Why does the space station not fall down?

R is the distance from the center of the Earth to the object in orbit. So, the object isfalling towards the Earth, but just keeps missing the Earth. This is the real reason astronauts float inside the International Space Station (ISS) - they, and the vehicle are in free-fall.

(I DID NOT WRITE THIS)

Actually the space station is always falling but never hitting the ground. Due to inertia, a moving object continues moving in a straight line unless a force acts on it. There is a force that acts on every object near Earth, the force of gravity. For ex. if you throw a ball, it does not continue moving indefinitely in a straight line because gravity causes it to move toward the center of the Earth. In a few seconds, the ball collides with Earth and the force of friction stops its motion.

Is a  vector quantity  that refers to "the rate at which an object changes its position." imagine a person moving rapidly - one step forward and one step back - always returning to the original starting position. while this might result in a frenzy of activity, it would result in a zero velocity. because the person always returns to the original position, the motion would never result in a change in position. since velocity is defined as the rate at which the position changes, this motion results in zero velocity. if a person in motion wishes to maximize their velocity, then that person must make every effort to maximize the amount that they are displaced from their original position. every step must go into moving that person further from where he or she started. for certain, the person should never change directions and begin to return to the starting position.