Publication

Journal Articles

1. M. Murohara, H. Koizumi, Z. Rucheng, K. Nishii,  and K. Komurasaki, "Experimental Study on Combustion of Water Vapor and Aluminum Powder for Chemical Micropropulsion," Transactions of the Japan Society for Aeronautical and Space Sciences, 67(2), pp. 86-98, 2024, doi: 10.2322/tjsass.67.86

2. K. Nishii and H. Koizumi, "Temperature Measurement on Condensed Combustion Products of Magnesium with Oxygen and Water Vapor,"  Combustion and Flame, 262 p. 113362, 2024, doi:10.1016/j.combustflame.2024.113362.

3. K. Nishii and D. Levin, “Three-Dimensional Kinetic Simulations of Carbon Backsputtering in Vacuum Chambers from Ion Thruster Plumes,” Journal of Propulsion and Power, 40 (1), pp. 123-137, 2024, doi: 10.2514/1.B39194 (preprint doi: 10.48550/ARXIV.2303.07496).

4. K. Nishii and D. Levin, "Kinetic Simulation of Ion Thruster Plume Neutralization in a Vacuum Chamber," Plasma Sources Science and Technology, 32, p. 115009, 2023, doi: 10.1088/1361-6595/ad0836  (preprint doi: 10.48550/arXiv.2306.16693).

5. K. Nishii, H. Koizumi, and K. Komurasaki, “Observation of Condensed Combustion Product Formation during Combustion of Magnesium Plate in Water Vapor,” Journal of Evolving Space Activities, 1(33), pp. 1-6, 2023, doi: 10.57350/jesa.33

6. K. Nishii, M. Akiyama, H. Koizumi, K. Komurasaki, “Combustion of Magnesium Wires with Oxygen and Water Vapor,” Combustion Science and Technology, 195, pp. 2364-2380, 2023, doi: 10.1080/00102202.2021.2019241

7. K. Nishii, H. Koizumi, and K. Komurasaki, “Background Pressure Effect on Thrust Efficiency of Low-Reynolds-Number Nozzles,” Journal of Propulsion and Power, 38 (6), pp. 1042-1050, 2022, doi: 10.2514/1.B38719

8. S. Izawa, K. Nishii, H. Koizumi, and K. Komurasaki, "The measurement of 2-D density distribution at the downstream of a micronozzle of a spacecraft using electron beam induced fluorescence," Journal of the Japan Society for Aeronautical and Space Sciences, 69, pp. 219-228, 2021, doi: 10.2322/jjsass.69.219 (in Japanese) 

9. K. Nishii, A. Hattori, H. Koizumi, and K. Komurasaki, “Low-pressure-vaporization of water droplets on wall under normal and microgravity conditions,” Acta Astronautica, 186, pp. 508-516, 2021, doi: 10.1016/j.actaastro.2021.05.039

10. K. Nishii, H. Koizumi, and K. Komurasaki, “Experimental Characterization of Nozzle Performance at Low Reynolds Numbers for Water Microthrusters,” Journal of Propulsion and Power, 37, pp. 595-603, 2021, doi: 10.2514/1.b38147

11. M. Akiyama, K. Nishii, Y. Mannami, M. Murohara, H. Koizumi, and K. Komurasaki, “Feasibility Study of a Hybrid Thruster using Wire-Shaped Magnesium and Water for Application to Small Spacecraft,” Transactions of the Japan Society for Aeronautical and Space Sciences, 64, pp. 223-233, 2021, doi: 10.2322/tjsass.64.223

12. Y. Murata, N. Funabiki, H. Aohama, S. Nakajima, S. Matsushita, K. Nishii, R. Takahashi, Y. Kawabata, S. Ikari, K. Miyoshi, and R. Funase, “Power Management of Lunar CubeSat Mission EQUULEUS Under Uncertainties of Power Generation and Consumption,” Transactions of the Japan Society for Aeronautical and Space Sciences, Aerospace Technology Japan, 19, pp. 377-383, 2021, doi: 10.2322/tastj.19.377

13. K. Nishii, J. Asakawa, K. Kikuchi, M. Akiyama, Q. Wang, M. Murohara, Y. Ataka, H. Koizumi, R. Funase and K. Komurasaki, “Flight Model Development and Ground Demonstration of Water Resistojet Propulsion System for CubeSats,” Transactions of the Japan Society for Aeronautical and Space Sciences, 63, pp. 141-150, 2020, doi: 10.2322/tjsass.63.141

