The Design of Guidance on Suborbital Reentry

The guidance technique for suborbital reentry is discussed based on the flight characteristics and constraints of RLV. The suborbital reentry is divided by three sequential phases: Alpha Hold, Nz Hold and Alpha Transition. Firstly, the factors contributing to dynamic pressure rate are analyzed, and the guidance strategy is designed to arrest the sink rate to restrict dynamic pressure. Secondly, the alpha and normal acceleration commands are chosen, and the simulation result shows the structure and control constraints are well satisfied. Lastly, an automatic guidance method is present to adjust the alpha and Nz command based on keeping the maximum dynamic pressure near that of the nominal when initial altitude is uncertain.