orbital velocity(redirected from Orbital speed)
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orbital velocityThe velocity of a satellite or other orbiting body at any given point in its orbit. It is also the velocity required by a satellite to enter an orbit around a body. The orbital velocity, v, is given by the expression
v = √[gR 2(2/r – 1/a )]where R is the radius of the orbited body, r is the distance from the center of mass of the system (i.e. from the approximate center of the primary), a is the semimajor axis of the orbit, and g is the standard acceleration of gravity. For a circular orbit, r = a and the circular velocity is given by
v = √(gR 2/r )
To escape from an orbit a must tend to infinity and the escape velocity is then given by
v e = √(2gR 2/r )
The orbital period for an elliptical orbit is given by
P = 2πa 3/2/√gR 2
orbital velocity[′ȯr·bəd·əl və′läs·əd·ē]
The instantaneous velocity at which an earth satellite or other orbiting body travels around the origin of its central force field.