I am the kind of guy that always needs to return to the horse-and-carriage problem to hone in my understanding of Newton's Third Law. Here's my question. Assume a rocket in space is applying a force to another object of equal mass in space. Now, I understand the object in space is experiencing an unbalanced force, and so, it will accelerate in the opposite direction of the rocket. What always perturbs me is when I begin to think of the force acting on the rocket - it will experience a force in the opposite direction - what does this mean exactly? Does this force prevent it from moving forward? Here, I say no, because the system is moving the direction of the force as the object in space is moving forward due to the unbalanced force. Are we trying to say the opposite force experienced by the rocket is what prevents it from going through the object? I'm just trying to wrap my head around this opposite force, experienced by the rocket, that does not prevent it from moving forward (as this system, including the rocket, moves forward), yet is still felt by the rocket.