記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Acta Astronautica  

This study introduces a new method to estimate the orbital parameters (inclination, nodal precession rate, and right ascension of the ascending node) of the broken-up object using in-situ debris measurements. To reduce collision probability with tiny debris generated from breakups of satellites, it is required to identify the origin of breakups and predict the orbit of debris. In general, small debris cannot be tracked from the ground, thus an in-situ measurement is an effective method to detect sub-millimeter-sized debris. Previous studies developed a method to identify the location of breakup origin from an in-situ measurement, however, it can be applied to an ideal situation where the detection occurs at the intersection of the orbit planes. This study introduces a new method to estimate the orbital parameters by fitting the model of geocentric declination to the measurement data. This method can be applied to practical situations that cannot be validated in previous studies. This paper also adopts iteratively reweighted least squares to improve estimation accuracy and mitigate initial value dependencies.

DOI： 10.1016/j.actaastro.2023.12.038

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Scopus

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Astrodynamics  

This paper answers how multiple satellites are seen from the ground. This question is inspired by space-advertising, a public exhibition in the night sky using a dot matrix of satellites that are bright enough to be seen by the naked eye. Thus, it is important for space advertisement that the specific dot matrix is seen. Moreover, the stability of the dot matrix during a visible span is very valuable. To stabilize the dot matrix, this study formulates an apparent position of a dot from a representative dot seen from the ground. The formulation, linear functions of a set of relative orbital elements, reveals the appearance of the dot matrix. The proposed relative variable in the formulation drives the instability of the dot matrix, thereby revealing an initial stable configuration of deputies from a chief. The arbitrary dot matrix designed using the configuration is stable even at low elevations without orbital control during the visible span.

DOI： 10.1007/s42064-023-0180-6

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出版者・発行元：Journal of Space Safety Engineering  

This paper proposes less fuel strategies for space debris removal. To mitigate the risk of space debris cost-efficiently, multi-rendezvous missions are under development. On the other hand, multi-rendezvous missions often require changing orbital planes of removal satellites, which requires a huge amount of ΔV. Therefore, this study focuses on exploiting the J2 perturbation force as an auxiliary force and aims to establish maneuver rules that minimize ΔV consumption while maximizing the benefit of the J2 perturbation. The J2 perturbation equation is explored analytically, which clarifies whether the change in the semi-major axis or the inclination dominates the efficiency of the exploitation. A straightforward criterion is extracted which determines the efficient maneuver based on the initial inclination of the satellite.

DOI： 10.1016/j.jsse.2024.08.002

Scopus

記述言語：英語   出版者・発行元：International Symposium on Space Technology and Science  

<p>The effects of GTO debris to LEO environment are revealed using evolutionary model. GTO debris orbits are modeled as a reference of distribution of actual objects in GTO extracted from JAXA's initial population file. Firstly, three cases of simulation with different perigee altitude were shown taking into accounts the distribution of GTO debris. It indicated that the debris with perigee altitude of over 400 km have long term effects while the debris with perigee altitude of 200 km decay shortly. The effect of continuously generation of GTO debris was secondly investigated. Since the GTO debris has long term orbital life, the number of its debris would keep increasing and accumulate in orbit. Lastly, the risk of GTO debris considering the actual number of debris and future works were discussed.<b><i> </i></b></p>

DOI： 10.57350/jesa.110

CiNii Research

記述言語：英語   出版者・発行元：THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES  

<p>This paper proposes an attitude estimation technique that focuses on rapid change in light intensity, called glint. The states of space objects, such as shape, attitude, and surface properties, are essential information for performing active debris removal and monitoring the operational states of the satellite. Light curve inversion is a cost-effective measure to inversely estimate dynamic states. However, the light curve inversion suffers from divergence when the initial estimate is far from the true state. The glint occurs when a specific geometrical constraint is satisfied, and this glint constraint can be exploited to correct the attitude estimate in a Kalman filter. Thus, assuming a target object as a flat plate, this paper examines whether glint can be used in attitude estimation to improve estimation accuracy. Numerical simulations verify that the attitude estimation filter successfully converges, even when the initial estimate contains a significant error.</p>

DOI： 10.2322/tastj.22.59

CiNii Research

出版者・発行元：AIAA SciTech Forum and Exposition, 2024  

This paper proposes a close approach analysis method considering object attitude change. Implementing a detailed close approach analysis is important for space situational awareness. Conventional conjunction assessment methods assume the shape of the object as a encompassing sphere, which excludes considering the attitude change. However, most of the spacecraft are not spherical, and conventional methods result in overestimation. The proposed method in this paper consists of two steps: 1) calculation of the time of close approach with two objects as point masses and 2) interpolation of the first and last states in the time duration when the close distance is less than a given threshold. Dual quaternions are employed to express the translational and rotational motions, which ensures the uniqueness of the interpolation. Numerical simulations are performed to verify the proposed method and compare it with a conventional method.

DOI： 10.2514/6.2024-1632

Scopus

出版者・発行元：Journal of Space Safety Engineering  

This study evaluates the environmental impacts of orbital fragmentation such as an anti-satellite test, collision between two objects, and explosion. A debris environment evolutionary model named NEODEEM, jointly developed by Kyushu University and JAXA, is used to predict future populations and calculate collision probabilities after a fragmentation. This study focuses on characteristics of the fragmented objects, such as altitude, mass, and whether they belong to a Large Constellation (LC). When a fragmentation occurs at higher altitudes, the new fragments will remain in orbit for a long time. Due to this accumulation, the fragments will not only keep the number of objects and probability of collision higher but also cause the risk of secondary collisions between fragments and background objects. When a collision occurs inside an LC at a lower altitude, the impacts will be short-term because most of fragments decay quickly. However, the number of conjunctions, i.e., operational roads, will increase rapidly because many satellites are operated at the same altitude. This study also discusses a collision probability to an LC taking into account the small size of fragments larger than 1 cm.

DOI： 10.1016/j.jsse.2024.07.008

Scopus

出版者・発行元：Journal of Space Safety Engineering  

This study proposes a relative orbit control law for laser debris removal missions considering the uncertainties of laser ablation and atmospheric drag. A removal spacecraft irradiates laser pulses to a target debris to generate the ablation force for deorbiting. The deorbiting force lowers the target altitude, and the removal spacecraft must follow it to maintain its relative position for continuous laser irradiation. The difficulty stems from uncertainties of the magnitude of laser ablation and external disturbances such as atmospheric drag. To tackle this problem, this study derives an adaptive control method using the Gaussian process regression to cancel the uncertainties with a nonparametric regression model. Numerical simulations verify the proposed control law under the uncertainties of laser ablation and atmospheric drag. The proposed control law can contribute to the realization of a safer and more secure mission not only for laser debris removal missions, but also for other on-orbit services.

DOI： 10.1016/j.jsse.2024.04.007

Scopus

記述言語：英語  

レポート番号: ASTRO-2023-C006(004)/In-person

CiNii Research

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： https://doi.org/10.1016/j.jsse.2023.03.007

出版者・発行元：Journal of Space Safety Engineering  

Because of its large number of satellites, a large constellation (a LC) greatly affects other objects in LEO. Several studies reveal the impact of a LC in LEO missions in various operational scenarios. This study evaluated the environmental impact of a LC explosion in the short and long-term using the Near-Earth Orbital Debris Environment Evolutionary Model (NEODEEM). Although setting mission scenarios and analysis conditions is important in LC simulations, it is difficult to consider all operational scenarios due to the many combinations. Therefore, this study conducted impact assessments of explosions in a LC, concentrating on the number of explosions, orbital altitude, and scaling factor of the explosions. The results indicated that it is not enough for LC to comply with the current requirement of probability of accidental explosions which is less than 0.001 during the operation. This is because, if the rate is applied directly to a LC with thousands of satellites, continuous explosions (i.e., several satellites explode every year) will occur during the mission duration of LC. The paper also discusses the behavior of fragments from explosions at different altitudes. The explosions at low altitudes have no significant impact in the long term, although it can cause an incremental change in collision risk in the short term. Similarly, the explosions at high altitudes, such as 1,250 km, have only slightly increments of the expected number of collisions, but its impact could last for over 100 years. The probability of explosions of a LC must be carefully determined through a series of simulations based on the number of satellites and the operational orbit of a LC. This paper also discusses what should be considered in future LC design and operations regarding explosion prevention.

DOI： 10.1016/j.jsse.2023.03.007

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Scopus

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： https://doi.org/10.2514/1.G005961

出版者・発行元：Proceedings of the International Astronautical Congress, IAC  

This paper examines the effect of shortening the post-mission disposal lifetime from 25 years to 5 or 1 year. Using NEODEEM, the debris evolutionary model developed by Kyushu University and JAXA, the change in the orbital environment at various altitude bands for long-term stability and short-term safety such as the number of collision avoidance maneuvers and collision rate are discussed. It was confirmed that the PMD compliance rate is more important than shortening the orbit lifetime for improving the long-term stability of the orbital environment. The collision rate below 700 km increased if the number of launches to high altitudes and the post-mission disposal (PMD) compliance rate increase, although the collision impact is not long-term. In the short term, the 5- or 1-year rule reduced the collision rate and collision avoidance frequency at an altitude around 600 km, more than the 25-year rule, thus shortening the PMD orbit lifetime improves short-term safety, especially at low altitudes. The paper also evaluates the effect of large constellations shows that the post-mission disposal lifetime and required compliance rate should be set according to the number and size of objects expected to be launched in the future.

Scopus

出版者・発行元：Proceedings of the International Astronautical Congress, IAC  

This paper discusses the processes which should be taken to establish debris indices that assess the orbital environmental impact of spacecraft or missions in orbit. The first process is establishing a methodology and criteria for evaluating an impact on the orbital environment. This study proposed an assessment method to evaluate the cumulative environmental changes during an evaluation period. It evaluated the impact of an uncontrolled LC mission abandoned in orbit This study used NEODEEM, an orbital environmental evolutionary model that Kyushu University and JAXA developed. The second process is the index formulation. This study considered four steps to establish the debris index, and proposed an index that could be evaluated by NEODEEM. The difference between the calculated index values and the environmental impact was also discussed. Further, this study conducted numerical simulations of un-controlled large-constellation satellites abandoned in low earth orbit in different scenarios, and of active debris removals of large intact objects by NEODEEM. This paper discusses the applicability of proposed environmental assessment methods and the debris index.

Scopus

出版者・発行元：Journal of Guidance, Control, and Dynamics  

DOI： 10.2514/1.G005961

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Scopus

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： https://doi.org/10.1016/j.jsse.2022.05.006

出版者・発行元：Journal of Space Safety Engineering  

Remediation measures, such as Active Debris Removal (ADR) has been studied in order to preserve the space environment. Large derelict objects in crowded orbits are considered ADR targets because they are the source of numerous small debris in case of fragmentation. The target for removal must be chosen carefully because cost is the major issue in realizing ADR, and it is necessary to remediate the orbital environment as efficiently as possible. Last year, Dr. McKnight et al. presented the top 50 debris removal targets by combining each of the top 50 lists compiled by eleven international teams. This paper discusses the considerations involved in selecting debris removal targets. This study first considered the top 50 objects, to be removed according to each index, and then evaluated the consequences of the removal using Near-Earth Orbit Debris Environment Evolutionary Model (NEODEEM), a debris evolutionary model developed by Kyushu University and JAXA. Differences in debris removal targets were studied for long-term stability or short-term safety. This paper discusses why some indices are effective in the short or long term in terms of the orbital distribution of selected targets and the effects of removal in each altitude band. It also discusses the differences between removing 50 objects and removing one object each year, and the effects of removal timing and so on. It found that integrating different indices is effective, and that the removal target must be determined according to the situation. It is more important to remove as much debris as possible as early as possible rather than focusing on an object's ranking in a list.

DOI： 10.1016/j.jsse.2022.05.006

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Scopus

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： https://doi.org/10.1016/j.actaastro.2022.04.024

記述言語：英語   出版者・発行元：Acta Astronautica  

An active debris removal method using a laser is a promising technology for its advantage in contactless operations. This paper deals with the attitude control of an uncooperative target by a laser, which is an important phase before deorbiting. The difficulty of attitude control by the laser stems from the torque directional constraint because the laser generates thrust along the normal vector of the irradiated face irrespective of the irradiating direction. Thus, the control torque along the normal vector cannot be generated, which makes the attitude control with the laser torque challenging. To tackle this problem, this paper first designs a reference controller that assumes arbitrary control torques are available. Then, a method for determining the irradiating point is proposed so that the difference between the reference torque and the actual one is minimized. Although the proposed controller does not guarantee theoretical convergence to the desired attitude, the effectiveness of the proposed controller is numerically verified for a box-type object. Furthermore, the robustness to the uncertainties of thrust magnitude and direction is also examined by Monte Carlo simulations.

DOI： 10.1016/j.actaastro.2022.04.024

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

This paper briefly introduces a new approach to estimate some orbital parameters of on-orbit satellite fragmentations (specifically, the direction of angular momentum at a specific time and the time change in direction of angular momentum) from in-situ debris measurements. This approach, as in previous studies, adopts a constraint equation derived from the fact that a piece of debris detected shares the geocentric position vector with an in-situ debris measurement satellite. However, unlike previous studies, this approach does not adopt a constraint equation that can be applied to the rate of change in right ascension of the ascending node of a broken-up object. Instead, this approach determines the inclination of a broken-up object from the maximum or minimum geocentric declination at the time of detection. Then, this approach finds out a candidate for the rate of change in right ascension of the ascending node of a broken-up object by assuming a circular orbit with a radius of the geocentric distance at the time of detection. Finally, using the constraint equation adopted, this approach estimates the right ascension of the ascending node at the time of breakup and calculates a correction for the rate of change in right ascension of the ascending node. This paper also verifies that this new approach works effectively under ideal conditions where all detections are assumed to be at the line of intersection of the two orbital planes of a broken-up object and an in-situ debris measurement satellite.

DOI： 10.3389/frspt.2022.867236

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その他リンク： https://doi.org/10.3389/frspt.2022.867236

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： https://doi.org/10.1016/j.jsse.2021.11.002

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： https://doi.org/10.1016/j.jsse.2021.11.002

出版者・発行元：Journal of Space Safety Engineering  

This paper presents an overview of space solar power satellites for the Moon and Mars mission and simultaneously demonstrates the compression of traditional power generation methods for the orbiter, lander, and habitat on Mars and the Moon. Interplanetary missions are where the space engineers work on the satellites, conceptual design of space habitat, and exploration system. The state of the art in those missions relies on radioisotope thermoelectric generators or solar panels attached with batteries to store power, both of which are plagued by limitations. For instance, when a spacecraft moves away from the Sun, the energy collection efficiency on the solar panel is reduced, and at temperatures below -100°Celsius, individual solar cells degrade unpredictably, deteriorating the performance of solar arrays. Furthermore, these power generation unit satellites carry a pack of batteries to store energy whose total system accounts for more than 10-25 % of the mass of the satellites. In an interplanetary mission, power generation and management are essential for research and investigation on the surface. For Mars, sandstorms affect the collection of energy at the attached solar panel to the rover. Moreover, the rovers must investigate at the far side of the Moon, where sunlight is unavailable for few consecutive days. This challenge can be suitably overcome by employing space solar power satellites, which can be used for wireless power transmission, independent of its location. Such techniques have possible applications towards power transmission for unmanned aerial vehicles for faster mapping purposes. As such, the dependence of those aerial vehicles towards fixed energy storage becomes alleviated. In hindsight, space solar power satellite serves as a potential for an improved energy transmission source than the traditional method for interplanetary rovers and habitat.

