Curriculum Vitaes
Profile Information
- Affiliation
- Director General, Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency
- Degree
- Ph.D(Mar, 1988, The University of Tokyo)Master(Mar, 1985, The University of Tokyo)
- ORCID ID
https://orcid.org/0000-0002-6871-3133- J-GLOBAL ID
- 200901080116851867
- researchmap Member ID
- 1000144511
- External link
Dr. Hitoshi Kuninaka received his Ph.D from the University of Tokyo in 1988. He was promoted to Associate Professor and Professor of the Japan Aerospace Exploration Agency, Japan, in 2000 and 2005, respectively. He held concurrently the post of Professor in the Department of Aeronautics and Astronautics, University of Tokyo, Japan, from 2004 to 2018. In 2018, he became the Director General of the Institute of Space and Astronautical Science (ISAS) as well as Vice President of Japan Aerospace Exploration Agency (JAXA).
He researches the plasma interaction of satellites and develops electric propulsions. He participated in the satellite project, Space Flyer Unit, from 1988 to 1996, and successfully brought it back to Earth via Space Shuttle STS-72. Microwave discharge ion engines, which were invented and developed by Dr. Kuninaka, took Hayabusa explorer on a round-trip journey between Earth and an asteroid from 2003 to 2010. The engines also have been propelling Hayabusa2 explorer toward another asteroid since 2014. The Hayabusa project team has been honored with the National Science Society (NSS) Space Pioneer Award, American Institute of Aeronautics and Astronautics (AIAA) Electric Propulsion Outstanding Technical Achievement Award, NSS Von Braun Award, International Academy of Astronautics Laurels for Team Achievement, SpaceOps Organization International SpaceOps Award for Outstanding Achievement among others. He received AIAA Fellow membership in 2012 and IAA Space Engineering Section Correspond Member in 2019.
Research Interests
3Research Areas
3Major Research History
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Apr, 2018 - Mar, 2025
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Apr, 2005 - Mar, 2018
Education
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Apr, 1983 - Mar, 1988
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Apr, 1979 - Mar, 1983
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Apr, 1976 - Mar, 1979
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Apr, 1973 - Mar, 1976
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Apr, 1967 - Mar, 1973
Major Awards
39-
Nov, 2021
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Dec, 2020
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Sep, 2020
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Nov, 2017
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Apr, 2015
Papers
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Journal of Applied Physics, 131(1) 013301-013301, Jan 7, 2022 Peer-reviewedLast author
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Acta Astronautica, 181 14-27, Jan, 2021 Peer-reviewedLast author
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Acta Astronautica, 176 77-88, Nov, 2020 Peer-reviewedCorresponding author
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Vacuum and Surface Science, 63(4) 183-188, Apr 10, 2020 InvitedLead authorThe microwave discharge plasma sources contributed to the reciprocating powered flight between Earth and the asteroids as the main propulsion system of the Hayabusa and Hayabusa2 asteroid explorers, and showed its high performance. The electron cyclotron resonance discharge only heats the electrons and does not induce ion sputtering damage. The reasons of high performance and long life are derived and proved theoretically, experimentally, and in practical use in space. In addition to further space applications, efforts are also being made for industrial applications.
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J. Inst. Electrostat. Jpn., 44(3) 128-134, Mar, 2020 Peer-reviewedLast authorElectric charge accumulation can cause failure during vacuum manufacturing processes. For the charge neutralization in vacuum environment, cyclical change of its pressure to produce intermittent passive discharges according to the Paschen's law is often used; however, it is still insufficient to increse production efficiency. The goal of this study is to increase the charge neutralization rate in vacuum environments (10-10-4 Pa) using an electron cyclotron resonance (ECR) plasma source developed by JAXA (Japan Aerospace Exploration Agency) to neutralize the charge of spacecrafts emitting ions from their thrusters. We investigated the charge neutralization of a 50 mm × 50 mm plate with capacitance of 1.7 μF at initial voltage of 200 V, where the plate is placed 30 cm away from the ECR neutralizer. The time required to reach 37% of the initial voltage was 0.1 s for positive charge and 27 s for negative charge. In addition, improvement of the electron extraction electrode for the ECR neutralizer led to five times higher neutralization current compared to the previous ECR neutralizer at 10 W power and 0.1 mg/s xenon flow rate.
