Communication satellites provide the bridges for a number of new, specialized markets in commercial and private telecommunications and make ties between nations. In the course of more than 40 ears they have obtained Fixed Satellite Communications (FSC). Soon after Mobile Satellite Communications (MSC), Navigation and Determination came to serve navy, ground and air forces worldwide and for of economic reasons, they also provided commercial MSC. For 35 years, MSC was used, particularly because ocean-going vessels have become dependent for their commercial and safety communications on Mobile Satellite Services (MSS). Although, aircraft and land vehicles started before ships, due to many unsuccessful experiments and projects they have had to follow the evident lead of Inmarsat maritime MSC service and engineering. The modified ship’s Mobile Earth Stations (MES) are today implemented on land (road or railway) vehicles and aircraft for all civil and military applications, including remote or rural locations and industrial onshore and offshore installations. The GPS, GLONASS and other new Global Navigation Satellite Systems (GNSS) provide precise positioning data for vessels, aircraft and land vehicles. Because of the need for enhanced services, these systems will be augmented with satellite Communications, Navigation and Surveillance (CNS) facilities.