A motor is started up for a certain amount of time, sometimes just one or two minutes, to push the satellite into place. It may take many burns, over a period of several days, to move the satellite into its assigned orbital position. These launch vehicles are used to send our satellites into space. The earth, the moon, and all the planets are held in place in the solar system by two opposing forces. One is called gravity.
Gravity is a force that pulls objects toward a planet or other large object.
When you hold a book in the air and let go, gravity pulls it toward the earth and it falls. The other force is called centrifugal force. It makes a rotating object fly outward from the center. In our solar system, nine planets revolve around the sun. Gravity and centrifugal force must be in balance for the planets to stay in their positions.