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Acta Astronautica, 166 69-77, Jan, 2020 Peer-reviewedLast author
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ACTA ASTRONAUTICA, 165 25-31, Dec, 2019
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Review of Scientific Instruments, 90(104706), Oct, 2019 Peer-reviewedLast author
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Acta Astronautica, 30, Aug, 2019 Peer-reviewed
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Journal of Propulsion and Power, 35(3) 565-571, May, 2019 Peer-reviewed
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Journal of Physics: Conference Series, 1322(1), Jan, 2019 Peer-reviewed
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Acta Astronautica, 157 425-434, 2019 Peer-reviewed
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Plasma Sources Science and Technology, 27(1), Jan 1, 2018 Peer-reviewed
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Plasma Sources Science and Technology, 27(10), 2018 Peer-reviewed
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Plasma Sources Science and Technology, 27(9), 2018 Peer-reviewed
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Biological Sciences in Space, 31 1-5, 2018 Peer-reviewed
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Review of Scientific Instruments, 89(9), 2018 Peer-reviewed
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Journal of Physics: Conference Series, 840 012010-012010, May, 2017 Peer-reviewed
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Frontier of Applied Plasma Technology, 10(1) 1-6, 2017 Peer-reviewedLast author
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ACTA ASTRONAUTICA, 127 702-709, Oct, 2016 Peer-reviewed
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JSAP Annual Meetings Extended Abstracts, 2016.1 192-192, Mar 3, 2016
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TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, AEROSPACE TECHNOLOGY JAPAN, 14(ists30) Pb_203-Pb_208, 2016 Peer-reviewed<p>Conventionally, neutralizers in ion thruster systems do not generate thrust force. Hence, the power consumption of a neutralizer negatively affects the thrust efficiency of the ion thruster system. Therefore, in this paper, a negative ion source that generates thrust force as well as neutralizes the positive ion beam was newly developed using fullerene as a propellant so as to realize a more efficient ion thruster system. To develop the negative ion source, two measurements were conducted. The first measurement was an E × B probe to identify the species of positive and negative ions. The second measurement was a magnetically filtered Faraday probe to measure quantitatively the negative ion currents. Based on the measurements, it is concluded that the negative current is not carried by electrons but by negatively charged fullerenes. Finally, the negative ion source was successfully coupled with a positive ion source. To the best of our knowledge, this is the first paper to report the demonstration of an ion thruster using a negative ion source instead of a cathode.</p>
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TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, AEROSPACE TECHNOLOGY JAPAN, 14(ists30) Pb_183-Pb_187, 2016 Peer-reviewed<p>As a part of a Japanese collaborative research and development project on practical use of a high power anode layer type Hall thruster, a 5 kW class anode layer Hall thruster (RAIJIN94) has been developed and the thrust performance has been evaluated. The thrust was measured in the ion engine endurance test facility at ISAS/JAXA using a pendulum thrust stand developed at the University of Tokyo. The thrust performance at 3 kW operation was measured (xenon anode mass flow rate of 9.8 mg/s and xenon cathode mass flow rate of 0.5 mg/s); the thrust, specific impulse, and thrust efficiency were found to be 160 mN, 1600 sec and 0.42, respectively. The thrust performance depends on magnetic field configuration, that is, the strength of the magnetic field and the ratio of trim coil to inner/outer coil.</p>
