Necessary Conditions for the Existence of Spacecraft in Closed Ultralow Orbits

The problem of stabilizing spacecraft in ultralow (for the Earth, 120–250 km) orbits with the help of air-breathing electric propulsion (ABEP) using the gases of the surrounding atmosphere as a propellant is considered. Qualitative differences of air-breathing electric propulsion from traditional electric propulsion are singled out, and, based on the fundamental laws of mechanics and electrodynamics, the necessary conditions for the existence of spacecraft with an air-breathing electric propulsion engine in closed ultralow orbits are substantiated.