In order to control the growth of space debris,a novel tethered space robot(TSR) was put forward.After capture,the platform,tether,and target constituted a tethered combination system.General nonlinear dynamics of the...In order to control the growth of space debris,a novel tethered space robot(TSR) was put forward.After capture,the platform,tether,and target constituted a tethered combination system.General nonlinear dynamics of the tethered combination system in the post-capture phase was established with the consideration of the attitudes of two spacecrafts and the quadratic nonlinear elasticity of the tether.The motion law of the tethered combination in the deorbiting process with different disturbances was simulated and discussed on the premise that the platform was only controlled by a constant thrust force.It is known that the four motion freedoms of the tethered combination are coupled with each other in the deorbiting process from the simulation results.A noticeable phenomenon is that the tether longitudinal vibration does not decay to vanish even under the large tether damping with initial attitude disturbances due to the coupling effect.The approximate analytical solutions of the dynamics for a simplified model are obtained through the perturbation method.The condition of the inter resonance phenomenon is the frequency ratio λ_1=2.The case study shows good accordance between the analytical solutions and numerical results,indicating the effectiveness and correctness of approximate analytical solutions.展开更多
This paper proposes a fuel-optimal deorbit scheme for space debris deorbit using tethered space tug.The scheme contains three stages named respectively as dragging,maintenance and swinging.In the first stage,the tug,p...This paper proposes a fuel-optimal deorbit scheme for space debris deorbit using tethered space tug.The scheme contains three stages named respectively as dragging,maintenance and swinging.In the first stage,the tug,propelled by continuous thrust,tows deorbit to a transfer orbit with a tether.Then in the second stage,the combination of the tug and the debris flies unpowered and uncontrolled to a swing point on the transfer orbit.Finally,in the third stage,the tug is propelled at the swing point and the rotation speed of the tethered system increases such that the debris obtains enough velocity increment.The trajectory optimization of the first stage is established considering the total fuel consumption of the three stages,whereas the dynamic model is simplified for computation efficiency.The solution to the optimal problem is obtained using a direct method based on Gauss pesudospectral discretization.Then a model predictive controller is designed to track the open-loop optimal reference trajectories,reducing the states’deviations caused by model simplification and ignorance of perturbations.Furthermore,it is proved that the fuel-optimal swing point is the apogee of the transfer orbit.The paper analyzes the fuel consumption of a typical scenario and demonstrates effectiveness of the proposed deorbit scheme numerically.展开更多
Electrodynamic tethered deorbit technology is a novel way to remove abandoned spacecrafts like upper stages or unusable satellites. This paper investigates and analyses the deorbit performance and mission applicabilit...Electrodynamic tethered deorbit technology is a novel way to remove abandoned spacecrafts like upper stages or unusable satellites. This paper investigates and analyses the deorbit performance and mission applicability of the electrodynamic tethered system. To do so, the electrodynamic tethered deorbit dynamics with multi-perturbation is firstly formulated, where the Earth magnetic field, the atmospheric drag, and the Earth oblateness effect are considered. Then, the key system parameters, including payload mass, tether length and tether type, are analyzed by numerical simulations to investigate their influences on the deorbit performance and to give the setting principles for choosing system parameters. Based on this and given an appropriate group of system parameters, numerical simulations are undertaken to study the impact of the mission parameters, including orbit height and orbit inclination, and thus to investigate the mission applicability of the electrodynamic tethered deorbit technology.展开更多
In the field of active deorbiting technologies,the electrodynamic tether has garnered attention due to its cost-effectiveness,light weight,and low fuel consumption.In this study,to address the low success rate of the ...In the field of active deorbiting technologies,the electrodynamic tether has garnered attention due to its cost-effectiveness,light weight,and low fuel consumption.In this study,to address the low success rate of the deployment mechanisms used in previous in-orbit experiments,a novel deployment mechanism with a size of 2 U and a weight 2.3 kg based on pusher motors is proposed.In order to achieve a smooth tether deployment without rupture and rebound,an optimization method was proposed for springs,and tether within the deployment mechanism.Finally,simulation and ground ejection experiment were conducted with the objective of deploying a 50-m tether.In the experiment,the top plate was ejected with a kinetic energy of 2.3 J,and the tether was successfully unfolded.The experimental results indicate that the device is capable of deploying a tether of at least 50 m,demonstrating the effectiveness of the optimization method.展开更多
