Time-coordinated reentry guidance law for reusable launch vehicle

Reusable launch vehicle (RLV) coordinated reentry guidance is one of the key conditions to determine the effect of coordinated flight. The existing RLV reentry guidance methods often take a single spacecraft as the research object and do not have the ability of coordinated reentry flight. To solve these problems, a coordinated reentry guidance scheme is designed. In this paper, a time coordination strategy is designed aiming at the predictability of reentry flight time. The pseudospectral method is used to predict the flight time of RLVs, and the coordinated flight time coordination of multiple RLVs is realized. Based on receding horizon control, a coordinated reentry guidance law is designed. In each guidance cycle, RLV flies according to the guidance instructions generated in the previous guidance cycle. At the same time, taking the previous reentry trajectory as the initial value and the coordinated flight time determined by the time coordination algorithm as the constraint condition, the pseudo-spectral method is used to generate the flight trajectory quickly. The angle of attack and inclination are used as guidance instructions for the next guidance cycle of RLV, so as to guide RLV to the target. Finally, the simulation results verify the performance of the reentry coordinated guidance law and the effectiveness of the whole reentry guidance scheme.