DOI： 10.1016/j.jsse.2021.10.008

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Scopus

出版者・発行元：Journal of Space Safety Engineering  

End-of-life support of satellites is necessary to improve post-mission-disposal compliance rates for maintaining space environment. Deorbit mission with low thrust, e.g. a laser, induces a low-level deceleration on the target object that gradually lowers the target altitude. Since such a low-thrust trajectory is time-consuming, the risk of collision greatly influences the mission success rate. In this context, this paper assesses the collision risk during deorbit trajectories with low thrust. Furthermore, parametric studies for the relationship between the re-entry time and the risk of collision are performed.

DOI： 10.1016/j.jsse.2021.11.002

Scopus

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES  

<p>This paper aims to assess the risk of mission termination for a large constellation of satellites in a low-Earth orbit. Many large constellations will be deployed to provide broadband network services using thousands of satellites. There is concern that such large constellations will have a serious impact on the long-term sustainability of outer space activities due to the rapid increase in population. First, therefore, the authors conducted an assessment under nominal activities (referred to as “business-as-usual”) on the basis of a prediction by ESA’s MASTER-2009 and NASA standard breakup model 2001 revision. The assessment found that nearly one catastrophic collision may happen in a large constellation, generating more than two million fragments as small as 1 mm in size. Second, the authors conducted a further assessment assuming a hypothetical collision of a satellite in a large constellation using the NASA standard breakup model and a spherical finite element model adopted in ESA’s MASTER-2009. In consequence, another catastrophic collision may happen to a large constellation, generating approximately a half-million fragments as small as 1 mm in size. Therefore, such catastrophic collisions and resulting secondary collisions should be prevented for large constellations.</p>

DOI： 10.2322/tastj.20.10

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リポジトリ公開URL： http://hdl.handle.net/2324/4755253

出版者・発行元：Proceedings of the International Astronautical Congress, IAC  

Because of its large number of satellites, a large constellation (an LC) greatly affects other objects in LEO. Several studies reveal the impact of an LC in LEO missions in various operational scenarios. This study evaluated the environmental impact of an LC explosion in the short and long-term using the Near-Earth Orbital Debris Environment Evolutionary Model (NEODEEM). Although setting mission scenarios and analysis conditions is important in LC simulations, it is difficult to consider all operational scenarios due to the many combinations. Therefore, this study conducted impact assessments of explosions in an LC, concentrating on the number of explosions, orbital altitude, and scaling factor of the explosions. The results indicated that it is not enough for LC to comply with the current requirement of probability of accidental explosions which is less than 0.001 during the operation. This is because, if the rate is applied directly to an LC with thousands of satellites, continuous explosions (i.e., several satellites explode every year) will occur during the duration of LC. The paper also discusses the behavior of fragments from explosions at different altitudes. The explosions at low altitudes have no significant impact in the long term, although it can cause an incremental change in collision risk in the short term. Similarly, the explosions at high altitudes, such as 1,250 km, have only slightly increments of the expected number of collisions, but its impact could last for over 100 years. The probability of explosions of an LC must be carefully determined through a series of simulations based on the number of satellites and the operational orbit of an LC. This paper also discusses what should be considered in future LC design and operations regarding explosion prevention.

Scopus

出版者・発行元：Proceedings of the International Astronautical Congress, IAC  

Space-advertisement is getting closer with advances in satellite formation flying, which displays an artificial constellation in the night sky. The formation shape composed of pixels of satellites equipping light sources is observed from the ground and different from formation in relative orbits. For realizing the advertisement shape of high quality, there are two requirements, placing the pixels of the advertisement shape properly and keeping the shape during a visible span. It is not enough to satisfy the requirements by the usual coordinate systems and equations. Considering a topocentric coordinate system, the new transforming equations are derived so that an arbitrary advertisement shape is designed at the target time. Also, stable orbits that keep the formation shape without control are found and an example of stable orbits is presented.

Scopus

出版者・発行元：Proceedings of the International Astronautical Congress, IAC  

The 21st century is marked by the unprecedented progress of human knowledge in space, quantum mechanics, and machine learning. This progress has in turn lead to a significant increase in satellite launches, with various organizations developing mega-constellations in space to provide new business opportunities. While current predictions estimate that space in Low Earth Orbit will be overcrowded in the future, and sustainability of space will become a critical question as the estimated traffic of 89,000 satellites will be launched by the year 2035. To allow sustainable development of space, especially in Low Earth Orbit, there is a need to develop accurate traffic management and active debris removal mission planning. Lately, several organizations proposed and completed space demonstration experiments for debris removal. Current their designs are part of an ongoing project to develop contact-based debris removal technology. However, this technology poses several problems for satellite removal. We propose a complementary method based on a laser system. The laser is capable to operate from a safe distance by stopping the continuous rotation (detumbling) of space objects. In this paper, we present a case study using the ENVISAT satellite. ENVISAT is an 8,211 kg satellite, launched by European Space Agency. Since 2012, communication has stopped, and it is no longer operational. It is predicted to self-deorbit in the next 150 years. However, the orbital simulation of existing objects found two cataloged space debris which will pass within 200 m., resulting in a close approach every year. The elevated mass of the satellite and the number of close approaches, therefore, pose a considerable threat, leading to the production of debris. SKY Perfect JSAT Corporation is working jointly with Japanese institutions to collaboratively develop laser satellites to stop detumbling and the careful removal of debris. The demonstration mission will be launched by the year 2026-2027. With this case study, a laser-based contactless method can be practiced for removing mega debris like ENVISAT from the Low Earth Orbit.

Scopus

出版者・発行元：Proceedings of the International Astronautical Congress, IAC  

Laser ablation is a vital technology for contactless active debris removal, where a service satellite with a laser system irradiates laser pulses to a target satellite to generate the ablation force for deorbiting. The deorbiting force decelerates the target, and the service satellite needs to maintain its relative position and keep irradiating. In other words, both the service satellite and the target are supposed to be deorbited simultaneously, where both satellites have accelerations. The difficulty of simultaneous deorbiting stems from the relative motion between the service satellite and the target in powered flight because conventional formation flying missions assume that only a service satellite maneuvers. This paper derives the relative equations of motion between the service satellite and the target in powered flight. A control law for the simultaneous deorbit is proposed, which determines the timing and direction of the laser ablation and the electrical thrust so that the formation periodically returns to the desired formation. Numerical simulations are performed for two test cases to verify the control law under the uncertainties of thrust magnitude and orbital perturbation.

Scopus

出版者・発行元：Proceedings of the International Astronautical Congress, IAC  

Collisions and explosions of satellites generate a large amount of sub-millimeter-size debris, which can cause fatal damage to a spacecraft. However, such tiny debris cannot be tracked from the ground. Therefore, an in-situ debris measurement satellite, which can detect impacts with sub-millimeter-size debris, has been proposed. Based on this concept, previous studies proposed the method to estimate some orbital parameters of the broken-up object. In those studies, it is assumed that the measurement satellite detects impacts at the intersection of the orbital planes of the measurement satellite and the broken-up object. However, simulated measurement data includes fragments contrary to this assumption. Thus, this study introduces a new approach to estimating the orbital parameters of the broken-up object from simulated measurement data. In this study, the inclination, the right ascension of the ascending node, and the nodal precession rate are estimated from the history of geocentric declination using the iteratively reweighted nonlinear least square method.

Scopus

記述言語：英語   出版者・発行元：Space Solar Power Systems Society  

<p>Wireless Power Transmission (WPT) technology using a satellite-to-satellite system represents a valuable and convenient technology for transferring power wirelessly among Space Solar Power Satellites (SSPS) to Satellite and potential upcoming interplanetary missions. This direct transmission offers a possible solution to deliver continuous, convenient, and unlimited energy supply to satellites to help replace traditional power storage and reduce the weight and ultimately the costs of launching satellites. Satellite industries traditionally use photovoltaic cells and nuclear generators to satisfy the needed electricity by spacecraft. Current power generation and effective management systems occupy up to 10-25% of the satellite's mass. The concept of laser-based WPT from Energy Satellite (E-Sat) can overcome substantial problems. This consistent idea can be adopted for spacecraft by developing a constellation of E-Sat called Energy Orbit (E-Orbit) to supply sufficient power to spacecraft within range. It will increase the impressive performance and operational lifetime. In addition, creating 1600 E-Sat’s constellations to fulfill the power demand in Low Earth Orbit. The overall efficiency variation depends on the selection of Laser, transmitter, transmission distance, and photovoltaic cells, the same as increasing the maximum transmission efficiency of information in a wireless communication network. Consequently, in general, and adequate guidelines of the satellite-to-satellite power transmission system design in practice. The development and demonstration of this technology can help fulfill Space Solar Power Satellite’s idea to transfer gigawatts of renewable energy to Earth.</p>

DOI： 10.24662/sspss.7.0_12

CiNii Research

出版者・発行元：Proceedings of the International Astronautical Congress, IAC  

Solar radiation pressure (SRP) is a major disturbance for a spacecraft operated in deep space missions, affecting its orbit and attitude, and high accuracy of the SRP calculation is required. The accuracy of SRP calculation is affected by the shape and surface characteristics of the satellite. However, existing computational models do not sufficiently take into account the exact reflective properties of the satellite surface. A detailed reflection model and considering the optical characteristics yield a different SRP and its torque from the conventional ones, resulting in a different attitude motion. In this study, an SRP calculation method that considers the exact reflective properties is applied to investigate the attitude dynamics.

Scopus

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： https://doi.org/10.1016/j.jsse.2021.08.004

リポジトリ公開URL： http://hdl.handle.net/2324/4741657

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.2514/1.G005877

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.2514/1.G004966

リポジトリ公開URL： http://hdl.handle.net/2324/4481550

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.2322/tastj.18.276

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： https://doi.org/10.1109/TCSS.2018.2890655

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： https://doi.org/10.1016/j.asr.2018.07.034

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.2322/tastj.16.599

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： https://doi.org/10.1016/j.asr.2018.04.042

記述言語：英語   掲載種別：研究論文（学術雑誌）  

The growth of the near-Earth debris population since the beginning of human space activities is now a fact commonly admitted by space agencies worldwide. Numerous entities have warned about the danger that debris may have over time. Presently mitigation meth- ods such as imposing post-mission disposal time after launch will no longer be sufficient; remediation processes seem necessary to limit the increase. In particular, this phenomenon is attributed to the generation of fragments due to more and more on-orbit collisions. There- fore, investigations on indexes to select potential removal targets were recently conducted, considering solely objects implicated in a col- lision course. This study also looks at the multiple fragmentation factors, including time through the altitude at time of impact (due to the behaviour of debris re-entering with time).
The focal point is here to compare different criteria to select removal targets that enable scenarios in best adequacy with the future in question (long term, mid term or short term). Aware of the uncertainty of evolutionary models, this study also incorporates the simu- lation method as an impactful factor and tries to overcome the potential randomness of the results. Therefore, this paper presents a way to establish a selection criterion the most adequate for the time period focused on.
In order to solve this issue, a ‘‘double-check” method is proposed. First, an analytical evolutionary model simulates the environment over 100 years, through 100 Monte-Carlo runs. Then, among the initial population of year 2009, the objects supposed to be at the origin of the debris detected at a given time are tracked back in time into the simulations, using a collision-detecting program. The ‘‘given per- iod” above mentioned for the presence of debris is based on a future as such that 2029 be considered a short-term scenario, 2059 a mid- term scenario and 2109 a long-term scenario. This step produces three lists of targets for removal (one for each future), and simulations are run once again, through different scenarios involving the removal of particular listed targets in order to verify the appropriateness of the proposed scenarios. The analysis of the results is based both on the mean of the simulations and on the recurrence considering each run.
Three studies were conducted one for each term, and a fourth one completed the work by establishing comparison between short, mid and long-term periods. As a result, three main criteria could be established: the altitude of the objects, the number of targets necessary to remove, and the phenomenon of chain collisions. According to the future that was investigated, the most adequate criterion appeared to be different, consisting in the number of objects in the long-term analysis or the ranking position at short term (linked to the close-time consideration). As a main conclusion and further perspectives, it should be more efficient to consider the collision-probability and mass product together with the time-depending generation of fragments. This would help increasing the precision in the prediction of collision impacts.
Rather than pinpointing specified targets to be removed, the aim of this study is simply to understand the mechanisms at the origin of the population increase around the Earth. Also to demonstrate that a careful definition of selection criteria would enable to adopt a suitable removal process in the period of action or for the goal to be reached.

DOI： http://dx.doi.org/10.1016/j.asr.2017.05.046

記述言語：英語   掲載種別：研究論文（学術雑誌）  

その他リンク： https://www.onlinejournal.in/IJIRV3I9/127.pdf

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： http://dx.doi.org/10.1016/j.actaastro.2016.10.032

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： http://dx.doi.org/10.1016/j.asr.2016.12.036

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： http://dx.doi.org/10.1016/j.actaastro.2016.05.003

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： http://dx.doi.org/10.20910/IJASE.2016.3.1.5

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： http://dx.doi.org/10.1016/j.asr.2015.10.034

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： http://dx.doi.org/10.1016/j.asr.2015.11.005

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： http://doi.org/10.2322/tastj.13.45

リポジトリ公開URL： http://hdl.handle.net/2324/4402934

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： http://dx.doi.org/10.1016/j.asr.2015.04.009

記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）  

DOI： http://dx.doi.org/10.1109/RAST.2015.7208446

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： http://dx.doi.org/10.2322/tastj.12.Pr_27

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： http://dx.doi.org/10.2322/tastj.12.Pr_21

記述言語：日本語   掲載種別：研究論文（学術雑誌）  

The purpose of this study is to research about removal effectiveness of debris removal spacecraft. It was investigated whether debris would be removable in one year using the property of spacecraft proposed by the first research. The removal method is passive debris removal. The assumed break up event is equivalent to Chinese Anti Satellite test that occurred in January, 2007. In consideration of a removal spacecraft moving by perturbation, removal effectiveness was compared for directions of orbit injection, effective cross sectional area, and orbit injection time as a parameter.

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： http://dx.doi.org/10.1016/j.asr.2013.11.052

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： http://dx.doi.org/10.1016/j.asr.2013.11.051

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.proeng.2013.12.040

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.2514/1.A32228

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： http://dx.doi.org/10.1016/j.asr.2013.02.008

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：日本語   掲載種別：研究論文（学術雑誌）  

This paper focuses on a collision risk of a tether system against other satellites. The tether system in this paper means a spacecraft for orbital debris removal using an electro-dynamic tether, and is expected to prevent the population growth of orbital debris in the low Earth orbit region. However, the tether system may encounter a high collision risk because of its thin and long configuration. Therefore, there is a possibility that the tether system collides with other orbiting satellites when the tether system conducts a mission of orbital debris removal. This paper estimates the collision probability and the success rate until the orbital debris removal mission is over and describes factors contributing to the reduction in the mission success rate.