14. J. Asakawa, K. Nishii, Y. Nakagawa, H. Koizumi and K. Komurasaki, “Direct measurement of 1-mN-class thrust and 100-s-class specific impulse for a CubeSat propulsion system,” Review of Scientific Instruments, 91, pp. 035116, 2020, doi: 10.1063/1.5121411

15. R. Funase, S. Ikari, K. Miyoshi, Y. Kawabata, S. Nakajima, S. Nomura, N. Funabiki, A. Ishikawa, K. Kakihara, S. Matsushita, R. Takahashi, K. Yanagida, D. Mori, Y. Murata, T. Shibukawa, R. Suzumoto, M. Fujiwara, K. Tomita, H. Aohama, K. Iiyama, S. Ishiwata, H. Kondo, W. Mikuriya, H. Seki, H. Koizumi, J. Asakawa, K. Nishii, A. Hattori, Y. Saito, K. Kikuchi, Y. Kobayashi, A. Tomiki, W. Torii, T. Ito, S. Campagnola, N. Ozaki, N. Baresi, I. Yoshikawa, K. Yoshioka, M. Kuwabara, R. Hikida, S. Arao, S. Abe, M. Yanagisawa, R. Fuse, Y. Masuda, H. Yano, T. Hirai, K. Arai, R. Jitsukawa, E. Ishioka, H. Nakano, T. Ikenaga, and T. Hashimoto, “Mission to Earth–Moon Lagrange Point by a 6U CubeSat: EQUULEUS,” IEEE Aerospace and Electronic Systems Magazine, 35, pp. 30-44, 2020, doi: 10.1109/maes.2019.2955577

16. H. Koizumi, J. Asakawa, Y. Nakagawa, K. Nishii, Y. Takao, M. Nakano and R. Funase, “Assessment of Micropropulsion System Unifying Water Ion Thrusters and Water Resistojet Thrusters,” Journal of Spacecraft and Rockets, 56, pp. Published Online: 9, 2019, doi: 10.2514/1.A34407

17. J. Asakawa, H. Koizumi, K. Nishii, N. Takeda, M. Murohara, R. Funase and K. Komurasaki, “Fundamental Ground Experiment of a Water Resistojet Propulsion System: AQUARIUS Installed on a 6U CubeSat: EQUULEUS,” Transactions of the Japan Society for Aeronautical and Space Sciences, Aerospace Technology Japan, 16, pp. 427-431, 2019, doi: 10.2322/tastj.16.427

18. K. Nishii, H. Koizumi, J. Asakawa and K. Komurasaki, "Experimental Effects of Ambient Pressure on Nozzle Efficiency at Low Reynolds Numbers," Journal of the Japan Society for Aeronautical and Space Science, 66, pp. 120-122, 2018, doi: 10.2322/jjsass.66.120 (in Japanese) 

Under Review / Preprint Papers

Books / Commentary

1.  西井啓太, "CubeSat 用超小型水推進機の開発と研究への展開," 日本航空宇宙学会誌, 71 (2), pp. 31-32, 2023, doi: 10.14822/kjsass.71.2_31

2. Asakawa, H. Koizumi, K. Nishii, A. Hattori, "Development of a Water Micro-resistojet Propulsion System : AQUARIUS," Aeronautical and Space Sciences Japan, 66, pp. 296-301, 2018, doi: 10.14822/kjsass.66.10_296 (in Japanese)

Conference Proceedings

1. T. Nakajima, K. Nishii, A. Kakami, "Performance of Double-Channel TAL-type Hall Thruster," 38th International Electric Propulsion Conference, June, Toulouse, France, IEPC-2024-455, 2024

2. D. Komatsu, K. Nishii, A. Kakami, "Performance of Water Direct Injection Type MPD Thruster," 38th International Electric Propulsion Conference, June, Toulouse, France, IEPC-2024-454, 2024

3. K. Yoshida, A. Kakami, K. Nishii, "Thrust Measurement of Water-Propellant Arcjet Thruster," 38th International Electric Propulsion Conference, June, Toulouse, France, IEPC-2024-452, 2024

4. R. Tanno, K. Nishii, A. Kakami, "Radio Frequency Plasma Cathode for Hall Thruster Using Water Propellant," 38th International Electric Propulsion Conference, June, Toulouse, France, IEPC-2024-343, 2024

