Improved Gradient-Based Algorithm for Solving Aeroassisted Vehicle Trajectory Optimization Problems

Space maneuver vehicles (SMVs) 1, 2 will play an increasingly important role in the future exploration of space because their on-orbit maneuverability can greatly increase the operational flexibility, and they are more difficult as a target to be tracked and intercepted. Therefore, a well-designed trajectory, particularly in the skip entry phase, is a key for stable flight and for improved guidance control of the vehicle 3, 4. Trajectory design for space vehicles can be treated as an optimal control problem. Because of the highly nonlinear characteristics and strict path constraints of the problem, direct methods are usually applied to calculate the optimal trajectories, such as the direct multiple shooting method 5, direct collocation method 5, 6, or hp -adaptive pseudospectral method 7, 8.