Definition
Space situational awareness encompasses the detection, tracking, characterisation, and prediction of all objects orbiting Earth — from operational satellites to small debris fragments. SSA is essential for collision avoidance, re-entry prediction, space weather assessment, and maintaining a safe orbital environment.
Who Provides SSA?
The US Space Force's 18th Space Defense Squadron (18 SDS) operates the Space Surveillance Network, the world's primary space tracking system. Other contributors include EU SST (European Space Surveillance and Tracking), ESA's Space Debris Office, LeoLabs (commercial radar), ExoAnalytic Solutions (commercial optical), and national agencies like ISRO and JAXA.
Key SSA Functions
Cataloguing: Maintaining a database of all tracked objects with orbital parameters (TLEs). Conjunction assessment: Predicting close approaches and issuing warnings. Re-entry prediction: Estimating when and where decaying objects will re-enter. Space weather: Monitoring solar activity that affects drag, communications, and satellite health. Anomaly detection: Identifying unexpected manoeuvres or break-ups.
SSA on Orbital Radar
Orbital Radar provides accessible SSA through its live tracker, bringing real-time visualisation of the orbital environment to the public. For a detailed walkthrough, see our SSA Guide.