Orbits are independent of the mass of the orbiting object Free motion in response to gravity is called free-fall . All four types of conic section orbits are free-fall. A planet's mass cancels out of the expression for acceleration in gravitational field.
Most communications satellites are in such orbits.
Newton's second law of motion and various elaborations of it are essential for understanding and designing rocket motors. All rights reserved. These notes are intended for the private, noncommercial use of students enrolled in Astronomy 121 at the University of Virginia. Reproduction, distribution, and commercial uses are prohibited.