This research focuse<span style="font-family:Verdana;">s</span><span style="font-family:Verdana;"> on multiple facts regard</span><span style="font-family:Verdana;&q...This research focuse<span style="font-family:Verdana;">s</span><span style="font-family:Verdana;"> on multiple facts regard</span><span style="font-family:Verdana;">ing</span><span style="font-family:Verdana;"> the earth gravity and the space mechanism, mainly on the solar systems including the Sun and the planets belonging to it. Our solar system consists of our star, the Sun, and everything bound to it by gravity based on Albert Einstein and Isaac Newton theories. The planets are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune and Pluto</span><span style="font-family:Verdana;">, </span><span style="font-family:Verdana;">dozens of moons, millions of asteroids, Comets and meteoroids </span><span style="font-family:Verdana;">[<a href="#ref1">1</a>]</span><span></span><span><span></span></span><span style="font-family:Verdana;">. Also, </span><span style="font-family:Verdana;">it </span><span style="font-family:Verdana;">will discuss about The Geocentric model and how scientifically proofed that the Earth is not orbiting the sun as it has a fixed position in the universe with the rotation around its axis and the sun is orbiting the Earth in one solar year. The output of the Geocentric model led to that the gravity is a feature generated by the planet itself to be measured reference to the weight granted to the matter.</span>展开更多
This paper deals with the optimization of the transfer trajectory of a solar sail-based spacecraft between circular and coplanar heliocentric orbits.The problem is addressed using both a direct and an indirect approac...This paper deals with the optimization of the transfer trajectory of a solar sail-based spacecraft between circular and coplanar heliocentric orbits.The problem is addressed using both a direct and an indirect approach,while an ideal and an optical force model are used to describe the propulsive acceleration of a flat solar sail.In the direct approach,the total flight time is partitioned into arcs of equal duration,within which the sail attitude is assumed to be constant with respect to an orbital reference frame,and a nonlinear programming solver is used to optimize the transfer trajectory.The aim of the paper is to compare the performance of the two(direct and indirect)approaches in term of optimal(minimum)flight time.In this context,the simulation results show that a direct transcription method using a small number of arcs is sufficient to obtain a good estimate of the global minimum flight time obtained through the classical calculus of variation.展开更多
This paper investigates the heliocentric time-optimal rendezvous performance of Sun-facing diffractive solar sails with various deflection angles and acceleration capabilities.Diffractive solar sails,which generate ta...This paper investigates the heliocentric time-optimal rendezvous performance of Sun-facing diffractive solar sails with various deflection angles and acceleration capabilities.Diffractive solar sails,which generate tangential radiation pressure force,are proposed and schematically designed to achieve diverse radiation pressure distributions.The radiation pressure force model and the time-optimal control problem for these innovative Sun-facing diffractive solar sails are established.Utilizing an indirect method and the optimal control law,we explore typical heliocentric rendezvous scenarios to assess the variational trends of transfer time in relation to different deflection angles and acceleration capabilities.The results for Sun-facing diffractive sails in specific rendezvous missions are compared to reflective sails with the same area-to-mass ratio,focusing on transfer trajectory and attitude control.Our findings reveal that diffractive sails exhibit significant advantages over reflective sails,particularly in the context of normal acceleration,paving the way for more efficient space exploration.展开更多
文摘This research focuse<span style="font-family:Verdana;">s</span><span style="font-family:Verdana;"> on multiple facts regard</span><span style="font-family:Verdana;">ing</span><span style="font-family:Verdana;"> the earth gravity and the space mechanism, mainly on the solar systems including the Sun and the planets belonging to it. Our solar system consists of our star, the Sun, and everything bound to it by gravity based on Albert Einstein and Isaac Newton theories. The planets are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune and Pluto</span><span style="font-family:Verdana;">, </span><span style="font-family:Verdana;">dozens of moons, millions of asteroids, Comets and meteoroids </span><span style="font-family:Verdana;">[<a href="#ref1">1</a>]</span><span></span><span><span></span></span><span style="font-family:Verdana;">. Also, </span><span style="font-family:Verdana;">it </span><span style="font-family:Verdana;">will discuss about The Geocentric model and how scientifically proofed that the Earth is not orbiting the sun as it has a fixed position in the universe with the rotation around its axis and the sun is orbiting the Earth in one solar year. The output of the Geocentric model led to that the gravity is a feature generated by the planet itself to be measured reference to the weight granted to the matter.</span>
文摘This paper deals with the optimization of the transfer trajectory of a solar sail-based spacecraft between circular and coplanar heliocentric orbits.The problem is addressed using both a direct and an indirect approach,while an ideal and an optical force model are used to describe the propulsive acceleration of a flat solar sail.In the direct approach,the total flight time is partitioned into arcs of equal duration,within which the sail attitude is assumed to be constant with respect to an orbital reference frame,and a nonlinear programming solver is used to optimize the transfer trajectory.The aim of the paper is to compare the performance of the two(direct and indirect)approaches in term of optimal(minimum)flight time.In this context,the simulation results show that a direct transcription method using a small number of arcs is sufficient to obtain a good estimate of the global minimum flight time obtained through the classical calculus of variation.
基金supported by the National Natural Science Foundation of China(Grant No.12372044).
文摘This paper investigates the heliocentric time-optimal rendezvous performance of Sun-facing diffractive solar sails with various deflection angles and acceleration capabilities.Diffractive solar sails,which generate tangential radiation pressure force,are proposed and schematically designed to achieve diverse radiation pressure distributions.The radiation pressure force model and the time-optimal control problem for these innovative Sun-facing diffractive solar sails are established.Utilizing an indirect method and the optimal control law,we explore typical heliocentric rendezvous scenarios to assess the variational trends of transfer time in relation to different deflection angles and acceleration capabilities.The results for Sun-facing diffractive sails in specific rendezvous missions are compared to reflective sails with the same area-to-mass ratio,focusing on transfer trajectory and attitude control.Our findings reveal that diffractive sails exhibit significant advantages over reflective sails,particularly in the context of normal acceleration,paving the way for more efficient space exploration.
