Results of research: 1. The analysis of modern electric propulsion (rocket) thrusters (EPTs) and their promising developments, their advantages and disadvantages in relation to rocket thrusters using the energy of expansion of gases, which are the products of combustion of rocket fuel. The main operational requirement of a promising spacecraft is the creation of a sufficiently powerful EPT, however, today no such thruster exists. The most powerful models of mass-produced EPT have a thrust in the range of 0.05‒ 0.10 N. The main problem on the way of their wide development and implementation is the problem of thermal destruction of the structures of a powerful EPT. 2. Based on an analysis of theoretical mechanisms of energy conversion in Electric Propulsion Thrusters, a methodological manual has been developed for assessing the processes of destruction of the EPT structures. 3. A multivariate physical and mathematical model of the EPT cooling system was developed based on the heat balance equation and EPT structural diagram, which includes three elements: a heat-receiving subsystem, a heat transfer subsystem, and a heat dissipation subsystem. When developing the mathematical model, the method of step-by-step problem solving was used. 4. On the basis of the physical and mathematical model, a step-by-step methodological manual and algorithm for calculating the EPT cooling system parameters have been developed. 7 5. An experimental Electric Propulsion Thruster with a cooling system developed by the author was manufactured and tested on a specially designed experimental facility and test bench. 6. A series of experiments was performed with a Magneto Plasma Dynamic Ion-Plasma Thruster with its own magnetic field without a cooling system (MPDO) and with a cooling system developed by the author. 7. Based on the analysis of the experiment results, the author provided an evidence that the cause of overheating and destruction of the thruster anode is electronic bombardment of the anode. 8. The correctness of the obtained experimental results was assessed by the author both on the basis of verification ‒ a comparison of the results obtained at several objects, and a comparison of the results obtained by calculation and experiment.