Curriculum Vitaes
Profile Information
- Affiliation
- Associate Professor, Institute of Space and Astronautical Science, Japan Aerospace Exploration AgencyAssociate Professor, Space and Astronautical Science, Department of Advanced Studies, The Graduate University for Advanced Studies, SOKENDAI
- Degree
- 博士（工学）(東京大学)
- Researcher number
- 90836222
- ORCID ID
https://orcid.org/0000-0002-8445-1575- J-GLOBAL ID
- 201801006720467786
- Researcher ID
- GXH-5604-2022
- researchmap Member ID
- B000312477
Research Interests
10Research History
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Apr, 2023 - Present
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Mar, 2019 - Mar, 2023
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Apr, 2018 - Feb, 2019
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Oct, 2016 - Dec, 2016
Education
3-
Apr, 2015 - Mar, 2018
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Apr, 2013 - Mar, 2015
Major Awards
7Papers
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Space Science Reviews, 220(1), Jan 24, 2024 Peer-reviewedAbstract Here we describe the novel, multi-point Comet Interceptor mission. It is dedicated to the exploration of a little-processed long-period comet, possibly entering the inner Solar System for the first time, or to encounter an interstellar object originating at another star. The objectives of the mission are to address the following questions: What are the surface composition, shape, morphology, and structure of the target object? What is the composition of the gas and dust in the coma, its connection to the nucleus, and the nature of its interaction with the solar wind? The mission was proposed to the European Space Agency in 2018, and formally adopted by the agency in June 2022, for launch in 2029 together with the Ariel mission. Comet Interceptor will take advantage of the opportunity presented by ESA’s F-Class call for fast, flexible, low-cost missions to which it was proposed. The call required a launch to a halo orbit around the Sun-Earth L2 point. The mission can take advantage of this placement to wait for the discovery of a suitable comet reachable with its minimum $\varDelta $V capability of $600\text{ ms}^{-1}$. Comet Interceptor will be unique in encountering and studying, at a nominal closest approach distance of 1000 km, a comet that represents a near-pristine sample of material from the formation of the Solar System. It will also add a capability that no previous cometary mission has had, which is to deploy two sub-probes – B1, provided by the Japanese space agency, JAXA, and B2 – that will follow different trajectories through the coma. While the main probe passes at a nominal 1000 km distance, probes B1 and B2 will follow different chords through the coma at distances of 850 km and 400 km, respectively. The result will be unique, simultaneous, spatially resolved information of the 3-dimensional properties of the target comet and its interaction with the space environment. We present the mission’s science background leading to these objectives, as well as an overview of the scientific instruments, mission design, and schedule.
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Journal of Evolving Space Activities, 2 n/a, 2024Comet Interceptor is ESA's F-class mission to explore a long-period comet. Comet Interceptor performs a flyby observation with 3 spacecraft: 1 main spacecraft (spacecraft A) and 2 small probes (probe B1 and probe B2). JAXA will provide one of the small probes, probe B1, taking advantage of its past achievements in micro spacecraft. The probe B1 is a micro spacecraft weighing about 35 kg. The bus size is about 24U, and the envelope including protrusions is about 50 cm cubic. This probe will carry three types of science instruments for complementary observations with ESA's instruments onboard the main spacecraft and another small probe at multiple points. The first instrument is a wide-angle camera and a narrow-angle camera (WAC/NAC) for optical observations of the nucleus. The second is Hydrogen Lyman-alpha Imager (HI) to observe a Lyman-alpha of coma, and the third is a Plasma Suite (PS) to observe plasma using an ion sensor and a magnetometer. The probe B1 performs a flyby observation without any commands from the ground, considering dust impacts during the closest approach to the comet. This paper presents the result of conceptual design for the small probe under severe constraints and its future challenges.
