Lapkhanov E. Development of methodological approaches for the synthesis of control algorithms for spacecraft deorbiting with using an aeromagnetic deorbiting system

Laphanov E. O. Development of methodological approaches for the synthesis of control algorithms for spacecraft deorbiting with using an aeromagnetic deorbiting system. – Qualified scientific work on the rights of the manuscript. PhD thesis for the scientific degree of Philosophy Doctor in the specialty 151 "Automation and computer-integrated technologies". – Institute of Technical Mechanics of the National Academy of Sciences of Ukraine and the State Space Agency of Ukraine, Dnipro, 2020. The scientific task is the development of methodological approaches to the synthesis of control algorithms for a spacecraft angular stabilization equipped by aerodynamically unstable sailing element during deorbiting from orbit using a new class of hybrid means of cleaning near-Earth orbits from space debris – aeromagnetic deorbiting systems. The analytical comparison of the advantages and disadvantages of existing means of space debris deorbiting from Earth orbits has been caried out in the first section. A classifier of space debris deorbiting systems has been formed according to the main efficiency criteria: speed, reliability in long-term use, fuel and (or) onboard energy consumption and the degree of practical implementation and application. Given certain limitations in the use of existing means of deorbiting, the development of new hybrid systems for deorbiting of space debris from Earth orbits has been substantiated. Given the aerodynamic instability of flat aerodynamic elements of the sailing type, the rationale for the development of a new class of hybrid means of space debris deorbiting – aeromagnetic deorbiting systems. The mathematical models of orbital motion and angular motion of a spacecraft with an aeromagnetic deorbiting system are presented in the second section. Models of perturbations that are taken into account in the study of orbital motion and angular motion of a spacecraft with an aeromagnetic deorbiting system are presented in this section. The expediency of taking into account the perturbing accelerations of the plasmodynamic braking forces in the right parts of the equations of the orbital motion of a spacecraft with an aeromagnetic deorbiting system is shown in the study of the deorbiting time. In the third section, a study of the features of the development of functional schemes of the control system of a spacecraft with an aeromagnetic deorbiting system has been carried out. The generalized functional scheme of the aeromagnetic system for spacecraft deorbiting from low Earth orbits is presented. The research of features of aeromagnetic deorbiting system constructive scheme development with use of executive bodies with rotary permanent magnets is carried out. Methodical approaches to the development of algorithms for angular motion control of a spacecraft with an aeromagnetic deorbiting system in the use of executive bodies with rotating permanent magnets and in the use of electromagnets (magnetorquers) have been developed. The research of features of synthesis of mobile control algorithms for angular stabilization of an aerodynamic element of spacecraft with aeromagnetic deorbiting system at application of electromagnets (magnetorquers) is carried out. Using Lyapunov stability criteria, infinitesimal calculus methods and Voltaire multiplicative integrals, Bellman's optimality principles, stability criteria were developed for the analysis of stabilization of a spacecraft with an aeromagnetic deorbiting system using different magnetic orientation systems. Criteria for optimal use of aeromagnetic deorbiting systems are proposed, which are to minimize onboard electrical energy consumption for the rough stabilization of the spacecraft equiped by aeromagnetic deorbiting systems in long-term space missions. An analytical comparison of the control features of the angular stabilization of the spacecraft with using the executive bodies with rotating permanent magnets and electromagnets has been carried out. Based on the technical features of such magnetic control bodies of angular motion, the relevant guidelines for the selection of executive bodies with rotating permanent magnets or electromagnets for various spacecraft with aeromagnetic deorbiting systems have been developed. In the fourth section, a study of Sich-class spacecraft developed by the Design Office "Pivdenne" deorbiting from orbits of different dislocations using aeromagnetic deorbiting systems was carried out. Internal and external factors influencing the efficiency of aeromagnetic drainage systems are determined. Taking into account these factors, methodological recommendations for the analysis of the feasibility of aeromagnetic deorbiting systems have been developed, which clearly outline the advantages of using these means of combating debrising of near-Earth space depending on the nature of a space mission of deorbiting space debris.