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TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, AEROSPACE TECHNOLOGY JAPAN, 14(ists30) Pb_131-Pb_140, 2016 Peer-reviewed<p>Hayabusa2 is the second asteroid sample return mission by JAXA. The ion engine system (IES) for Hayabusa2 is based on that developed for Hayabusa with modifications necessary to improve durability, to increase thrust by 20%, and to reflect on lessons learned from Hayabusa mission. Hayabusa2 will rendezvous with a near-earth asteroid 1999 JU3 and will take samples from its surfaces. More scientific instruments than Hayabusa including an impactor to make a crater and landers will be on board thanks to the thrust enhancement of the IES. An improved neutralizer with stronger magnetic field for longer life has been under endurance test in diode mode since August 2012 and has accumulated the operational hours of 25600 h ( > mission requirement: 14000 h) by July 2015. The IES flight model was developed within 2.5 years. The spacecraft was launched from Tanegashima Space Center in Kagoshima Prefecture on-board an H-IIA launch vehicle on December 3, 2014. </p>
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プラズマ応用科学, 23(2) 69-74, Dec, 2015 Peer-reviewedLast author
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Planetary People, 24(3) 247-257, 2015 Peer-reviewed
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JOURNAL OF PROPULSION AND POWER, 30(5) 1368-1372, Sep, 2014 Peer-reviewed
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JOURNAL OF PROPULSION AND POWER, 30(5) 1383-1389, Sep, 2014 Peer-reviewed
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TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, AEROSPACE TECHNOLOGY JAPAN, 12(ists29) Pc_43-Pc_48, 2014 Peer-reviewed
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TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, AEROSPACE TECHNOLOGY JAPAN, 12(ists29) To_1_1-To_1_5, 2014 Peer-reviewedNext generation arcjets should have light-weight design and prolonged lifetime. For the former topic, it is shown that the radiator mass can be drastically reduced by the effective use of propellant as a coolant at the lower temperature region on the radiator. Resulting thruster weight of 2.0 kg including the radiator is possible for 15 kWe arcjet. For the latter topic, replaceable cathode system is proposed and some key issues are mentioned.
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TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, AEROSPACE TECHNOLOGY JAPAN, 12(ists29) Tr_19-Tr_25, 2014 Peer-reviewedThe Small Demonstration Satellite-4 (SDS-4) of JAXA launched on May 18, 2012 (JST) is equipped with a Japan's first quartz crystal microbalance (QCM) for spacecraft surface contamination monitoring. The QCM was installed on one of the satellite outer surface and occasionally observed gradual frequency decrease (=contamination) under the ground clean room environment for about a year. The QCM frequencies just before and after the launch by the H-IIA Launch Vehicle No. 21 (H-IIA F21) were almost the same, which indicated good cleanness inside the H-IIA's payload fairing. The frequency rapidly increased to the initial level during the first week after the launch probably due to removal or erosion of contaminants on the crystal surface by attack of atoms and ions in the orbit at an altitude of about 700 km. Contamination was never dominant during seventeen months of the space operation. Long term trend of the QCM frequency seems to be affected by the upper atmosphere density changing with the F10.7 solar radio flux.
