Implementing the flyby to Near-Earth Asteroids (NEAs) with the potential impact risks to the Earth allows for obtaining detailed physical parameters, thereby supporting the high-precision orbit prediction and planetar...Implementing the flyby to Near-Earth Asteroids (NEAs) with the potential impact risks to the Earth allows for obtaining detailed physical parameters, thereby supporting the high-precision orbit prediction and planetary defense strategy. Different from those conducted asteroid flyby missions, in the 12th China Trajectory Optimization Competition (CTOC-12), a NEAs flyby trajectory design problem using reusable probes that depart from a Lunar Distant Retrograde Orbit (DRO) station in the cislunar space was released. The objective was flyby to as many NEAs as possible using up to 20 probes within a total of 10 years. The ∑ team proposed a solution that can explore 47 NEAs using 11 probes, ranking the first in the competition. In this paper, the methods and results from the winning team are introduced, including mission analysis and preliminary design, and low-energy transfer trajectory optimization. In particular, a round-trip trajectory is divided into three phases: deep space transfer, indirect transfer between the Earth to DRO, and DRO phasing and rendezvous. With the combination of global optimization and local optimization algorithms, the required velocity increments to change the orbital planes are effectively reduced, thus increasing the number of the explored NEAs. The final solution of our team is presented and the results are compared with those of the top three teams. The competition demonstrates that the regularization of flyby missions from the cislunar space to explore NEAs with the potential impact risks to the Earth is the feasible and promising.展开更多
The architecture of cislunar multi-hop communication networks, which focuses on the requirements of lunar full-coverage and continuous cislunar communications, is presented on the basis of Geosynchronous Orbit (GEO) s...The architecture of cislunar multi-hop communication networks, which focuses on the requirements of lunar full-coverage and continuous cislunar communications, is presented on the basis of Geosynchronous Orbit (GEO) satellite network relays. According to the geographical distribution of the forthcoming Chinese Deep Space Measuring and Controlling Network (DSMCN), two networking schemes are proposed and two elevation angle optimization models are established for locating GEO relay satellites. To analyze the dynamic connectivity, a dynamic network model is constructed with respect to the time-varying characteristics of cislunar trunk links. The advantages of the two proposed schemes, in terms of the Connectivity Rate (CR), Interruption Frequency (IF), and Average Length of Connecting Duration (ALCD), are corroborated by several simulations. In the case of the lunar polar orbit constellation case, the gains in the performance of scheme I are observed to be 134.55%, 117.03%, and 217.47% compared with DSMCN for three evaluation indicators, and the gains in the performance of scheme II are observed to be 238. 22%, 240.40%, and 572.71%. The results validate that the connectivity of GEO satellites outperforms that of earth facilities significantly and schemes based on GEO satellite relays are promising options for cislunar multi-hop communication networking.展开更多
In the lunar missions,relay satellites on the various orbits play critical roles in the cislunar communications,i.e.telemetry and telecommand to the probers on the far side of moon,which could help achieving the const...In the lunar missions,relay satellites on the various orbits play critical roles in the cislunar communications,i.e.telemetry and telecommand to the probers on the far side of moon,which could help achieving the constant visibility between the actuator and the controller.However,huge time span in the end-to-end communication incurs obvious delay during the control loop which current controller design could not deal with effectively.In this work,therefore,we propose a greedy algorithm-based scheduling mechanism(GASM)for multiple time-delay control loops through the cislunar relay communication.In particular,we develop a novel metric of information value loss(IVL)to measure the utility of the proposed GASM by considering the timeliness of telemetry and telecommand data on the control loop.The simulations show that the proposed GASM could achieve excellent control stability and timeliness of data compared with typical scheduling algorithms based on age of information(AoI).展开更多
Ground-and space-based optical observation is an efficient way to catalog objects in the cislunar space.Initial orbit determination based on optical data is still an open problem for cislunar objects.The motion of the...Ground-and space-based optical observation is an efficient way to catalog objects in the cislunar space.Initial orbit determination based on optical data is still an open problem for cislunar objects.The motion of these objects usually follows the law of three bodies instead of the two-body one,so current algorithms based on the two-body relation should be revised.Moreover,due to the long duration of most cislunar objects,optical observations of even hours can cover only a small fraction of one orbit,making the initial orbit determination of these objects a typical too-short-arc problem,which is difficult.A way to address this problem is to use the admissible region.In this study,an efficient algorithm constrained by the admissible region is proposed.It is easy to implement because it uses only simple iterations.Its efficiency is proven by comparing it with that of one traditional initial orbit determination algorithm.展开更多
Cislunar space,asthe first station for mankind to go into space,will be the main destination and outpost of space missions for a long period oftime in the future.During the course of the cislunar space exploration and...Cislunar space,asthe first station for mankind to go into space,will be the main destination and outpost of space missions for a long period oftime in the future.During the course of the cislunar space exploration and development,information and control technology will play an important role.In view of the object scope and mission background of cislunar space exploration and development,this paper firstly summarizes the mission characteristics,i.e.farther,longer,more and complex,and then analyzes the requirements and challenges for information and control technology.After that,the strategy including intelligent algorithm,open architecture,cloud-enabled information and reliable flight is proposed.Finally,several prospectives are given to deal with some issues in future large-scale cislunar space exploration and development.展开更多
