Selection of Conditions for Ensuring Long-Term Passive Inspection in the Close Vicinity of a Spacecraft in a Highly Elliptical Orbit

The present article investigates passive inspection motion in highly elliptical orbits, in which a spacecraft (SC) performs a flyby of an inspection object (IO) in its orbital plane. An osculating trajectory of relative motion is used as a nominal inspection trajectory. It has a complex shape and depends on the eccentricity of the orbit and the value of the IO true anomaly at the initial time. The influence of two perturbing factors on the inspection motion is considered: the inhomogeneity of the Earth’s gravitational field and the attraction of the Moon, as their impact leads to the deformation of the inspection trajectory. In order to estimate the duration of the passive inspection motion, the concept of allowable flyby time is used, i.e., the interval during which the distance between the IO and SC will not exceed a given value. A separate consideration was given to the influence of errors in determining the position and velocity of the SC relative to the IO during the formation of the nominal inspection trajectory on the duration of the allowable flyby time.