研究者業績

川口 淳一郎

カワグチ ジュンイチロウ  (Jun'ichiro Kawaguchi)

基本情報

所属
国立研究開発法人宇宙航空研究開発機構 宇宙科学研究所 宇宙飛翔工学研究系 特任教授 (シニアフェロー)
学位
工学博士

J-GLOBAL ID
200901015159678275
researchmap会員ID
0000023634

学歴

 1

論文

 278
  • M. Yoshikawa, A. Fujiwara, J. Kawaguchi
    Proceedings of the International Astronomical Union 2(S236) 401-416 2006年8月  
    The spacecraft Hayabusa, which was launched in 2003, arrived at its destination, asteroid (25143) Itokawa in September 2005. The appearance of Itokawa, a small S-type near Earth asteroids, was totally unexpected. The surface is covered with a lot of boulders and there are only a few craters on it. It looks like a contact binary asteroid. The surface composition is quite similar to LL-chondrite. The estimated density is 1.9 0.13 (g/cm ), so the macro-porosity is about 40%. This means that Itokawa is a rubble pile object. In Itokawa, we may see such things that are very close to building blocks of asteroids. In this paper, we review the mission and the first scientific results. © 2007 International Astronomical Union. 3
  • Makoto Yoshikawa, Akira Fujiwara, Jun'Ichiro Kawaguchi
    Proceedings of the International Astronomical Union 2(14) 323-324 2006年8月  
    Results of the Hayabusa mission to image and sample the asteroid Itokawa are summarized. © 2007 International Astronomical Union.
  • A. Fujiwara, J. Kawaguchi, D. K. Yeomans, M. Abe, T. Mukai, T. Okada, J. Saito, H. Yano, M. Yoshikawa, D. J. Scheeres, O. Barnouin-Jha, A. F. Cheng, H. Demura, R. W. Gaskell, N. Hirata, H. Ikeda, T. Kominato, H. Miyamoto, A. M. Nakamura, R. Nakamura, S. Sasaki, K. Uesugi
    Science 312(5778) 1330-1334 2006年6月2日  
    During the interval from September through early December 2005, the Hayabusa spacecraft was in close proximity to near-Earth asteroid 25143 Itokawa, and a variety of data were taken on its shape, mass, and surface topography as well as its mineralogic and elemental abundances. The asteroid's orthogonal axes are 535, 294, and 209 meters, the mass is 3.51 × 10 kilograms, and the estimated bulk density is 1.9 ± 0.13 grams per cubic centimeter. The correspondence between the smooth areas on the surface (Muses Sea and Sagamihara) and the gravitationally low regions suggests mass movement and an effective resurfacing process by impact jolting. Itokawa is considered to be a rubble-pile body because of its low bulk density, high porosity, boulder-rich appearance, and shape. The existence of very large boulders and pillars suggests an early collisional breakup of a preexisting parent asteroid followed by a re-agglomeration into a rubble-pile object. 10
  • Hajime Yano, T. Kubota, H. Miyamoto, T. Okada, D. Scheeres, Y. Takagi, K. Yoshida, M. Abe, S. Abe, O. Barnouin-Jha, A. Fujiwara, S. Hasegawa, T. Hashimoto, M. Ishiguro, M. Kato, J. Kawaguchi, T. Mukai, J. Saito, S. Sasaki, M. Yoshikawa
    Science 312(5778) 1350-1353 2006年6月2日  
    After global observations of asteroid 25143 Itokawa by the Hayabusa spacecraft, we selected the smooth terrain of the Muses Sea for two touchdowns carried out on 19 and 25 November 2005 UTC for the first asteroid sample collection with an impact sampling mechanism. Here, we report initial findings about geological features, surface condition, regolith grain size, compositional variation, and constraints on the physical properties of this site by using both scientific and housekeeping data during the descent sequence of the first touchdown. Close-up images revealed the first touchdown site as a regolith field densely filled with size-sorted, millimeter- to centimeter-sized grains.
  • Tetsuo Yoshimitsu, Jun'ichiro Kawaguchi, Tatsuaki Hashimoto, Takashi Kubota, Masashi Uo, Hideo Morita, Kenichi Shirakawa
    AIAA 57th International Astronautical Congress, IAC 2006 7 4588-4594 2006年  
    In November of 2005, Hayabusa performed descent flights to the Itokawa surface five times. The Itokawa surface is full of boulders against expectation and there are few flat areas where the spacecraft can touch down safely. With the reaction wheels lost prior to the events, it was very difficult to control translation motion accurately, since the guidance accuracy of several millimeters per second was requested. The guidance and navigation before launch assumed the autonomous guidance by identifying the illumination center aboard. However, it was not successful due to the highly irregular shape of the asteroid. On the other hand, the scenario based on the terrain recognition in quasi real time well worked. It was anticipated not useful before launch, since such process was conceived to take a lot of time and not effectively useful in real time operation. The Hayabusa project team devised and built the special tool on the ground and had tuned it before the successful three touch downs and one long landing on the surface.
  • Takashi Kubota, Tatsuaki Hashimoto, Masashi Uo, Katsuhiko Tsuno, JuN'Ichiro Kawaguchi
    Advances in the Astronautical Sciences 124 1827-1841 2006年  
    Hayabusa spacecraft autonomously performed a terrain alignment maneuver that accomplished both altitude and attitude control whose reference was the surface itself. Hayabusa spacecraft was equipped with four beams Laser Range Finder (LRF) onboard. LRF played a very important role to control its position and attitude at the very low altitude, when the spacecraft was out of remote control and was supposed to perform this task pure autonomously. Actually, Hayabusa spacecraft hovered with this method at 17 meters high at the first touching-down attempt and at 7 meters high at the second touching-down attempt. This paper presents how these autonomous controls were performed in detail.
