This paper describes the guidance and navigation technique used by Hayabusa2 for the asteroid rendezvous operation to reach Ryugu.The operation results,including the achieved guidance and navigation performance,are al...This paper describes the guidance and navigation technique used by Hayabusa2 for the asteroid rendezvous operation to reach Ryugu.The operation results,including the achieved guidance and navigation performance,are also summarized.Multiple assessment and navigation teams worked closely to provide reliable navigation solutions with a short solution delivery cycle.Although the uncertainty of the Ryugu’s ephemeris was considerable before Hayabusa2’s arrival,a combination of radiometric-optical hybrid navigation and a stochastic-constrained optimum guidance method was able to achieve an accuracy of less than 100 m and 1 cm/s,and the arrival was precisely timed.展开更多
The deep-space multi-object orbit determination system(DMOODS)and its application in the asteroid proximity operation of the Hayabusa2 mission are described.DMOODS was developed by the Japan Aerospace Exploration Agen...The deep-space multi-object orbit determination system(DMOODS)and its application in the asteroid proximity operation of the Hayabusa2 mission are described.DMOODS was developed by the Japan Aerospace Exploration Agency(JAXA)for the primary purpose of determining the trajectory of deep-space spacecraft for JAXA’s planetary missions.The weighted least-squares batch filter is used for the orbit estimator of DMOODS.The orbit estimator supports more than 10 data types,some of which are used for relative trajectory measurements between multiple space objects including natural satellites and small bodies.This system consists of a set of computer programs running on Linux-based consumer PCs on the ground,which are used for orbit determination and the generation of radiometric tracking data,such as delta differential one-way ranging and doppler tracking data.During the asteroid proximity phase of Hayabusa2,this system played an essential role in operations that had very strict navigation requirements or operations in which few optical data were obtained owing to special constraints on the spacecraft attitude or distance from the asteroid.One example is orbit determination during the solar conjunction phase,in which the navigation accuracy is degraded by the effect of the solar corona.The large range bias caused by the solar corona was accurately estimated with DMOODS by combining light detection and ranging(LIDAR)and ranging measurements in the superior solar conjunction phase of Hayabusa2.For the orbiting operations of target markers and the MINERVA-II2 rover,the simultaneous estimation of six trajectories of four artificial objects and a natural object was made by DMOODS.This type of simultaneous orbit determination of multi-artificial objects in deep-space has never been accomplished before.展开更多
This paper describes the orbit design of the deployable payload Rover 2 of MINERVA-II,installed on the Hayabusa2 spacecraft.Because Rover 2 did not have surface exploration capabilities,the operation team decided to e...This paper describes the orbit design of the deployable payload Rover 2 of MINERVA-II,installed on the Hayabusa2 spacecraft.Because Rover 2 did not have surface exploration capabilities,the operation team decided to experiment with a new strategy for its deployment to the surface.The rover was ejected at a high altitude and made a semi-hard landing on the surface of the asteroid Ryugu after several orbits.Based on the orbital analysis around Ryugu,the expected collision speed was tolerable for the rover to function post-impact.Because the rover could not control its position,its motion was entirely governed by the initial conditions.Thus,the largest challenge was to insert the rover into a stable orbit(despite its large release uncertainty),and avoid its escape from Ryugu due to an environment strongly perturbed by solar radiation pressure and gravitational irregularities.This study investigates the solution space of the orbit around Ryugu and evaluates the orbit’s robustness by utilizing Monte Carlo simulations to determine the orbit insertion policy.Upon analyzing the flight data of the rover operation,we verified that the rover orbited Ryugu for more than one period and established the possibility of a novel method for estimating the gravity of an asteroid.展开更多
In late 2018,the asteroid Ryugu was in the Sun's shadow during the superior solar conjunction phase.As the Sun-Earth-Ryugu angle decreased to below 3°,the Hayabusa2 spacecraft experienced 21 days of planned b...In late 2018,the asteroid Ryugu was in the Sun's shadow during the superior solar conjunction phase.As the Sun-Earth-Ryugu angle decreased to below 3°,the Hayabusa2 spacecraft experienced 21 days of planned blackout in the Earth-probe communication link.This was the first time a spacecraft had experienced solar conjunction while hovering around a minor body.For the safety of the spacecraft,a low energy transfer trajectory named Ayu was designed in the Hill reference frame to increase its altitude from 20 to 110 km.The trajectory was planned with the newly developed optNEAR tool and validated with real time data.This article shows the results of the conjunction operation,from planning to fight data.展开更多
Correction to:Oki,Y.,Yoshikawa,K.,Takeuchi,H.et al.Orbit insertion strategy of Hayabusa2's rover with large release uncertainty around the asteroid Ryugu.Astrodynamics 2020,4(4):309-329 https://doi.org/10.1007/s42...Correction to:Oki,Y.,Yoshikawa,K.,Takeuchi,H.et al.Orbit insertion strategy of Hayabusa2's rover with large release uncertainty around the asteroid Ryugu.Astrodynamics 2020,4(4):309-329 https://doi.org/10.1007/s42064-020-0080-y The article“Orbit insertion strategy of Hayabusa2’s rover with large release uncertainty around the asteroid Ryugu”written by Yusuke Oki,Kent Yoshikawa,Hiroshi Takeuchi et al.,was originally published electronically on the publisher’s internet portal(currently SpringerLink)on 05 November 2020 without open access.After publication in Volume 4,Issue 4,page 309–329,the author(s)decided to opt for Open Choice and to make the article an open access publication.展开更多
基金JSPS KAKENHI Grant No.18H01628 also supported this work.
