CeramTec North America (CTNA), based in Laurens, S.C., is a supplier to the European Geostationary Navigation Overlay Service (EGNOS) system, which started its first signal transmission tests in April. By early next year, EGNOS, a European Ceramaseal feedthroughs within hermetic package for space-bound atomic clock. (Photo: CeramTec North America) Space Agency program, will deliver Europe's first satellite navigation service. CeramTec’s Ceramaseal feedthroughs have been used in a Swiss company's high-reliability clock and test systems, including a Swiss atomic clock, the most precise time measuring device that has ever been used in space. The feedthroughs provide necessary electrical isolation and a hermetic seal. When completed, EGNOS will consist of three geostationary satellites and a network of ground stations that will transmit signals containing information on the reliability and accuracy of the positioning signals sent out by the US GPA (Global Positioning System) and Russian GLONASS (Global Navigation Satellite System).