  • Masatoshi Matsuoka, Takashi Kominato, JuN'ichiro Kawaguchi
    Advances in the Astronautical Sciences 124 1739-1751 2006年  
    The MUSES-C[1] was launched on May 9th, 2003. It was renamed "Hayabusa" (falcon in Japanese). The spacecraft is a kind of technology demonstrator with five key technologies including the use of ion engines in interplanetary cruise as a primary propulsion means. After the flight of 2 years, Hayabusa arrived at the asteroid 1998SF36 (It was renamed "Itokawa") on Sep 12th, 2005. This paper presents the trajectory synthesis technique and results for Hayabusa. For this Hayabusa's trajectory synthesis using the electrical propulsion, it was important to allow enough time for the electrical propulsion operation for assuring the margin. And taking the multi-staged approach made it easier to cope with the problems that unexpectedly happened. Hayabusa's Trajectory Synthesis actually incorporated and demonstrated these points, and had coped with and had overcome all the difficulties, incidents such as the loss of reaction wheels (RW) and finally and successfully achieved the rendezvous with Itokawa.
  • Takashi Kominato, Masatoshi Matsuoka, Masashi Uo, Tatsuaki Hashimoto, Jun'ichiro Kawaguchi
    Advances in the Astronautical Sciences 124 1753-1772 2006年  
    Hayabusa (MUSES-C), of which mission is to establish and demonstrate the various technologies required for the future planetary exploration missions, performed an approach to rendezvous with its target asteroid Itokawa and has performed a proximity operation including station keeping and hovering around Itokawa. In order to navigate and to guide the spacecraft to Itokawa, it made highly use of optical hybrid navigation technique combined with the radio-metric information obtained on the ground. Hayabusa is equipped with a sophisticated autonomous navigation and guidance function including onboard image processing and the like. This paper reports how those autonomous capabilities have been utilized in the actual flight operation, at the same time showing the flight results.
  • Ken'ichi Shirakawa, Hideo Morita, Masashi Uo, Tatsuaki Hashimoto, Takashi Kubota, Jun'ichiro Kawaguchi
    Advances in the Astronautical Sciences 124 1817-1825 2006年  
    What Hayabusa demonstrated was, first of all, a pin-point landing whose size is just 20 to 30 meters in radius. This required an extraordinary accurate orbit estimation during the descent, since just one centimeter per sec dispersion may have resulted in 36 meters in one hour. And the flight needed almost Worms' speed control and management. What contributed to this was in the landmark tracking navigation. Conventional landmark tracking took a lot of time. But the Hayabusa project team developed a new tool that combines human's assist with the computer aided terminal display. A real-time landmark navigation did contribute to the successful precise navigation to the specified area on the surface. This paper presents the essence of it.
  • Makoto Maruya, Hiroshi Ohyama, Masashi Uo, Noboru Muranaka, Hideo Morita, Takashi Kubota, Tatsuaki Hashimoto, Jun Saito, Jun'ichiro Kawaguchi
    Collection of Technical Papers - AIAA/AAS Astrodynamics Specialist Conference, 2006 3 1522-1540 2006年  
    This paper describes the process of creating Itokawa shape and surface topography model during the Hayabusa's proximity observation. It can be divided into two processes. First half is to estimate camera motion relative to Itokawa and determining its spin axis. Latter half is to estimate 3D shape of Itokawa and to analyze the topography. The authors employed two kinds of methods for shape modeling: a limb profile method and a stereo image analysis method. The combination of the two methods yielded a precise Itokawa model for both rough and smooth surfaces of Itokawa. This paper also describes the process of analyzing surface topography and creating a surface gradient map of Itokawa. The map built by the proposed method was actually used to determine the landing and sampling sites. Copyright © 2006 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.
  • Hideo Morita, Ken'ichi Shirakawa, Takashi Kubota, Tatsuaki Hashimoto, Jun'ichiro Kawaguchi
    Collection of Technical Papers - AIAA/AAS Astrodynamics Specialist Conference, 2006 2 1384-1394 2006年  
    In November of 2005, Hayabusa performed descent flights to the Itokawa surface five times. The Itokawa surface is full of boulders against expectation and there are few flat areas where the spacecraft can touch down safely. With the reaction wheels lost prior to the events, it was very difficult to control translation motion accurately, since the guidance accuracy of several millimeters per second was requested. The guidance and navigation before launch assumed the autonomous guidance by identifying the illumination center aboard. However, it was not successful due to the highly irregular shape of the asteroid. On the other hand, the scenario based on the terrain recognition in quasi real time well worked. It was anticipated not useful before launch, since such process was conceived to take a lot of time and not effectively useful in real time operation. The Hayabusa project team devised and built the special tool on the ground and had tuned it before the successful three touch downs and one long landing on the surface © 2006 by the American Institute of Aeronautics and Astronautics. Inc. All rights reserved.
  • Takashi Kominato, Masatoshi Matsuoka, Masashi Uo, Tatsuaki Hashimoto, Jun'ichiro Kawaguchi
    Collection of Technical Papers - AIAA/AAS Astrodynamics Specialist Conference, 2006 2 1352-1366 2006年  
    Hayabusa has performed a proximity operation including station keeping and hovering around Itokawa. In order to navigate and to guide the spacecraft to Itokawa, it made highly use of optical hybrid navigation technique combined with the radiometric information obtained on the ground. Hayabusa is also equipped with a sophisticated autonomous navigation and guidance function including onboard image processing and the like. Although one of three reaction wheels failed in late July of 2005, and the second wheel failed in early October, we had succeeded to continue the technology demonstrations and the science observations. This paper presents how those navigation and guidance in proximity phase were carried out, showing flight results. Copyright © 2006 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.
  • Masashi Uo, Kenichi Shirakawa, Tatsuaki Hashimoto, Takashi Kubota, Jun'ichiro Kawaguchi
    Collection of Technical Papers - AIAA/AAS Astrodynamics Specialist Conference, 2006 2 1342-1351 2006年  
    Hayabusa attempted to touch-down two times in November, 2005 after two years of cruising and two months of proximity observation around ITOKAWA. One of three reaction wheels failed in late July of 2005, and the second wheel failed in early October. While the attitude stabilization logic with two wheels was inherent in the onboard system, the stabilization with one wheel required the use of onboard re-programming function and special ground support operations. This paper describes how the attitude control system and operation were adapted to cope with the loss of reaction wheels, along with the introduction of attitude control system that was designed to realize various attitude functions with minimum onboard resources. Copyright © 2006 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.
