"The emergence, existence and development of the surrounding world, both on Earth and throughout the universe, are due to the gravitational interactions of many bodies. This book is devoted to the calculation of bodies' movements in various cases of interaction that are relevant now and in the future. They are developed for the free access of the Galactica system, which is designed to provide the numerical solution for problems of the gravitational interaction of N-bodies. It tackles a whole range of problems: The optimal motion of the spacecraft, the evolution of the solar system for 100 million years, the influence of the Sun on Mercury's perihelion, the motion of near-Earth asteroids, the evolution of Earth's rotation axis, etc. As a result of solvinga number of problems, new knowledge about our world was obtained. The optimal trajectory of the spacecraft approaching the Sun is determined by numerical integration of the equations of motion for spacecraft, planets, the Sun, and the Moon. Exact solutions to the problem of the Newtonian gravitational interaction of N material points moving around N2 concentric circular orbits are reviewed. Each circular orbit contains N3 located bodies and the body system rotates as an entity. Solutions in various formswere obtained. A computer program has been developed. Structures comprising up to one million bodies have been calculated. The Galactica system is used for computing movements of two asteroids: Apophis and 1950DA. The evolution of their movement over a span of 1,000 years is investigated. The moments of their closest passages near the Earth are defined. The different ways of asteroid trajectory transformations into orbits of the Earth's satellites are considered"--