Curriculum Vitaes
Profile Information
- Affiliation
- Professor, Institute of Space and Astronautical Science, Japan Aerospace Exploration AgencyProfessor, School of Physical Sciences Department of Space and Astronautical Science, The Graduate University for Advanced Studies
- Degree
- Doctor of Philosophy in Engineering(Mar, 1995, The University of Tokyo)
- J-GLOBAL ID
- 200901056190267532
- researchmap Member ID
- 1000253787
- External link
Research Interests
4Research Areas
3Major Research History
18Education
2Committee Memberships
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2020 - Present
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2014 - Present
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2014 - 2015
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2011 - 2015
Awards
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2014
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2012
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1999
Papers
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Journal of Evolving Space Activities, 71(2) 67-77, Mar, 2024 Peer-reviewedMagsail is a space propulsion system using the interactions between the solar wind and the magnetic field generated by the onboard coils. Magnetoplasma sail is a propulsion system that increases thrust by expanding the magnetosphere through plasma injection from the spacecraft. There are two mechanisms on the magnetospheric inflation: method using frozen-in of magnetic field to carry magnetic field lines by high dynamic pressure plasma and method using the diamagnetic current by thermal plasma, which is called the ring current. We investigated the effect of the dynamic pressure and thermal pressure on the MPS thrust performance used electromagnetic hydrodynamic simulation. It was shown that the ring current is enhanced by adding dynamic pressure to the thermal plasma and increases thrust gain. The high thrust gain over 2.25 was obtained at βth = 0.5 - 2 and βk = 4 - 8. However, the thrust is reduced because the super magneto acoustic wave region is generated in the magnetosphere, which prevents the propagation of thrust in large β conditions. The wide parameter survey reveals injection plasma parameter regions where thrust reduction is restrained and high thrust gain is obtained.
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Acta Astronautica, 213 645-656, Oct, 2023 Peer-reviewed
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EPJ Techniques and Instrumentation, 10(1), Apr 17, 2023 Peer-reviewedAbstract This review deals with the selection of the electric propulsion system (EPS) for the internationally developed and designed, primary nuclear-electric space tug International Nuclear Power and Propulsion System (INPPS). INPPS is scheduled for interplanetary missions to Mars and Jupiter moon Europa missions by the end of decade 2020. Regarding specific technical and mission parameters preselected electric thruster (ET) types, developed by international companies and institutions, are analysed, evaluated and investigated for a possible application as propulsion system (PS), the so-called CET (Cluster of Electric Thrusters). It is analysed whether solely electric thrusters, combined in an adequate CET, enable the envisaged interplanetary missions—robotic and astronautic/crewed with the INPPS flagship. Thruster clusters with strategic consortium considerations are analysed as a feasible PS of the INPPS. The studied CET consists of the following: (a) only European ETs, (b) combination of German and European ETs, (c) Japanese and European ETs or at least (d) Japanese, European and US thrusters. The main results are (1) Robotic and crewed INPPS mission to Mars/Europa are realizable with EPS only (no chemical propulsion is needed), (2) that every CET, except (c) of only Japanese and part of European thrusters, is capable to perform the main part of envisaged INPPS flagship mission orbit to Mars, back to Earth and to Jupiter/Europa moon.
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Journal of Propulsion and Power, 1-11, Feb 21, 2023 Peer-reviewedRotating detonation engines (RDEs) have been actively researched around the world for application to next-generation aerospace propulsion systems because detonation combustion has theoretically higher thermal efficiency than conventional combustion. Moreover, because cylindrical RDEs have simpler combustors, further miniaturization of conventional combustors is expected. Therefore, in this study, with the aim of applying RDEs to space propulsion systems, a cylindrical RDE with a converging–diverging nozzle was manufactured; the combustor length [Formula: see text] was changed to 0, 10, 30, 50, and 200 mm; and the thrust performance and combustion mode with the different combustor lengths were compared. As a result, four combustion modes were confirmed. Detonation combustion occurred with a combustor length of [Formula: see text]: that is, a converging rotating detonation engine. The thrust performance of this engine was 94 to 100% of the theoretical rocket thrust performance, which is equivalent to the thrust performance of conventional rocket combustion generated at [Formula: see text]. This study shows that detonation combustion can significantly reduce engine weight while maintaining thrust performance.
Misc.