Incorporating quasi-periodic orbits into the preliminary design process offers a wide range of options to meet mission constraints and address the challenges in a complex trade space.In this investigation,linear stabi...Incorporating quasi-periodic orbits into the preliminary design process offers a wide range of options to meet mission constraints and address the challenges in a complex trade space.In this investigation,linear stability and quasi-periodic orbit family continuation schemes are examined to meet various types of constraints.Applications in eclipse avoidance and transfer design are examined by leveraging quasi-periodic orbits and their associated hyperbolic manifolds in the lunar region.Solutions are transitioned to an ephemeris model to validate that geometries are maintained in higher-fidelity models.When the natural dynamical structures associated with quasi-periodic orbits are leveraged,novel trajectory solutions can emerge.展开更多
The 8th edition of the Global Trajectory Optimization Competition(GTOC8)presented a novel concept of a space-based very-long-baseline interferometry(VLBI)telescope in cislunar space for observing selected radio source...The 8th edition of the Global Trajectory Optimization Competition(GTOC8)presented a novel concept of a space-based very-long-baseline interferometry(VLBI)telescope in cislunar space for observing selected radio sources in cosmos.It requires designing a three-spacecraft triangular formation with changeable sizes and orientations such that observation can be scheduled as efficiently as possible.We first review the problem,and then describe the methods employed by representative teams participating in the competition.Subsequently,we present the design techniques employed by the team from the Chinese Academy of Sciences,which are primarily based on orbital-geometry analysis.Two efficient trajectory patterns are summarized:million-kilometer triangular formations with symmetric circular orbits,and consecutive-lunar-flyby trajectories with Moon-to-Moon transfer orbits.These two trajectory patterns enable establishing and reconfiguring the triangular formation with sufficiently different sizes so that a number of radio sources can be observed,thus maximizing the performance index.Finally,we present a solution with the best currently known score of J=158 million km.展开更多
基金supported by the Special Funding Project for Space Debris and Near-Earth Asteroids Defense Research, China (No. KJSP2023020303)Beijing Municipal Science and Technology Commission, China (No. Z181100002918004)the Youth Innovation Promotion Association, Chinese Academy of Sciences (No. 2022146)
文摘Implementing the flyby to Near-Earth Asteroids (NEAs) with the potential impact risks to the Earth allows for obtaining detailed physical parameters, thereby supporting the high-precision orbit prediction and planetary defense strategy. Different from those conducted asteroid flyby missions, in the 12th China Trajectory Optimization Competition (CTOC-12), a NEAs flyby trajectory design problem using reusable probes that depart from a Lunar Distant Retrograde Orbit (DRO) station in the cislunar space was released. The objective was flyby to as many NEAs as possible using up to 20 probes within a total of 10 years. The ∑ team proposed a solution that can explore 47 NEAs using 11 probes, ranking the first in the competition. In this paper, the methods and results from the winning team are introduced, including mission analysis and preliminary design, and low-energy transfer trajectory optimization. In particular, a round-trip trajectory is divided into three phases: deep space transfer, indirect transfer between the Earth to DRO, and DRO phasing and rendezvous. With the combination of global optimization and local optimization algorithms, the required velocity increments to change the orbital planes are effectively reduced, thus increasing the number of the explored NEAs. The final solution of our team is presented and the results are compared with those of the top three teams. The competition demonstrates that the regularization of flyby missions from the cislunar space to explore NEAs with the potential impact risks to the Earth is the feasible and promising.
基金supported by the National High Technology Research and Development Program of P.R.China under Grant No.2012 AA121604 the National Natural Science Foundation of China under Grants No.60902042,No.61170014,No.61202079+1 种基金 the National Research Foundation for the Doctoral Program of Higher Education of China under Grant No.20090006110014 the Foundation for Key Program of Ministry of Education of China under Grant No.311007
文摘The architecture of cislunar multi-hop communication networks, which focuses on the requirements of lunar full-coverage and continuous cislunar communications, is presented on the basis of Geosynchronous Orbit (GEO) satellite network relays. According to the geographical distribution of the forthcoming Chinese Deep Space Measuring and Controlling Network (DSMCN), two networking schemes are proposed and two elevation angle optimization models are established for locating GEO relay satellites. To analyze the dynamic connectivity, a dynamic network model is constructed with respect to the time-varying characteristics of cislunar trunk links. The advantages of the two proposed schemes, in terms of the Connectivity Rate (CR), Interruption Frequency (IF), and Average Length of Connecting Duration (ALCD), are corroborated by several simulations. In the case of the lunar polar orbit constellation case, the gains in the performance of scheme I are observed to be 134.55%, 117.03%, and 217.47% compared with DSMCN for three evaluation indicators, and the gains in the performance of scheme II are observed to be 238. 22%, 240.40%, and 572.71%. The results validate that the connectivity of GEO satellites outperforms that of earth facilities significantly and schemes based on GEO satellite relays are promising options for cislunar multi-hop communication networking.
