Gravitational force decreases with distance. what does this mean for a space traveler who leaves earth in a spaceship?

This means that the farther away the astronaut is from the Earth, the less force gravity will be applying to his/her spacecraft. With this being said, once the astronaut breaks Earth's atmosphere, he can reduce the throttles a little to save on fuel, because he doesn't need all of that power to escape such a weak gravitational pull : D.