Artificial Satellites Around The Earth
For launch vehicles and artificial satellites, the orbital plane is a defining parameter of an orbit; as in general, it will take a very large amount of propellant to change the orbital plane of an object. Other parameters, such as the orbital period, the eccentricity of the orbit and the phase of the orbit are more easily changed by propulsion systems.
Orbital planes of satellites are perturbed by the non-spherical nature of the Earth's gravity. This causes the orbital plane of the satellite's orbit to slowly rotate around the Earth, depending on the angle the plane makes with the Earth's equator. For planes that are at a critical angle this can mean that the plane will track the Sun around the Earth, forming a Sun-synchronous orbit.
A launch vehicle's launch window is usually determined by the times when the target orbital plane intersects the launch site.
Read more about this topic: Orbital Plane (astronomy)
Famous quotes containing the words artificial, satellites and/or earth:
“It had not a New England but an Oriental character, reminding us of trim Persian gardens, of Haroun Al-raschid, and the artificial lakes of the East.”
—Henry David Thoreau (1817–1862)
“To the Japanese, Portugal and Russia are neutral enemies, England and America are belligerent enemies, and Germany and her satellites are friendly enemies. They draw very fine distinctions.”
—Jerome Cady, U.S. screenwriter, and Lewis Milestone. Peter Voroshevski (Howard Clinton?)
“The motive of science was the extension of man, on all sides, into Nature, till his hands should touch the stars, his eyes see through the earth, his ears understand the language of beast and bird, and the sense of the wind; and, through his sympathy, heaven and earth should talk with him. But that is not our science.”
—Ralph Waldo Emerson (1803–1882)