Largest space surveillance network

The US Strategic Command through its Joint Functional Component Command for Space (JFCC Space) at Vandenberg AFB (Lompoc, California) is ultimately responsible for the Space Surveillance Network (SSN) of the U.S. Army, Navy and Air Force, which operates ground-based radars and optical sensors at 30 sites worldwide. It is set up to detect, catalogue, and identify all artificial objects orbiting the earth, such as satellites, rockets and space debris. It also predicts objects re-entering the atmosphere. It has catalogued more than 39,000 man-made objects and currently, through the Joint Space Operations Centre, tracks more than 16,000 objects in orbit making around 380,000 to 420,000 observations each day. NASA has reported that there are some 500,000 pieces of space debris all travelling at speeds up to 17,500 mph, and that the SSN tracks objects larger than 2 inches (5 cm) in low Earth orbit and around 3 feet (I metre) in geosynchronous orbit.