This report summarizes the findings of one of fourteen panels that studied progress in space science applications and defined user needs potentially capable of being met by space-system applications. The study was requested by the National Aeronautics and Space Administration (NASA) and was conducted by the Space Applications Board. The panels comprised user specialists drawn from federal, state, and local governments and from business and industry. In this report, the Panel on Uses of Communications explores more than 20 potential new services that can be provided by future satellite communications systems. Such services include improvement in the transmission of information; provision of greater safety to persons and craft at sea, on land, or in the air; location of those in distress; and warning of impending natural disasters. Recommendations are made with regard to mobile communications for use on land and sea, position determination, mineral and energy exploration, and the possibility of using electronic means to assist in mail delivery, and education and health-care experiments. (MH)