There are literally thousands of artificial "satellites." The US Space Command's Space Surveillance Center near Colorado Springs, Colorado, monitors the whereabouts of more than 7,000 artificial objects. A few hundred are working satellites and spacecraft, but thousands more are spent rocket boosters, shards from exploded rockets, chunks of solar panels, screws and tools from previous space missions, and several thousand defunct satellites. This space debris is becoming a bíg safety issue. A fleck of paint moving at speeds of 17,000 miles per hour (27,000 km/h) has the energy to chip a space shuttle window or pierce the skin of a satellite. Imagine how damaging, and dangerous, an errant screw or a large piece of metal coul'd be moving at that velocity.
Objects in low Earth orbit reenter the atmosphere and burn up after a few months."Objects at greater altitudes could remain in orbit for centuries. Each piece of debris must be diligently tracked to avoid harm to spacecraft.
