Planning orbits for artificial satellites depends on solving equations of motion for planets and satellites. The authors first present and solve the classical two-body motion problem, using vector algebra to develop the six integrals of motion from Newton's laws, then apply modern perturbation techniques to practical cases, such as the effect of drag on a satellite or rotation of nonsymmetric planets. They place greater importance on rigorous development of the equations than on their solutions, so few numerical problems appear, but necessary algorithms have been provided throughout the book.