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:
“Look not too long in the face of the fire, O man! Never dream with thy hand on the helm! Turn not they back to the compass; accept the first hint of the hitching tiller; believe not the artificial fire, when its redness makes all things look ghastly.”
—Herman Melville (1819–1891)
“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?)
“Well said, old mole, canst work i’ th’ earth so fast?”
—William Shakespeare (1564–1616)