Considerations
Newton's Universal Law of Gravitation explains that "the force of gravity between two bodies is equal to the product of their masses divided by the distance between them squared and multiplied by what we call the universal gravitational constant." That means that no matter how far a rocket shoots up, it will return to earth, as long as it's within earth's gravitational pull.
Identification
Escape velocity is the speed required to escape earth's gravitational hold. As a rocket soars higher in earth's atmosphere, gravity's pull diminishes until the rocket finally propels itself into space.
The Speed of Escape Velocity
Earth's escape velocity is approximately 10 km (7 miles) per second, or about 40,000 km (25,000 miles) per hour. The space shuttle climbs at speeds of 15,000 miles (24140.16 km) per hour to reach orbital velocity, which is fast enough to keep it orbiting the planet but not fast enough to send it flying off into space.