5. K. Nishii and D. A. Levin, "Numerical Study of Facility Effects on Gridded Ion Thrusters through a Multi-GPU PIC-DSMC Solver," 38th International Electric Propulsion Conference, June, Toulouse, France, IEPC-2024-323, 2024

6. F. Matsuo, T. Nakajima, K. Nishii, A. Kakami, "Evaluation of TAL-type Hall Thruster Using Water Propellant," 38th International Electric Propulsion Conference, June, Toulouse, France, IEPC-2024-296, 2024

7. G. Lim, K. Nishii, H. Tran, H. B. Chew, D. A. Levin, "Kinetic Simulation of Carbon Sputtering by a Gridded Ion Thruster with a Molecular Dynamics Based Model," 38th International Electric Propulsion Conference, June, Toulouse, France, IEPC-2024-186, 2024

8. K. Nishii, S. Srinivasan and D. Levin, "Modeling of Ion Thruster Plume Neutralization using Kinetic Simulations," AIAA SciTech 2024 Forum, January, Orlando, FL, USA, AIAA 2024-1142, 2024, doi: 10.2514/6.2024-1142

9. K. Nishii, A. Kakami, and H. Koizumi, "Numerical Investigation of Facility Effect on Performance Measurements of Low-Reynolds-Number Nozzles," 34th  International Symposium on Space Technology and Science, June, Kurume, Fukuoka, Japan, 2023-b-66, 2023

10. K. Nishii, D. Levin, "Numerical Investigation of Carbon Sputtering and Transport for the Ion Thruster Testing in the Ground Facility," AIAA SciTech 2023 Forum, January, National Harbor MD, USA, AIAA 2023-0065, 2023, doi: 10.2514/6.2023-0065

11. K. Nishii, S. Clark, N. Nuwal, D. Levin, J. Rovey, "Numerical Simulation of Carbon Sputtering for Electric Propulsion in the Ground Facility," 37th International Electric Propulsion Conference, June, Boston, MA, USA, IEPC-2022-379, 2022

12. S. Clark, J. Tompkins, K. Nishii, J. Rovey, D. Levin, "Diagnostic Development of Isotopic Carbon Labelling for Hall Thrusters," 37th International Electric Propulsion Conference, June, Boston, MA, USA, IEPC-2022-163, 2022

13. K. Nishii, S. Clark, H. Tran, D. Levin, J. Rovey, H. Chew, "Carbon Sputtering and Transport in a Ground Facility during Electric Propulsion Testing," AIAA Aviation 2022 Forum, June, Chicago, IL, USA, AIAA 2022-3497, 2022, doi: 10.2514/6.2022-3497

14. K. Nishii, H. Koizumi, K. Komurasaki, "Experimental Observation of Condensed Combustion Products during Combustion of Magnesium in Water Vapor," 33rd  International Symposium on Space Technology and Science, February, Online, 2022-o-1-23, 2022

15. M. Akiyama, K. Nishii, Y. Mannami, M. Murohara, H. Koizumi, and K. Komurasaki, "Estimation of Thrust Performance from the Experimental Results of the Combustion of Magnesium Wires in Water Vapor," 7th edition of the Space Propulsion Conference, March, Online, SP2020_00038, 2021

16. K. Nishii, Y. Mannami, M. Akiyama, M. Murohara, K. Hiroyuki and K. Komurasaki, "Experimental Study on Bulk Metal-Water Combustion for Small Spacecraft Propulsion," AIAA Propulsion and Energy 2020 Forum, August, Online, AIAA 2020-3744, 2020, doi: 10.2514/6.2020-3744

17. T. Shibukawa, S. Matsushita, K. Iiyama, A. Ishikawa, K. Nishii and, R. Funase, "Flight Model Thermal Design and Verification for the 6U Deep Space CubeSat EQUULEUS," 50th International Conference on Environmental Systems, July, Online, ICES-2020-282, 2020

18. M. Akiyama, K. Nishii, K. Kikuchi, Q. Wang, M. Murohara, Y. Ataka, J. Asakawa, H. Koizumi, K. Kakihara, K. Yanagida, R. Suzumoto, R. Funase and K. Komurasaki, "Ground Test Results of the Water Resistojet Propulsion System AQUARIUS Flight Model Installed on a 6U CubeSat: EQUULEUS," 70th International Astronautical Congress, October, Washington D.C., USA, IAC-19,C4,8-B4.5A,3,x53723, 2019