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Journal of Evolving Space Activities, 1, Dec, 2023 Peer-reviewed
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8th IAA Planetary Defense Conference, Apr, 2023 Lead authorCorresponding author
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Acta Astronautica, 196 42-56, Jul, 2022 Peer-reviewedLead authorCorresponding author
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The Journal of the Astronautical Sciences, Feb 4, 2022 Peer-reviewedLead authorCorresponding author
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Journal of Guidance, Control, and Dynamics, 2022 Peer-reviewedLead authorCorresponding author
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EARTH PLANETS AND SPACE, 73(1), Dec, 2021
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Acta Astronautica, 180 679-692, Mar, 2021
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Journal of Guidance, Control, and Dynamics, 43(4) 645-655, Mar, 2020 Peer-reviewedLead authorCorresponding authorRecent low-thrust space missions have highlighted the importance of designing trajectories that are robust against uncertainties. In its complete form, this process is formulated as a nonlinear constrained stochastic optimal control problem. This problem is among the most complex in control theory, and no practically applicable method to low-thrust trajectory optimization problems has been proposed to date. This paper presents a new algorithm to solve stochastic optimal control problems with nonlinear systems and constraints. The proposed algorithm uses the unscented transform to convert a stochastic optimal control problem into a deterministic problem, which is then solved by trajectory optimization methods such as differential dynamic programming. Two numerical examples, one of which applies the proposed method to low-thrust trajectory design, illustrate that it automatically introduces margins that improve robustness. Finally, Monte Carlo simulations are used to evaluate the robustness and optimality of the solution.
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Proceedings of the International Astronautical Congress, IAC, 2020-, 2020
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AIAA Scitech 2020 Forum, 1, 2020
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AIAA Scitech 2020 Forum, 1, 2020
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Proceedings of the International Astronautical Congress, IAC, 2020-October, 2020
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Proceedings of the International Astronautical Congress, IAC, 2020-October, 2020
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AIAA Scitech 2020 Forum, 1 PartF, 2020
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Journal of Spacecraft and Rockets, 1 PartF, 2020 Peer-reviewedLead author
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JOURNAL OF THE ASTRONAUTICAL SCIENCES, 67(3) 950-976, Jan, 2020 Peer-reviewed
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IEEE Aerospace & Electro. Systems Magazine, Nov, 2019 Peer-reviewed
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33rd Annual AIAA/USU Conference on Small Satellites, SSC18(VII-05) 1-5, Aug 3, 2019 Peer-reviewed
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IEEE AEROSPACE AND ELECTRONIC SYSTEMS MAGAZINE, 34(4) 38-44, Apr, 2019 Peer-reviewed
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Advances in the Astronautical Sciences, 168 281-300, 2019
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Advances in the Astronautical Sciences, 168 4015-4026, 2019
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Advances in the Astronautical Sciences, 168 301-318, 2019
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Proceedings of the International Astronautical Congress, IAC, 2019-October, 2019
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Advances in the Astronautical Sciences, 168 653-667, 2019
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SPACEFLIGHT MECHANICS 2019, VOL 168, PTS I-IV, 168 653-667, 2019
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SPACEFLIGHT MECHANICS 2019, VOL 168, PTS I-IV, 168 4015-4026, 2019 Peer-reviewed
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SPACEFLIGHT MECHANICS 2019, VOL 168, PTS I-IV, 168 301-318, 2019 Peer-reviewed
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SPACEFLIGHT MECHANICS 2019, VOL 168, PTS I-IV, 168 281-300, 2019 Peer-reviewedLead author
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the University of Tokyo, Mar, 2018 Peer-reviewed
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JOURNAL OF GUIDANCE CONTROL AND DYNAMICS, 41(2) 377-387, Feb, 2018 Peer-reviewed
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Proceedings of the International Astronautical Congress, IAC, 2018-October, 2018
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AIAA Guidance, Navigation, and Control Conference, 2018, (210039), Jan 1, 2018 Peer-reviewed
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Proceedings of the International Astronautical Congress, IAC, 2018-October, 2018 Peer-reviewed
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JOURNAL OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, 65(6) 219-226, 2017 Peer-reviewedEarth observation satellites can improve the flexibility of observation sites by having “maneuverability,” and low-thrust obtained by ion thruster will be a promising method for orbital change for micro-satellites. Designing low-thrust trajectories for these satellites is a multi-revolution and multi-objective (time/fuel-optimal) optimization problem, which usually requires high computational cost to solve numerically. This paper derives an analytical and approximate optimal orbit change strategy between two circular orbits with the same semi-major axis and different local time of ascending node, and proposes a graph-based method to optimize the multi-objective criteria. The optimal control problem results in a problem to search a switching point on the proposed graph, and mission designers can design an approximate switching point on this graph, by using two heuristic and reasonable assumptions that 1) the optimal thrust direction should be tangential to orbit and 2) the optimal thrust magnitude should be bang-bang control with an intermediate coast. Finally, numerical simulation with feedback control algorithm taking thrust margin demonstrates that the proposed method can be applicable in the presence of deterministic and stochastic fluctuation of aerodynamic disturbances.
