This chapter outlines the development and evolution of the Cospas-Sarsat system, describes the principle of operation, presents the current status and looks at the future of the system. Cospas-Sarsat, an international satellite system for search and rescue, started operating in 1982 and has been credited with saving many thousands of lives since then. More than a million aviators, mariners and land users worldwide are equipped with Cospas-Sarsat distress beacons that could help save their lives in emergency situations anywhere in the world. A constellation of satellites is circling the globe monitoring for distress signals, while tracking stations on six continents receive the satellite signals, compute the location of the emergency and quickly forward the distress alert information to the appropriate rescue authorities. This is a big improvement over the pre-satellite era, when distress signals from remote regions or far out at sea might not have been heard for many days or even weeks.