Are astrodynamics and orbital mechanics the same subjects?

Question

I am learning over the internet and this subject look very similar to me.

Is one of them part of the other?

Thanks in advance

Answer 1

Not exactly - Astrodynamics include the behavior of propelled objects. Orbital mechanics are, thus, to be strict, a subset of Astrodynamics.

Answer 2

Celestial mechanics, orbital mechanics, and astrodynamics all rely upon the same physical principles and employ many of the same techniques.  So in a sense they're just names for the same body of science.

Celestial mechanics emphasizes the motion of natural objects -- stars, planets, asteroids, comets, etc.  Celestial mechanics as a science is rather old.

Astrodynamics emphasizes the navigation of spacecraft.  As such it computes the effects of propulsion upon the spacecraft orbit and considers modes of motion (e.g., changing the plane of the orbit) that aren't often exhibited by natural objects.  It is a relatively new science.

Orbital mechanics can mean either celestial mechanics or astrodynamics, depending on the context of the distinctions in the discussion at hand.

Answer 3

Hi Omar -

When I took a class in orbital mechanics, it included the prediction of spacecraft trajectories - with the addition of thrust to get from one orbit to another. I took another class in astronomy that included astrodynamics, and we discussed the orbits of planets, comets, asteroids, etc. including the effects of perturbations. We used the same equations.

I think they are two different words meaning essentially the same thing mathematically.