文摘This paper describes the guidance and navigation technique used by Hayabusa2 for the asteroid rendezvous operation to reach Ryugu.The operation results,including the achieved guidance and navigation performance,are also summarized.Multiple assessment and navigation teams worked closely to provide reliable navigation solutions with a short solution delivery cycle.Although the uncertainty of the Ryugu’s ephemeris was considerable before Hayabusa2’s arrival,a combination of radiometric-optical hybrid navigation and a stochastic-constrained optimum guidance method was able to achieve an accuracy of less than 100 m and 1 cm/s,and the arrival was precisely timed.
文摘The deep-space multi-object orbit determination system(DMOODS)and its application in the asteroid proximity operation of the Hayabusa2 mission are described.DMOODS was developed by the Japan Aerospace Exploration Agency(JAXA)for the primary purpose of determining the trajectory of deep-space spacecraft for JAXA’s planetary missions.The weighted least-squares batch filter is used for the orbit estimator of DMOODS.The orbit estimator supports more than 10 data types,some of which are used for relative trajectory measurements between multiple space objects including natural satellites and small bodies.This system consists of a set of computer programs running on Linux-based consumer PCs on the ground,which are used for orbit determination and the generation of radiometric tracking data,such as delta differential one-way ranging and doppler tracking data.During the asteroid proximity phase of Hayabusa2,this system played an essential role in operations that had very strict navigation requirements or operations in which few optical data were obtained owing to special constraints on the spacecraft attitude or distance from the asteroid.One example is orbit determination during the solar conjunction phase,in which the navigation accuracy is degraded by the effect of the solar corona.The large range bias caused by the solar corona was accurately estimated with DMOODS by combining light detection and ranging(LIDAR)and ranging measurements in the superior solar conjunction phase of Hayabusa2.For the orbiting operations of target markers and the MINERVA-II2 rover,the simultaneous estimation of six trajectories of four artificial objects and a natural object was made by DMOODS.This type of simultaneous orbit determination of multi-artificial objects in deep-space has never been accomplished before.
基金This work was partially supported by JSPS KAKENHI Grant(No.18H01628).
文摘This paper describes the orbit design of the deployable payload Rover 2 of MINERVA-II,installed on the Hayabusa2 spacecraft.Because Rover 2 did not have surface exploration capabilities,the operation team decided to experiment with a new strategy for its deployment to the surface.The rover was ejected at a high altitude and made a semi-hard landing on the surface of the asteroid Ryugu after several orbits.Based on the orbital analysis around Ryugu,the expected collision speed was tolerable for the rover to function post-impact.Because the rover could not control its position,its motion was entirely governed by the initial conditions.Thus,the largest challenge was to insert the rover into a stable orbit(despite its large release uncertainty),and avoid its escape from Ryugu due to an environment strongly perturbed by solar radiation pressure and gravitational irregularities.This study investigates the solution space of the orbit around Ryugu and evaluates the orbit’s robustness by utilizing Monte Carlo simulations to determine the orbit insertion policy.Upon analyzing the flight data of the rover operation,we verified that the rover orbited Ryugu for more than one period and established the possibility of a novel method for estimating the gravity of an asteroid.
文摘In late 2018,the asteroid Ryugu was in the Sun's shadow during the superior solar conjunction phase.As the Sun-Earth-Ryugu angle decreased to below 3°,the Hayabusa2 spacecraft experienced 21 days of planned blackout in the Earth-probe communication link.This was the first time a spacecraft had experienced solar conjunction while hovering around a minor body.For the safety of the spacecraft,a low energy transfer trajectory named Ayu was designed in the Hill reference frame to increase its altitude from 20 to 110 km.The trajectory was planned with the newly developed optNEAR tool and validated with real time data.This article shows the results of the conjunction operation,from planning to fight data.
文摘Correction to:Oki,Y.,Yoshikawa,K.,Takeuchi,H.et al.Orbit insertion strategy of Hayabusa2's rover with large release uncertainty around the asteroid Ryugu.Astrodynamics 2020,4(4):309-329 https://doi.org/10.1007/s42064-020-0080-y The article“Orbit insertion strategy of Hayabusa2’s rover with large release uncertainty around the asteroid Ryugu”written by Yusuke Oki,Kent Yoshikawa,Hiroshi Takeuchi et al.,was originally published electronically on the publisher’s internet portal(currently SpringerLink)on 05 November 2020 without open access.After publication in Volume 4,Issue 4,page 309–329,the author(s)decided to opt for Open Choice and to make the article an open access publication.