  • Takashi Kubota, Shujiro Sawai, Tatsuaki Hashimoto, Junichiro Kawaguchi
    2006 IEEE/RSJ INTERNATIONAL CONFERENCE ON INTELLIGENT ROBOTS AND SYSTEMS, VOLS 1-12 657-+ 2006年  査読有り
    The MUSES-C mission is the world first sample and return attempt to or from the near Earth asteroid. In deep space, it is hard to navigate, guide, and control a spacecraft on a real-time basis remotely from the earth mainly due to the communication delay. So autonomy is required for final approach and landing to an unknown body. It is important to navigate and guide a spacecraft to the landing point without hitting rocks or big stones. In the final descent phase, cancellation of the horizontal speed relative to the surface of the landing site is essential. This paper describes various kinds of robotics technologies applied for MUSES-C mission. An autonomous descent scheme and a novel visual navigation system are proposed and presented in detail. The validity and the effectiveness of the proposed methods are confirmed and evaluated by numerical simulations and flight results.
  • Takashi Kubota, Tatsuaki Hashimoto, Jun'ichiro Kawaguchi, Masashi Uo, Ken'ichi Shirakawa
    2006 SICE-ICASE INTERNATIONAL JOINT CONFERENCE, VOLS 1-13 436-+ 2006年  査読有り
    The Japanese asteroid exploration spacecraft Hayabusa autonomously performed touchdown two times in November 2005. The autonomous guidance and navigation capability is installed aboard the spacecraft. The GNC system collects the laser altimeter, laser range finders and navigation cameras information aboard and is designed to estimate where the spacecraft is and to decide the path correction maneuvers. The programmed function includes the image processing designed to detect an artificial target marker location to approach and cancel the relative velocity. A terrain alignment maneuver is also accomplished by both altitude and attitude control. This paper presents how autonomous guidance and navigation was performed in Hayabusa mission.
  • D. J. Scheeres, R. Gaskell, S. Abe, O. Barnouin-Jha, T. Hashimoto, J. Kawaguchi, T. Kubota, J. Saito, M. Yoshikawa, N. Hirata, T. Mukai, M. Ishiguro, T. Kominato, K. Shirakawa, M. Uo
    Collection of Technical Papers - AIAA/AAS Astrodynamics Specialist Conference, 2006 3 1553-1574 2006年  
    The dynamical environment about and on Asteroid 25143 Itokawa is studied using the shape and rotation state model estimated during the close proximity phase of the Hayabusa mission to that asteroid. We first discuss the general gravitational properties of the shape model assuming a constant density. Next we discuss the actual dynamical environment about this body, both on the surface and in orbit, and consider the orbital dynamics of a Hayabusa-like spacecraft. Then we detail one of the approaches used to estimate the mass of the body, using optical and lidar imaging, during the close proximity phase.
  • R. Gaskell, O. Barnouin-Jha, D. Scheeres, T. Mukai, N. Hirata, S. Abe, J. Saito, M. Ishiguro, T. Kubota, T. Hashimoto, J. Kawaguchi, M. Yoshikawa, K. Shirakawa, T. Kominato
    Collection of Technical Papers - AIAA/AAS Astrodynamics Specialist Conference, 2006 3 1541-1552 2006年  
  • Hitoshi Kuninaka, Kazutaka Nishiyama, Ikko Funaki, Tetsuya Yamada, Yukio Shimizu, Jun'ichiro Kawaguchi
    Collection of Technical Papers - AIAA/ASME/SAE/ASEE 42nd Joint Propulsion Conference 1 151-164 2006年  
    The electron cyclotron resonance ion engine, "μ10,"" has a long life and high reliability because of electrodeless plasma generation in both the ion generator and the neutralizer. Four μ10, each generating a thrust of 8 mN, specific impulse of 3,200 seconds, and consuming 350 W of electric power, propel the "HAYABUSA" asteroid explorer that was launched on May 2003. After vacuum exposure and several runs of bailing to reduce residual gas, the ion engine system established continuous acceleration. Delta-V Earth Gravity Assist, a new orbit change scheme that uses electric propulsion with a high specific impulse was applied to change from a terrestrial orbit to an asteroid-based orbit. In 2005, HAYABUSA, using solar electric propulsion, managed to successfully cover the distance between 0.86 AU and 1.7 AU in the solar system, as well as rendezvous with, land on, and lift off from the asteroid Itokawa. During the 3-year flight, the ion engine system generated a delta-V of 1,400 m/s while consuming 22 kg of xenon propellant and operating for 25,900 hours.
  • Jun'ichiro Kawaguchi, Osamu Mori
    AIAA 57th International Astronautical Congress, IAC 2006 10 6912-6924 2006年  
    A large scale system including multi-elements that turn on and off their electric circuits such as heaters has some high risk of running short of the resource, that is power in this case, and may sometimes go down. The power consumed may exceed the capacity of the power supply, when a lot of the elemental heaters are switched on at the same instance. On average, even in that case, the power consumed may be enough low for the power to be supplied with adequate margin. If a very sophisticated server is built and concentrates allocating resource to the elements keeping the peak power consumed in the whole system lowered by gathering information from them, this shutdown may be circumvented. However, such specific server, even though built, is very much tuned to a specific system structure and not flexible, while the system had better be easily reconfigured and be robust for small mull functions that could occur. The paper here presents a novel multi-agent heater controller that maintains the temperature at each element, while the whole power consumed is kept constant, without any specific server in the system.