With the escalating frequency of space activities,particularly the launch of constellation satellites,the amount of space debris experienced gradually increases,posing threats to the safety and sustainability of the s...With the escalating frequency of space activities,particularly the launch of constellation satellites,the amount of space debris experienced gradually increases,posing threats to the safety and sustainability of the space environment.To counteract the growth of debris,active deorbit devices are imperative for spacecrafts.In low Earth orbit(LEO),the drag sail device has emerged as a highly effective solution due to its ability to increase the spacecraft’s windward area,facilitating rapid deorbit by leveraging atmospheric drag as the primary perturbation.In this study,recent developments of membrane drag sail deorbit technology for LEO satellites are summarized,as well as the current problems such as attitude instability,dangerous space environment,and folding and unfolding issues.Moreover,crucial technologies such as modeling and simulation of deorbit efficiency,attitude stabilization,collision risk analysis and protection design,sail surface atomic oxygen protection design,and folding and unfolding of the drag sail are discussed.Finally,the development trends and technology applications of membrane drag sail deorbit for LEO satellites are presented.展开更多
On February 16,2021,an artificial object moving slowly over the Mediterranean was recorded by the Spanish Meteor Network(SPMN).Based on astrometric measurements,we identified this event as the reentry engine burn of a...On February 16,2021,an artificial object moving slowly over the Mediterranean was recorded by the Spanish Meteor Network(SPMN).Based on astrometric measurements,we identified this event as the reentry engine burn of a SpaceX Falcon 9 launch vehicle’s upper stage.To study this event in detail,we adapted the plane intersection method for near-straight meteoroid trajectories to analyze the slow and curved orbits associated with artificial objects.To corroborate our results,we approximated the orbital elements of the upper stage using four pieces of“debris”cataloged by the U.S.Government’s Combined Space Operations Center.Based on these calculations,we also estimated the possible deorbit hazard zone using the MSISE90 model atmosphere.We provide guidance regarding the interference that these artificial bolides may generate in fireball studies.Additionally,because artificial bolides will likely become more frequent in the future,we point out the new role that ground-based detection networks can play in the monitoring of potentially hazardous artificial objects in near-Earth space and in determining the strewn fields of artificial space debris.展开更多
基金Project (51475411) supported by the National Natural Science Foundation of ChinaProject (LY15E070002) supported by Zhejiang Provincial Natural Science Foundation of China
文摘In order to control the growth of space debris,a novel tethered space robot(TSR) was put forward.After capture,the platform,tether,and target constituted a tethered combination system.General nonlinear dynamics of the tethered combination system in the post-capture phase was established with the consideration of the attitudes of two spacecrafts and the quadratic nonlinear elasticity of the tether.The motion law of the tethered combination in the deorbiting process with different disturbances was simulated and discussed on the premise that the platform was only controlled by a constant thrust force.It is known that the four motion freedoms of the tethered combination are coupled with each other in the deorbiting process from the simulation results.A noticeable phenomenon is that the tether longitudinal vibration does not decay to vanish even under the large tether damping with initial attitude disturbances due to the coupling effect.The approximate analytical solutions of the dynamics for a simplified model are obtained through the perturbation method.The condition of the inter resonance phenomenon is the frequency ratio λ_1=2.The case study shows good accordance between the analytical solutions and numerical results,indicating the effectiveness and correctness of approximate analytical solutions.
基金supported by the National Natural Science Foundation of China(No.11772023)。
文摘This paper proposes a fuel-optimal deorbit scheme for space debris deorbit using tethered space tug.The scheme contains three stages named respectively as dragging,maintenance and swinging.In the first stage,the tug,propelled by continuous thrust,tows deorbit to a transfer orbit with a tether.Then in the second stage,the combination of the tug and the debris flies unpowered and uncontrolled to a swing point on the transfer orbit.Finally,in the third stage,the tug is propelled at the swing point and the rotation speed of the tethered system increases such that the debris obtains enough velocity increment.The trajectory optimization of the first stage is established considering the total fuel consumption of the three stages,whereas the dynamic model is simplified for computation efficiency.The solution to the optimal problem is obtained using a direct method based on Gauss pesudospectral discretization.Then a model predictive controller is designed to track the open-loop optimal reference trajectories,reducing the states’deviations caused by model simplification and ignorance of perturbations.Furthermore,it is proved that the fuel-optimal swing point is the apogee of the transfer orbit.The paper analyzes the fuel consumption of a typical scenario and demonstrates effectiveness of the proposed deorbit scheme numerically.