19. K. Kikuchi, K. Nishii, M. Akiyama, Q. Wang, M. Murohara, Y. Ataka, A. Hattori, J. Asakawa, H. Koizumi, K. Kakihara, K. Yanagida, R. Suzumoto, R. Funase and K. Komurasaki, "Comparison of performance by different operation of a water resisto-jet propulsion system: AQUARIUS installed on 6U CubeSat: EQUULEUS," AIAA Propulsion and Energy 2019 Forum, August, Logan, IN, USA, AIAA 2019-3955, 2019, doi: 10.2514/6.2019-3955

20. K. Nishii, H. Koizumi and K. Komurasaki, "Experimental characterization of nozzle performance at low reynolds numbers for water resistojet thrusters," AIAA Propulsion and Energy 2019 Forum, August, Logan, IN, USA, AIAA 2019-4244, 2019, doi: 10.2514/6.2019-4244

21. K. Nishii, J. Asakawa, A. Hattori, Y. Saito, K. Kikuchi, M. Akiyama, Q. Wang, Y. Ataka, M. Murohara, K. Kakihara, K. Yanagida, H. Koizumi, R. Funase, and K. Komurasaki, "Flight Model Development of aWater Resistojet Propulsion System: AQUARIUS Installed on a 6U CubeSat: EQUULEUS," 32nd International Symposium on Space Technology and Science, June, Fukui, Japan, 2019-f-49, 2019

22. M. Akiyama, Y. Saito, K. Nishii, H. Koizumi, K. Komurasaki, "Application of an Al/Fe2O3 Thermite Reaction to an Igniter of a Hybrid Rocket," 32nd International Symposium on Space Technology and Science, June, Fukui, Japan, 2019-a-87, 2019

23. Y. Murata, N. Funabiki, H. Aohama, S. Nakajima, R. Funase, K. Miyoshi, S. Ikari, Y. Kawabata, S. Matsushita, R. Takahashi, K. Nishii, "Power Management of Lunar CubeSat Mission EQUULEUSUnder Uncertainties of Power Generation and Consumption," 32nd International Symposium on Space Technology and Science, June, Fukui, Japan, 2019-f-34, 2019

24. J. Asakawa, K. Nishii, A. Hattori, H. Koizumi, Y. Saito, K. Kikuchi, M. Akiyama, Q. Wang, Y. Ataka, K. Komurasaki, "Flight Model Development of the Water Resistojet Propulsion System for Deep Space Exploration by the CubeSat: EQUULEUS," 69th International Astronautical Congress, October, Bremen, Germany, IAC-19,C4,8-B4.5A,3,x47580, 2018

25. R. Funase, S. Ikari, Y. Kawabata, S. Nakajima, S. Nomura, K. Kakihara, R. Takahashi, K. Yanagida, S. Matsushita, A. Ishikawa, N. Funabiki, Y. Murata, R. Suzumoto, T. Shibukawa, D. Mori, M. Fujiwara, K. Tomita, H. Koizumi, J. Asakawa, K. Nishii, I. Yoshikawa, K. Yoshioka, T. Hirai, S. Abe, R. Fuse, M. Yanagisawa, K. Miyoshi, Y. Kobayashi, A. Tomiki, W. Torii, T. Ito, M. Kuwabara, H. Yano, N. Ozaki, T. Ikenaga, T. Hashimoto, "Flight Model Design and Development Status of the Earth - Moon Lagrange Point Exploration CubeSat EQUULEUS Onboard SLS EM-1," 32nd Annual AIAA/USU Conference on Small Satellites, August, Logan, IN, USA, SSC18-VII-05, 2018

26. A. Hattori, J. Asakawa, K. Nishii, N. Takeda, H. Koizumi, R. Funase, K. Komurasaki, "Performance Improvement and Flight Model Design of the Water Resistojet Propulsion System, AQUARIUS for 6U CubeSat: EQUULEUS," Space Propulsion 2018, May, Sevilla, Spain, SP2018-00261, 2018

27. K. Nishii, N. Takeda, A. Hattori, J. Asakawa, H. Koizumi, K. Komurasaki, "Performance Evaluation of 10 W Class Water Resistojet: AQUARIUS for CubeSats," Space Propulsion 2018, May, Sevilla, Spain, SP2018-00300, 2018

