This calculator computes the orbital velocity of an orbit, where:

*v* is orbital velocity.
*G* is the gravitational constant.
*M* is the combined mass of the central body and the orbiting body. In the case of spacecraft, the mass of the spacecraft is insignificant and may be ignored.
*r* is the distance between the orbiting body and the central body.
*a* is the semi-major axis of the orbit.
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