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：日本語   掲載種別：研究論文（学術雑誌）  

Space debris environment evolutionary model for the geosynchronous Earth orbit region, GEODEEM, developed by Kyushu University was upgraded for better understanding. This paper explain the key features of this upgraded model. One of keys of this upgrade is that all satellites larger than 10 cm in size are tracked individually. The benefits of this upgrade are: 1) collision accidents can be estimated based upon one-by-one collision probabilities, and 2) more realistic scenarios like removing certain objects from orbits can be applied. This paper also present the latest prediction of future space debris environment from 2008 to 2108. The model indicates that explosion is the main debris production mode in next 100 years.

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： http://dx.doi.org/10.1016/j.asr.2012.01.012

記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）  

記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：日本語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： http://dx.doi.org/10.1016/j.asr.2011.01.008

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： http://dx.doi.org/10.1016/j.asr.2011.12.010

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：日本語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：日本語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：日本語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（大学，研究機関等紀要）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（大学，研究機関等紀要）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：日本語   掲載種別：研究論文（学術雑誌）  

記述言語：日本語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.2514/1.11998

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.2514/1.11600

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.asr.2003.11.018

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：日本語   掲載種別：研究論文（学術雑誌）  

記述言語：日本語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.ijimpeng.2003.09.028

記述言語：日本語   掲載種別：研究論文（学術雑誌）  

記述言語：日本語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.2514/2.3786

記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）  

DOI： 10.1016/S0273-1177(01)00398-2

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/S0094-5765(00)00127-2

記述言語：日本語  

記述言語：日本語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/S0273-1177(99)00004-6

記述言語：日本語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：日本語  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1006/jsvi.1996.0390

記述言語：日本語  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：日本語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（大学，研究機関等紀要）  

記述言語：日本語   掲載種別：研究論文（学術雑誌）  

記述言語：日本語   掲載種別：研究論文（学術雑誌）  

記述言語：日本語   掲載種別：研究論文（学術雑誌）  

開催年月日： 2023年12月

記述言語：英語   会議種別：口頭発表（一般）  

国名：アメリカ合衆国  

開催年月日： 2023年12月

記述言語：英語   会議種別：口頭発表（一般）  

国名：アメリカ合衆国  

開催年月日： 2023年12月

記述言語：英語   会議種別：口頭発表（一般）  

国名：アメリカ合衆国  

開催年月日： 2023年12月

記述言語：英語   会議種別：口頭発表（一般）  

国名：アメリカ合衆国  

開催年月日： 2023年10月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：富山市   国名：日本国  

This paper proposes a design method for a constellation of satellites. Aiming at improving the prediction accuracy of meteorological disasters (e.g., typhoons, linear rainbands, etc.), observation missions using a constellation of satellites, targeting the East Asian region including Japan have been proposed. An ultra-low orbit is desired from the viewpoint of resolution and weight of the observation equipment, but in general, the swash width from an ultra-low orbit is narrow and it is difficult to observe a specific area at a high frequency. Therefore, this paper proposes the design of a constellation that can observe a specific area with high frequency even with a small satellite in an ultra-low earth orbit.

開催年月日： 2023年10月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：富山市   国名：日本国  

This paper proposes an attitude control method of an uncooperative spacecraft using lasers. The attitude motion of the spacecraft must be controlled in advance for space debris removal by laser ablation. The control gain in a conven- tional attitude control law is empirically given and is sensitive to assumed preconditions. Thus, this paper improves the conventional attitude control law by providing a method to theoretically obtain the control gain by setting a reference torque based on the angular momentum error. Numerical simulations verify the effectiveness of the control gain designed and robustness against gravity gradient torques and solar radiation pressure torques.

開催年月日： 2023年10月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：富山市   国名：日本国  

This study proposes a nonparametric regression model to describe the attitude motion of space objects. Understand- ing the attitude of space objects is crucial for accurate orbit propagation. Light curve inversion is known as one of the methods of space objects ’attitude inference. However, previous studies have assumed known shapes for the estimation. Thus, this paper constructs nonparametric attitude and light curve models without shape information using Gaussian process regression. The shape of space objects is implicitly learned from the attitude differences that stem from dis- turbance torques, i.e., solar radiation pressure torques in this paper. Numerical examples include three types of object shape and evaluate the regression models.

開催年月日： 2023年10月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：富山市   国名：日本国  

This paper proposes a close approach analysis method considering the attitude motion of two colliding objects. De- tailed close approach analysis is important because the number of space objects has been increasing in recent years. Conventional conjunction assessments assume two colliding objects to be point masses with no volume, but they are ob- jects with volume. In the proposed method in this paper, the first step calculates the time of close approach considering two objects as point masses. Next step chooses two poses (i.e., attitude and position) when the distance becomes less than a given threshold, and the third step interpolates the two poses using dual quaternions. Dual quaternions can de- scribe the translational and rotational motions, which ensures the uniquness of the interpolation. Numerical simulations are conducted to verify the proposed method and compre it with a conventional method.

開催年月日： 2023年10月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：富山市   国名：日本国  

This paper proposes a method to classify LEO objects detected via EISCAT radar, based on orbital characteristics of the fragmentation debris　originated from different breakup events. Since many of the detected objects can be identified with the known cataloged objects, most of them can also be classified as one of the groups of debris correlated to specific breakup events. In this paper, aided by a concept of Admissible Region, a classification method for the radar observation objects in　LEO is derived and applied to results of an observation campaign in 2022.

開催年月日： 2023年10月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：富山市   国名：日本国  

This paper solves a singular problem to stabilize a space-advertisement formation. The space advertisement is a dot　matrix illuminating in the night sky seen from the ground. Using multiple satellites with light sources, the arbitrary dot matrix can be made by considering relative apparent position of each dot from a representative dot. This study solves a singular problem of a coordinate system which describes the positions of the dots to finally stabilize the dot matrix. This study introduces a new topocentric coordinate system to solve the singular problem and formulates the relative apparent position of the dot as linear functions. The formulation generally describes the relative apparent position of satellites seen from the ground. The proposed formulation reveals a stability of the dot matrix as well as solving the singular problem. The stability of the dot matrix is decomposable into six coefficients related to a set of relative orbital elements. Considering the characteristics of the six coefficients, a stable condition is revealed. Even with semi-major axis difference, the dot matrix can be stabilized during a visible span.

開催年月日： 2023年10月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：富山市   国名：日本国  

This study proposes the relative orbit control law considering uncertainties of disturbance force. The relative orbit　control of a spacecraft about non-cooperative objects is an promising technology for future on-orbit servicing and debris removal missions. The uncertainties of disturbance force may increase the relative position error, resulting in a high risk of collision. To tackle this problem, this study derives an adaptive control method using Gaussian process. Gaussian process is a data-driven machine learning model and is suitable for function regression problems. Furthermore, Gaussian process can learn non-parametric models and cancel the uncertainties in control architecture. Numerical simulations verify the proposed control law under differential drag.

開催年月日： 2023年6月

記述言語：英語   会議種別：口頭発表（一般）  

国名：日本国  

開催年月日： 2023年6月

記述言語：英語   会議種別：口頭発表（一般）  

国名：日本国  

開催年月日： 2022年11月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：東京都調布市   国名：日本国  

This paper describes an analysis of radar observation data detecting space objects in low-earth orbit (LEO), which are correlated to cataloged ones. In this work, the objects detected by an atmospheric radar system called EISCAT Svalbard Radar (ESR) are treated. When the objects observed in March of 2022 (totally 14 hours for two days) were applied to the correlation analysis, sixty percent of the observed objects were highly correlated with all the cataloged objects including space debris, which are known and constantly tracked. This paper investigates altitudes and sizes of the correlated and uncorrelated objects, respectively, as well as discusses cause of the lack of correlation and problems how to identify the uncorrelated objects.

開催年月日： 2022年11月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：東京都調布市   国名：日本国  

To remediate the orbital environment, active debris removal (ADR) from low Earth orbit is required. Laser ablation is a vital technology for contactless active debris removal, where a service satellite irradiates laser pulses to a target satellite to generate the ablation force for deorbiting. Since the ADR method using a laser requires no deorbiting device to attach, the ADR by laser enables simultaneously deorbiting multi-targets, which is a promising ADR technology. As a preliminary study of multi-deorbit, this paper designs the formation with respect to multi-targets to maximize the laser duration or minimize collision probability. Furthermore, the laser system has significant constraints such as laser focal length, laser irradiating angle, and camera angle. Thus, the designed formations must satisfy the constraints of the laser system. To this end, two formations that require attitude control or no attitude control are proposed. Their performances are compared in terms of safety and deorbit efficiency.

開催年月日： 2022年11月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：東京都調布市   国名：日本国  

As the number of spacecraft and orbital debris is rapidly increasing, Active Debris Removal is becoming an essential technology to maintain a sustainable space environment. SKY Perfect JSAT and RIKEN are developing a laser-equipped ADR satellite that adopts laser ablation technology to generate a thrusting force on the target object. This ADR method does not require any physical contact with the target object, which is a remarkable characteristic compared to the widely proposed methods. The laser satellite can perform detumbling and deorbiting of the target object as long as its relative distance is within the laser range. For that reason, docking or capturing is no longer needed for this ADR method. On the other hand, proximity operations need to be considered over the entire mission period. ADR mission provided by Laser satellite can be divided into several phases, such as detumbling phase and deorbiting phase, and each phase requires individual orbit design. This presentation will show the concept of the orbital design for each mission phase and provides the validation results by using Hill coordinate systems and relative orbital elements.

開催年月日： 2022年11月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：東京都調布市   国名：日本国  

This presentation describes the status of the Space Debris Index study by the debris modeling team of JAXA's Research and Development Directorate. The debris index which indicates the environmental impact of spacecraft or missions has been the subject of international discussion and research. The modeling team organized the definitions and applications of the debris index and summarized which characteristics of the environmental impact of spacecraft should be evaluated. From this result, we narrowed down the features to be considered, and are working on an index formulation. The index is formulated in terms of short-term and long-term effects on the orbital environment. The environmental evaluation criteria are also discussed to confirm that the index values correctly represent the impact of spacecraft on the orbital environment. This presentation also shows the effect of environmental improvement using the debris index. The objects in the orbit are evaluated based on several indices, and the top 50 objects are removed from the orbit.

開催年月日： 2022年11月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：東京都調布市   国名：日本国  

There is a growing concern about climate change caused by greenhouse gases. Especially, carbon dioxide has significant influences not only on the lower atmosphere but also on the upper atmosphere such as the thermosphere where space objects are orbiting. One of the problems of increasing carbon dioxide is that it reduces the density of the thermosphere, resulting in a less atmospheric drag on space objects. This paper evaluates the long-term influence of decreasing the atmospheric drag on the space environment and space activities using an orbital debris evolutionary model. In this study, Jacchia-Roberts 1971 atmospheric model is used to calculate the atmospheric density. In addition, this study makes corrections to atmospheric density with considering the long-term density decrease. This paper also reveals the long-term impact of density decrease on space activity by calculating the debris number transition, the extension of debris orbital lifetime, and collision probability with debris. Furthermore, this study shows the change of delta-v and the collision probability with other objects to satisfy the 25-year rule.

開催年月日： 2022年11月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：東京都調布市   国名：日本国  

JAXA has been evaluating the future space debris environment using a debris evolutionary model named NEODEEM, developed in collaboration with Kyushu University. This evolutionary model is able to generate orbital debris generated by on-orbit collisions and explosions, and also to estimate and evaluate the impact of debris on the long-time orbital environment. In addition, by using this model, ASAT events also may simulate and evaluate, which has become a problem in recent years, can also be simulated. In this presentation, various analysis examples based on this evolutionary model are introduced.

開催年月日： 2022年11月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：東京都調布市   国名：日本国  

The Breakup model includes cases of collisions and explosions, and this study examines the breakup model for satellite explosions. Explosive fragmentation experiments were conducted using a mock-up satellite in a simple vacuum vessel. Then, the fragment size and typical velocity are measured using the high-speed photographing results and recovered fragments after the experiment, and an explosion breakup model is examined. A PETN explosive has predictable explosive energy and is used as the explosion source. This presentation compares the results obtained by changing the location of the explosion source inside and outside the mock-up satellite. Then, the effect of the location of the explosion source on the broken condition and the breakup model is examined. And It is reported that different results were obtained depending on the location of the explosion source. In addition, the situation of Ekran2 and its fragments was examined as a case of a breakup. As a result, the source of the explosion may be outside.

開催年月日： 2022年11月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：東京都調布市   国名：日本国  

This paper briefly introduces a new approach to estimating some orbital parameters of on-orbit satellite fragmentations (precisely, the direction of angular momentum at a specific time and its time change) from in-situ debris measurements. Previous studies have applied a nonlinear least-squares fitting to a constraint equation derived from the fact that a piece of debris detected shares the geocentric position vector with an in-situ debris measurement satellite. However, the new approach applies a nonlinear least-squares fitting to the history of geocentric declination at the detection time. The previous studies have been verified under ideal conditions where all detections are assumed to be at the intersection of the two orbital planes of a broken-up object and an in-situ debris measurement satellite. However, this study verifies using more realistic measurements from a close approach analysis.

開催年月日： 2022年11月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：オンライン   国名：日本国  

This paper investigates on-orbit satellite fragmentations in the geostationary region. First, this paper reviews the on-orbit fragmentation of a US TITAN 3C TRANSTAGE based on a previous study and indicates that it was a relatively major fragmentation. Second, this paper reviews the on-orbit fragmentation of the Russian EKRAN 2 spacecraft based on longitudinal perturbation and indicates that it was a relatively minor fragmentation. Finally, this paper concludes that the gas and fragments generated by the burst of batteries placed outside pushed the main body to release appendages such as solar array paddles.

開催年月日： 2022年11月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：オンライン   国名：日本国  

The space-advertisement mission gives an artificial constellation in the night sky using a satellite formation with light sources. The formation shape observed from the ground which was not discussed by previous studies is revealed. A proper design of satellites using present equations makes an arbitrary advertisement shape. Moreover, some stable orbits whose advertisement shape can be kept during the visible span are revealed, which makes a stable advertisement design without control.

開催年月日： 2022年11月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：オンライン   国名：日本国  

This paper describes an analysis of radar observation data detecting space objects in low-earth orbit (LEO), which are correlated to cataloged ones. In this work, the objects detected by an atmospheric radar system called EISCAT Svalbard Radar (ESR) are treated. During the observation campaign in March of 2022 (total 14 hours for two days), about 7 hundred hard targets were detected through the radar facility. This paper shows the results of a correlation analysis between the detected objects and known and tracked ones, or so-called cataloged objects, and discusses them from a viewpoint of identification for space debris generated via collisions and explosions in orbit.

