This equation computes the escape velocity, `V_"cs"` for a satellite in a circular orbit given the orbit radius, r.

This is assuming a spherical Earth model and uses the fact that for a circular orbit the semi-major axis equals the radius of the orbit, which is constant.

`V_"cs"`= `(mu/r)^(1/2)`

Notes

For many analyses the spherical Earth approximation is adequate.  See the WGS-84 constants to see the variations in Earth models.

Note that the orbit's radius, r, must be greater than the radius of the Earth `R_e` or else we would be hearing a very strange rumbling beneath or feet.