The Optimal Control by the Thrust Vector of Air-Breathing Electric Propulsion to Maximize the Apogee Altitude of Orbit with an Ultra-Low Perigee

The problem of changing the apogee altitude of orbits with ultralow perigee (altitude 120-250 km) is considered. To compensate for the aerodynamic drag of the spacecraft, an air-breathing electric propulsion (ABEP) is used, the fuel for which is the gases of the outboard atmosphere. The decrease in the efficiency of an ABEP with an increase in the angle of attack and the possibility of ABEP operation only at a sufficient gas concentration in the ionization chamber are taken into account. The problem is solved on the basis of the Pontryagin maximum principle under the assumption that the aerodynamic drag and thrust are small compared to the gravitational forces. The results of studies of optimal programs for controlling the thrust vector of an ABEP depending on the parameters of the orbit, the layout of the spacecraft, the engine, and the power of the energy source are presented.