文摘Electrodynamic tethered deorbit technology is a novel way to remove abandoned spacecrafts like upper stages or unusable satellites. This paper investigates and analyses the deorbit performance and mission applicability of the electrodynamic tethered system. To do so, the electrodynamic tethered deorbit dynamics with multi-perturbation is firstly formulated, where the Earth magnetic field, the atmospheric drag, and the Earth oblateness effect are considered. Then, the key system parameters, including payload mass, tether length and tether type, are analyzed by numerical simulations to investigate their influences on the deorbit performance and to give the setting principles for choosing system parameters. Based on this and given an appropriate group of system parameters, numerical simulations are undertaken to study the impact of the mission parameters, including orbit height and orbit inclination, and thus to investigate the mission applicability of the electrodynamic tethered deorbit technology.
基金supported by the State Administration of Science,Technology and Industry for National Defense KJSP202360201.
文摘In the field of active deorbiting technologies,the electrodynamic tether has garnered attention due to its cost-effectiveness,light weight,and low fuel consumption.In this study,to address the low success rate of the deployment mechanisms used in previous in-orbit experiments,a novel deployment mechanism with a size of 2 U and a weight 2.3 kg based on pusher motors is proposed.In order to achieve a smooth tether deployment without rupture and rebound,an optimization method was proposed for springs,and tether within the deployment mechanism.Finally,simulation and ground ejection experiment were conducted with the objective of deploying a 50-m tether.In the experiment,the top plate was ejected with a kinetic energy of 2.3 J,and the tether was successfully unfolded.The experimental results indicate that the device is capable of deploying a tether of at least 50 m,demonstrating the effectiveness of the optimization method.
基金supported by the National Natural Science Foundation of China(No.12232003)the State Administration of Science,Technology and Industry for National Defense KJSP2020010301.
文摘With the escalating frequency of space activities,particularly the launch of constellation satellites,the amount of space debris experienced gradually increases,posing threats to the safety and sustainability of the space environment.To counteract the growth of debris,active deorbit devices are imperative for spacecrafts.In low Earth orbit(LEO),the drag sail device has emerged as a highly effective solution due to its ability to increase the spacecraft’s windward area,facilitating rapid deorbit by leveraging atmospheric drag as the primary perturbation.In this study,recent developments of membrane drag sail deorbit technology for LEO satellites are summarized,as well as the current problems such as attitude instability,dangerous space environment,and folding and unfolding issues.Moreover,crucial technologies such as modeling and simulation of deorbit efficiency,attitude stabilization,collision risk analysis and protection design,sail surface atomic oxygen protection design,and folding and unfolding of the drag sail are discussed.Finally,the development trends and technology applications of membrane drag sail deorbit for LEO satellites are presented.
基金This research was supported by the research project(Grant No.PGC2018-097374-B-I00,PI:JMT-R)which is funded by FEDER/Ministerio de Ciencia e Innovación-Agencia Estatal de Investigación.This project has also received funding from the European Research Council(ERC)under the European Union’s Horizon 2020 Research and Innovation Programme(Grant No.865657)for the project“Quantum Chemistry on Interstellar Grains”(QUANTUMGRAIN)We also express appreciation for the valuable video recordings obtained from Benicàssim(Castellón)by Vicent Ibanez(AVAMET).
文摘On February 16,2021,an artificial object moving slowly over the Mediterranean was recorded by the Spanish Meteor Network(SPMN).Based on astrometric measurements,we identified this event as the reentry engine burn of a SpaceX Falcon 9 launch vehicle’s upper stage.To study this event in detail,we adapted the plane intersection method for near-straight meteoroid trajectories to analyze the slow and curved orbits associated with artificial objects.To corroborate our results,we approximated the orbital elements of the upper stage using four pieces of“debris”cataloged by the U.S.Government’s Combined Space Operations Center.Based on these calculations,we also estimated the possible deorbit hazard zone using the MSISE90 model atmosphere.We provide guidance regarding the interference that these artificial bolides may generate in fireball studies.Additionally,because artificial bolides will likely become more frequent in the future,we point out the new role that ground-based detection networks can play in the monitoring of potentially hazardous artificial objects in near-Earth space and in determining the strewn fields of artificial space debris.
