LEOCOM-SPES: Low cost message communications

For the user categories which do not need real time connections, LEOCOM-SPES (Space Pony Express) is an economic and attractive personal communications system based on a sparse constellation applicable to message/data communications. The system architecture, the major system elements, the orbit and constellation selection, the system implementation, the ground segment, the user terminal, the network operation, and traffic scenario and requirements are outlined. Satellite and launch costs, investment costs for the central control station, and user charges are also discussed. To conclude, the Leostar spacecraft performances are summerized: Leostar is a stabilized satellite designed for operation in low altitude Earth orbits.