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TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, AEROSPACE TECHNOLOGY JAPAN, 12(ists29) Tk_29-Tk_33, 2014 Peer-reviewed
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Trans Jpn Soc Aeronaut Space Sci Aerosp Technol Jpn (Web), 12(ists29) TB.31-TB.35 (J-STAGE), 2014 Peer-reviewed
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GEOCHEMICAL JOURNAL, 48(6) 571-587, 2014 Peer-reviewed
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韓國航空宇宙學會誌, 42(11) 974-980, 2014 Peer-reviewed
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JOURNAL OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, 62(6) 212-218, 2014 Peer-reviewedThe microwave ion thruster μ10's ion beam current saturated at a large mass flow rate when propellant gas was injected from a waveguide inlet and it was improved by additional propellant inlets to a discharge chamber. In order to understand the mechanism of these phenomena, it is important to measure distributions of the microwave electric field inside the discharge chamber, which is directly related to plasma production. In this study, we applied an electro-optic (EO) probe to measuring the microwave electric field. The probe contains no metal and can be accessed in the discharge chamber with less disruption to the microwave distribution. We measured electric-field profiles along the centerline and in the ECR area of μ10 with the EO probe. Consequently, this paper revealed that when the propellant was injected from the waveguide inlet, microwave was reflected in the waveguide at large mass flow rate, which disturbed a propagation of microwave to the ECR area. It also revealed that when the propellant was injected from the discharge chamber inlet, the mass flow rate where the microwave reflection occurred shifted to larger rate, which resulted in the increase of the beam current．
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プラズマ応用科学, 21(1) 9-14, Jun, 2013 Peer-reviewed
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JOURNAL OF PROPULSION AND POWER, 29(3) 501-506, May, 2013 Peer-reviewed
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日本惑星科学会誌, 22(2), 2013 Invited宇宙工学は、宇宙への往来の実現を目指し、技術を切磋琢磨してきた。その成果の端的な例は、「はやぶさ」にて実現された地球〜小惑星間往復航行（２００３年〜２０１０年）である。それにより、科学や技術分野を越えて、より大きな世界観を得ることができた。次の新しい知見を得るために、科学的な意義はもちろんのこと、「宇宙を自在に往来する独自能力の維持発展」と「人類の活動領域の宇宙への拡大」という宇宙工学・宇宙探査に跨る目標を担い、「はやぶさ２」小惑星探査ミッションが開発中である。
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REVIEW OF SCIENTIFIC INSTRUMENTS, 83(12), Dec, 2012 Peer-reviewed
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JOURNAL OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, 60(3) 128-134, Jun 5, 2012 Peer-reviewedThis study evaluates the system performances of a 10-W-class miniature ion thruster designed for 50kg small spacecraft. The miniature ion thruster used here, using microwave discharge, was specially designed for low microwave power operation, as low as 1.0W. Thruster performance of this thruster (ion beam current, required microwave power, and required gas flow rate) was measured by the experiments. This experiment included a neutralizer and power and gas needed for its operation. Specifications of sub-components needed for a miniature ion thruster system was estimated based on commercially available or space qualified products. As a result, performance of the miniature ion thruster system was evaluated using those thruster performance and sub-component specifications. One of the results is that the miniature ion thruster system can generate 297μN thrust with 1100s specific impulse and ΔV of 300m/s for 50kg spacecraft by 15.6W total power consumption and 2.7–3.5kg total wet weight of the system.
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TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, AEROSPACE TECHNOLOGY JAPAN, 10(ists28) Tb_1-Tb_8, 2012 Peer-reviewed
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JOURNAL OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, 60(3) 135-141, 2012 Peer-reviewedThe microwave discharge ion engine μ10's thrust force was improved by additional propellant inlets to a discharge chamber. However, internal plasma diagnostics was not carried out while ion beam was extracted. In order to understand the effects of the new propellant inlets, we measured excitation temperatures and axial number density distributions of metastable Xe I 5p5(2P03/2)6s[3/2]02 inside of μ10 by a line pair method and laser absorption spectroscopy respectively. Firstly, the measurement of excitation temperatures was operated in two positions of the probe tip: 0cm and 5cm from a screen grid. This measurement confirmed that the temperatures marked between 0.42 and 0.68eV. Secondly, the number density distribution measurements were realized by a novel laser absorption spectroscopy utilizing optical fibers. As a result, 1017m-3 order of metastable neutral particles were measured by coupling with the excitation temperatures. Consequently, this paper will reveal that the propellant injection from a waveguide inlet increased the electron number density in the waveguide, which disturbed a propagation of microwave to the discharge chamber. It will also reveal that the propellant injection from the discharge chamber was effective to suppress the plasma production in the waveguide, which resulted in the increase of the thrust.
