Abstract: For the guidance law design problem of lunar spacecraft reentry at the second cosmic velocity, a predictor-corrector guidance method is adopted. The flight characteristic of spacecraft at the balanced attack angel is analyzed, and then the three degrees of freedom motion equation for reentry is established. Furthermore, the theory of predictor-corrector and its longitudinal and lateral guidance laws are introduced in detail. Reentry simulation in such two conditions, one in standard initial condition and other in error initial condition shows that the predictor-corrector can not only acquire higher accuracy, but has strong robustness to the initial errors at all constraints to be satistied, even at the uncertain conditions.

Key words: lunar mission spacecraft, predictor-corrector, reentry guidance