Velocity
Under standard assumptions the orbital speed of a body traveling along elliptic orbit can be computed from the Vis-viva equation as:
where:
- is the standard gravitational parameter,
- is the distance between the orbiting bodies.
- is the length of the semi-major axis.
The velocity equation for a hyperbolic trajectory has either +, or it is the same with the convention that in that case a is negative.
Read more about this topic: Elliptic Orbit