開催年月日： 2022年11月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：オンライン   国名：日本国  

A fragmentation model representing the situation at the time of generation is necessary for the prediction of the space debris environment. Explosive fragmentation is one of the causes of space debris generation. Explosive fragmentation produces more space debris. Therefore, in this study, an explosion fragmentation experiment using a small mock-up satellite was performed. A PETN explosive installed inside the small mock-up satellite was used as the explosion source. The fragments were collected and photographed with a high-speed camera. This paper reports the results obtained by examining the difference in internal explosive energy and the results obtained with the NASA standard break-up model.

開催年月日： 2022年11月

記述言語：日本語  

開催地：熊本県熊本市   国名：日本国  

This paper briefly introduces a new approach to estimate some orbital parameters of on-orbit satellite fragmentations (specifically, the direction of angular momentum at a specific time and its time change) from in-situ debris measurements. Previous studies have applied a nonlinear least-square method to a constraint equation derived from the fact that a piece of debris detected shares the geocentric position vector with an in-situ debris measurement satellite. However, the new approach applies a nonlinear model fit to the history of geocentric declination at the time of detection. This paper also verifies that the new approach works effectively under ideal conditions where all detections are assumed to be at the line of intersection of the two orbital planes of a broken-up object and an in-situ debris measurement satellite.

開催年月日： 2022年11月

記述言語：日本語  

開催地：熊本県熊本市   国名：日本国  

This paper provides experiment results of a satellite fragmentation due to battery. The current explosion model in the NASA standard breakup model is based on the outcome of rocket upper stage explosions. The NASA breakup model may not be able to describe the physical properties of fragments from satellite battery-induced explosions, however. Therefore, this study conducts satellite battery-induced explosions using mock-up satellites. To simplify the experiment, an 1 g of PETN explosives were used instead of batteries. The explosion experiments were filmed by a high-speed video camera. The delta-velocity of the fragments were obtained from these images. The target satellite was completely fragmented after the experiments. Approximately 40,000 fragments were collected. Each fragment was measured and analyzed based on the methods proposed in the NASA standard breakup model. The size, average cross-sectional area, area-to-mass ratio, and delta-velocity distributions were compared with the NASA standard breakup model.

開催年月日： 2022年11月

記述言語：日本語  

開催地：熊本県熊本市   国名：日本国  

On-orbit servicing, where a service satellite performs missions such as life-extension or deorbit of a target satellite, has been planned by many commercial entities. Relative pose estimation (i.e., attitude and orbit estimation) is essential to conduct on-orbit servicing missions successfully because the target satellite is noncooperative in many practical cases. This paper proposes a satellite pose estimation method that allows us to conduct a more accurate and efficient estima- tion using the unscented Kalman filter (UKF). There is a significant advantage in estimating both attitude and orbit motion simultaneously because they are coulle in general. To this end, the unified parameterization of both attitude and orbit using dual quaternions is applied in this paper. Employing the dual quaternions in the UKF, however, has a difficulty that stems from the algebraic constraints of the dual quaternions. That is, the algebraic constraints of dual quaternions are violated when calculating the weight-mean dual quaternion in the UKF sequence. This paper proposes and compares the following two methods to compute the averaged dual quaternion: 1) dual quaternion linear blending and 2) dual quaternion averaging. These two methods allow us to calculate the weight-mean dual quaternions while keeping the algebraic constraints. Numerical examples for relative pose estimation are conducted to discuss the accuracy and effectiveness of the proposed methods.

開催年月日： 2022年11月

記述言語：日本語  

開催地：熊本県熊本市   国名：日本国  

This paper proposes a control law for simultaneous deorbit using laser ablation. Laser ablation is a vital technology for contactless active debris removal, where a service satellite with a laser system irradiates a target satellite to generate the ablation force for deorbiting. The deorbiting force decelerates the target, and the service satellite must maintain its relative position and continue irradiating. The difficulty of simultaneous deorbiting stems from the relative motion between the service satellite and the target in powered flight because conventional formation flying missions assume that only a service satellite maneuvers. This paper derives the relative equations of motion between the service satellite and the target in powered flight. A control law for the simultaneous deorbit is proposed, which determines the timing and direction of the laser ablation and the electrical thrust so that the formation periodically returns to the desired formation. Numerical simulations are performed for two test cases to verify the control law involving the uncertainties of thrust magnitude.

開催年月日： 2022年11月

記述言語：日本語  

開催地：熊本県熊本市   国名：日本国  

Solar radiation pressure (SRP) is a major disturbance for a spacecraft operated in deep space missions, affecting its orbit and attitude, and high accuracy of SRP calculation is required. SRP calculations are affected by the shape and surface characteristics of the satellite. However, existing computational models do not sufficiently take into account the exact reflective properties of the satellite surface. A detailed reflection model and considering the optical characteristics yield a different SRP and its torque from the conventional ones, resulting in a different attitude motion. In this study, an SRP calculation method that considers exact reflective properties is applied to investigate attitude dynamics using high-fidelity SRP.

開催年月日： 2022年11月

記述言語：日本語  

開催地：熊本県熊本市   国名：日本国  

Low-energy transition orbits in the Earth-Moon three-body problem are known to be chaotic in nature, hence orbit prediction and design are difficult. In this study, in order to predict chaotic behavior, a new method is proposed to approximate high-dimensional chaotic transition trajectories as maps of low-dimensional periapsis maps by dynamic mode decomposition, which is a data-driven approach. Moreover, comparing the approximation errors caused by this method with the dynamical structure of the circle-restricted three-body problem, it is found that orbits with large approximation error are on the boundary of the dynamical structure, therefore the proposed method also leads to the clarification of the dynamical structure of the chaotic orbits.

開催年月日： 2022年11月

記述言語：日本語  

開催地：熊本県熊本市   国名：日本国  

This paper mainly investigates potentials of the “Tomo-e Gozen” system on 1.05 m Kiso Schmidt telescope to be a significant tool for searching missing space debris towards a sustainable space activity. The system is featured by its wide-field and high-cadence videos observations with mosaic CMOS sensors. This paper conducts the investigation through comparing the Tomo-e Gozen's observation data of breakup-originated debris and an observation path based on prediction of the debris population. That work made it clear that the system is useful enough for searching missing space debris. It is also recognized that a long-term observation is needed to complete the task. As well as those results, plotting observation data of uncorrelated target (UCT) objects on a celestial sphere, we confirmed path-like curves which maybe lead to tracking the UCT objects.

開催年月日： 2022年11月

記述言語：日本語  

開催地：熊本県熊本市   国名：日本国  

There is a growing concern about climate change caused by greenhouse gases. Especially, carbon dioxide has significant influences not only on the lower atmosphere but also on the upper atmosphere such as the thermosphere where space objects are orbiting. One of the problems of increasing carbon dioxide is that it reduces the density of the thermosphere, resulting in less drag on space objects. This paper evaluates the influence of decreasing the air drag by an orbital debris evolutionary model. In this study, the motion of space objects is calculated by considering the reduction of atmospheric density in the Jacchia-Roberts 1971 atmospheric model.

開催年月日： 2022年9月

記述言語：英語   会議種別：口頭発表（一般）  

国名：フランス共和国  

開催年月日： 2022年9月

記述言語：英語   会議種別：口頭発表（一般）  

国名：フランス共和国  

開催年月日： 2022年9月

記述言語：英語   会議種別：口頭発表（一般）  

国名：フランス共和国  

開催年月日： 2022年9月

記述言語：英語   会議種別：口頭発表（一般）  

国名：フランス共和国  

開催年月日： 2022年9月

記述言語：英語   会議種別：口頭発表（一般）  

国名：フランス共和国  

開催年月日： 2022年9月

記述言語：英語   会議種別：口頭発表（一般）  

国名：フランス共和国  

開催年月日： 2022年2月 - 2022年3月

記述言語：英語   会議種別：口頭発表（一般）  

国名：日本国  

開催年月日： 2022年2月 - 2022年3月

記述言語：英語   会議種別：口頭発表（一般）  

国名：日本国  

開催年月日： 2022年2月 - 2022年3月

記述言語：英語   会議種別：口頭発表（一般）  

国名：日本国  

開催年月日： 2022年2月 - 2022年3月

記述言語：英語   会議種別：口頭発表（一般）  

国名：日本国  

開催年月日： 2022年2月 - 2022年3月

記述言語：英語  

開催地：Beppu-Oita   国名：日本国  

This study proposes a method of classification prior to identification of space debris fragmented in a low earth orbit, which are detected through a ground-based observation. The proposed method is incorporated by a concept of Admissible Region, which can give a reasonable region of unknown two-dimensional parameters such as time-derivative of declination and right ascension for an observational direction. As the two unknown parameters are necessary to estimate orbital elements from observation data obtained through a radar system or a telescope, a method to find their existence region leads to effectively classify the radar observation data based on their orbital elements. The classification method derived in this study is finally verified using results of a correlation analysis between cataloged fragmentation debris and observation data obtained in a campaign at EISCAT Svalbard Radar in 2020.

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開催年月日： 2022年2月 - 2022年3月

記述言語：英語  

開催地：Beppu-Oita   国名：日本国  

Because of the expansion of outer space activities, space debris is increasing considerably. To sustain the outer space activities, it is necessary to inhibit the generation and increase of space debris by active debris removal. By evaluating “timeliness”, this study determines the space debris to be removed which is a significant issue to improve the orbital environment efficiently. Then, the aims of this study are 1) proposing new evaluation indices considering dangerousness and timeliness and 2) discussing the effects of the indices on future environmental improvement. First, by focusing on the origins of space debris in the future orbital environment from the results of future projections, the necessary factors for the evaluation index are examined. Second, by applying the ridge regression model, the weighting of each factor is evaluated and then new evaluation indices are proposed. Finally, by discussing the future orbital environment following the removals of the objects selected by new evaluation indices, these indices have great effects for future environmental improvement.

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開催年月日： 2022年2月 - 2022年3月

記述言語：英語  

開催地：Beppu-Oita   国名：日本国  

The effects of GTO debris to LEO environment are revealed using evolutionary model. GTO debris orbits are modeled as a reference of distribution of actual objects in GTO extracted from JAXA’s initial population file. Firstly, three cases of simulation with different perigee altitude were shown taking into accounts the distribution of GTO debris. It indicated that the debris with perigee altitude of over 400 km have long term effects while the debris with perigee altitude of 200 km decay shortly. The effect of continuously generation of GTO debris was secondly investigated. Since the GTO debris has long term orbital life, the number of its debris would keep increasing and accumulate in orbit. Lastly, the risk of GTO debris considering the actual number of debris and future works were discussed.

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開催年月日： 2022年2月 - 2022年3月

記述言語：英語  

開催地：Beppu-Oita   国名：日本国  

This study addresses and models the features of the global error accumulation generated though a numerical orbit prop- agation. To obtain fundamental findings and insights, the Cowell’s form, Runge-Kutta-Fehlberg (4, 5) method, and a variable step-size method are considered as the form of equation, numerical scheme, and stepping method, respectively. By measuring and observing the error generated, it is revealed that the error grows in proportion to the desired tolerance, squared calculation span, and squared mean motion. The influence of eccentricity is also investigated. The error accumulation model proposed here is valid for orbits whose eccentricity is less than 0.1 under the geopotential and third-body perturbations. Under the atmospheric drag and solar radiation pressure in association with the shadow of the Earth, the features of error accumulation cloud be more or less distorted. The findings and the model presented here enable evaluating the intrinsic error in the result from a numerical orbit propagation in a quantitative way.

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開催年月日： 2021年12月

記述言語：英語   会議種別：口頭発表（一般）  

開催地：横浜市港北区   国名：日本国  

This paper illustrates and explains the benefits of Laser-based Wireless Power Transmission system models, including functional principles and mathematical formulation. Wireless power transfer is a possible solution to deliver continuous, convenient, and unlimited energy supply to satellites. Satellite industries traditionally use photovoltaic cells and nuclear generators to satisfy the demand for electricity required by spacecraft. Current power generation and management systems occupy a considerable portion of up to 10-25% of the satellite's mass. The concept of laser-based wireless power transmission from Space Solar Power Satellite can solve significant problems. The current design of Space Solar Power Satellite primarily focuses on creating a massive satellite to generate and transmit gigawatts of energy to an Earth-based ground receiving antenna. This idea can be adopted for spacecraft by developing a constellation of small-scale Space Solar Power Satellites or Energy Orbit to supply sufficient power to spacecraft within range. The theoretical and simulation modeling allows the analysis of power conversion or transmission for each individual unit in terms of the impacts of laser, transmission efficiency, and photovoltaic-cell thermal property. Maximum power transmission efficiency is calculated based on a linear approximation of power conversation between electricity-to-laser and laser-to-electricity validated by numerical simulation. This efficiency variation depends on the selection of Laser, transmitter, transmission distance, and photovoltaic cells, precisely increasing the maximum transmission efficiency of information in a wireless communication network. Consequently, this paper gives insight into wireless power transmission in general and adequate guidelines of the satellite to satellite power transmission system design in practice.

開催年月日： 2021年11月

記述言語：英語   会議種別：口頭発表（一般）  

国名：日本国  

開催年月日： 2021年11月

記述言語：日本語  

開催地：山形県山形市（オンライン）   国名：日本国  

This paper describes results of an analysis for certain groups of fragmentation debris in low earth orbit, which were detected via EISCAT radar during a campaign in 2020. In order to separate known or so-called the cataloged objects from the actually observed ones, a correlation analysis is conducted. Whereas some objects, especially the targeted space debris in the observation campaign are relatively well sorted, many other ones are not, which seem to be caused from specific effects from a typical radar observation. This paper also discusses about observed objects which were not correlated with the cataloged objects.

開催年月日： 2021年11月

記述言語：日本語  

開催地：山形県山形市（オンライン）   国名：日本国  

This paper proposes an attitude stabilization method for a non-cooperative satellite using laser ablation. Due to the nature of laser ablation, the system has constraints in the direction of control torques. Such constraints disable generating desired　torques in three-dimensional directions, and generated torques partially yield disturbances for attitude stabilization. The proposed method in this paper minimizes the undesirable disturbance torques, where the irradiation spot of laser is theoretically clarified. Numerical simulations are conducted to verify and discuss the effectiveness of the proposed method.

開催年月日： 2021年11月

記述言語：日本語  

開催地：山形県山形市（オンライン）   国名：日本国  

With the expansion of the information infrastructure such as the launch of large constellation of satellites, the orbital environment is becoming more densely populated, and there is a need for the navigation focused on emergency from the viewpoint of Space Situational Awareness. This paper proposes a method for estimating the relative orbit of spacecraft with unknown thrust accelerations. In relative orbital motion, the target motion with unknown maneuver is estimated with optical observations (i.e., azimuth and elevation angles of non-resolved images). The proposed method estimates the thrust history　of the target satellite by expressing it with a Fourier series expansion formula.changes are evaluated.

開催年月日： 2021年11月

記述言語：日本語  

開催地：山形県山形市（オンライン）   国名：日本国  

This paper addresses the degree of an impact of the fidelity of Earth shadows modeled on orbit propagation accuracy for spacecrafts orbiting Earth. When reproducing Earth shadows, there are two essential parts: the geometry and the solar ephemeris. Lots of them are introduced and utilized now for the orbit propagations. With demonstrating the gap of propagation results occurred due to the condition difference, this paper offers a clue of how to consider the fidelities of　Earth shadow and solar radiation pressure properly so that propagation results satisfy desired accuracy.changes are evaluated.

