The United States Space Surveillance Network (SSN) is a system operated by the U.S. Department of Defense that tracks objects in Earth's orbit. It monitors satellites, space debris, and other man-made objects to ensure the safety of space operations. The SSN collects data from various radar and optical sensors located around the world. The information gathered by the SSN is crucial for space situational awareness, helping to prevent collisions in space. It also supports national security and scientific research by providing insights into the activities of foreign satellites and other space assets.