End-to-End GNC Solution for Reusable Launch Vehicles

This paper presents an autonomous end-to-end guidance, navigation, and control (GNC) solution for a reusable launcher, addressing the challenges of precision pinpoint landing and reusability. The proposed GNC system integrates advanced onboard trajectory optimization and H∞ control to ensure robust performance across re-entry, aerodynamics, and landing phases. This work discusses the GNC design and definition and introduces the strategies adopted both for the guidance and the control design to handle rapidly varying dynamic environments and strict landing requirements. Particular attention is given to design choices in the guidance optimization problem and the control definition for each phase, which were made to enhance the harmonization of the guidance and control (G&C) system. The proposed GNC is integrated in a high-fidelity Functional Engineering Simulator (FES) and its robustness is assessed in a real-world scenario, considering a downrange landing mission of the RETALT1 (RETro propulsion Assisted Landing Technologies Two-Stage-To-Orbit vehicle) rocket.