Abstract
This paper proposes an optimal guidance law for manned space transportation systems with constraints on terminal area. The motivation behind this study is to provide a general and efficient method for onboard path planning of reusable launch vehicles. This study presents onboard path planning by utilizing the Homotopy method. The method is remarkable in that the computational time can be predicted because the method does not use iterative calculations. This study reveals that the optimal variables are parameterized by cubic spline curves from the small number of points. The resulting nonlinear programming problem can be solved quickly, and with low computational burden. It can be said the trajectory is easy to track. The number of possible destinations will significantly increase by treating the scale of destination.
