The movement of the satellite, in addition to gravitational forces, is influenced by the resistance forces of the upper layers of the earth’s atmosphere, the pressure of the sun’s rays, and the impacts of micrometeorites. As a result, the motion of the satellite is not, strictly speaking, Keplerian. To exclude the influence of non-gravitational forces, the satellite must be enclosed in a sealed satellite – a case equipped with reactive orbit correction engines. Thanks to their traction, the movement of the case adjusts to the undistorted movement of the inner satellite. Such a Trayad-1 satellite was designed and launched for navigation purposes.
Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.