206-
Transactions of the Japan Society for Aeronautical and Space Sciences, 53(180) 84-90, 2010To propel a spacecraft away from the Sun, a magneto plasma sail (MPS) spacecraft produces an artificial magnetic cavity to block the hypersonic solar wind. To make a large magnetic cavity sufficient to obtain significant thrust, the MPS spacecraft increases the magnetic cavity size using an onboard coil with assistance from a plasma jet. This process is called magnetic field inflation. In this study, we performed ideal and resistive magneto hydrodynamic (MHD) analyses to investigate the magnetic diffusion effect on the magnetic field inflation process. Our results indicate that a dipole-like magnetic field is drastically deformed by a plasma jet when the magnetic Reynolds number Rm was 10 or more, the magnetic field lines were nearly identical to the streamlines of the plasma jet. Hence, no magnetic diffusion effect appeared for Rm > 10. Meanwhile, when Rm is an order of unity, the magnetic diffusion effect was remarkable in the current sheet formed around equatorial region. For example, when the divergence angle of a plasma jet in the polar direction was 30°, the magnetic field strength at 40m from the spacecraft (calculated by resistive MHD model) was 19% smaller than the ideal MHD model (Rm=∞). © 2010 The Japan Society for Aeronautical and Space Sciences.
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Transactions of JSASS Space Technology Japan, 8 Vol. 8, (2010) pp., 2010
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Transactions of JSASS Space Technology Japan, 8 Pb_19-Pb_25, 2010
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Advances in Applied Plasma Science, 7 107-110, Aug 20, 2009
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47th AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition, 2009In rocket flights, ionized exhaust plumes from solid rocket motors may interfere with RF transmission under some conditions. In order to clarify the important physical process involved, microwave attenuation and phase delay due to rocket exhaust plumes were measured during sea-level static firing tests conducted on two types of full-scale solid propellant rocket motors. The measured data were analyzed by comparing them with numerical results such as flowfield simulations of exhaust plumes and by employing a detailed analysis of microwave transmission by using a frequency-dependent finite-difference time-domain (FD2TD) method. The results revealed that either the line-of-sight microwave transmission through ionized plumes or the diffracted path around the exhaust plume mainly affects the received RF level, which depends on the magnitude of the plasma RF interaction. For the actual launch vehicle flight, the transmission process is dominated by the diffraction effect so that we applied a two-dimensional diffraction theory to analyze the communication between a vehicle and a ground station. The attenuation levels estimated using diffraction theory agree with the data recorded in-flight. Copyright © 2009 by the American Institute of Aeronautics and Astronautics, Inc.
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AIP Conference Proceedings, 1084 754-759, 2009 Peer-reviewedMagnetic sail (MagSail) is a deep space propulsion system, in which an artificial magnetic cavity captures the energy of the solar wind to propel a spacecraft in the direction leaving the sun. For a scale-model experiment of the plasma flow of MagSail, we employed a magnetoplasmadynamic arcjet as a solar wind simulator. It is observed that a plasma flow from the solar wind simulator reaches a quasi-steady state of about 0.8 ms duration after a transient phase when initiating the discharge. During this initial phase of the discharge, a blast-wave was observed to develop radially in a vacuum chamber. When a solenoidal coil (MagSail scale model) is immersed into the quasi-steady flow where the velocity is 45 km/s, and the number density is 1019 m-3, a bow shock as well as a magnetic cavity were formed in front of the coil. As a result of the interaction between the plasma flow and the magnetic cavity, the momentum of the simulated solar wind is decreased, and it is found from the thrust measurement that the solar wind momentum is transferred to the coil simulating MagSail. © 2009 American Institute of Physics.
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RAREFIED GAS DYNAMICS, 1084 721-+, 2009 Peer-reviewedWe extended the two-dimensional analytical theory of the boundary shape of the geomagnetosphere in the solar wind to take the coil dimension of magnetic sail into account. The boundary electric currents and the induced magnetic field around the coils are used to obtain the thrust of the magnetic sail.
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Journal of Physics: Conference Series, 154, 2009 Peer-reviewedDECi-hertz Interferometer Gravitational wave Observatory (DECIGO) is the planned Japanese space gravitational wave antenna, aiming to detect gravitational waves from astrophysically and cosmologically significant sources mainly between 0.1 Hz and 10 Hz and thus to open a new window for gravitational wave astronomy and for the universe. DECIGO will consist of three drag-free spacecraft, 1000 km apart from each other, whose relative displacements are measured by a differential Fabry-Perot interferometer. We plan to launch DECIGO in middle of 2020s, after sequence of two precursor satellite missions, DECIGO pathfinder and Pre-DECIGO, for technology demonstration required to realize DECIGO and hopefully for detection of gravitational waves from our galaxy or nearby galaxies. © 2009 IOP Publishing Ltd.