基金supported in part by the National Natural Science Foundation of China under Grants 62371158 and 62027802in part by the Major Key Project of PCL under Grant PCL2024A01.
文摘In the lunar missions,relay satellites on the various orbits play critical roles in the cislunar communications,i.e.telemetry and telecommand to the probers on the far side of moon,which could help achieving the constant visibility between the actuator and the controller.However,huge time span in the end-to-end communication incurs obvious delay during the control loop which current controller design could not deal with effectively.In this work,therefore,we propose a greedy algorithm-based scheduling mechanism(GASM)for multiple time-delay control loops through the cislunar relay communication.In particular,we develop a novel metric of information value loss(IVL)to measure the utility of the proposed GASM by considering the timeliness of telemetry and telecommand data on the control loop.The simulations show that the proposed GASM could achieve excellent control stability and timeliness of data compared with typical scheduling algorithms based on age of information(AoI).
基金supported by the National Natural Science Foundation of China(No.12233003)The author Xiyun Hou also wishes to thank support from the Space Debris and Near-Earth Asteroid Defense Research Project of China(No.KJSP2020020205)support from the Laboratory of Pinghu,Pinghu,China.
文摘Ground-and space-based optical observation is an efficient way to catalog objects in the cislunar space.Initial orbit determination based on optical data is still an open problem for cislunar objects.The motion of these objects usually follows the law of three bodies instead of the two-body one,so current algorithms based on the two-body relation should be revised.Moreover,due to the long duration of most cislunar objects,optical observations of even hours can cover only a small fraction of one orbit,making the initial orbit determination of these objects a typical too-short-arc problem,which is difficult.A way to address this problem is to use the admissible region.In this study,an efficient algorithm constrained by the admissible region is proposed.It is easy to implement because it uses only simple iterations.Its efficiency is proven by comparing it with that of one traditional initial orbit determination algorithm.
文摘Cislunar space,asthe first station for mankind to go into space,will be the main destination and outpost of space missions for a long period oftime in the future.During the course of the cislunar space exploration and development,information and control technology will play an important role.In view of the object scope and mission background of cislunar space exploration and development,this paper firstly summarizes the mission characteristics,i.e.farther,longer,more and complex,and then analyzes the requirements and challenges for information and control technology.After that,the strategy including intelligent algorithm,open architecture,cloud-enabled information and reliable flight is proposed.Finally,several prospectives are given to deal with some issues in future large-scale cislunar space exploration and development.
文摘Incorporating quasi-periodic orbits into the preliminary design process offers a wide range of options to meet mission constraints and address the challenges in a complex trade space.In this investigation,linear stability and quasi-periodic orbit family continuation schemes are examined to meet various types of constraints.Applications in eclipse avoidance and transfer design are examined by leveraging quasi-periodic orbits and their associated hyperbolic manifolds in the lunar region.Solutions are transitioned to an ephemeris model to validate that geometries are maintained in higher-fidelity models.When the natural dynamical structures associated with quasi-periodic orbits are leveraged,novel trajectory solutions can emerge.
基金supported by the National Natural Science Foundation of China(No.11372311)the Key Research Program of the Chinese Academy of Sciences(No.ZDRW-KT-2019-1).
文摘The 8th edition of the Global Trajectory Optimization Competition(GTOC8)presented a novel concept of a space-based very-long-baseline interferometry(VLBI)telescope in cislunar space for observing selected radio sources in cosmos.It requires designing a three-spacecraft triangular formation with changeable sizes and orientations such that observation can be scheduled as efficiently as possible.We first review the problem,and then describe the methods employed by representative teams participating in the competition.Subsequently,we present the design techniques employed by the team from the Chinese Academy of Sciences,which are primarily based on orbital-geometry analysis.Two efficient trajectory patterns are summarized:million-kilometer triangular formations with symmetric circular orbits,and consecutive-lunar-flyby trajectories with Moon-to-Moon transfer orbits.These two trajectory patterns enable establishing and reconfiguring the triangular formation with sufficiently different sizes so that a number of radio sources can be observed,thus maximizing the performance index.Finally,we present a solution with the best currently known score of J=158 million km.
