We are at the of implementing, worldwide, one of the most important developments in communications - a Mobile Satellite Service (MSS) offering a full range of low cost land, aeronautical and maritime mobile communications (Figure 1). This new service will have a profound universal effect on economic, social and cultural activity. because of the large number and variety of Geostationar (GEO) and Low Earth Orbiting (LEO) mobile satellite systems planned for the Western Hemisphere the dominant problem for the user will be which system to choose. Several systems are briefly described along with their potential impact on economic development, health care and emergency response. Datails are provided about a recently signed agreement between the Pan American Health Organization (PAHO) and the American Mobile Satellite Corp (AMSC) for AMSC to provide communications support to PAHO and its member countries for disaster management and relief operations. The application of this new space technology to AIDS education and disaster medicine is also described.