Orbiting smoothly and predictably high above the Earth, satellites can see and be seen from anywhere on the planet. This makes them ideal navigation system platforms, able to send or receive highly accurate location data regardless of the conditions on the ground. Global search and rescue systems (such as the international Cospas-Sarsat program) rely on navigation satellites to detect and locate emergency distress beacons. We built the ground segment of the Galileo Search and Rescue system for the European Space Agency and have also developed and operate the French mission control center.