ИСТИНА

Spacecraft (SC) in ultra-low orbits (120-250 km for the Earth) have significant advantages for communication and monitoring planetary surfaces. The use of outboard rarefied atmosphere gases as a propellant in air-breathing electric propulsion (ABEP) and solar arrays (SA) as a primary energy source makes it possible to ensure long-term maintenance of SC in orbits using renewable resources only. The application of elliptical orbits allows expanding the area of possible quasi-stationary flight of such SC due to the optimal redistribution of accumulation and consumption energy. In this paper, we consider the problem of integrated optimization of ABEP, SC layout and scenarios for SC long-term maintenance in elliptical orbits with an ultra-low periapsises. Specific characteristics of primary (SA) and secondary (batteries) energy sources, the minimum admissible gas concentration in the ABEP for stable plasma ionization, the total thruster efficiency and the spacecraft volume are considered as given parameters. The SC power is regarded as objective function. The optimal dependences of the SC shape, the SA area, the dimensions of inlet and outlet ABEP sections, the altitudes of the periapsis and apoapsis of the quasi-stable orbit, as well as the location of the active orbital arcs on the parameters of the problem are obtained. The solutions obtained make it possible to determine the requirements for the characteristics of ABEP and power supply system for long-term SC maintenance in orbits with an ultra-low periapsises.