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33(12), 2012 InvitedThe cathode-less electron cyclotron resonance ion engines propelled the Hayabusa asteroid explorer, launched in May 2003, which is focused on demonstrating the technology necessary for a sample return from an asteroid, using electric propulsion, optical navigation, material sampling in a zero gravity field, and direct re-entry from a heliocentric orbit. It rendezvoused with the asteroid Itokawa after a two-year deep space flight using the ion engines in 2005 and accomplished a round trip space mission between Earth and an asteroid in 2010. For the deep space odyssey between Earth and the asteroid, the ion engines served the total accumulated operational time 39637 hour·unit, the powered spaceflight in 25590 hours. Hayabusa and microwave discharge ion engines pioneered the space exploration and will bring us further deep space. This paper also report recent topics in space technology associated with the surface science.
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REVIEW OF SCIENTIFIC INSTRUMENTS, 82(12), Dec, 2011 Peer-reviewed
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Theoretical and Applied Mechanics Japan, 59 49-57-57, Aug, 2011 Peer-reviewed
Misc.
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令和3年度宇宙輸送シンポジウム: 講演集録 = Proceedings of Space Transportation Symposium FY2021, Jan, 2022令和3年度宇宙輸送シンポジウム（2022年1月13日-14日. オンライン開催) Space Transportation Symposium FY2021 (January 13-14, 2022. Online Meeting) 非化学推進優秀学生賞 資料番号: SA6000173064 STEP-2021-025
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令和二年度宇宙輸送シンポジウム: 講演集録 = Proceedings of Space Transportation Symposium FY2020, Jan, 2021令和二年度宇宙輸送シンポジウム（2021年1月14日-15日. オンライン開催) Space Transportation Symposium FY2020 (January 14-15, 2021. Online Meeting) PDF再処理の為、2023年2月27日に差替 資料番号: SA6000160089 レポート番号: STEP-2020-053
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マイクロ波放電型イオンスラスタの放電室形状と性能の関係—Effect of Discharge Chamber Geometry on the ECR Ion Thruster Performance平成30年度宇宙輸送シンポジウム: 講演集録 = Proceedings of Space Transportation Symposium FY2018, Jan, 2019平成30年度宇宙輸送シンポジウム（2019年1月17日-18日. 宇宙航空研究開発機構宇宙科学研究所（JAXA)(ISAS)）, 相模原市, 神奈川県 Space Transportation Symposium FY2018 (January 17-18, 2019. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (JAXA)(ISAS)), Sagamihara, Kanagawa Japan 資料番号: SA6000136059 レポート番号: STEP-2018-003
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平成30年度宇宙輸送シンポジウム: 講演集録 = Proceedings of Space Transportation Symposium FY2018, Jan, 2019平成30年度宇宙輸送シンポジウム（2019年1月17日-18日. 宇宙航空研究開発機構宇宙科学研究所（JAXA)(ISAS)）, 相模原市, 神奈川県 Space Transportation Symposium FY2018 (January 17-18, 2019. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (JAXA)(ISAS)), Sagamihara, Kanagawa Japan 資料番号: SA6000136077 レポート番号: STEP-2018-021
Major Books and Other Publications
5Presentations
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Jan, 2021, Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency(JAXA)(ISAS)Space Transportation Symposium FY2020 (January 14-15, 2021. Online Meeting)
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Advances in Optical and Mechanical Technologies for Telescopes and Instrumentation IV, Dec 14, 2020, SPIE Invited
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Feb, 2019, Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency(JAXA)(ISAS)2019 Symposium on Laboratory Experiment for Space Science (February 28 - March 1, 2019. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (JAXA)(ISAS)), Sagamihara, Kanagawa Japan
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Proceedings of the International Astronautical Congress, IAC, 2019
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航空原動機・宇宙推進講演会講演論文集(CD-ROM), 2019
Professional Memberships
5Works
9Major Research Projects
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研究成果展開事業（産学官の連携による共創の「場」の形成支援）, 科学技術振興機構, Jul, 2015 - Mar, 2020
Industrial Property Rights
17Major Media Coverage
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ＮＨＫ, ＮＨＫスペシャル, https://www.facebook.com/NHKonline/posts/2639642986062350/, Mar 17, 2019 TV or radio program