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SICE Journal of Control, Measurement, and System Integration, 10(3) 192-197, 2017 Peer-reviewed
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宇宙科学技術連合講演会講演集(CD-ROM), 61st ROMBUNNO.3G04, 2017
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2016 55th Annual Conference of the Society of Instrument and Control Engineers of Japan, SICE 2016, 654-659, Nov 18, 2016 Peer-reviewed
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AIAA/AAS Astrodynamics Specialist Conference, 2016, 2016
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Advances in the Astronautical Sciences, 158 239-258, 2016
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Proceedings of the International Astronautical Congress, IAC, 2016
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IFAC PAPERSONLINE, 49(17) 391-396, 2016 Peer-reviewed
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SPACEFLIGHT MECHANICS 2016, PTS I-IV, 158 4269-4290, 2016 Peer-reviewed
Misc.
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Apr 2, 2025DESTINY+ is an upcoming JAXA Epsilon medium-class mission to flyby multiple asteroids including Phaethon. As an asteroid flyby observation instrument, a telescope mechanically capable of single-axis rotation, named TCAP, is mounted on the spacecraft to track and observe the target asteroids during flyby. As in past flyby missions utilizing rotating telescopes, TCAP is also used as a navigation camera for autonomous optical navigation during the closest-approach phase. To mitigate the degradation of the navigation accuracy, past missions performed calibration of the navigation camera's alignment before starting optical navigation. However, such calibration requires significant operational time to complete and imposes constraints on the operation sequence. From the above background, the DESTINY+ team has studied the possibility of reducing operational costs by allowing TCAP alignment errors to remain. This paper describes an autonomous optical navigation algorithm robust to the misalignment of rotating telescopes, proposed in this context. In the proposed method, the misalignment of the telescope is estimated simultaneously with the spacecraft's orbit relative to the flyby target. To deal with the nonlinearity between the misalignment and the observation value, the proposed method utilizes the unscented Kalman filter, instead of the extended Kalman filter widely used in past studies. The proposed method was evaluated with numerical simulations on a PC and with hardware-in-the-loop simulation, taking the Phaethon flyby in the DESTINY+ mission as an example. The validation results suggest that the proposed method can mitigate the misalignment-induced degradation of the optical navigation accuracy with reasonable computational costs suited for onboard computers.
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AAS/AIAA Space Flight Mechanics Meeting, Jan, 2025
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AAS/AIAA Space Flight Mechanics Meeting, Jan, 2025 Last author
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AAS/AIAA Space Flight Mechanics Meeting, Jan, 2025 Last author
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AAS/AIAA Space Flight Mechanics Meeting, Jan, 2025 Last author
Professional Memberships
2Major Works
4Major Research Projects
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学術変革領域研究(B), 日本学術振興会, Oct, 2020 - Mar, 2023
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Grants-in-Aid for Scientific Research Grant-in-Aid for Early-Career Scientists, Japan Society for the Promotion of Science, Apr, 2019 - Mar, 2023
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Adaptable Seamless Technology Transfer Program through Target-driven R&D, Japan Science and Technology Agency, Oct, 2020 - Mar, 2022
