Trajectory optimization and closed-loop guidance law design of aero-assisted obital transfer problem

Using aerodynamic force to finish the orbital transfer mission can save a lot of fuels and increase the payload. In this paper,After giving the mathmatical description of the Aero-assisted Obital Transfer(AOT) problem, we discrete it through the Guass-pseudospectral method and then apply SNOPT algorithm to get the optimal state trajectory. After that we do some simplify to original dynamic equations and design a real-time closed-Loop state feedback guidance law. About the singularity issue of the control variable,we give an effective method to deal with it.Though the comparison of this closed-loop guidance law with the Matched Asymptotic Expansion(MAE) predictor-corrector method, this method can save a lot of calculation quantity and have some improvement in its guidance performance,Simulation result shows that even when the external parameter vary, guidance trajectory can still track the optimal trajectory perfectly, so it has an excellent robustness.