The Desktop Satellite Data Processor (DSDP) is a prototype computer system for processing telemetry data received from, and command data to be transmitted to, a spacecraft in orbit around the Earth (see figure). The design of the system utilizes very-large-scale integrated (VLSI) application-specific integrated circuits (ASICs), parallel computer architectures, and pipelined data processing. Advanced software and a high level of integration of hardware and software components are expected to make a fully developed version of the system fit into a desktop-sized package at relatively low cost; the fully developed system is expected to be less than one-fourth as large as an equally capable system made entirely from commercial off-the-shelf (COTS) components.

The DSDP Acts as an Earth/Satellite Gateway that communicates with other terrestrial computer systems (from which commands are received and to which telemetry data are delivered) via standard commercial computer-network interfaces.

The DSDP contains ASIC components that perform frame synchronization, Reed-Solomon decoding, and other standard telemetric processing functions (e.g., sorting and annotation of data packets) that are denoted generally as "service processing" and are performed according to recommendations of the Consultative Committee for Space Data Systems (CCSDS). The ASIC components are integrated onto custom-designed, highly reusable circuit cards based on the industry-standard peripheral component interconnect (PCI) bus. By high-level integration of the telemetry-processing functions into VLSI chips and cards, the design of the system affords high performance and high reliability and, relative to older telemetry systems, low cost.

The DSDP hardware comprises several custom-designed PCI-bus modules containing the ASIC circuit cards plus COTS components. The functions of the modules, ASICs, and COTS components are integrated by use of the DSDP control software, which provides a generic environment for controlling and monitoring diverse hardware components within a system.

The DSDP control software is a distributed, modular, platform- (operating-system)-independent, highly reconfigurable, reusable, software system that facilitates customization by and for users and is easily modifiable to support system upgrades and new system components. It affords a general-purpose capability for displaying data and creating graphical user interfaces for controlling and monitoring systems. The graphical user interfaces are easy to use (and highly automated) making it possible for a nonspecialist to configure and operate the system. The software also includes tools for planning and scheduling operations, and for the management, processing, generation, and assurance of the quality of, scientific data products. These characteristics make the DSDP control software attractive for other applications that involve scheduling, planning, and the distribution of data; examples include medical, banking, stock-exchange, and automotive-production applications.

This work was done by Barbie Brown, Parminder Ghuman, Jeremey Jones, Johnny Medina, and Greg Schmidt ofGoddard Space Flight Center; Tom Brooks, Lisa Koons, and Randy Wilke of Century Computing Inc.; John Stachniewiczs and Keith Wichmann of GS&T; and Daryl Halliday of Visix.