開催年月日： 2021年11月

記述言語：日本語  

開催地：山形県山形市（オンライン）   国名：日本国  

This paper conducts an observability analysis for attitude estimation of space debris with light curves considering self- shadowing. Light curves, which are time-varying apparent brightness of objects, are obtained as photometric observations for attitude estimation of space debris. The difficulty of the attitude estimation with light curves stems from sparse and limited observations. To improve the estimation accuracy, self-shadowing is incorporated with the observability analysis. As a preliminary study, this paper investigates the self-shadowing effect in the light curve observations and its observability changes are evaluated.

開催年月日： 2021年11月

記述言語：日本語  

開催地：山形県山形市（オンライン）   国名：日本国  

While the scale of outer space activities is expanding, space debris is also increasing considerably. To sustain outer space activities, it is necessary to prevent the increase of space debris by Active Debris Removal (ADR). One of the problems in ADR is to determine targets to be removed from the orbital environment. Previous studies have proposed several indices to evaluate whether debris must be removed or not, but different indices yield different results for removal targets. Therefore, further discussion is needed to establish an effective and reliable index. This paper proposes a new index that focuses on　timeliness using space debris evolutionary model and regression models to obtain further improvement effects.over a long period of time because larger time steps can be employed to reduce the computational time.cataloged objects.

開催年月日： 2021年11月

記述言語：日本語  

開催地：山形県山形市（オンライン）   国名：日本国  

To counter the increasing threat of space debris in recent years, simulation tools for projecting the future population of space debris have been developed. It is indispensable for more accurate projection to improve the accuracy of orbit propagation. Therefore, this study compares methods (stepper) and step-size to solve a set of differential equations of motion to find out a better orbit propagation.

開催年月日： 2021年11月

記述言語：日本語  

開催地：山形県山形市（オンライン）   国名：日本国  

The number of objects in LEO region is increasing and the accurate tracking of all objects around the Earth is important. This paper studies the application of dual quaternions to attitude and orbit propagation. Dual quaternions are the extended concept of quaternions, which are widely used to describe attitude angles because of its singularity-free property. Since the set of dual quaternions forms a Lie group under the dual quaternion multiplication, Lie group geometric integration methods can be applied to integrate the state equation. This paper evaluates the accuracy of the calculation between a conventional Runge–Kutta method and the Crouch–Grossman (geometric integration) method. The results show that especially when larger time steps are considered, the Crouch–Grossman method outperforms the conventional Runge–Kutta method in terms of the structure preservation and the accuracy. This means that geometric integration schemes can be useful for propagation over a long period of time because larger time steps can be employed to reduce the computational time.cataloged objects.

開催年月日： 2021年10月

記述言語：英語   会議種別：口頭発表（一般）  

国名：アラブ首長国連邦  

開催年月日： 2021年6月

記述言語：英語   会議種別：口頭発表（一般）  

国名：ロシア連邦  

開催年月日： 2021年2月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：東京都調布市   国名：日本国  

The building of space debris evolutionary models makes it possible to discuss how to reduce space debris and improve future orbital environment. In order to have a better discussion, it is essential to improve the accuracy of estimation in space debris evolutionary models. In collision breakup models implemented in current space debris evolutionary models, it is somewhat unrealistic that the distribution of fragments generated during a collision depends on the primary object. Therefore, this paper proposes a method to determine which object generated each fragment and form the distribution of fragments not only around the primary object but also around the secondary object. This paper also compares future orbital environment before and after the improvement of collision breakup models and describes differences of future orbital environment by improved collision breakup models.

開催年月日： 2021年2月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：東京都調布市   国名：日本国  

Space debris is an emerging global environmental problem. PMD of 90% and ADR of 5 to 10 every year is required for maintaining the status of LEO. Fulfillment rate of PMD is, however, still in unsatisfied level and its associated cost of ADR is unclear. This provides the challenge from both of technology and economics. Previous studies on economics of space debris are mostly analogy from environmental problems on the earth. Environmental economics, holding two Nobel Prize winners, can potentially provide key tool to understand this problem. In this study, we provide how environmental economics merits on understanding and solving debris problem including cost of PMD and ADR. Finally, we discuss requirements for economic scheme which are acceptable in international space scene.

開催年月日： 2021年2月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：東京都調布市   国名：日本国  

The orbital congestion is becoming an urgent issue with increasing space activities, such as satellite constellations for high-speed and large-capacity communications. Therefore, SKY Perfect JSAT Corporation has started out designing and developing an ADR satellite. The satellite applies laser ablation technologies so that it does not require any physical contact with a target object. ADR mission generally requires grasping the rotational motion of the target object in advance and reflecting it in its mission operations. The target object’s motion is usually complicated due to various disturbance torques acting on it. This presentation shows the short-term and long-term variation of attitude and angular velocities of the target object in Low Earth Orbit, considering the shift of the center of gravity.

開催年月日： 2021年2月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：東京都調布市   国名：日本国  

A debris evolutionary model is indispensable for investigating effective debris mitigation measures and for developing international rules regarding space debris. JAXA has been evaluating the future space debris population using an evolutionary debris model named NEODEEM, developed in collaboration with Kyushu University. A baseline file is required for the debris Evolutionary model, which is the initial population data of the on-orbit environment, such as mass characteristics and orbits of all objects larger than 10 cm. JAXA has created its own baseline file by taking into account the area-mass-ratio evaluation from the TLE (Two Line Elements) history, literature review, and uncatalogued objects observed with the JAXA telescope, and so on. The baseline files provided by ESA at IADC have been used for research purposes only, but due to lack of information, for example, evaluation of specific debris removal targets was not possible. In this talk, the methods for developing the baseline file, the results of comparison with some debris models, and the results of debris evolutionary model predicted using the developed baseline files are reported. In particular, the evaluation of debris removal targets and the effectiveness of debris mitigation measures using the developed baseline files are introduced. In addition, the information that can be analyzed from the TLE history survey is introduced.

開催年月日： 2021年2月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：東京都調布市   国名：日本国  

For the purpose of effective utilization of the orbital environment, the environmental capacity tolerance of insertions is studied using an orbital debris evolutionary model, developed in collaboration with Kyushu University. By inserting multiple spacecraft into a specific orbit regime and observing the impact on the orbital environment, the number of spacecraft that can be inserted into orbit (orbit insertion capacity tolerance) is evaluated. In this presentation, the results of studying the orbit insertion capacity tolerance due to differences in orbital regime, the number of inserted spacecraft, etc. Fig.1 demonstrates the difference in Effective Number of objects in LEO (Low Earth Orbit: altitude 200 to 2000 km) with and without 3000 spacecraft inserted into various orbital regimes. At altitudes below 800 km, natural decay due to the atmosphere may suppress the impact of insertions (and the generated debris). At altitudes between 800 and 1000 km, however, a remarkable increase in objects can be observed because of the many orbital residuals.

開催年月日： 2021年1月 - 2021年2月

記述言語：英語   会議種別：口頭発表（一般）  

国名：オーストラリア連邦  

開催年月日： 2021年1月

記述言語：英語   会議種別：口頭発表（一般）  

国名：その他  

その他リンク： https://doi.org/10.2514/6.2021-0559

開催年月日： 2020年12月

記述言語：日本語   会議種別：口頭発表（一般）  

国名：日本国  

開催年月日： 2020年11月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：熊本市   国名：日本国  

This study aims to design realistic multi-rendezvous trajectories for multiple removal spacecraft in low earth orbit.　　Genetic Algorithms is adopted to optimize the order of multi-rendezvous and the orbital parameters of the parking orbits,　which minimize the velocity increment necessary for changing orbital planes between removal targets. 　Although single　spacecraft may successfully rendezvous with selected targets within reasonable amounts of velocity increment and time,　subsequent spacecraft need large velocity increment and time to complete the multi-rendezvous.　　Rendezvous trajectory　design by utilizing not only incremental velocity but also nodal regression due to J2 perturbation in LEO obtains the reasonable solutions, however, it is necessary to optimize the whole, not partially to sustain the outer space activities.

開催年月日： 2020年10月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：zoom.us   国名：日本国  

Space Elevator is a space transportation system for carrying payloads to outer space through tethers that connect between ground and outer space stations. Assumed that the construction cost of a space elevator can be recovered in 10 years, this paper evaluates the survivability of the space elevator after 10 years against space debris impacts. As a result, it is difficult to realize the space elevator without environmental remediation down to less than 10% of the present space debris population.

開催年月日： 2020年10月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：zoom.us   国名：日本国  

開催年月日： 2020年10月

記述言語：英語   会議種別：口頭発表（一般）  

国名：その他  

開催年月日： 2020年4月

記述言語：英語   会議種別：口頭発表（一般）  

国名：日本国  

開催年月日： 2020年1月

記述言語：英語   会議種別：口頭発表（一般）  

国名：アメリカ合衆国  

その他リンク： https://doi.org/10.2514/6.2020-1433

開催年月日： 2019年12月

記述言語：英語  

国名：アメリカ合衆国  

開催年月日： 2019年12月

記述言語：英語  

国名：アメリカ合衆国  

開催年月日： 2019年12月

記述言語：英語  

国名：アメリカ合衆国  

開催年月日： 2019年12月

記述言語：英語  

国名：アメリカ合衆国  

開催年月日： 2019年12月

記述言語：英語  

国名：アメリカ合衆国  

開催年月日： 2019年12月

記述言語：英語  

国名：日本国  

開催年月日： 2019年11月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：熊本市   国名：日本国  

Space debris has become a huge problem for outer space activity in the space. Observations are conducted around the world to detect and track space debris. One of the important problems in optical observation is how to get useful information from large amounts of image data to determine the orbit of space debris. In order to determine the orbit of space debris in the geostationary region, this paper proposes a new method to detect space debris and its trajectories from a series of images. Then, a Particle filter is applied to determine the orbit of space debris. This paper also verifies that the proposed method can successful determine the orbit of space debris.

開催年月日： 2019年11月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：熊本市   国名：日本国  

In order to detect and identify fragmentation space debris in low-earth orbit (LEO), observation experiments using EISCAT radar in the Scandinavian Peninsula have been conducted. This study aims to derive an efficient method for observation of unknown and known space debris originated from break-up events occurred to artificial satellites or spacecraft in LEO. Whereas the past study applied a stepwise method combining predicted orbital position distributions of cataloged space debris and a predictive observation simulation for them based on their Two-Line-Element (TLE) data and orbit propagation algorithms, this study takes an analytical approach using 2-dimensional histogram to the above predicted orbital position distributions considering their time change. The effectiveness of the derived method is also shown through comparing with results of a past observation campaign.

開催年月日： 2019年11月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：熊本市   国名：日本国  

Outer space activities are currently developing. At the same time, space debris are increasing considerably, so that Active Debris Removal (ADR) is necessary to prevent an increase in space debris that affect outer space activities. One of the problems in ADR is to determine targets to be removed from the environment. Priority Lists depending on various indexes have been proposed, but are too different to trust. This paper compares the resulting space environment based on various Priority List proposed herein to find out the right space debris index that can make the space environment better.

開催年月日： 2019年11月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：熊本市   国名：日本国  

Cleaning up space debris out there is recently needed for environmental remediation. Tether satellite system is one of those candidates. That satellite system is known that it has many prospects to achieve such missions. However, there are difficulties on analysis of the behavior of those tether satellite systems due to elastic behavior of tether. Because of that, the step-size when integrating the equations of motion is empirically set to a small constant value to stabilize the behavior. In that context, this research proposes a new analysis method which can set the step-size adaptively. In particular, we apply distance function to settle the problem.

開催年月日： 2019年11月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：熊本市   国名：日本国  

The space elevator is a space transportation system to carry payload to outer space through a tether connecting between stations on the ground and in outer space. Its transportation cost is approximately one-tenth of the present transportation cost, so that it is possible to expect a substantial cost reduction. However, considering the collision of the space elevator with space debris, the survival probability of the space elevator after 10 years is nearly 0%. Therefore, this paper proposes a highly redundant system against space debris and an effective environmental remediation.

開催年月日： 2019年11月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：徳島県徳島市   国名：日本国  

An impact of space debris smaller than 2 mm, which cannot be detected by ground-based observations can cause a fatal damage on a spacecraft. Therefore, in-situ measurements that detect small debris utilizing on-orbit impact sensors are promoted to monitor the environment of small debris. This paper proposes two statistical methods that detect environmental changes utilizing time-series impact data obtained by in-situ measurements. The first and the second methods focus on drastic and continuous changes of environment, respectively. This paper also demonstrates the statistical detection of environmental changes with numerical simulations. The simulations and discussions in this paper clarifiy correlations between area of impact sensor, mission duration and detectable scale of environmental changes. Outcomes of this paper can contribute to design in-situ measurement missions.

開催年月日： 2019年11月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：徳島県徳島市   国名：日本国  

開催年月日： 2019年11月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：徳島県徳島市   国名：日本国  

An impact of space debris smaller than 2 mm, which cannot be detected by ground-based observations can cause a fatal damage on a spacecraft. Therefore, in-situ measurements that detect small debris utilizing on-orbit impact sensors are promoted to monitor the environment of small debris. This paper proposes two statistical methods that detect environmental changes utilizing time-series impact data obtained by in-situ measurements. The first and the second methods focus on drastic and continuous changes of environment, respectively. This paper also demonstrates the statistical detection of environmental changes with numerical simulations. The simulations and discussions in this paper clarifiy correlations between area of impact sensor, mission duration and detectable scale of environmental changes. Outcomes of this paper can contribute to design in-situ measurement missions.

開催年月日： 2019年10月

記述言語：英語   会議種別：口頭発表（一般）  

国名：アメリカ合衆国  

開催年月日： 2019年10月

記述言語：英語   会議種別：口頭発表（一般）  

国名：アメリカ合衆国  

開催年月日： 2019年9月

記述言語：英語  

国名：アメリカ合衆国  

開催年月日： 2019年7月

記述言語：日本語   会議種別：口頭発表（一般）  

国名：日本国  

開催年月日： 2019年6月

記述言語：英語   会議種別：口頭発表（一般）  

国名：日本国  

開催年月日： 2018年12月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：宇宙航空研究開発機構 調布航空宇宙センター   国名：日本国  

We propose that the cost of ADR (Active Debris Removal) can be paid by circulating digital currency tokens whose values decrease over time. Such tokens are issued by global cooperation (a consortium) of parties interested in space development to parties who actually performed ADR, in exchange with proofs of removals. The tokens represent debts of the consortium, which is repaid through contributions by the token holders (as values of tokens decrease while holding them), who are likely to be benefited by removal of debris. This scheme imposes virtually no cost to the consortium. We have generalized this concept as PoD (Proof of Disposal), which, we believe, provides a more accountable foundation for solving social problems with digital currency than many ICO (Initial Coin Offering) in practice today.

