Two-level parametric method for low-thrust trajectory optimization

A direct method is proposed for solving the optimal control problem of a spacecraft equipped with a low-thrust engine. The control function is parameterized using polynomials and switching moments between active and passive control modes. The essence of the method lies in separating optimization parameters: at the outer level, the switching time moments of control modes are optimized, while at the inner level, the coefficients of auxiliary polynomials are optimized. The method’s performance is demonstrated on problems of interplanetary flight to Mars and the conversion of impulse control to continuous control.