Trajectory Optimization of Multi-Pass Aeroassisted Orbital Transfer by Sequential Convex Programming

Aeroassisted transfer technology is that spacecraft utilizes aerodynamic forces generated during atmospheric flight to alter orbit dimensions or achieve changes in orbital inclination, which offers advantages in fuel cost. In this paper, a multi-pass aeroassisted orbit transfer scheme is proposed, with only deorbit and insertion maneuver impulse. On this basis, the optimal control problem of multi-pass is constructed with the bank angle as the control variable. The detailed derivation of the optimization problem with interior constraint and the endpoint constraint is given. After that, the non-linear problem is transformed into a convex problem, and a sequential convex optimization method is used to solve the optimal control problem numerically. Simulation show that the multi-pass aeroassist transfer has lower peak values of heating rate, dynamic pressure, and load factor. Compared to initial trajectories with constant bank angle, the scheme can save over 30% in fuel consumption.