# Orbital angular momentum

As I understand the Angular Momentum of orbit is directed perpendicular to the orbital plane and is the cross product of position and velocity vector. In case of nodal regression, how does the position and velocity vary so that the Angular momentum is conserved ?

These darn $\frac{1}{r^2}$ forces never reach zero, so everything is an approximation, and energy, momentum, angular momentum are never perfectly conserved locally.