What does gravity have to do with launching a rocket?
Gravity plays the major role in the launch.. a rocket has to cross the escape velocity so as to get out of the atmosphere. Escape Velocity is the speed at which any space shuttel or rocket or anything has to achieve if it wants to escape the earth's gravitational field. Gravity attracts the rocket and all the things coming from the space and going in to the space from the earth towards itself.. that is the reason that whenever you jump, you come back to earth!!!