A pseudospectral feedback method for real-time optimal guidance of reentry vehicles

Motivated by the emerging needs of the next-generation of reusable launch vehicles (RLV), a pseudospectral (PS) feedback method is designed and applied to guide an RLV across multiple phases of an entry trajectory. That is, by generating real-time, open-loop, optimal controls, it is shown that a single PS-feedback law successfully guides an X-33-type vehicle in the presence of large disturbances, g-load and heating-rate constraints. The notion of a Caratheodory-pi solution is used to design, develop and implement the guidance algorithm.