Space Fence

Space Fence is vital for our life down here. Thanks to this tracking system, space sciences can move forward, Earth-monitoring, weather and communications satellites can be put in orbit, and astronauts can fly spacecraft or the ISS in an almost safe way.

Operated by the Air Force 20th Space Control Squadron and created by Lockheed Martin, Northrop Grumman and Raytheon, Space Fence is a multistatic radar system capable of detecting almost everything that moves in orbits up to 18,641 miles (30,000 kilometers).

via gizmodo