The United States, Soviet Union, Canada and France joined together in 1979 to establish COSPAS-SARSAT. The SARSAT system was developed as a joint effort between the United States, Canada, and France. The COSPAS system was developed by the Soviet Union. In 1982, the first satellite was launched, and by 1984 the system was declared fully operational. The four original member nations have now been joined by 25 other nations that operate 39 ground stations and 23 mission control centers worldwide or serve as Search and Rescue Points of Contact.

In the United States, the SARSAT system was developed by NASA. Once the system was functional, its operation was turned over to NOAA. SARSAT is an instrument package flown aboard the NOAA Series of environmental satellites operated by NOAA's National Environmental Satellite, Data and Information Service (NESDIS). SARSAT is the abbreviation for Search and Rescue Satellites. Each NOAA satellite carries a Search and Rescue Repeater (SARR) which receives and retransmits 121.5 MHz and 243 MHz signals anytime the satellite is in view of a ground station. Also carried is a Search and Rescue Processor (SARP) which receives 406 MHz transmissions, provides measurements of the frequency and time, then retransmits this data in real-time and stores it aboard for later transmission. The SARR is provided by the Canadian Department of National Defence and the SARP is provided by the French Center National D'Etudes Spatiales (CNES). 

The COSPAS instrument is carried aboard the Russian Nadezhda navigation satellite. The COSPAS instrument was built by the former Soviet Union and continues to be operated by the Russian Federation. The only major difference between COSPAS and SARSAT is that the Russian satellites do not receive 243 MHz distress signals. COSPAS is the abbreviation for Cosmicheskaya Sistyema Poiska Avariynich Sudov, which means, "Space System for the Search of Vessels in Distress".

Worldwide discussions are currently taking place regarding the discontinuation of COSPAS-SARSAT satellite coverage for 121.5 MHz and 243 MHz beacons. The 121.5 MHz frequency is used by older beacons which do not transmit any encoded information. The power output of these beacons is specified as 50, 75, or 100 mWatts. 121.5 MHz is also the transmission frequency of low power (25 mWatts) final homing transmitters included in many newer 406 MHz beacons. Presently there are approximately 590,000 beacons which operate on 121.5 MHz in use worldwide. The 243 MHz frequency is used in some older beacons deployed by the U.S. military and NATO forces. The 243 MHz frequency is not monitored by the Russian COSPAS satellites. Modern beacons which transmit digitally encoded information within the message use the 406.025 MHz frequency. Encoded information can include beacon ID to allow use of a user reference data base and beacon location determined by a sophisticated navigation device such as GPS. The RF power output of 406 MHz beacons is specified as 5 Watts. This higher output power allows these beacons to be received reliably by geostationary orbiting satellites. There are approximately 156,000 beacons presently in use worldwide which operate on 406.025 MHz.

COSPAS-SARSAT has been experimenting with 406 MHz receivers on geostationary earth orbiting (GEO) satellites. These experiments have proven the capability of GEOSAR to provide immediate alerting and identification of 406 MHz beacons. The GEO satellites are not able to use Doppler location processing since they have no relative motion between them and the emergency beacons. Therefore, they are not able to determine a location for a beacon. They can, however, provide immediate alerts. This is a valuable tool for SAR personnel since it allows them to begin their initial verification of the alert using the NOAA beacon registration database. Often this detective work yields a general location of the vessel or aircraft in distress and SAR assets can be readied or dispatched to that general area. Ideally, a SARSAT or COSPAS polar orbiting satellite will overfly the beacon within the next hour and calculate a Doppler location which will be forwarded to the SAR personnel who may already be enroute.