About physics and cosmonautics

Orbital mechanics or astrodynamics is the application of ballistics and celestial mechanics to the practical problems concerning the motion of rockets and other spacecraft . The motion of these objects is usually calculated from Newton's laws of motion and Newton's law of universal gravitation . It is a core discipline within space mission design and control. Celestial mechanics treats more broadly the orbital dynamics of systems under the influence of gravity , including both spacecraft and natural astronomical bodies such as star systems, planets , moons and comets . Orbital mechanics focuses on spacecraft trajectories , including orbital maneuvers , orbit plane changes, and interplanetary transfers, and is used by mission planners to predict the results of propulsive maneuvers . General relativity is a more exact theory than Newton's laws for calculating orbits, and is sometimes necessary for greater accuracy or in high-gravity situations (such as orbits c