Comparative effectiveness of throttled and relay rocket engines for low-gravity near-Earth flights

Abstract

Within the framework of solving the Mayer problem of optimal control of a flight from an elongated elliptical orbit to a geostationary one with a maximum payload at a given initial mass of the low-thrust spacecraft and a fixed duration of the dynamic maneuver, a comparative analysis was made of the efficiency of throttled and relay thrust modes. Based on the data of the numerical solution of the corresponding twopoint boundary value problem, the expected gain was confirmed of the throttling mode over the relay mode in the case of practically interesting low-thrust near-Earth maneuvers. Also the numerical results confirmed the adequacy of the constructed fixed-power relay rocket engine mathematical model and made it possible to reveal a number of qualitative features of the control functions along the optimal transition trajectories.