Off-optimum timing of interplanetary midcourse guidance maneuvers

Abstract

The nature of the optimum solution with respect to the timing of interplanetary midcourse guidance maneuvers is investigated. The analysis provides a realistic cost function, defined as the sum of the root-mean-square mid-course maneuvers, for both the fixed-time-of-arrival and the variable-time-of-arrival guidance logics and uses the time of the last maneuver as a functional constraint. The results of the analysis indicate that only the timing of the first and of the last maneuvers is sensitive to perturbation about the optimal values and that a variation in the timing of the intermediate maneuvers produces small changes in the total midcourse velocity requirement.