CospasSarsat

COSPAS-SARSAT is an international satellite-aided search and rescue program established in 1982 by Russia (COSPAS) and the United States (SARSAT) to detect emergency beacons and coordinate worldwide rescue operations. The program operates through a global network of satellite systems, ground receiving stations, Mission Control Centers, and Rescue Coordination Centers in participating countries. It has since grown to include many member states and partners, making it a standard framework for maritime, aviation, and personal locator beacons.

The core technology relies on distress beacons that transmit on 406 MHz, issued for ships, aircraft, and individuals. When activated, these beacons send a unique identification signal and, if equipped, precise location data. The signals are captured by satellite constellations in low Earth orbit and geostationary orbit, with a newer MEOSAR (Medium Earth Orbit Search and Rescue) component enhancing global coverage and reducing alert latency by using modern navigation satellites. In the past, 121.5 and 243.0 MHz frequencies supported homing aids, but they are no longer the primary alerting channels.

Once a beacon is detected, the alert is relayed to the appropriate national Rescue Coordination Center, which coordinates the search and rescue with local authorities. The system relies on registries to identify beacon owners and equipment, enabling faster response and better-tailored searches.

COSPAS-SARSAT is regarded as a cornerstone of international emergency response, saving lives by providing timely, coordinated detection and alerting for distress situations at sea, in the air, and on land.