ORBITAL STRUCTURE OPTIMIZATION TECHNIQUE OF THE LOW-ORBIT COMPLEX OF ON-ORBIT SERVICE
Authors:   Institute of Technical Mechanics of the National Academy of Sciences of Ukraine and State Space Agency of Ukraine, GOLDSHTEIN Yu. M. 
Published: September 2023

Most of the currently planned on-orbit servicing (OOS) missions involve the use of disposable OOS spacecraft. The use of disposable OOS spacecraft may be profitable in the near future. But it is not a reliable solution for OOS in the long term. As an alternative, a more useful concept is the use of reusable OOS complexes, which allow responding to scheduled and random requests from OOS clients. This concept can ensure the timeliness and efficiency of OOS implementation during planned services and random requests of OOS clients. However, despite the potential advantage of a reusable OOS, the design of its orbital structure and operational maintenance is much more complicated in comparison with the traditional concept of the organization of OOS. This is because when planning the response of reusable OOS complexes to requests, it is necessary to distribute OOS client service operations between space vehicles of the reusable OOS complex. Now the space industry is switching its attention to the area of low Earth orbits. This causes an increase in deployed and planned low-orbit satellite groups, the number of satellites in them, the difference in structural schemes of satellite groups, and the significant influence of the environment on orbital parameters. As you know, the orbital parameters of low orbits of space vehicles can differ significantly, and the difference between them can reach tens or even hundreds of degrees in the longitude of the ascending node. This leads to unacceptably high energy costs for modern OOS spacecraft for active rotation of the planes of their original orbits to the planes of the destination orbits. In some works, the possibility of reducing these energy costs due to the use of the difference in the speed of the nodal precession of the parking and destination orbits of the OOS spacecraft due to the non-centrality of the Earth’s gravitational field is considered. However, due to the long wait of the OOS spacecraft in the parking orbit, the flight time with the wait between the parking and destination orbits increases significantly. Its reduction can be achieved by increasing the number and rational selection of the semi-major axis and inclination of the parking orbits of the OOS spacecraft. The purpose of the article is to develop a technique for the optimal synthesis of the orbital structure and optimal operational planning of the low-orbit OOS complex in near-Earth orbits with a small eccentricity. Methods for solving the problem are the averaging method, the branch-and-bound method, and the multiobjective optimization method. The novelty of the obtained results lies in the development of a technique for optimal synthesis of the orbital structure and optimal operational planning of the low-orbit space OOS complex in near-Earth orbits with low eccentricity. The developed technique can be used in the previous planning and design of space OOS complexes in low near-Earth orbits with a small eccentricity.