Question

how the Rockets move towards the sub planets

Answer 1

To figure out how to get from Earth to another planet, and to figure out how much fuel will be needed in various cases, we need to start with Newton's laws of motion, again:

Newton's First Law: A body will remain at rest or in motion in a straight line unless acted upon by a force.

Newton's Second Law: Change in motion is proportional to the applied force and parallel to it.

Newton's Third Law: To every action there is an equal and opposite reaction.

By Newton's first law, two things are really cheap: Coasting and sitting still. Out in space, sitting still is a little hard to define - do I mean compared with the Sun, or Mars? Also, most of the time we are in an orbit of some sort, so sitting still doesn't really make sense. What we need to think about is how to change from one kind of orbit to another kind of orbit.

Newton's Third Law contains the "secret" of rocket propulsion for space travel. Take A and B. If A exerts a force on B, then B exerts an equal and opposite force on A. Or, in the case of space travel, if a mass (m) of fuel is pushed out the exhaust of a rocket, then the rocket will accelerate in the opposite direction the direction the exhaust fuel went.