  • Shuhei Nishiniaki, Osamu Mori, Masaki Shida, Jun'ichiro Kawaguchi
    AIAA 57th International Astronautical Congress, IAC 2006 6 4082-4089 2006年  
    At the Institute of Space and Astronautical Science(ISAS),Japan Aerospace Exploration Agency(JAXA), Spinning Solar Sail-craft is proposed and examined the possibility. In August 2006, a membrane of 20[m] in diameter was deployed statically by using a flying balloon. The size of membrane is the largest in the world, furthermore, to deploy statically is the first achievement in the world. This paper shows the experiment apparatus and the results. Additionally, numerical simulation is used to analyze the behavior of the membrane. The deployment of membrane is divided first stage and second stage. At first stage deployment, the membrane deploys dynamically because the accident occurs. However, the deployment is successful. At second stage deployment, the membrane deploys statically and finally forms square-shape. The numerical simulation accords with the behavior of membrane. The membrane has the inclination by gravity, so the experiment can examine the out-of-motion of the membrane. And the membrane is affected by air drag, the contortion of the membrane is also examined. As a conclusion, to deploy a membrane of 20[m] in diameter statically is the first achievement in the world, and to analyze the behavior of the membrane is meaningful for the realization of Solar Sail-craft.
  • Osamu Mori, Jun'ichiro Kawaguchi
    Advances in the Astronautical Sciences 124 I 3-15 2006年  
    This paper shows the dynamic properties interpreted about a falling cat motion. A new interpretation on non-holonomic turns was presented from coning effect point of view. It infers even the kinematics effect independent of dynamics may still drive the non-holonomic turn. However, that motion is, in this paper, proved not fully true and shown partly dependent on the inertia properties. This paper presents new interpretation findings which show the resulted non-holonomic turn may become reverse dependent on the moment of inertia ratio. This paper corrects the motion structure interpretation, in which a very interesting combination of kinematics and dynamics is found to govern the motion. And a numerical example is given for the spacecraft attitude maneuver, whose time history is explicitly described. A special feedforward control law is derived and applied to the maneuver. The results show the control strategy established well functions and enables the reorientation to be accomplished only via internal torque. What is presented does provide a comprehensive strategy widely applicable to spacecraft and space robots.
  • Yuichi Tsuda, Osamu Mori, Shinsuke Takeuchi, Jun'ichiro Kawaguchi
    Space Technology 26(1-2) 33-39 2006年  
    Japan Aerospace Exploration Agency (JAXA) is currently studying "Solar Sail" populsion for future deep space explorations. One of the key technologies to realize a solar sail is how light and how compact we can make the photon acceptance surface. JAXA has conducted extensive studies on utlizing centrifugal force to deploy the photon acceptance surface. The final objective is to realize a 7.5μm-thickness and 50m diameter polyimide membrane, combined with a thin flexible solar cells, as the photon acceptance surface that will be needed around the Jupiter orbit. In August 9, 2004, JAXA launched the S-310 sounding rocket, which tested two different shapes of membranes during the zero-gravity flight. The first type of membrane looked like a "clover-leaf", and another is like a "fan". These two membranes, both of them having 10m diameter, were unfolded sequentially during the zero-gravity flight under the free spin condition, and their behavior was observed by onboard cameras. This paper focuses on the "clover-leaf" solar sail, which was fully deployed successfully, and introduces the S-310-34 experiments, and then shows the flight results and postflight evaluations. © 2006 Lister Science. All rights reserved.
  • Keiko Kuroshima, Shuhei Nishimaki, Takanao Saiki, Jun'ichiro Kawaguchi
    Advances in the Astronautical Sciences 123 III 2593-2607 2006年  
    This paper presents a very high altitude, Sun-Synchronous orbit around the Earth for astronomy satellites. It includes a cart wheel orbit in Hill's motion. Considering the perturbation owing to the Earth gravity, the period of the in-plane motion and out-of-plane motion are different and trajectory becomes Lissajous. The results analytically obtained are examined and compared with those via numerical integration. In addition, it is shown that the fuels amount, which is inquired to keep nominal Cart Wheel orbit properties, decreases as the altitude increases. And, the conclusion is that the Cart Wheel orbit is a kind of sun-synchronous orbit and highly practical with affordable correction velocity increment.
  • Takanao Saiki, Jun'ichiro Kawaguchi
    Advances in the Astronautical Sciences 124 I 879-893 2006年  
    In formation flight missions, it is very important to control and keep the relative positions of spacecrafts. Although there have been many researches on the relative position control, most of them assumes that each spacecraft uses the absolute information about its position and velocity. In this case, various optimizations with the absolute information are possible. However, in order to keep the formation strictly and to avoid the collisions, the feedback control with the relative information between the members is effective. The formations of birds, insects and fish and automatic control of cars are classified as this control system. In this control system, the information propagation structure of the system as well as the local control law of each member determines the control performance of the system. This information propagation structure means the adjacency relation of the formation, that is, "whose relative information can each spacecraft acquire". In this study, the information propagation structure of the formation is focused on and how the information propagation structure influences the behavior of the formation is investigated.
  • Takayuki Yamamoto, Jun'ichiro Kawaguchi
    Advances in the Astronautical Sciences 123 II 1565-1576 2006年  
    The paper proposes the new guidance strategy in the aerodynamic ascent path. This guidance form has only four parameters comprised of Linear and Logarithmic functions. And the paper presents the guidance results for the practical application cases with certain constraints. The results show the guidance is well performed and satisfies the terminal boundary conditions specified. This guidance strategy does not include the optimization process aboard but solves a simple two-by-two linear algebraic equations along with forward integration. This strategy does guarantee the robust and real-time solutions, excluding any optimization process, and it is concluded quite practical.
  • Takayuki Yamamoto, Jun'ichiro Kawaguchi
    ASTRODYNAMICS 2005, VOL 123, PTS 1-3 123 1565-+ 2006年  
    The paper proposes the new guidance strategy in the aerodynamic ascent path. This guidance form has only four parameters comprised of Linear and Logarithmic functions. And the paper presents the guidance results for the practical application cases with certain constraints. The results show the guidance is well performed and satisfies the terminal boundary conditions specified. This guidance strategy does not include the optimization process aboard but solves a simple two-by-two linear algebraic equations along with forward integration. This strategy does guarantee the robust and real-time solutions, excluding any optimization process, and it is concluded quite practical.
