Research On Aeroassisted Orbital Transfer Of Spacecraft

Spacecraft commit to maneuver or transfer to and from the space station, platform and the satellites with thrust impulse or continuous mode, but consuming large energy, while aeroassisted orbit transferring can be efficient program for fuel saving. By using the planet's atmosphere surrounding this natural resource, the way of aeroassisted orbital transfer can reduce fuel consumption, which makes the vehicle gain a larger payload. Therefore, it is of great significance to study aeroassisted orbital transfer.This paper analyzes the characteristics of the aeroassisted orbital transfer vehicle, studies the influence factors in orbit transferring, identifies lift-to-drag ratio as the main control parameters, minimum fuel consumption as the target. First, to establish the atmospheric kinematics equations and the equations have been simplified and non-dimensional quantities.Second, with the process of the coplanar HEO-LEO aeroassisted orbital transfer, according to atmospheric boundary conditions and the optimal target it determines performance index, this paper analyzes performance index by introducing the Pontryagin maximum method and using the Hamiltonian function, it obtained the optimal control law of the lift coefficient, which is substituted into orbit kinematics control law equation, to commit the optimal control. To simulate when the lift coefficient is fettered and unfettered respectively, and change the transfer orbit perigee altitude to simulate.Third, with the process of the nonplanar HEO-LEO aeroassisted orbital transfer, this paper designs the control law with the control parameters of the lift-drag ratio and roll angle. To find good of the orbital inclination in atmospheric flight segment, it is to simulate when the orbital inclination is different.Finally, with a large number of optimization simulation experiments on both of the coplanar and nonplanar orbit transfer, this paper analyzes the impacts of the lift coefficient when it is fettered and unfettered respectively, and analyze the impacts of transfer orbit perigee height to the coplanar orbital transfer and the orbit inclination changes to the nonplanar orbital transfer, it presents the verification of the algorithm effective and reasonable.