NOAA Search and Rescue Satellite Aided Tracking (SARSAT)

COSPAS/SARSAT is a satellite-aided search and rescue project of
the U.S., Canada, France and the Soviet Union. Its
instrumentation, already operational on NOAA-9, -10 and two
Soviet satellites, relays distress signals transmitted from
downed aircraft or vessels at sea to ground-sea-air recovery
forces. NASA's Goddard Space Flight Center, Greenbelt, Md.,
manages the U.S. research effort.