  • Yasuhiro Kawakatsu, Osamu Mori, Yuichi Tsuda, Kota Tarao, Jun'ichiro Kawaguchi
    Advances in the Astronautical Sciences 124 II 1773-1787 2006年  
    Discussed in this paper are the results of the mission analysis of near Earth asteroid flyby missions using miniature Asteroid Interceptors. The Interceptor is an autonomous self-contained interplanetary probe with 10kg mass which is now under development in ISAS/JAXA. It has the capability of navigating itself autonomously to flyby the target asteroid using optical navigation system. The image of the asteroid taken by the camera onboard at the closest approach is the main science output of the mission. Firstly discussed is the mission by a single Interceptor, which enables the minimum size interplanetary mission. The interceptor is launched as a piggy back mission on a geostationary mission, separated on a geostationary transfer orbit (GTO), kicked by a solid rocket motor, and injected into an orbit suitable for encountering the asteroid. It is shown that the utilization of the Earth synchronous orbit and the Earth swing-by drastically increase the number of the possible target asteroids, which enables the selection of more scientifically interesting target for a given opportunity. The second mission concept discussed is the multiple asteroids exploration with a single launch. A straightforward application of the single Interceptor mission, that is, the mission by several independent Interceptors is shown firstly, and an option to overcome the difficulty in performing critical operation of multiple spacecrafts simultaneously is also discussed. The list of the target asteroid candidates, detailed mission sequence and maneuver parameters are shown for the assumed example mission.
  • Hitoshi Kuninaka, Kazutaka Nishiyama, Ikko Funaki, Yukio Shimizu, Tetsuya Yamada, Jun'ichiro Kawaguchi
    IEEE Transaction on Plasma Science 34(5,Pt.2) 2125-2132 2006年  
  • Makoto Yoshikawa, Jun'Ichiro Kawaguchi, Hiroshi Yamakawa, Takaji Kato, Tsutomu Ichikawa, Takafumi Ohnishi, Shiro Ishibashi
    Acta Astronautica 57(2-8) 510-519 2005年7月  
    Japanese first Mars explorer NOZOMI, which was launched in July 1998, suffered several problems during the operation period of more than five years. It could have reached near Mars at the end of 2003, but it was not put into the orbit around Mars. Although NOZOMI was not able to execute its main mission, it provided us a lot of good experiences from the point of the orbit determination of spacecraft. One of the most difficult works was the orbit determination for the period without the telemetry. In this period, for the most of the time the high gain antenna did not point to the earth because of a constraint of the attitude. Therefore, the quality of the tracking data was not good, and for some period it was impossible to get the tracking data at all. Under such critical condition, we managed to get the solution of the orbit, and in a near-miraculous way, we were able to control NOZOMI and execute two earth swingbys successfully. Other issues related to the orbit determination are the spin modulation, the solar radiation pressure, the small force related to the attitude change, and the solar conjunction. We tried to solve these issues by the conventional way using range and Doppler data. However, we also tried the new method, that is the orbit determination by using the Delta-VLBI method (VLBI: Very Long Baseline Interferometry). In addition to this, we tried optical observations of NOZOMI at the earth swingbys. © 2005 Elsevier Ltd. All rights reserved.
  • Takayuki Yamamoto, JuN'Ichiro Kawaguchi
    International Astronautical Federation - 56th International Astronautical Congress 2005 5 3182-3190 2005年  
    Reusable Launch Vehicles are conceived to constitute the future space transportation system. If these vehicles use air-breathing propulsion and lift taking-off horizontally, the optimal steering for these vehicles exhibits completely different behavior from that in conventional rockets flight. In this paper, the new guidance strategy is proposed. This method derives from the optimality condition as for steering and an analysis concludes that the steering function takes the form comprised of Linear and Logarithmic terms, which include only four parameters. The parameter optimization of this method shows the acquired terminal horizontal velocity is almost same with that obtained by the direct numerical optimization. This supports the parameterized Liner Logarithmic steering law. And here is shown that there exists a simple linear relation between the terminal states and the parameters to be corrected. The relation easily makes the parameters determined to satisfy the terminal boundary conditions in real-time. The paper presents the guidance results for the practical application cases. The results show the guidance is well performed and satisfies the terminal boundary conditions specified. The strategy built and presented here does guarantee the robust solution in real-time excluding any optimization process, and it is found quite practical.
  • T Kubota, S Sawai, T Hashimoto, J Kawaguchi
    2005 12th International Conference on Advanced Robotics 31-38 2005年  査読有り
    The MUSES-C mission is the world's first sample and return attempt to/from the near Earth asteroid. In deep space, it is hard to navigate, guide, and control a spacecraft on a real-time basis remotely from the earth mainly due to the communication delay. So autonomy is required for final approach and landing on an unknown body. It is important to navigate and guide a spacecraft to the landing point without hitting rocks or big stones. In the final descent phase, cancellation of the horizontal speed relative to the surface of the landing site is essential. This paper describes various kinds of robotics technologies applied for MUSES-C mission. A global mapping method, an autonomous descent scheme, and a novel sample-collection method, and asteroid exploration robot are proposed and presented in detail. The validity and the effectiveness of the proposed methods are confirmed and evaluated by numerical simulations and some experiments.
  • 松本 道弘, 川口 淳一郎
    宇宙技術 4 43-52 2005年  
    今日の電気推進機関の技術進歩により,高比推力の推進機関が実用化されるようになり,さまざまな惑星探査が可能となった.そして今後も,火星や木星をはじめとする,深宇宙の惑星を探査する機会が増えていくと考えられている.宇宙航空研究開発機構・宇宙科学研究本部では,地球近傍ではなく地球引力圏界に,中継拠点として深宇宙港を建設しようという検討を行っている.本研究では,太陽-地球系L2点に深宇宙港を設置することを想定し,低推力推進機関を搭載した宇宙機によるL2点を発着地とした深宇宙往還システムを考え,その脱出軌道を論じる.また同時に,本軌道設計において地球と同期する回帰惑星間軌道上で軌道エネルギーを離心率の拡大によって蓄積する手法(Electric Delta-V Earth Gravity Assist(EDVEGA))が有効であることを示し,EDVEGA軌道への接続を考えた脱出軌道についても提案する. なお,本検討は,その対称性からL1点深宇宙港に対しても,同様に当てはめることができる.