開催年月日： 2018年12月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：宇宙航空研究開発機構 調布航空宇宙センター   国名：日本国  

Kyushu University aims to establish a state estimation technique, called light curve inversion, which extracts dynamic states such as attitude motion and configuration from light curves. Light curves are brightness of space objects as a function of time and are obtained by ground-based observations. In order to demonstrate this technique, “Q-Li” the 3U Cubesat for Light Curve Inversion is being developed in Kyushu University. The primary mission of Q-Li is the on-orbit verification of the light curve inversion by comparing actual state and estimated one by light curve measurements. To this end, Q-Li deploys a membrane to reflect sunlight so that one can be observed from the ground. Q-Li measures her own attitude angles and angular rates in orbit and transmits them to the ground. As the secondary mission, Q-Li detects tiny debris collisions with the membrane by sensors located on its surface. In this workshop, not only the whole systems of Q-Li but also the deployment mechanism of the membrane and light curve inversion technique are presented.

開催年月日： 2018年12月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：宇宙航空研究開発機構 調布航空宇宙センター   国名：日本国  

Optical measurements such as photometric observations and imaging observations have been widely applied for estimating the shape, surface characteristics, and attitude motion of space objects. Photometric observation-based methods use light curves, the time history of the brightness of a space object, whereas imaging observation-based methods use images captured by the optical telescope and processed with adaptive optics. In Kyushu University, studies on the state estimation of space object with photometric observations have been conducted. In addition, an imaging observation-based method to determine an initial value for photometric observations and its feasibility have been studied. The current study describes a photometric observation-based method and verifies its accuracy by numerical simulations. Furthermore, a state estimation method that exploits both photometric observations and imaging observations is presented. The proposed method also shows the efficiency to apply image identification by convolutional neural network, a kind of machine learning, in imaging observations.

開催年月日： 2018年12月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：宇宙航空研究開発機構 調布航空宇宙センター   国名：日本国  

The orbital debris modeling can build evolutionary models as essential tools to predict the current or future orbital debris populations, and also to discuss what and how to do for orbital debris mitigation and environmental remediation. The orbital debris modeling can also devise an effective search strategy applicable for breakup fragments in the geostationary region using ground-based optical sensors, and to evaluate the effectiveness of space-based measurements of objects not tracked from the ground, both to contribute to space situational awareness. Another application of the orbital debris modeling is to estimate attitude motion of space objects to be removed for environmental remediation. This paper briefly introduces efforts into orbital debris modeling and applications.

開催年月日： 2018年12月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：宇宙航空研究開発機構 調布航空宇宙センター   国名：日本国  

Space debris smaller than 2 mm cannot be tracked or detected by ground-based observations even though an impact of such small debris can cause a fatal damage on a spacecraft. Therefore, the environment of sub-millimeter-size debris must be monitored utilizing in-situ measurements. This paper proposes a statistical method to estimate the environment of sub-millimeter-size debris utilizing in-situ measurements. The proposed method consists of a sequential Monte Carlo filter and natures of orbits on which debris may be detected by the satellite. This paper also evaluates that the proposed method can sufficiently estimate the environment utilizing simulated impacts onto the satellite. Furthermore, this paper describes modifications to apply the proposed method to measurement data obtained by a satellite in an elliptic orbit.

開催年月日： 2018年12月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：宇宙航空研究開発機構 調布航空宇宙センター   国名：日本国  

After the long space activities, large numbers of fragments generated by explosions and collisions of space objects are gradually increasing. In recent, many research organizations have reported that as a result of self-proliferation of these space debris without some mitigation process, future space activities will be affected. Also, in the private sector, mega constellation with thousands of satellites are also planned as a continuous communication infrastructure, and it should be necessary to consider the influence on the space environments. In this report, one guideline for improvement of future orbital environment after the result of space debris mitigation effect by some removal indexes for orbital objects with the propagation model of space debris created to predict the future debris distribution.

開催年月日： 2018年11月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：熊本市   国名：日本国  

This study aims to design realistic multiple space debris removal mission for long-term environmental remediation. In the previous study, as mission criteria, velocity increment for successive orbit transfers and mission duration are optimized. This study examines the case of active debris removal with multiple satellites. Therefore, the multi-objective genetic algorithm with quasi-optimum solutions is adopted to derive optimal solutions.

開催年月日： 2018年11月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：熊本市   国名：日本国  

Space-based optical observation for space debris has excellent advantages compared to ground-based observation. This paper proposes a new concept to evaluate the coverage performance by a constellation of satellites in Sun-synchronous orbit in terms of the number of orbital planes based on several geometrical models and reasonable assumptions. According to the initial assumptions of the research, when the number of orbital planes is 6 or 7, we find that the constellation will lose the observable coverage of one satellite which circling one circle around the earth.

開催年月日： 2018年11月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：熊本市   国名：日本国  

Space debris has been jeopardizing the lives of many spacecraft around the Earth since the beginning of the space age. Debris with a size less than 2 mm are called sub-millimeter-size debris.They have enough energy to cause a fatal damage on a spacecraft , but cannot be tracked from the ground.For that reason，Kyushu University has initiated IDEA the project for In-situ Debris Environmental Awareness to have a better understanding of this yet unfamiliar sub-millimeter-size debris environment.In order to investigate the relationship between debris and measurement satellites，the previous study has developed a practical approximation method to calculate the collision flux of debris into measurement satellites，assuming that measurement satellites are on circular orbits.This paper proposes a new approximation method which can be applied to measurement satellites in elliptical orbits.

開催年月日： 2018年10月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：福岡県久留米市   国名：日本国  

This paper discusses a method to classify and estimate a distribution of the orbital elements for a cloud of debris fragments originated from a specific breakup event by utilizing data obtained from EISCAT radar observation. In the proposed method, by constraining admissible region of unobserved data set which are theoretically necessary to determine their orbits, the candidate objects as well as statistical distributions of their orbital elements are estimated from the original radar observation data. Finally, this study shows an effectiveness of the proposed method based on a real observation data.

開催年月日： 2018年10月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：福岡県久留米市   国名：日本国  

This paper proposes a method to reevaluate closest approach between space objects. The purpose of this study is to confirm the effectiveness of the proposed method and determine the observation requirements. This study allows operators who own spacecraft to reevaluate closest approach by a telescope. The reevaluation method consists of optical observation, orbit determination, and conjunction assessment. Numerical simulations are conducted under the assumption that a collision occur in a geostationary orbit. The result shows that it is necessary to observe for two nights for orbit determination and three nights for conjunction assessment.

開催年月日： 2018年10月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：福岡県久留米市   国名：日本国  

開催年月日： 2018年10月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：福岡県久留米市   国名：日本国  

Relative attitude and inertial property estimation is an important phase in on-orbit servicing missions to provide information necessary for safe approach to a target object. Although the estimation usually uses optical devices, such observations may suffer from sudden change of the optical environment and intensive computational burden. To tackle these problems, this study shows an attitude and inertial property estimation method for an asymmetric target with low-rate observations. Using attitude angles periodically observed, the proposed method enables defining target states with constant parameters, which causes no error in state predictions of Kalman filter scheme even if the observation rate is low. Thus, the proposed estimation method is robust against the data deficiency and applicable with low-cost processors. Furthermore, the low-rate observations make the filtering easy to implement Iterated Extended Kalman Filter. Numerical examples verify the effectiveness of the proposed method and compare the results between Extended Kalman Filter and Iterated Extended Kalman Filter.

開催年月日： 2018年10月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：福岡県久留米市   国名：日本国  

This paper describes a CubeSat named “Q-Li”, being developed at Kyushu University. The Q-Li intends to verify a light- curve inversion developed at Kyushu University for estimating the attitude motion of a spacecraft. The Q-Li deploys a sail with a high reflectance surface to make it easy to be observed from the ground, and records data of attitude motion using sensors to verify the light curve inversion. The verification can be conducted by comparing attitude motion between the light-curve inversion and the on-orbit measurement. This paper analyzes the mission of the Q-Li by simulating attitude motion and observed light curve. This paper also describes the design of the deployment sail. The design of the sail considers the reliability of deployment and the survivability against debris impacts.

開催年月日： 2018年10月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：福岡県久留米市   国名：日本国  

This paper proposes and evaluates a method that estimates the environment of sub-millimeter-size debris utilizing in-situ measurements. Space debris smaller than 2 mm are too small to be detected by ground-based observations, in spite of the dangerousness of sub-millimeter-size debris. Therefore, the environment of sub-millimeter-size debris should be estimated on the basis of the in-situ measurement data. This paper establishes an estimation method with a sequential Monte Carlo filter, which befits non-linear estimation problems. The estimation method consists of the natures of the orbits on which debris may be measured in-situ. This paper also evaluates the proposed method by simulations with an existing environmental model. The simulations demonstrate that the proposed method can sufficiently estimate the sub-millimeter-size debris utilizing the in-situ measurement data.

開催年月日： 2018年10月

記述言語：英語   会議種別：口頭発表（一般）  

国名：ドイツ連邦共和国  

開催年月日： 2018年7月

記述言語：英語   会議種別：口頭発表（一般）  

国名：アメリカ合衆国  

開催年月日： 2018年7月

記述言語：英語   会議種別：口頭発表（一般）  

国名：アメリカ合衆国  

開催年月日： 2017年12月

記述言語：英語   会議種別：口頭発表（一般）  

国名：日本国  

開催年月日： 2017年12月

記述言語：英語  

国名：日本国  

開催年月日： 2017年11月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：熊本市   国名：日本国  

Defining a state of space objects by optical observation is major theme for many researchers. optical measurements of cosmic object enables us to obtain the information of attitude motion, surface characteristics and shape of the object which cannot be got by telemetry data. Using these information, we can contribute to grasp the health. Various methods exist for optical observation, but photometric observation and imaging observation are considered in this research. In this paper, we discuss the estimation of the attitude motion of a space object in the Geostationary region(GEO) using imaging observation. This analysis is based on simulations considering the performance of the AO system and the telescope and atmospheric fluctuation, and proposes the attitude determination method applying the method using computer vision. In the future, we aim at improving the accuracy of dynamic estimation by combining this method with photometric observation and clarifying the system requirements for actual observation.

開催年月日： 2017年10月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：新潟県新潟市   国名：日本国  

欧州非干渉散乱(EISCAT)レーダーを用いたスペースデブリ観測の研究概要および2016年度に行われた予備実験で得られた観測データ解析の結果について述べる．本研究では，本来地球の超高層大気の組成・動態解析を目的としたEISCATレーダーを地球周回低軌道上におけるスペースデブリ観測に適用することを目的としている．ここでは，３年間の研究計画中，初年度に行われた低軌道上の人工物体検出および同定を目的とした予備実験の概要，観測結果，および観測データから検出された人工物体の解析結果について説明を行う．

開催年月日： 2017年9月

記述言語：英語   会議種別：口頭発表（一般）  

国名：オーストラリア連邦  

開催年月日： 2017年9月

記述言語：英語  

国名：オーストラリア連邦  

開催年月日： 2017年9月

記述言語：英語  

国名：アメリカ合衆国  

開催年月日： 2017年6月

記述言語：英語   会議種別：口頭発表（一般）  

国名：日本国  

開催年月日： 2017年6月

記述言語：英語   会議種別：口頭発表（一般）  

国名：日本国  

開催年月日： 2017年6月

記述言語：英語   会議種別：口頭発表（一般）  

国名：日本国  

開催年月日： 2017年6月

記述言語：英語   会議種別：口頭発表（一般）  

国名：日本国  

開催年月日： 2017年6月

記述言語：英語   会議種別：口頭発表（一般）  

国名：日本国  

開催年月日： 2017年6月

記述言語：英語   会議種別：口頭発表（一般）  

国名：日本国  

開催年月日： 2017年6月

記述言語：英語   会議種別：口頭発表（一般）  

国名：日本国  

開催年月日： 2017年4月

記述言語：英語   会議種別：口頭発表（一般）  

国名：ドイツ連邦共和国  

開催年月日： 2017年2月

記述言語：英語   会議種別：口頭発表（一般）  

国名：アメリカ合衆国  

開催年月日： 2017年2月

記述言語：英語   会議種別：口頭発表（一般）  

国名：アメリカ合衆国  

開催年月日： 2016年11月

記述言語：日本語   会議種別：口頭発表（招待・特別）  

開催地：福岡市   国名：日本国  

開催年月日： 2016年11月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：福岡市   国名：日本国  

開催年月日： 2016年11月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：東京都小金井市   国名：日本国  

開催年月日： 2016年10月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：宇宙航空研究開発機構 調布航空宇宙センター   国名：日本国  

For the sustainable human space development activities, space agencies have developed their own orbital debris environment evolutionary model, projected the debris environmental prediction considering various future scenarios, and studied better mitigation ways. Currently, some companies are developing space broadband network systems and planning to deploy hundreds or thousands of satellites into LEO, which might impose enormous impacts on the debris environment. The influences of such large constellations, called MEGA constellations, are necessary and urgent tasks to be evaluated. In Japan, JAXA and Kyushu University have jointly developed the evolutionary model “NEODEEM”. Present study assumes a large constellation with 1,000 small satellites and evaluates its impacts on the debris environment. The mechanisms of the environmental deteriorations are explained and then various scenarios are simulated and compared to each other.

開催年月日： 2016年10月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：宇宙航空研究開発機構 調布航空宇宙センター   国名：日本国  

Space debris is the collection of defunct objects made by human being in space. One of the causes of space debris source/sink is space weather (for example, solar flare, solar energetic particle, geomagnetic storm) effect on space debris. To evaluate the effects of long term space weather activities on space debris environmental changes, this study conducts some simulations under different space weather activities using NEODEEM, a Near-Earth Orbital Debris Environment Evolutionary Model. F10.7 and Kp indexes are used as space weather related parameters. As a result, it is found that space debris environment would become significantly worse because of collision cascading even with no launches in the case of low solar activity, like as solar cycle 24.

開催年月日： 2016年10月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：宇宙航空研究開発機構 調布航空宇宙センター   国名：日本国  

It is important to observe not only the shape and surface characteristic of space objects but also their change over time to correlate them and understand their origin and behavior. In case of objects in low Earth orbit, we cannot track always them. For example, we may lose an object while it is in Earth’s shadow, so that we may need to identify the lost object when it comes up again. Then, estimation of space object behavior using optical measurements is essential to identify it again. Therefore, it is necessary to figure out how space object behavior changes through measurements using medium- and small-aperture telescopes. Space object behavior in optical measurements have been studied for a long time. The imaging correction method using adaptive optics and the attitude and shape estimation method using photometric observation are picked up in this presentation.