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Laboratory Experiment of the Interaction between Plasma Flow and Magnetosphere of Magnetoplasma Sail衝撃波シンポジウム講演論文集, 2007 57-60, Mar 17, 2008
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流体力学講演会/航空宇宙数値シミュレーション技術シンポジウム講演集, 40th-2008 205-208, 2008
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26th International Symposium on Rarefied Gas Dynamics, 2008/7/21-25, Kyoto, 784-789, 2008 Peer-reviewed
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44th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit, 2008 Peer-reviewed
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Journal of Physics: Conference Series, 122, 2008 Peer-reviewed
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日本地球惑星科学連合大会・ J250-P001（ポスター）・ 幕張メッセ・ 千葉, May, 2007
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宇宙航空研究開発機構特別資料 JAXA-SP-, (06-019) 75-81, Mar 30, 2007
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Meeting Abstracts of the Physical Society of Japan, 62, 2007
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Collection of Technical Papers - 43rd AIAA/ASME/SAE/ASEE Joint Propulsion Conference, 8 8410-8418, 2007Magnetic sail (MagSail) is a deep space propulsion system, which uses the energy of the solar wind. MagSail produces an artificial magnetic field and captures the energy of the solar wind plasma to propel a spacecraft in the direction of the solar wind. In order to conduct a scale-model experiment of the plasma flow of a MagSail, we developed a solar wind simulator based on a magnetoplasmadynamic arcjet in a quasi-steady mode of about 1 ms duration. Based on scaling considerations, a solenoidal coil was designed and it was immersed into the plasma flow. In this setup, a magnetic cavity, which is similar to that of the geomagnetic field, was observed, although the magnetic cavity of MagSail is usually much smaller than the geomagnetic cavity of the Earth. It was experimentally confirmed that MagSail could produce thrust even in such ion Larmor scale. Also, an extension of this MagSail experiment to MagSail with plasma jet (M2P2 or MPS) is in progress, and some preliminary results are reported.
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宇宙科学技術連合講演会講演集(CD-ROM), 51st 2E17, 2007
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宇宙航空研究開発機構・情報・計算工学センター・衛星環境プラズマ数値シミュレーションワークショップ報告書,宇宙航空研究開発機構特別資料,JAXA-SP-06-014, pp. 100-110, 2007 Peer-reviewed
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宇宙航空研究開発機構・情報・計算工学センター・衛星環境プラズマ数値シミュレーションワークショップ報告書, 宇宙航空研究開発機構特別資料,JAXA-SP-06-014, pp. 111-121, 2007 Peer-reviewed
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JAXA-SP-06-19, 1-81, Mar, 2006
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磁気プラズマセイルの推力発生メカニズムの解明,JAXA RR (Research and Development Report) -05-014, Edited by I. Funaki and H. Yamakawa, 2006 Peer-reviewed
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JAXA RR (Research and Development Report) -05-014, Edited by I. Funaki and H. Yamakawa, 2006 Peer-reviewed
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Collection of Technical Papers - AIAA/ASME/SAE/ASEE 42nd Joint Propulsion Conference, 11 8669-8682, 2006 Peer-reviewedIn order to simulate the interaction between the artificially deployed magnetic field produced around a magnetic sail spacecraft and the solar wind, a laboratory simulator in a space chamber was designed. As a solar wind simulator, a high-power magnetoplasmadynamic arcjet was operated in a quasisteady mode of about 0.8 ms duration to provide a high-speed hydrogen plasma plume of about 0.7 m in diameter, which is accelerated to above 20 km/s with high plasma densities around 1017-1019 m-3. Into this high-density and high-velocity plasma jet, a small coil of 2-cm-diameter was immersed to obtain 1.9-T magnetic field at the center of the coil. These devices are operation in a large 2-m-diameter space chamber, and the formation of a magnetic cavity was observed around the coil. From the analysis of scaling parameters, it is found that the laboratory experiment of the plasma flow around the coil of the magnetic sail corresponds to a sub-Newton-class magnetic sail.
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ISAS Research Note, Vol. 789, 2005 Peer-reviewed
Major Books and Other Publications
6Presentations
561-
第63回航空原動機・宇宙推進講演会／北部支部2024年講演会ならびに第5回再使用型宇宙輸送系シンポジウム, 日本航空宇宙学会
Major Professional Memberships
4Research Projects
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Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (S), Japan Society for the Promotion of Science, Aug, 2020 - Mar, 2025
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Grants-in-Aid for Scientific Research Grant-in-Aid for Specially Promoted Research, Japan Society for the Promotion of Science, Apr, 2019 - Mar, 2024
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Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B), Japan Society for the Promotion of Science, Apr, 2018 - Mar, 2021
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科学研究費助成事業 基盤研究(B), 日本学術振興会, Apr, 2017 - Mar, 2021
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Grants-in-Aid for Scientific Research Challenging Research (Exploratory), Japan Society for the Promotion of Science, Jun, 2019 - Mar, 2021
