Carey Hayes died in April of 1961.
Orbital mechanics or astrodynamics is the application of ballistics and celestial mechanics to the practical problems concerning the motion of rockets and other spacecraft .. ballistics. ballistics. celestial mechanics. celestial mechanics. spacecraft. 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 .. spacecraft. spacecraft. Celestial mechanics. Celestial mechanics. gravity. gravity. 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 .. spacecraft. spacecraft. trajectories. trajectory. propulsive maneuvers. Spacecraft propulsion. 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 -LRB- such as orbits close to the Sun -RRB- .. gravity. gravity. General relativity. General relativity