開催年月日： 2016年9月

記述言語：英語  

国名：メキシコ合衆国  

開催年月日： 2016年9月

記述言語：英語  

国名：メキシコ合衆国  

開催年月日： 2016年9月

記述言語：英語  

国名：メキシコ合衆国  

開催年月日： 2016年9月

記述言語：英語   会議種別：口頭発表（一般）  

国名：アメリカ合衆国  

開催年月日： 2016年9月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：北海道函館市   国名：日本国  

This paper describes an evaluation and improvement for a scheme to estimate orbital parameters of sub-millimeter-size debris cloud using impact data on measurement satellites. Sub-millimeter-size debris generated from a satellite fragmentation have a greater possibility to collide with measurement satellites on a line of intersection between the debris’ and measurement satellite’s orbital planes. If enough impact data from at least two measurement satellites in different orbits are given, a couple of debris’ orbital parameters, which define their orbital plane, can be efficiently identified. This work evaluates a performance of the proposed scheme based on data of near collision obtained from conjunction analyses, which consider a real break-up event and virtual measurement satellites in orbits. An improvement method of data screening is finally proposed and the effectiveness of the proposed method is demonstrated through error analyses for the measurement data from the numerical simulations.

開催年月日： 2016年9月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：北海道函館市   国名：日本国  

Space debris is the collection of defunct objects made by human being in space. One of the causes of space debris generation is space weather effect to space debris. In past time, many satellites were broken because of space weather effect, solar energetic particle, atmosphere drag, and so on. NEODEEM (Near-Earth Orbital Debris Environment Evolutionary Model) is the space debris evolutionary model developed by Kyushu University and JAXA. It helps us to evaluate how space weather activities contribute to the space debris environment changes. This paper performs some simulations under different space weather activities on NEODEEM. F10.7 solar flux is used as space weather related parameter. This paper also introduces the effects of space weather activities to long term space debris environment changes.

開催年月日： 2016年9月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：北海道函館市   国名：日本国  

This paper briefly introduces efforts into space debris modeling towards a better understanding of space debris environment. Space debris modeling mainly consists of debris generation and orbit propagation. Debris generation can characterize and predict physical properties of fragments originating from explosions or collisions. Orbit propagation can characterize, track, and predict the behavior of individual or groups of space objects. Therefore, space debris modeling can build evolutionary models as essential tools to predict the stability of the current or future space debris populations. Space debris modeling is also useful and effective to improve the efficiency of measurements to be aware of the present environment.

開催年月日： 2016年5月

記述言語：英語   会議種別：口頭発表（招待・特別）  

国名：大韓民国  

開催年月日： 2016年2月

記述言語：日本語  

開催地：名古屋大学   国名：日本国  

開催年月日： 2015年12月

記述言語：日本語  

開催地：北九州市   国名：日本国  

開催年月日： 2015年12月

記述言語：日本語  

国名：日本国  

IDEA the Project for In-situ Debris Environmental Awareness

開催年月日： 2015年10月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：鹿児島県鹿児島市   国名：日本国  

In this paper, a scheme to estimate orbital parameters of debris cloud using impact data on measurement satellites is proposed. Sub-millimeter-sized debris generated from a spacecraft’s breakup event have greater possibility to conflict measurement satellites on a line of intersection between two orbital planes. If enough impact data from at least two measurement satellites in different orbits are given, a couple of debris’ orbital parameters, which correspond to their orbital plane, can be efficiently identified. The effectiveness of the proposed scheme is finally validated through measurement data obtained from a numerical simulation of debris impacts between target debris and two measurement satellites.

開催年月日： 2015年10月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：鹿児島県鹿児島市   国名：日本国  

Kyushu University established International Centre for Space Weather Science and Education shortly ICSWSE in April 2012. The ICSWSE is leading two major research areas: 1) magnetized environment of the Earth and 2) space debris environment. To contribute to the protection of space environment and space situational awareness the ICSWSE fuses these two major research areas into one new project through a technical and human network established under the MAGnetic Data Acquisition System / Circum pan Pacific Magnetometer Array (MAGDAS/CPMN) project at the ICSWSE. Now the ICSWSE is willing to establish a measurement network for space debris using small-aperture optical telescopes and a small satellite constellation being named DEBris Data Acquisition System / In-situ Debris Environmental Awareness (DEBDAS/IDEA). The telescopes are well organized to be robotically and remotely controlled including sophisticated image processing techniques and orbit estimation software. The satellites are conducting in-situ measurements of micron-size debris using an easy-to-operate new sensor developed at JAXA. Data acquired from the systems will be analyzed and modeled in a manner coupled with space weather science to provide a better understanding of the present and future space environment. The ICSWSE also aims at education for practical astronomy and space engineering at Kyushu University collaborative measurements in combination between robotic telescopes and small satellites space environmental awareness and space science including debris generation and resulting environment. origin identification. Practical astronomy provides you with planning and observation processing and detection and Space engineering provides you with small satellite design production and operation.

開催年月日： 2015年10月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：鹿児島県鹿児島市   国名：日本国  

The “IDEA project” has been initiated at Kyushu University in 2011 to estimate the environment on sub-millimeter-sized debris that cannot be detected from ground-based observations. A piece of sub-millimeter-sized debris has large kinetic energy enough to cause fatal damage on a spacecraft, so that the environment of sub-millimeter-sized debris must be understood for safe and secure space development and utilization. For this purpose, the project aims to develop the small measurement satellites and construct the in-situ measurement network with satellite constellation. The feasibility study of the first satellite named “IDEA-1” has been conducted at Kyushu University, and now IDEA-1 is in the process of production at ASTROSCALE based on outcome of the feasibility study. This paper describes the outline of space debris issue, history of small satellite development at Kyushu University, IDEA project and IDEA-1. Post IDEA-1 is also considered at Kyushu University. IDEA-1 has two impact sensors to measure only the position of impact with a piece of debris. This paper also discusses what should be included in the post IDEA-1.

開催年月日： 2015年9月

記述言語：英語   会議種別：口頭発表（一般）  

国名：アメリカ合衆国  

開催年月日： 2015年7月

記述言語：英語   会議種別：口頭発表（一般）  

国名：日本国  

開催年月日： 2015年7月

記述言語：英語   会議種別：口頭発表（一般）  

国名：日本国  

開催年月日： 2015年7月

記述言語：英語   会議種別：口頭発表（一般）  

国名：日本国  

開催年月日： 2015年7月

記述言語：英語   会議種別：口頭発表（一般）  

国名：日本国  

開催年月日： 2015年7月

記述言語：英語   会議種別：口頭発表（一般）  

国名：日本国  

開催年月日： 2015年6月

記述言語：英語   会議種別：口頭発表（一般）  

国名：トルコ共和国  

その他リンク： http://dx.doi.org/10.1109/RAST.2015.7208446

開催年月日： 2015年5月

記述言語：英語   会議種別：口頭発表（一般）  

国名：大韓民国  

開催年月日： 2014年12月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：宇宙航空研究開発機構 調布航空宇宙センター   国名：日本国  

開催年月日： 2014年12月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：宇宙航空研究開発機構 調布航空宇宙センター   国名：日本国  

The orbital debris modeling can build evolutionary models as essential tools to predict the current or future orbital debris populations, and also to discuss what and how to do for orbital debris mitigation and environmental remediation. The orbital debris modeling can also devise an effective search strategy applicable for breakup fragments in the geostationary region using ground-based optical sensors, and to evaluate the effectiveness of space-based measurements of objects not tracked from the ground, both to contribute to space situational awareness. Another application of the orbital debris modeling is to estimate attitude motion of space objects to be removed for environmental remediation. This paper briefly introduces efforts into orbital debris modeling and applications.

開催年月日： 2014年12月

記述言語：日本語  

開催地：宇宙航空研究開発機構 調布航空宇宙センター   国名：日本国  

開催年月日： 2014年12月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：宇宙航空研究開発機構 調布航空宇宙センター   国名：日本国  

開催年月日： 2014年12月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：宇宙航空研究開発機構 調布航空宇宙センター   国名：日本国  

開催年月日： 2014年12月

記述言語：日本語  

国名：日本国  

Kyushu University established International Centre for Space Weather Science and Education, shortly ICSWSE, in April 2012. The ICSWSE is leading two major research areas: 1) magnetized environment of the Earth, and 2) space debris environment. To contribute to the protection of space environment and space situational awareness the ICSWSE fuses these two major research areas into one new project through a technical and human network established under the MAGnetic Data Acquisition System / Circum pan Pacific Magnetometer Array (MAGDAS/CPMN) project at the ICSWSE. Now, the ICSWSE is willing to establish a measurement network for space debris using small-aperture optical telescopes and a small satellite constellation, being named DEBris Data Acquisition System (DEBDAS). The telescopes are well organized to be robotically and remotely controlled, including sophisticated image processing techniques and orbit estimation software. The satellites are conducting in-situ measurements of micron-size debris using an easy-to-operate new sensor developed at JAXA. Data acquired from the systems will be analyzed and modeled in a manner coupled with space weather science to provide a better understanding of the present and future space debris environment. The ICSWSE also aims at education for practical astronomy and space engineering at Kyushu University, collaborative measurements in combination between robotic telescopes and small satellites, space environmental awareness and space science, including debris generation and resulting environment. Practical astronomy provides you with planning and observation, processing and detection, and origin identification. Space engineering provides you with small satellite design, production, and operation.

開催年月日： 2014年11月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：福岡市   国名：日本国  

This paper verifies the feasibility of sensing attitude motion of a rocket body remained in space by using a small satellite not released from the rocket body. satellite can bear up under the space. This paper analyzes the mission by assuming the H-2A upper stage and whether the Especially, the satellite is analyzed in the point of thermal and electrical balance.

開催年月日： 2014年11月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：福岡市   国名：日本国  

“Space environment observed by telescope” offered at Kyushu University is a practical course to learn astronomical observation and analytical methods for the observational results. In the course, one of the two groups aimed at observing artificial objects such as an artificial satellite and an abandoned rocket body in Earth’s orbit. In this paper, a tracking method to observe artificial objects in Low Earth Orbit (LEO) is described. Then, using image sequences captured on July 11 in 2014, results of an analysis to identify a target object, CZ-3 R/B are shown.

開催年月日： 2014年11月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：福岡市   国名：日本国  

An educational program of astronomy and space engineering was established by cooperated academic staffs in various fields at Kyushu University since 2011, and related activities have been performed under the title of “Pegasus Project”. The purposes of this project lie in 1) providing interdisciplinary courses under the keyword “the Universe”, 2) practicing of management education using the system of the star guide qualification and contributing to the general public by outreach activities. The interdisciplinary education free from boundaries fixed between academic subjects yielded to broaden interest and to make students understand that academic subjects were linked closely with each other. It was also confirmed that it led students to have high motivation for learning and that it resulted maturing. Furthermore, outreach activities (i.e. visiting lectures and star parties) mainly carried out by qualified students as a star guide were expected not only to render services to the general public but also to promote sociability (ability of planning, presentation and communication) of students themselves. A developed course using a larger telescope is arrange for senior students. Through observations of transient objects (i.e. small solar system bodies and supernovae) or of artificial objects (i.e. satellites and space debris), they learn the technique of scientific and engineering approaches.

開催年月日： 2014年11月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：長崎県長崎市   国名：日本国  

This paper proposes a new algorithm to detect apparently fast orbital objects by optical observations. The algorithm improves target object’s signal-to-noise-ratio against background by summing signals along expected streak direction. The signal-to-noise-ratio can be improved with proportional to square root of summed pixel number, theoretically. This algorithm is applied to actual observation datasets to confirm its feasibility. The application test results that the algorithm can detect an object appeared on images as streaks even if pixels’ intensity of each streak are weaker than background noise. It indicates that the algorithm can improve efficiency of geosynchronous object survey conducted by JAXA. The algorithm is applied to actual observation datasets to confirm its feasibility. The test results that the algorithm newly detects three detections correlated to two objects. It is also estimated that the darkest result of the three detections is composed of pixels with low signal intensity 0.66.

開催年月日： 2014年11月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：長崎県長崎市   国名：日本国  

This paper present, method of calculating on original apply to search safety radius of the space elevator cable in the troposphere assuming strong window. The authors can’t write down the detail of experiment due to regulation of the quantity in this paper, but checked the Long column equation whether it was proper. The positive point on this method, can get analytically solution(but wind pressure distribution is idealized).Furthermore, able to clarify the stress properties in the time during reinforced cable, through the figure of analysis results. Then, can estimate an appropriate cable radius at initial cable[1.0mm respond to 1t (cruiser mass)], medium term[3.0mm respond to 10t ], and operative term[9.7mm respond to 30t ].

開催年月日： 2014年11月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：長崎県長崎市   国名：日本国  

This research intends to build a dynamic model on micron-size orbital debris environment that is updated every time small satellites send impact data to the ground. A piece of micron-size debris can cause fatal damage on a spacecraft because of its high impact velocity. However, measurement data of micron-size debris are quite limited because its size is too small to be observed from the ground. Therefore, we have initiated IDEA the project for in- situ debris environmental awareness to aim to construct an in-situ debris measurement network using a constellation of small satellites. This dynamic model can provide a better definition of the current orbital debris environment to contribute safe and secure space development. For optimization of the satellites constellation and dynamic modeling on micron-size debris environment, this paper investigates the detectability of debris in terms of orbital parameters and time.

開催年月日： 2014年9月 - 2014年10月

記述言語：英語  

国名：カナダ  

開催年月日： 2014年9月 - 2014年10月

記述言語：英語  

国名：カナダ  

開催年月日： 2014年9月 - 2014年10月

記述言語：英語  

国名：カナダ  

開催年月日： 2014年9月 - 2014年10月

記述言語：英語  

国名：カナダ  

開催年月日： 2014年9月 - 2014年10月

記述言語：英語  

国名：カナダ  

開催年月日： 2014年9月

記述言語：英語   会議種別：口頭発表（一般）  

国名：アメリカ合衆国  

開催年月日： 2014年8月

記述言語：英語  

国名：ロシア連邦  

開催年月日： 2014年8月

記述言語：英語   会議種別：口頭発表（一般）  

国名：ロシア連邦  

開催年月日： 2014年5月

記述言語：英語  

国名：グレートブリテン・北アイルランド連合王国(英国)  

開催年月日： 2014年5月

記述言語：英語  

国名：グレートブリテン・北アイルランド連合王国(英国)  

開催年月日： 2014年5月

記述言語：英語  

国名：グレートブリテン・北アイルランド連合王国(英国)  

開催年月日： 2014年3月

記述言語：日本語  

開催地：九州大学西新プラザ   国名：日本国  

開催年月日： 2014年2月

記述言語：日本語  

開催地：福岡市   国名：日本国  

開催年月日： 2014年1月

記述言語：英語   会議種別：口頭発表（一般）  

国名：アメリカ合衆国  

開催年月日： 2014年1月

記述言語：英語   会議種別：口頭発表（一般）  

国名：アメリカ合衆国  

開催年月日： 2014年1月

記述言語：英語   会議種別：口頭発表（一般）  

国名：アメリカ合衆国  

開催年月日： 2014年1月

記述言語：英語   会議種別：口頭発表（一般）  

国名：アメリカ合衆国  

開催年月日： 2014年1月

記述言語：日本語  

国名：日本国  

開催年月日： 2013年11月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：福岡市   国名：日本国  

Recently, space debris issues draw attention as what is impossible to overlook. However, we have only ground-based observation for space debris. Hence, this paper reveals the dynamics of environmental fluctuation caused by breakup events in order to identify them by using space-based measurements. The result was that maximum collision flux of space debris derived from breakup events is on the parent object’s orbit plane.

