Wednesday, 10 September 2008

Indonesian Space Sciences Technology School

Orbital Mechanics 

From Wikipedia, the free encyclopedia 
 Added and Edited By: Arip Nurahman 

Department of Physics Education, Faculty of Sciences and Mathematics 
Indonesia University of Education 

Follower Open Course Ware at Massachusetts Institute of Technology
Cambridge, USA
Department of Physics
Aeronautics and Astronautics Engineering

Orbital mechanics or astrodynamics is the application of 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 close to the Sun).




Until the rise of space travel in the twentieth century, there was little distinction between orbital and celestial mechanics. The fundamental techniques, such as those used to solve the Keplerian problem (determining position as a function of time), are therefore the same in both fields. Furthermore, the history of the fields is almost entirely shared.
Johannes Kepler was the first to successfully model planetary orbits to a high degree of accuracy, publishing his laws in 1605. Isaac Newton published more general laws of celestial motion in his 1687 book, PhilosophiƦ Naturalis Principia Mathematica.

See also


  • Bate, Roger R.; Mueller, Donald D., and White, Jerry E. (1971). Fundamentals of Astrodynamics. Dover Publications. ISBN 0-486-60061-0.
  • Sellers, Jerry J.; Astore, William J., Giffen, Robert B., Larson, Wiley J. (2004). Kirkpatrick, Douglas H.. ed.. Understanding Space: An Introduction to Astronautics (2 ed.). McGraw Hill. pp. 228. ISBN 0072424680.

External links