Orbiting Platform Communication and Data Management Systems

The communications and tracking (C&T) system on board the orbiting platform communicates with the ground facilities through the TDRS satellites. The C&T system operates on Ku and S-band. Using a high gain antenna the Ku-band channel can support a downlink data rate of 300 Mbps through the TDRS single axis channel. The S-band system communicates with the orbiter and with both multiple and single axis TDRS channels. The Data Management System (DMS) provides the following services to the orbiting platform: data distribution within and between core systems and payloads, data processing facilities for core systems, data base management, time and frequency standards, and overall platform management and control. The DMS is a distributed data processing network. The nodes are connected by a local area network (LAN). Each node is autonomous. Since the design is modular, nodes can be added or deleted without disturbing the system. Sensors and effectors communicate with the core system software via the network through multiplexers/demultiplexers.