開催年月日： 2013年11月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：福岡市   国名：日本国  

This paper investigates a possibility for a micro satellite to measure the impact velocity of micron-size debris not being tracked from the ground. This paper also establishes a method to determine the orbit of the debris impacted, and evaluates the effect of error in measurement of the velocity on error in orbit determination.

開催年月日： 2013年11月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：福岡市   国名：日本国  

Kyushu University has established a method of origin identification of fragments from breakups in the geostationary region. This method can identify right origin of uncorrelated targets by comparing measured angular velocity and predicted angular velocity. Ground-based optical survey observations in February 2013, dedicated to possible 1967-066G fragments, have detected 87 uncorrelated targets and successfully followed up 3 uncorrelated targets. This paper explains the above method and the result of its application to these UCTs.

開催年月日： 2013年11月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：福岡市   国名：日本国  

The geostationary orbit is a unique natural resource that is useful for mankind activities. If accidental collisions occur in the geostationary region, space communities suffer great inconveniences. This paper estimates and evaluates the collision probability between a geostationary satellite controlled to stay at a specified longitude slot and its uncontrolled neighbors. Then this paper also investigates whether or not these uncontrolled neighbors should be removed.

開催年月日： 2013年10月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：鳥取県米子市   国名：日本国  

The JAXA has been evaluating the risk of the micro-debris impact with spacecraft with regard to ADEOS-II (Midori-II) satellite anomalies. The results showed the damage on the wire harness and other equipment even when the impact of the micro-debris was due to particles in the range of 100um to several millimeters. It is difficult to obtain data on the environment space in required to evaluate the frequency of impact on a satellite by micro-debris, and currently, we are unable to get real-time data. Under these circumstances, it is urgent that environmental data be measured to understand the effect of impact by micro-debris on the safe operation of a satellite and the accurate evaluation of the frequency of these impacts. This paper reports a new-type active dust sensor and a In-situ Observation of Micrometeoroid and Orbital Debris by ELMOS satellite.

開催年月日： 2013年10月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：鳥取県米子市   国名：日本国  

Developers of small satellites may think of enlarging their effective cross-sectional area to minimize the long-term presence in the low Earth orbit region. However, the enlargement of their effective cross-sectional area causes the temporal increase of cumulative probability of accidental collisions. This paper evaluates the influence of small satellites ppost-mission disposal by enlarging their cross-sectional area on the future population using an orbital debris environment evolutionary model. According to the result of the future projections, the small satellites ppost-mission disposals by enlarging the effective cross-sectional area have the potential risk of increasing the accidental collision. However in the case that small satellites are inserted into orbit below 800 km, the fragments to be generated by collision expected to decay within short term. The effective number of objects below 2,000 km altitude is not different between the case with post-mission disposals and the case without post-mission disposals.

開催年月日： 2013年10月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：鳥取県米子市   国名：日本国  

This paper proposes Asia-Pacific regional collaboration for long-term sustainability of outer space activities. This regional collaboration aims to establish an orbital debris measurements network using ground-based optical and small aperture telescopes to be deployed in Asia-Pacific region and a group of small satellites detecting micron-sized debris. This measurements network aims at a prompt and clear understanding of the current orbital debris environment. This regional collaboration also offers capacity building in the area of space environmental science and engineering for students and young researches in Asia-Pacific region. Both activities will be cooperated with International Centre for Space Weather Science and Education of Kyushu University.the case with post-mission disposals and the case without post-mission disposals.

開催年月日： 2013年10月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：鳥取県米子市   国名：日本国  

The Earth orbital environment has been fouled by debris for decades and it is a threat for safe and sustainable space development and its utilization. There are two major countermeasures for this threat; one is protection and the other is collision avoidance. However, current collision avoidance maneuvers may be applicable only for objects larger than 10 cm and it is ten times larger than present maximum of protectable size. This study proposes a collaborative observation between space-based sensors and ground observatories. According to an initial analysis, approximately 10% of small objects in the Low Earth Orbit can be discovered by a single space-based sensor in four years. And it is found that an orbit initially determined by the single space-based sensor has enough accuracy to detect object smaller than 5 cm by ground observatories with assumed specifications.

開催年月日： 2013年9月

記述言語：英語   会議種別：口頭発表（一般）  

国名：アメリカ合衆国  

開催年月日： 2013年6月

記述言語：英語   会議種別：口頭発表（一般）  

国名：日本国  

開催年月日： 2013年6月

記述言語：英語   会議種別：口頭発表（一般）  

開催地：Nagoya-Aichi   国名：日本国  

Developers of small satellites may think of enlarging their effective cross-sectional area to minimize the long-term presence in the low Earth orbit region. However, the enlargement of their effective cross-sectional area causes the temporal increase of cumulative probability of accidental collisions. This paper evaluates the influence of small satellites’ post-mission disposal by enlarging their cross-sectional area on the future population using an orbital debris environment evolutionary model. According to the result of the future projections, the small satellites’ post-mission disposals by enlarging the effective cross-sectional area have the potential risk of increasing the accidental collision. However small satellites are inserted into orbit below 800 km in this paper, the fragments to be generated by collision expected to decay within short term. The effective number of objects below 2,000 km altitude is not different between the case with post-mission disposals and the case without post-mission disposals.

開催年月日： 2013年6月

記述言語：英語   会議種別：口頭発表（一般）  

国名：日本国  

開催年月日： 2013年6月

記述言語：英語   会議種別：口頭発表（一般）  

国名：日本国  

開催年月日： 2013年6月

記述言語：英語   会議種別：口頭発表（一般）  

国名：日本国  

開催年月日： 2013年6月

記述言語：英語   会議種別：口頭発表（一般）  

国名：日本国  

開催年月日： 2013年6月

記述言語：英語   会議種別：口頭発表（一般）  

国名：日本国  

開催年月日： 2013年6月

記述言語：英語   会議種別：口頭発表（一般）  

開催地：Nagoya-Aichi   国名：日本国  

Light curves observation attracts the attention of researchers to investigate and estimate spacecraft’ attitude motion from the measurement because the spacecraft they concern is most likely orbital debris that should be removed for better space environment. This estimation technique is often derived from asteroid’s research. This technique might come into some problems when the technique is applied to objects in low earth orbit because the spacecraft is exposed to different perturbation and disturbance forces that differ from asteroids. Therefore, it is important to model the orbit and the attitude motion very precisely to obtain good estimation. This paper presents that how the light curves change with different perturbations and disturbance forces about a rocket body that is a major target for active debris removal.

開催年月日： 2013年6月

記述言語：英語   会議種別：口頭発表（一般）  

国名：日本国  

開催年月日： 2013年6月

記述言語：英語   会議種別：口頭発表（一般）  

国名：日本国  

開催年月日： 2013年6月

記述言語：英語  

国名：日本国  

開催年月日： 2013年6月

記述言語：英語   会議種別：口頭発表（一般）  

国名：日本国  

開催年月日： 2013年6月

記述言語：英語   会議種別：口頭発表（一般）  

国名：日本国  

開催年月日： 2013年6月

記述言語：英語   会議種別：口頭発表（一般）  

国名：日本国  

開催年月日： 2013年6月

記述言語：英語   会議種別：口頭発表（一般）  

国名：日本国  

開催年月日： 2013年5月

記述言語：英語   会議種別：口頭発表（一般）  

国名：台湾  

開催年月日： 2013年5月

記述言語：英語  

国名：日本国  

開催年月日： 2013年4月

記述言語：英語  

国名：ドイツ連邦共和国  

開催年月日： 2013年4月

記述言語：英語   会議種別：口頭発表（一般）  

国名：ドイツ連邦共和国  

開催年月日： 2013年4月

記述言語：英語   会議種別：口頭発表（一般）  

国名：ドイツ連邦共和国  

開催年月日： 2013年4月

記述言語：英語  

国名：ドイツ連邦共和国  

開催年月日： 2013年4月

記述言語：英語  

国名：ドイツ連邦共和国  

開催年月日： 2013年4月

記述言語：日本語  

開催地：東京都文京区   国名：日本国  

This paper briefly introduces a dynamic model of the orbital debris environment to provide a prompt and clear understanding. To dynamically describe the environment knowledge is necessary to be updated based on real-time measurements. This paper also introduces a measurement network by combining in-situ measurements and ground-based optical observations.

開催年月日： 2013年3月

記述言語：日本語  

開催地：埼玉大学   国名：日本国  

開催年月日： 2013年2月

記述言語：英語   会議種別：口頭発表（一般）  

国名：アメリカ合衆国  

開催年月日： 2013年2月

記述言語：英語   会議種別：口頭発表（一般）  

国名：アメリカ合衆国  

開催年月日： 2013年1月

会議種別：シンポジウム・ワークショップ パネル（公募）  

開催地：福岡アメリカン・センター   国名：日本国  

開催年月日： 2013年1月

開催地：宇宙航空研究開発機構 調布航空宇宙センター   国名：日本国  

スペースデブリの存在は持続的な宇宙開発利用に対する大きな脅威である．特に地球低軌道（LEO）には追跡されている宇宙機のおよそ7割が集中しており，衝突による破砕リスクが高いため早急な対策が必要である．衝突による破砕を防止するために有効な手段の一つが，軌道上物体の高精度な追跡情報に基づく衝突回避運用である．現状で，LEOにおいて定常的に追跡されている物体サイズの下限はおよそ10cmである．本研究では，LEOに配置した光学センサによって観測能力を向上させることを提案する．効果的なシステム提案を行うためには，LEO同士の観測における能力評価を適切に行う必要がある．著者らは能力評価のツールとして軌道上観測シミュレータの開発を進めている．また軌道上観測結果に対する初期軌道推定手法やフィルタの検討も行なっている．それらツール開発や検討結果の現状とあわせて技術的課題などについて報告を行う．

開催年月日： 2013年1月

開催地：宇宙航空研究開発機構 調布航空宇宙センター   国名：日本国  

宇宙航空研究開発機構と九州大学は，デブリ推移モデルの開発・維持と推移モデルを用いたデブリ分布の予測を行っている．このデブリ推移モデルは10 cm以上の軌道上物体の軌道伝播と衝突率の計算・判定により将来のデブリ分布を予測するものである．これまでに図のような低軌道でのデブリ分布の不安定性の確認やデブリ除去の効果について，推移モデルを用いて予測を行ってきた．本発表では，これらデブリ推移モデルによる結果として，特に種々のデブリ低減対策や除去条件を仮定した場合の将来のデブリ分布の予測結果について紹介する．

開催年月日： 2013年1月

開催地：宇宙航空研究開発機構 調布航空宇宙センター   国名：日本国  

軌道上微小デブリ（ダスト）計測の国内での研究開発を概観するとともにJAXA宇宙環境グループで開発中のアクティブセンサの開発状況について報告する。軌道上ダスト計測の研究開発は１９８０年代後半からメテオロイドの計測を目的として活発化した。アクティブ型の計測器は１９９０年の「ひてん」（Muses-A）に搭載されたMDC（Munich Dust Counter）が日本最初の搭載である。一方、パッシブ型の計測器は宇宙科学研究所で計画された彗星からのサンプルリターンミッション(SOCCOR計画)での研究成果をベースに開発された「キャリブレーテッド・エアロジェル」を用いたダストコレクタが1997年にスペースシャトルに搭載されたのが最初である。その後、アクティブ型、パッシブ型とも多くの研究が行われてきている。JAXA宇宙環境グループは諸外国で計測実績がなく、かつ、宇宙機への影響が懸念されるサイズ領域である大きさ１００μｍ～数ｍｍのデブリの存在量の計測を目的としたアクティブ型計測器を開発した。このセンサは２０１４年の「こうのとり」（HTV）に搭載され実装実証試験を行う予定である。

開催年月日： 2013年1月

開催地：宇宙航空研究開発機構 調布航空宇宙センター   国名：日本国  

昨今活発に議論されているデブリの発生防止策・低減策の立案には，軌道上のデブリ環境を推定・予測した数値計算結果が積極的に用いられている．時々刻々と変化するデブリ環境に対して推定・予測結果の不確定性を抑えるためには観測・モデル化技術の向上が必要不可欠である．本研究の目的は，静止軌道周辺で発生した破砕事象の観測とモデル化である．運用中の人工衛星が約400機存在する重要な領域である静止軌道周辺では，未知デブリ(起源未同定のデブリ)がこれまでに数多く発見されている．未知デブリの起源は破砕を起こした宇宙機である可能性が高い．本発表では，観測における破砕事象の識別や未知デブリの起源同定方法，そして観測結果に基づく個々の破砕事象のモデル化方法について紹介する．

開催年月日： 2012年12月

国名：マレーシア  

開催年月日： 2012年12月

会議種別：口頭発表（一般）  

国名：マレーシア  

開催年月日： 2012年11月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：大分県別府市   国名：日本国  

開催年月日： 2012年11月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：大分県別府市   国名：日本国  

開催年月日： 2012年11月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：大分県別府市   国名：日本国  

開催年月日： 2012年11月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：大分県別府市   国名：日本国  

開催年月日： 2012年11月

記述言語：日本語   会議種別：口頭発表（一般）  

国名：日本国  

IDEA: In-situ Debris Environmental Awareness

開催年月日： 2012年11月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：大分県別府市   国名：日本国  

開催年月日： 2012年11月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：東京都   国名：日本国  

開催年月日： 2012年10月

会議種別：口頭発表（一般）  

国名：イタリア共和国  

開催年月日： 2012年10月

会議種別：口頭発表（一般）  

国名：イタリア共和国  

開催年月日： 2012年9月

会議種別：口頭発表（一般）  

国名：アメリカ合衆国  

開催年月日： 2012年7月

記述言語：日本語   会議種別：シンポジウム・ワークショップ パネル（公募）  

国名：日本国  

開催年月日： 2012年7月

記述言語：日本語   会議種別：シンポジウム・ワークショップ パネル（公募）  

国名：日本国  

開催年月日： 2012年7月

記述言語：英語   会議種別：口頭発表（一般）  

国名：インド  

開催年月日： 2012年7月

記述言語：英語   会議種別：口頭発表（一般）  

国名：インド  

開催年月日： 2012年7月

記述言語：英語   会議種別：口頭発表（一般）  

国名：インド  

開催年月日： 2012年7月

記述言語：英語   会議種別：口頭発表（一般）  

国名：インド  

開催年月日： 2012年6月

開催地：群馬県吾妻郡   国名：日本国  

開催年月日： 2012年3月

記述言語：日本語   会議種別：口頭発表（招待・特別）  

開催地：関西大学 千里山キャンパス   国名：日本国  

ΠΛΑΝΗΤΕΣ(プラネテス)は長年にわたる宇宙開発で廃棄されてきた人工衛星などの「スペースデブリ（宇宙ごみ）」を拾い集める日々を送る回収員を描いた日本のSF漫画（幸村誠原作）である．近い将来，宇宙ごみは人間の生活を脅かすまでに増え，回収しなければならなくなるのだろうか．国際機関間スペースデブリ調整委員会が結成した研究チームの一員として，著者が現在の宇宙ごみ環境の不安定性を検証した結果について議論した．

開催年月日： 2012年2月