  • Makoto Yoshikawa, Takaji Kato, Tsutomu Ichikawa, Hiroshi Yamakawa, Jun'ichiro Kawaguchi, Takafumi Ohnishi, Shiro Ishibashi
    International Astronautical Federation - 56th International Astronautical Congress 2005 5 3139-3148 2005年  
    HAYABUSA, which was launched in May 2003, is the first asteroid sample return mission in the world. It has arrived at its destination, Asteroid (25143) Itokawa, at the beginning of September 2005 successfully. HAYABUSA has an ion engine system (IBS) as the main thrusting system and it makes difficult to carry out the orbit determination because of the continuous low acceleration. We have tried many attempts to estimate the acceleration by IES. However, the accuracy of the orbit determination is not good enough when IBS is working, so we make ballistic period of at least three passes once in three weeks or so. We carry out accurate orbit determination at the ballistic period, and we propagate the orbit by using the telemetry information of IBS with some correction by estimating the acceleration by IBS. By this way we have carried out the orbital operation of HAYABUSA. We summarize here the status of the estimation of IBS acceleration. There are several important phases for the orbit operation, such as the launch, the earth swingby, the solar conjunction, and the asteroid arrival. The earth swingby was done on 19 May 2004, and it was successful. We were able to put the spacecraft into the orbit that approach to Asteroid Itokawa. In July of 2005, the solar conjunction occurred and HAYABUSA was opposite side of the Sun. We were able to go through the solar conjunction without any problem, and after that we carried out the optical navigation by using the optical camera on board. In this paper, we also summarize the results of our orbit determination at the launch, the earth swingby, and the solar conjunction. The first result of the optical navigation is mentioned briefly.
  • Tomoki Nakano, Osamu Mori, Jun'ichiro Kawaguchi
    International Astronautical Federation - 56th International Astronautical Congress 2005 5 2795-2804 2005年  
    Solar sails are the spacecraft that are propelled by sunlight. The Institute of Space and Astronautical Science (ISAS) of Japan Aerospace Exploration Agency (JAXA) has studied the solar sails which are spinning and deployed by centrifugal force. One of the technological difficulties to be realized is how to design the spanned spinning solar sails to maintain the stability while those huge membranes unfurl with deformation and oscillation. In this paper, an attention is focused on the out-of-plane oscillation and an analysis is presented about the dynamics so that the characteristic parameters are identified as for the stability of those spinning solar sails.
  • Yuichi Tsuda, Osamu Mori, Shinsuke Takeuchi, Jun'ichiro Kawaguchi
    International Astronautical Federation - 56th International Astronautical Congress 2005 5 2935-2941 2005年  
    Japan Aerospace Exploration Agency (JAXA) is currently studying on the "Solar Sail" propulsion for future deep space explorations. One of the key technologies to realize the solar sail is how light and how compact we can make the photon acceptance surface. JAXA has conducted extensive studies on utilizing centrifugal force to deploy the photon acceptance surface. The final objective is to realize the 7.5μmthickness and 50m diameter polyimide membrane, combined with thin flexible solar cells, as the photon acceptance surface that will be needed around the Jupiter orbit. In the August 9, 2004, JAXA has launched the S-310 sounding rocket, which tested two different shapes of membranes during the zerogravity flight. The first type of the membrane looks like a "clover-leaf", and another is like a "fan". These two membranes, both of them have 10m diameter, were unfolded sequentially during the zerogravity flight under the free spin condition, and their behavior was observed by onboard cameras. This paper focuses on the "clover-leaf" solar sail, which was fully deployed successfully, and introduces the S-310-34 experiments, and then shows the flight results and postflight evaluations.
  • Tomoki Nakano, Osamu Mori, Jun'ichiro Kawaguchi
    Collection of Technical Papers - AIAA Guidance, Navigation, and Control Conference 5 3425-3437 2005年  
    Solar sails are the spacecraft that are propelled by sunlight. The Institute of Space and Astronautical Science (ISAS) of Japan Aerospace Exploration Agency(JAXA) has studied the solar sails which are spinning and deployed by centrifugal force. One of the technological difficulties to be realized is how to design the spanned spinning solar sails to maintain the stability while those huge membranes unfurl with deformation and oscillation. In this paper, an attention is focused on the out-of-plane oscillation and an analysis is presented about the dynamics so that the characteristic parameters are identified as for the stability of those spinning solar sails. Copyright © 2005 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.
  • Kohta Tarao, Osamu Mori, Jun'ichiro Kawaguchi
    International Astronautical Federation - 56th International Astronautical Congress 2005 5 3210-3214 2005年  
    Institute of Space and Astronautical Science (ISAS) of Japan Aerospace Exploration Agency (JAXA) is currently planning the missions that the small probe 'intercepter' flybys near-Earth objects. In general, it is impossible to determine the relative orbit during fly-by only with optical information. And usually the optical navigation needs combined with the radio navigation that should provide the relative velocity vector information. This paper first discusses the new integrated guidance and navigation strategy, provided the relative velocity vector between the probe and the object is obtained. And next, paper presents how to obtain full orbit property using the camera and velocity collection information for the guidance. Finally, this paper shows the outline of experiment to verify this strategy.
