Estimating the degree of disposal of a launch vehicle casing made from polyolefins in the earth’s atmosphere

The object of this study is the process of disposing of the upper stage body of a launch vehicle made of polyolefins by burning in the dense layers of the Earth’s atmosphere during removal from Earth orbit. The task addressed was to determine the possibility of disposal of the upper stage bodies of launch vehicles made of polyolefins during deorbiting. The mathematical model built makes it possible to take into account the effect of ballistic and aerothermodynamic aspects at the same time. The application of this model makes it possible to estimate the degree of disposal of the upper stage bodies of launch vehicles made of polyolefins in the Earth’s atmosphere at the stage of scientific research. In turn, this makes it possible to rationally choose the design parameters of materials for launch vehicle bodies, taking into account the disposal phase in the dense layers of the atmosphere, as well as rationally select the initial parameters for deorbiting orbits. This makes it possible to maximize the level of disposal and minimize the probability of debris falling on uninhabited areas of the Earth. The results of the study showed that launch vehicle bodies made of polymer materials such as polyethylene and polypropylene could burn up in the atmospheric part of the trajectory by 90–100 %, depending on the mass-dimensional characteristics and the type of orbit. In turn, increasing the ellipticity of the orbit makes it possible to increase the steepness of the entry of the upper body of the launch vehicle into the dense layers of the atmosphere, and hence, to increase the heat flows that contribute to the combustion of the body. With this in mind, methodological recommendations have been compiled for choosing orbits of the necessary ellipticity, taking into account the place of fall of fragments of the upper bodies of carrier rockets that did not burn up in the atmosphere