Integrated Optimal Guidance for Reentry and Landing of a Rocket Using Multi-Phase Pseudo-Spectral Convex Optimization

Abstract

This paper proposes integrated optimal guidance for the reentry and landing of a rocket using the multi-phase pseudo-spectral convex optimization method. For a successful return of the launch vehicle, it is crucial to generate the onboard real-time trajectory of the rocket from stage separation to landing, considering vehicle/ground safety and precision landing. Recently, improved computation capability enables online trajectory optimization in real time, especially using the convex optimization method. This paper formulates a multi-phase optimal control problem involving the reentry and landing phases. Then, the original problem is converted to a convex optimization problem based on pseudo-spectral discretization and successive convexification. A case study on the reentry/landing guidance of an actual reusable launch vehicle is conducted to demonstrate the effectiveness of the proposed procedure.