  • Jun'ichiro Kawaguchi, Osamu Mori, Koki Minamikawa
    International Astronautical Federation - 56th International Astronautical Congress 2005 5 2830-2836 2005年  
    This paper shows the dynamic properties interpreted about a falling cat motion. In the IAC in Vancouver last year, a new interpretation on non-holonomic turns was presented from coning effect point of view. While the last year's synthesis infers even the kinematics effect independent of dynamics may still drive the non-holonomic turn. However, that motion is, in this paper, proved not fully true and shown partly dependent on the inertia properties. This paper presents new interpretation findings which show the resulted non-holonomic turn may become reverse dependent on the moment of inertia ratio. This Fukuoka conference paper corrects the motion structure interpretation, in which a very interesting combination of kinematics and dynamics is found to govern the motion. And a numerical example is given for the spacecraft attitude maneuver, whose time history is explicitly described. A special feedforward control law is derived and applied to the maneuver. The results show the control strategy established well functions and enables the reorientation to be accomplished only via internal torque. What is presented does provide a comprehensive strategy widely applicable to spacecraft and space robots.
  • Takanao Saiki, Jun'ichiro Kawaguchi
    Advances in the Astronautical Sciences 119(SUPPL.) 2555-2569 2005年  
    In formation flight missions, it is very important to control the relative positions of satellites. Although there have been many researches on the relative position control for formation flight, most of them assumes the centralized architecture in which an administrator collects every relative position and velocity information about the formation. However, in case the formation consists of many satellites, it takes long time to collect the information of all the satellites and to distribute the command to every satellite. Therefore, the centralized architecture is unsuitable for the control system that requires a rapid response. Beside, if the central control is down, the system loses the formation control functions thoroughly. One strategy that overcomes these flaws is to make each satellite be controlled by using the information on its nearby satellites. This paper discusses the guidance law based on the regional limited information to maintain the formation. In this case, the information structure of the system greatly influences the control law and the control performance. In this study, we discuss how the control laws are designed, first. And how the information structure influence the configuration of the formation is focused on. Copyright © 2004 by The American Astronautical Society.
  • Takanao Saiki, Jun'ichiro Kawaguchi
    International Astronautical Federation - 56th International Astronautical Congress 2005 5 2993-3001 2005年  
    In formation flying missions, the spacecrafts should keep particular formation, so it is very important to control the relative positions between them. Although there have been many researches on the relative position control, most of them assumes that each satellite use the absolute information about its position and velocity. However, in order to keep the formation strictly and to avoid the collisions, the feedback control with the relative information between the members is effective. In such formation maintenance control, 1) the local control law (control gain, etc.) of each spacecraft and 2) "whose relative information can each spacecraft acquire" (we call this "the information propagation structure") determine the behavior of the formation. Especially, the information propagation structure significantly influences the behavior of the formation. However there are few researches about the information propagation structure. In this study, the information propagation structure of the formation is focused on and how the information propagation structure influences the behavior of the formation is investigated. First, we express the information propagation structure of the formation by a matrix and derive the transfer function matrix of the whole system. Next, from this transfer function matrix, we clarify the relation between the information propagation structure and the stability, the steady-state error and the reactivity of the formation and derive the indexes of these control performances. Finally the method for constructing the information propagation structure by optimizing these indexes is shown.
  • Takayuki Yamamoto, Jun'ichiro Kawaguchi
    Advances in the Astronautical Sciences 119(SUPPL.) 743-757 2005年  
    As the authors reported, the optimal steering for the ascending vehicles like a spaceplane, which has the air breathing engines and the large wings, shows oscillatory behavior in contrast to a conventional law for rockets. In the case of more complicated and proper equations of motion, it is difficult to solve two-point boundary value problem on the on-board computer. This paper firstly shows the analytical description of this periodic behavior emerged from the optimal steering. It concludes that a conventional linear tangent law is applicable only to non-lift vehicles. Then the numerical analysis of the optimal control law with the state constraint is achieved by DCNLP method. Next, the paper proposes two kind of the new guidance schemes to compensate the flight path error aroused by the disturbance. The first one is the way to approximate the optimal steering using the trigonometric function form and the second one is the newly proposed guidance scheme in this paper using the approximate expression of the dynamics derived from the result of the optimal steering. Adopting this method, the guidance scheme with only a few parameters is easily obtained by substituting the approximate expression of the dynamics into the equation of motion and can keep maximizing the terminal horizontal speed by the consumption of a few percentage fuel margins.
  • Osamu Mori, Kohta Tarao, Yasuhiro Kawakatsu, Takayuki Yamamoto, Jun'ichiro Kawaguchi
    International Astronautical Federation - 56th International Astronautical Congress 2005 3 2084-2091 2005年  
    Institute of Space and Astronautical Science (ISAS) of Japan Aerospace Exploration Agency (JAXA) is currently planning the missions that the small probe 'interceptor' flybys near-Earth objects. Interceptor is very small probe. An interceptor observes spectrum, takes close images, and determines mass of a NEO (near earth object) during a flyby. The weight of interceptor is less than 10 kg. This paper shows three types of missions. In general, it is impossible to determine the relative orbit during flyby only with optical information. Thus the optical navigation needs to be combined with the radio navigation that should provide the relative velocity vector information. In this paper, the integrated guidance and navigation strategy of interceptor is proposed. The interceptor needs the thruster for the attitude and orbit control. This paper introduces the development of the gas-thrust equilibrium thruster for small satellites.
  • Michihiro Matsumoto, Jun'ichiro Kawaguchi
    European Space Agency, (Special Publication) ESA SP (548) 499-504 2004年  
    It is known that there is an asteroid family around L4 or L5 Lagrange point of the Sun-Jupiter system, and it is called the Trojan asteroid family. As one of outer planet exploration mission, a plan to explore the Trojan asteroids using Jupiter swing-by is considered. Based on this mission, this paper discusses multiple flybys trajectory for Trojan asteroids exploration. A trajectory optimization of Trojan asteroids exploration using multiple flybys depends largely on objects of exploration. For this reason, the stage of choosing the candidates of exploration is important, and it is indispensable to choose most qualified candidate for the mission. As the first step, this paper proposes the flyby sequence search strategy which uses a ballistic orbit, and using these results, the multiple flybys trajectory to Trojan asteroids by impulsive velocity change is designed. Next, this paper considers an optimization of multiple slow-flybys trajectory of the spacecraft which uses low thrust propulsion. Furthermore feasibility of the sequence of main-belt asteroid flyby on the way to Trojan asteroid was studied.
