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27 July 2019: a yacht leaves harbour at La Trinité-sur-Mer with four people aboard, planning to spend a few days at sea. The next day, a storm forms and is bearing down on Brittany and Charentes, with winds gusting to over 50 knots and an 8-metre swell. Sailing 70 nautical miles off the French coast, the yacht is soon overwhelmed by the elements, dismasts and capsizes. The crew of four manages to board the life raft and activate their emergency locator beacon, the only way they have of calling for help.
The beacon emits on the 406-MHz frequency and its signal is received by satellites in the Cospas-Sarsat constellation in Earth orbit. The beacon data are then downlinked to one or more ground stations, which calculate the beacon’s position and send alert information to their mission control centre (MCC). As MCCs around the globe are all interconnected, the information arrives at the French Mission Control Centre (FMCC) in Toulouse, the centre responsible for handling this distress call. This whole process takes just seconds. The FMCC then forwards the information to the relevant search-and-rescue centre and rescue teams are dispatched to pick up the stricken pleasure boaters.
Formed in 1979, Cospas-Sarsat is a global programme using radio beacons capable of locating any craft or person in distress, at sea, in the air or on land. Today, more than two million Cospas-Sarsat beacons are in operation around the world. They are mandatory aboard commercial airliners and merchant ships, as well as pleasure boats sailing 60 nautical miles or more from a safe haven.
Founded by France, Canada, the United States and Russia, the Cospas-Sarsat programme has evolved considerably over the years and now counts 45 member nations. Its mission is to collect, locate and forward distress signals from 406-MHz beacons relayed by a constellation of satellites and then a network of local user terminals (LUTs) and interconnected MCCs.
The French Mission Control Centre (FMCC) is located at CNES’s Toulouse Space Centre since 1982 and is one of the 32 Cospas-Sarsat mission control centres covering the globe.
The FMCC collects, processes, forwards and archives alerts from distress beacons within its coverage zone. It also coordinates the operations of six other MCCs in Cyprus, Greece, Italy, Norway, Turkey and the United Kingdom.
FMCC operations are overseen by the Ministry for the Ecological and Inclusive Transition (for maritime and civil aviation affairs), while its facilities are provided by CNES. In addition to the FMCC, the Toulouse site also has LEOLUT, GEOLUT and MEOLUT stations compatible with the corresponding constellations.
The European Commission’s SAR Galileo search-and-rescue programme is operated by CNES on behalf of GSA, the European GNSS Agency. As such, it contributes to the international Cospas-Sarsat programme alongside other GNSS systems: the U.S. Global Position System (GPS), Russia’s Glonass and soon China’s Beidou. Each of the 24 satellites in the Galileo constellation is carrying an SAR repeater. The European Commission is also contributing to the programme by providing a network of stations in Europe operated and maintained by CNES.
Thanks to Cospas-Sarsat, 258 people were saved in 2019 by 99 search-and-rescue operations within the FMCC’s coverage zone, taking the total lives saved since the programme’s inception to more than 46,000.
Cospas-Sarsat is able to locate a distress signal almost immediately and forward it quickly to rescue services.