In this paper we calculate the volume, mass, gravitational attraction to the Earth, angular momentum the orbit of the Trojan asteroid (TK7) [1]. In this paper, we use classical Newtonian mechanics to analyse some of t...In this paper we calculate the volume, mass, gravitational attraction to the Earth, angular momentum the orbit of the Trojan asteroid (TK7) [1]. In this paper, we use classical Newtonian mechanics to analyse some of the physical and orbital properties of the Trojan asteroid, which are still experimentally unknown. The asteroid should remain in Earth’s orbit for the next 100 years. We conclude by providing informed estimates of 2010 TK7’s yet unknown physical properties: i.e. mass, volume, gravitational attraction to Earth and angular momentum.展开更多
Jupiter is one of the major targets for planetary exploration,and dust in the Jovian system is of great interest to researchers in the field of planetary science.In this paper,we review the five dust populations outsi...Jupiter is one of the major targets for planetary exploration,and dust in the Jovian system is of great interest to researchers in the field of planetary science.In this paper,we review the five dust populations outside the ring system:grains in the region of the Galilean moons,potential dust from plumes on Europa,Jovian stream particles,particles in the outer region of the Jovian system ejected from the irregular satellites,and dust in the region of the Trojan asteroids.The physical environment for the dust dynamics is described,including the gravity,the magnetic field and the plasma environment.For each population,the dust sources are described,and the relevant perturbation forces are discussed.Observations and results from modeling are reviewed,and the distributions of the individual dust populations are shown.The understanding of the Jovian dust environment allows to assess the dust hazard to spacecraft,and to characterize the material exchange between the Jovian moons,their surface properties and distribution of non-icy constituents.展开更多
The solar power sail is an original Japanese concept in which electric power is generated by thin-film solar cells attached on the solar sail membrane.Japan Aerospace Exploration Agency(JAXA)successfully demonstrated ...The solar power sail is an original Japanese concept in which electric power is generated by thin-film solar cells attached on the solar sail membrane.Japan Aerospace Exploration Agency(JAXA)successfully demonstrated the world’s first solar power sail technology through IKAROS(Interplanetary Kite-craft Accelerated by Radiation of the Sun)mission in 2010.IKAROS demonstrated photon propulsion and power generation using thin-film solar cells during its interplanetary cruise.Scaled up,solar power sails can generate enough power to drive high specific impulse ion thrusters in the outer planetary region.With this concept,we propose a landing or sample return mission to directly explore a Jupiter Trojan asteroid using solar power sail-craft OKEANOS(Oversize Kite-craft for Exploration and AstroNautics in the Outer Solar System).After rendezvousing with a Trojan asteroid,a lander separates from OKEANOS to collect samples,and perform in-situ analyses in three proposed mission sequences,including sending samples back to Earth.This paper proposes a system design for OKEANOS and includes analyses of the latest mission.展开更多
文摘In this paper we calculate the volume, mass, gravitational attraction to the Earth, angular momentum the orbit of the Trojan asteroid (TK7) [1]. In this paper, we use classical Newtonian mechanics to analyse some of the physical and orbital properties of the Trojan asteroid, which are still experimentally unknown. The asteroid should remain in Earth’s orbit for the next 100 years. We conclude by providing informed estimates of 2010 TK7’s yet unknown physical properties: i.e. mass, volume, gravitational attraction to Earth and angular momentum.
基金the European Space Agency under the project“Jovian Micrometeoroid Environment Model”(JMEM)(Contract No.4000107249/12/NL/AF)at the University of Oulu,and by the Academy of Finland under the project“Earth and Near-Space System and Environmental Change”.
文摘Jupiter is one of the major targets for planetary exploration,and dust in the Jovian system is of great interest to researchers in the field of planetary science.In this paper,we review the five dust populations outside the ring system:grains in the region of the Galilean moons,potential dust from plumes on Europa,Jovian stream particles,particles in the outer region of the Jovian system ejected from the irregular satellites,and dust in the region of the Trojan asteroids.The physical environment for the dust dynamics is described,including the gravity,the magnetic field and the plasma environment.For each population,the dust sources are described,and the relevant perturbation forces are discussed.Observations and results from modeling are reviewed,and the distributions of the individual dust populations are shown.The understanding of the Jovian dust environment allows to assess the dust hazard to spacecraft,and to characterize the material exchange between the Jovian moons,their surface properties and distribution of non-icy constituents.
文摘The solar power sail is an original Japanese concept in which electric power is generated by thin-film solar cells attached on the solar sail membrane.Japan Aerospace Exploration Agency(JAXA)successfully demonstrated the world’s first solar power sail technology through IKAROS(Interplanetary Kite-craft Accelerated by Radiation of the Sun)mission in 2010.IKAROS demonstrated photon propulsion and power generation using thin-film solar cells during its interplanetary cruise.Scaled up,solar power sails can generate enough power to drive high specific impulse ion thrusters in the outer planetary region.With this concept,we propose a landing or sample return mission to directly explore a Jupiter Trojan asteroid using solar power sail-craft OKEANOS(Oversize Kite-craft for Exploration and AstroNautics in the Outer Solar System).After rendezvousing with a Trojan asteroid,a lander separates from OKEANOS to collect samples,and perform in-situ analyses in three proposed mission sequences,including sending samples back to Earth.This paper proposes a system design for OKEANOS and includes analyses of the latest mission.
