A)
KOGISO NOZOMU, ISHIMURA KOSEI, OGI YOSHIRO
Grant amount：\40820000 （ Direct Cost: \31400000 、 Indirect Cost：\9420000 ）
This research project focuses on the "space smart structure system" which can adaptively change the shape according to the perturbation of the environmental factor as the future space structure system required for the future space mission. The objective of this research project is to establish a design verification framework combining the computational and experimental verification methods. The computer verification focuses on the structural analysis under uncertainty based on several computational statistic methods. The experimental verification considers thermal deformation under environmental uncertainty.
The constructed framework is applied to the design problem of the smart space structure systems and then, the validity of the framework is clarified. -
Development of Boom-Membrane Integrated Deployable Space Structures
Grant number：25289305 2013.4 - 2017.3
Japan Society for the Promotion of Science Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B) Grant-in-Aid for Scientific Research (B)
Furuya Hiroshi, MORI Osamu, SHIRASAWA Yoji, OKUIZUMI Nobukatsu, KATSUMATS Nobuhisa, TORISAKA Ayako
Grant amount：\17420000 （ Direct Cost: \13400000 、 Indirect Cost：\4020000 ）
The boom-menbrane integrated deployable space structures have been proposed, which are characterized by the simultaneous retraction and deployment with deployable boom and membrane. The properties of storing and deployment for the boom-membrane integrated deployable structures were investigated by scaled model experiments to design a flight model for small satellites through the ground testing, the micro-gravity experiments, and the vacuum chamber experiments. Finally, the proposed boom-menbrane integrated deployable structures were verified by developing the engineering model for a small satellite.
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Design Exploration of Space Gossamer Structures for Next Generation
Grant number：22760623 2010.4 - 2013.3
Japan Society for the Promotion of Science Grants-in-Aid for Scientific Research Grant-in-Aid for Young Scientists (B) Grant-in-Aid for Young Scientists (B)
SAKAMOTO Hiraku
Grant amount：\4160000 （ Direct Cost: \3200000 、 Indirect Cost：\960000 ）
The present study aimed at developing design-support tools for space gossamer (membrane-cable structure) spacecraft. The tool enables the visualization of design space during the conceptual design phase of space systems. It enables to consider the effect of parameter uncertainties or the coupling with control subsystems. Geometrically nonlinear finite-element methods are mainly used in the tool. This study has successfully applied the tools to the following three practical problems: (1) one-step deployment of a solar sail, (2) shape estimation of a tension-stabilized reflector, and (3) non-synchronous deployment motion of a solar sail.
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Dynamical Property Identification and Vibration Control of Gossamer Space Structures
Grant number：20860037 2008 - 2009
Japan Society for the Promotion of Science Grants-in-Aid for Scientific Research Grant-in-Aid for Young Scientists (Start-up) Grant-in-Aid for Young Scientists (Start-up)
SAKAMOTO Hiraku
Grant amount：\3289000 （ Direct Cost: \2530000 、 Indirect Cost：\759000 ）
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膜・ケーブル宇宙構造の構造・制御の同時最適設計に関する研究
Grant number：07J05939 2007 - 2009
日本学術振興会 科学研究費助成事業 特別研究員奨励費 特別研究員奨励費
坂本 啓
Grant amount：\1100000 （ Direct Cost: \1100000 ）
初年度は研究計画に従い,膜面宇宙構造(以下,ゴサマー構造と呼称)の地上実験と数値解析の両方を実施し,まず地上実験によって数値解析結果の精度検証を行うことを目指した.しかしゴサマー構造の動力学を地上において観察することは非常に困難であり,2008年2月22日に筑波の低圧環境設備で実施したソーラーセイル展開実験では,数値解析結果と比較できるほど精度の良い定量データを計測することができなかった.私は就職のため当初の3年の研究計画うちの1年目終了時で特別研究員を辞退するが,今後も,この1度の低圧実験失敗で得た知見を礎として,受入れ研究者・宮崎教授との共同研究を続け,ゴサマー構造の地上実験法のひとつの手法の確立を目指していく所存である.いっぽう数値解析に関する研究では,宮崎教授の指導のもと,幾何学的非線形有限要素法の枠組みの中で新たな要素を開発し,その解析法を用いて,現在JAXA宇宙科学研究本部で検討されているソーラーセイル実証衛星の動力学シミュレーションを行った.具体的には,ソーラーセイル膜が次第に繰り出されていく機構を模擬し,「長さを変える要素」に対し「ヒンジのような幾何学的拘束」を与えるモデルを開発した.これを別のモデリング方法(多粒子モデル)での解析結果と比較し,それぞれのモデリング方法の特徴を明らかにし,さらにそれらの解析結果を実機の設計へ活かす検討を行った.この研究については近く論文を執筆・投稿する予定である.
今後は,スケールモデルによる地上実験と,数値解析,という二つの手法をどのように組み合わせることで信頼性の高い人工衛星の設計につなげていくか,という方法論を知識化することが重要と考えている.そしてゴサマー構造の動力学の解明による制御系の同時設計へとつなげていきたい.1年間という短期ではあったが,申請書に記した研究目的へ一歩向かう成果を挙げることができた.