> Space Stations are in orbit - the space battleship doesn't have to be

I mean, you did say:

> space battleship - one that never comes down to the surface, just sits in orbit.

So I think it's understandable for people to take that at face value.

Furthermore, if it isn't in orbit, then where would it be?

> and a lot more of tug-boating it into the exact right spot, in the way of earth, so that earth hits the asteroid - not anything complicated like the asteroid hitting earth.

From an orbital mechanics standpoint I don't think there's actually a difference. You're changing an orbit either way.