28. J. Asakawa, K. Nishii, H. Koizumi, N. Takeda, R. Funase, K. Komurasaki, "Engineering Model Development of the Water Resistojet Propulsion System: AQUARIUS for the SLS EM-1 CubeSat: EQUULEUS," 35th International Electric Propulsion Conference, October, Atlanta, GA, USA, IEPC-2017-401, 2017

29. K. Nishii, J. Asakawa, H. Koizumi, N. Takeda, R. Funase, K. Komurasaki, "Performance Evaluation of the Water Resistojet Propulsion System: AQUARIUS for the SLS EM-1 CubeSat: EQUULEUS," 35th International Electric Propulsion Conference, October, Atlanta, GA, USA, IEPC-2017-446, 2017

30. J. Asakawa, H. Koizumi, K. Nishii, N. Takeda, R. Funase, "Development of the Water Resistojet Propulsion System for Deep Space Exploration by the CubeSat: EQUULEUS," 31st Annual AIAA/USU Conference on Small Satellites, August, Logan, IN, USA, SSC17-VII-02, 2017

31. J. Asakawa, H. Koizumi, N. Takeda, K. Nishii, M. Murohara, R. Funase, K. Komurasaki, "Fundamental Ground Experiment of a Water Resistojet Propulsion System: AQUARIUS Installed on a 6U CubeSat: EQUULEUS," 31st International Symposium on Space Technology and Science, June, Ehime, Japan, 2017-f-045, 2017

Symposiums / Talks (w/o Proceedings)

1. K. Nishii and D. Levin, "Fully Kinetic PIC Simulations of the Electrical Facility Effect on the Gridded Ion Thruster Testing," 50th IEEE International Conference on Plasma Science, June, Santa Fe, New Mexico, USA, O-2.3.4, 2023

2. M. Murohara, K. Nishii, K. Kikuchi, M. Akiyama, Q. Wang, S. Izawa, Y. Mannami, H. Koizumi, K. Kakihara, W. Mikuriya, S. Ishiwata, S. Nomura, R. Takahashi, S. Ikari, S. Nakajima, Y. Kawabata, "Hardware-in-the-Loop Simulation Results of Water Resistojet Propulsion System AQUARIUS Integrated into 6U EQUULEUS," 60th Asian Joint Conference on Propulsion and Power, March, Online, P00130, 2021

3. K. Nishii, J. Asakawa, R. Matsushita, T. Shibukawa, H. Koizumi, R. Funase and K. Komurasaki, "Experimental Evaluation of the Micro Water Thruster Recovering Waste Heat of a Spacecraft," 36th International Electric Propulsion Conference, September, Vienna, Austria, A809, 2019

4. K. Nishii, H. Koizumi, J. Asakawa A. Hattori, K. Kikuchi, M. Akiyama Q. Wang and M. Murohara, "Pre-flight Testing of AQUARIUS: the Water Resistojet Thruster on the SLS EM-1 CubeSat for Deep Space Exploration," 33rd Annual AIAA/USU Conference on Small Satellites, August, Logan, IN, USA, Pre-Conference Posters Session I, 2019

5. H. Koizumi, J. Asakawa, Y. Nakagawa, K. Nishii, D. Tomita, A. Hattori, R. Funase, K. Komurasaki, "Innovative Unified Water Propulsion System for Upcoming CubeSat Missions," 4S Symposium 2018, May, Sorrento, Italia, In-flight Experience 2 & Propulsion, 2018

Thesis

1. Keita Nishii, "Experimental study of the multiphase flow inside water thrusters for microspacecraft," Department of Aeronautics and Astronautics, Graduate School of Engineering, The University of Tokyo, Ph.D. Thesis, 2021, UTokyo Repository (full article)

2. Keita Nishii, "Vaporizing Mechanisms and Micro-nozzle flows of the Water Resistojet Thruster for CubeSats," Department of Advanced Energy, Graduate School of Frontier Sciences, The University of Tokyo, Master Thesis, 2018, Utokyo Repository (in Japanese)

Patents

1. H. Koizumi, M. Akiyama, K. Nishii, M. Murohara, Y. Mannami, "Rocket engine," Utility Patent application, US 2023/0213004 A1, 2023

2. 小泉 宏之，秋山 茉莉子，西井 啓太，室原 昌弥，万浪 義史，ロケットエンジン，特願2020-150595／特開2022-045096