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 study made use of a shape-based method to analyze the orbital dynamics of a spacecraft subject to a continuous propulsive acceleration acting along the circumferential direction.Under the assumption of a logarith...This study made use of a shape-based method to analyze the orbital dynamics of a spacecraft subject to a continuous propulsive acceleration acting along the circumferential direction.Under the assumption of a logarithmic spiral trajectory,an exact solution to the equations of motion exists,which allows the spacecraft state variables and flight time to be expressed as a function of the angular coordinate.There is also a case characterized by specific initial conditions in which the time evolution of the state variables may be analytically determined.In this context,the presented solution is used to analyze circle-to-circle trajectories,where the combination of two impulsive maneuvers and a logarithmic spiral path are used to accomplish the transfer.The determined results are then applied to the achievement of the Earth–Mars and the Earth–Venus transfers using actual data from a recent thruster developed by NASA.展开更多
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.
文摘This study made use of a shape-based method to analyze the orbital dynamics of a spacecraft subject to a continuous propulsive acceleration acting along the circumferential direction.Under the assumption of a logarithmic spiral trajectory,an exact solution to the equations of motion exists,which allows the spacecraft state variables and flight time to be expressed as a function of the angular coordinate.There is also a case characterized by specific initial conditions in which the time evolution of the state variables may be analytically determined.In this context,the presented solution is used to analyze circle-to-circle trajectories,where the combination of two impulsive maneuvers and a logarithmic spiral path are used to accomplish the transfer.The determined results are then applied to the achievement of the Earth–Mars and the Earth–Venus transfers using actual data from a recent thruster developed by NASA.
