OPTIMAL LOW THRUST TRAJECTORIES USING DIFFERENTIAL INCLUSION CONCEPTS

A direct optimization method based on differential inclusion concepts has been developed and used to compute low thrust trajectories. This n ew formulation removes explicit control dependence from the problem st atement thereby reducing the dimension of the parameter space of the r esulting nonlinear programming problem. A simple example of a two-dime nsional gravity-free trajectory involving a maximum velocity transfer to a rectilinear path is discussed. Three interplanetary trajectory ex amples, an Earth-Mars constant specific impulse transfer, an Earth-Jup iter constant specific impulse transfer, and an Earth-Venus-Mars varia ble specific impulse gravity assist, are also included. An evaluation of the technique's performance is provided.