Orbital mechanics, also known as celestial mechanics, is the study of the motions of artificial and natural celestial bodies under the influence of gravitational forces. It is fundamental for understanding satellite trajectories, space mission planning, and the dynamics of planetary systems.
The celestial equator is an imaginary circle on the celestial sphere that is the projection of Earth's equator into space, equidistant from the celestial poles. It is fundamental in celestial navigation and astronomy, serving as a reference point for the equatorial coordinate system used to locate celestial objects.
Nodes of orbit refer to the two points where an orbiting body crosses the plane of reference, typically the ecliptic plane for celestial bodies in the solar system. These nodes are crucial for predicting eclipses and understanding the orbital dynamics of celestial bodies, as they determine the intersection points of the orbit with the reference plane.
The argument of periapsis is the angular measurement that defines the orientation of an orbiting body's closest approach to the central body, relative to the ascending node of its orbit. It is a crucial element in celestial mechanics for understanding the geometry of orbits and predicting the position of orbiting objects at any given time.
The Right Ascension of the Ascending Node (RAAN) is a critical orbital parameter that defines the angle from a reference direction, typically the vernal equinox, to the direction of the ascending node of an orbiting body. It is essential for determining the orientation of an orbit in the celestial coordinate system, especially in satellite and space mission planning.