Nazgul Kaliyeva

The problem of satellite formation motion is considered, described by the modified Lawden-Sedwick-Schweighart equations. The formation mission is real-time Earth observation. The primary satellite with a mass of 65 kg moves in a geostationary orbit. Three accompanying spacecrafts, positioned in the plane of the tetrahedron base, are with masses of 50 kg each. A control algorithm has been developed to ensure a sufficient level of formation stability in the presence of a disturbed reference orbit and various uncertainties, based on robust control algorithms such as H2 and H∞. The maximum control force required to maintain the satellite formation's configuration using these control algorithms is 7 mN. It is necessary to determine the types of propulsion systems that meet these requirements. Among the electric propulsion systems available on the market, such as ion engines and Hall thrusters, the specific impulse allows them to generate a maximum thrust of about 15 mN and a minimum of about 6.6 mN. Comparing the obtained thrust values with the control force required to maintain the satellite configuration, it can be concluded that the developed mathematical framework can be successfully implemented in the satellite formation’s control system, ensuring the control of satellite motion and their relative positions.

A control system for a tetrahedral satellite formation flying representing a synthetic aperture telescope in the geostationary orbit was developed.

When the formation flying consists of satellites that are independent from each other and forms a virtual synthetic aperture telescope that replaces a single large telescope with all of its optical elements it is required mutual coordination between the satellites with high accuracy in order to achieve good optical observations. In this paper we consider the problem of developing a control system for a tetrahedral satellite formation flying representing a synthetic aperture telescope in the geostationary orbit for high resolution monitoring of fire in the forest area in infrared spectrum. Synthesizing the image with good quality requires to keep the configuration of formation with µm-class accuracy. Study of dynamics of passive uncontrolled motion of formation flying showed a significant deviation of the configuration from the required shape with a high frequency due to the action of gravitational forces. To keep the configuration in the required form with µm accuracy the analysis of efficiency of various controllers was carried out in the process of numerical simulation. The simulation results made it possible to highlight the features of using various approaches to the development of control system for the satellite formation flying representing a synthetic aperture telescope.