  • Takanao Saiki, Jun'ichiro Kawaguchi
    Advances in the Astronautical Sciences 117 343-355 2004年  
    Formation flight is the key technology for deep space and orbital applications that involve multiple spacecraft operations. For the formation flying missions, orbit design, relative satellite-to-satellite navigation and formation control are the important technologies. Especially, the formation control is the important technology for the formation flight, because many formation flying missions require particular formations for the observation. After launch, the formation deployment should be performed and the formation changing and keeping are indispensable. The desired trajectory for the formation changing should be optimized in term of total fuel consumption or the fuel expense variation. In this study, the guidance algorithms for the spacecraft around the earth with the linearized equation of motion are shown. The algorithms generate the two-impulse trajectory and the trajectory for the spacecraft with continuous low thrust engine. In addition, this paper presents the collision avoidance strategies for formation flight. The method of searching the trajectory under the restriction conditions of the distance between satellites is show.
  • Makoto Yoshikawa, Jun'ichiro Kawaguchi, Hiroshi Yamakawa, Takaji Kato, Tsutomu Ichikawa, Takafumi Ohnishi, Shiro Ishibashi
    International Astronautical Federation - 55th International Astronautical Congress 2004 2 691-700 2004年  
    Japanese first Mars explorer NOZOMI, which was launched in July 1998, suffered several problems during the operation period of more than five years. It could have reached near Mars at the end of 2003, but it was not put into the orbit around Mars. Although NOZOMI was not able to execute its main mission, it provided us a lot of good experiences from the point of the orbit determination of spacecraft. One of the most difficult works was the orbit determination for the period without the telemetry. In this period, for the most of the time the high gain antenna did not point to the earth because of a constraint of the attitude. Therefore the quality of the tracking data was not good, and for some period it was impossible to get the tracking data at all. Under such critical condition, we managed to get the solution of the orbit, and in a near-miraculous way, we were able to control NOZOMI and execute two earth swingbys successfully. Other issues related to the orbit determination are the spin modulation, the solar radiation pressure, the small force related to the attitude change, and the solar conjunction. We tried to solve these issues by the conventional way using range and Doppler data. However, we also tried the new method, that is the orbit determination by using the Delta-VLBI method (VLBI: Very Long Baseline Interferometry). In addition to this, we tried optical observations of NOZOMI at the earth swingbys.
  • Kazutaka Nishiyama, Hitoshi Kuninaka, Jun'ichiro Kawaguchi
    International Astronautical Federation - 55th International Astronautical Congress 2004 1 653-662 2004年  
    The MUSES-C spacecraft was launched on May 9, 2003 and has been propelled by microwave discharge ion engines. The mission duration is four years in total and most of it is the cruising phase driven by ion propulsion. After one-year acceleration it succeeded the Earth swing-by on May 19, 2004 and still on the way to the asteroid "ITOKAWA". Active thrust vector control contributes to keep the reaction wheels within an appropriate rotation rate. The hydrazine thruster firing tunes off the ion engines before it and restart them again after it. Depending on the operation of ion engines the heater power is adjusted. These operations are autonomously controlled on the spacecraft without supervisions from Earth. A ground operation system that integrates all the process required for ion engine operations such as orbit synthesis, orbit determination, operation scheduling, command generation and telemetry data analysis has been developed. Automation of on-board and ground operations saves the operation cost and time, and makes the operation stable and reliable.
  • Osamu Mori, Yuichi Tsuda, Maki Shida, Jun'ichiro Kawaguchi
    European Space Agency, (Special Publication) ESA SP (548) 117-122 2004年  
    ISAS/JAXA is studying a deployment method using centrifugal force for solar sail mission. In this paper, the clover type sail is investigated. The deployment sequence consists of two stages. In order to analyze the motion of the dynamic deployment, S-310 flight experiment is conducted. In this experiment, the clover type sail of 10 m diameter is deployed dynamically. Numerical simulations by multi-particle model are also conducted to analyze the complicated motion. The experiment and simulation results are compared with each other to validate the analytical model. On the other hand, we schedule to conduct a balloon experiment. The clover type sail of 20 m diameter is deployed statically. The mechanisms for first stage and second stage deployments are introduced.
  • Yusuke Nishimura, Yuichi Tsuda, Osamu Mori, Jun'ichiro Kawaguchi
    International Astronautical Federation - 55th International Astronautical Congress 2004 1 468-475 2004年  
    As one means of propulsion for the future deep space explorers, Japan Aerospace Exploration Agency (JAXA) is conducting research on the "Solar Sail", which is driven by the momentum of photons from the sunlight. Among several candidates of deployment and shape-forming strategies of the sail, JAXA has been focusing on the utilization of centrifugal force. However, it is very difficult to conduct the deployment experiment of the large membrane structure due to aerodynamic drag and gravity. Then, In August in 2004, we performed the experiment to deploy two types of membrane structures made by polyimide film with a sounding rocket. During the ballistic flight, two types of membranes are deployed in turn. We call the two sails "Clover-type sail" and "Fan-type sail", respectively. The cameras on the rocket recorded the images of the membrane and various sensors measured the behavior of the membrane. The data are transmitted to the ground as the telemetry. We succeeded in deploying the membrane whose diameter is 10 meters in space for the first time in the world. This paper deals with the experiment with the rocket and the result of the Clover-type sail.
  • Jun'ichiro Kawaguchi, Takanao Saiki
    European Space Agency, (Special Publication) ESA SP (548) 417-422 2004年  
    The paper presents how the formation is controlled to the intended shape by a decentralized control. The formation behaviour is dealt via a z-transformation method and a uniformly convergent strategy that each spacecraft performs is proposed. Not only one-dimensional but tow-dimensional examples are shown. Since the strategy is highly flexible, it is applicable to a variety of the formation flying space missions.
  • Saiki Takanao, Natsume Koichi, Kawaguchi Jun'ichiro
    SPACE TECHNOLOGY JAPAN, THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES 3 19-25 2004年  

MISC

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共同研究・競争的資金等の研究課題

 8