International Telemetering Conference Proceedings / October 27-30, 1997 / Riviera Hotel and Convention Center, Las Vegas, Nevada / The international space community, including National Aeronautics and Space Administration (NASA), European Space Agency (ESA), Japanese National Space Agency (NASDA) and others, are committed to using the Consultative Committee for Space Data Systems (CCSDS) recommendations for low earth orbiting satellites. With the advent of the CCSDS standards and the availability of direct broadcast data from a number of current and future spacecraft, a large number of users could have access to earth science data. However, to allow for the largest possible user base, the cost of processing this data must be as low as possible. By utilizing Very Large Scale Integration (VLSI) Application-Specific Integrated Circuits (ASIC), pipelined data processing, and advanced software development technology and tools, highly integrated CCSDS data processing can be attained in a single desktop system. This paper describes a prototype desktop system based on the Peripheral Component Interconnect (PCI) bus that performs CCSDS standard frame synchronization, bit transition density decoding, Cyclical Redundancy Check (CRC) error checking, Reed-Solomon decoding, data unit sorting, packet extraction, annotation and other CCSDS service processing. Also discussed is software technology used to increase the flexibility and usability of the desktop system. The reproduction cost for the system described is less than 1/8th the current cost of commercially available CCSDS data processing systems.

International Telemetering Conference Proceedings / October 30-November 02, 1995 / Riviera Hotel, Las Vegas, Nevada / The Earth Observing System-AM (EOS-AM) spacecraft, the first in a series of spacecraft for the EOS, is scheduled for launch in June of 1998. This spacecraft will carry high resolution instruments capable of generating large volumes of earth science data at rates up to 150 Mbps. Data will be transmitted in a packet format based upon the Consultative Committee for Space Data Systems (CCSDS) Advanced Orbiting Systems (AOS) recommendations. The Data Systems Technology Division (DSTD) at NASA's Goddard Space Flight Center (GSFC) has developed a set of high performance CCSDS return-link processing systems to support testing and verification of the EOS-AM spacecraft. These CCSDS processing systems use Versa Module Eurocard bus (VMEBus) Very Large Scale Integration (VLSI)-based processing modules developed for the EOS ground segment to acquire and handle the high rate EOS data. Functions performed by these systems include frame synchronization, Reed-Solomon error correction, fill frame removal, virtual channel sorting, packet service processing, and data quality accounting. The first of the systems was delivered in October 1994 to support testing of the onboard formatting equipment. The second and third systems, delivered in April 1995, support spacecraft checkout and verification. This paper will describe the function and implementation of these systems.

International Telemetering Conference Proceedings / October 30-November 02, 1995 / Riviera Hotel, Las Vegas, Nevada / The wide use of standard packet telemetry protocols based on the Consultative Committee for Space Data Systems (CCSDS) recommendations in future space science missions has created a large demand for low-cost ground CCSDS processing systems. Some of the National Aeronautics and Space Administration (NASA) missions using CCSDS telemetry include Small Explorer, Earth Observing System (EOS), Space Station, and Advanced Composite Explorer. For each mission, ground telemetry systems are typically used in a variety of applications including spacecraft development facilities, mission control centers, science data processing sites, tracking stations, launch support equipment, and compatibility test systems. The future deployment of EOS spacecraft allowing direct broadcast of data to science users will further increase demand for such systems. For the last ten years, the Data Systems Technology Division (DSTD) at NASA Goddard Space Flight Center (GSFC) has been applying state-of-the-art commercial Very Large Scale Integration (VLSI) Application Specific Integrated Circuit (ASIC) technology to further reduce the cost of ground telemetry data systems. As a continuation of this effort, a new desktop CCSDS processing system is being prototyped that offers up to 150 Mbps performance at a replication cost of less than $20K. This system acts as a gateway that captures and processes CCSDS telemetry streams and delivers them to users over standard commercial network interfaces. This paper describes the development of this prototype system based on the Peripheral Component Interconnect (PCI) bus and 0.6 micron complementary metal oxide semiconductor (CMOS) ASIC technology. The system performs frame synchronization, bit transition density decoding, cyclic redundancy code (CRC) error checking, Reed-Solomon decoding, virtual channel sorting/filtering, packet extraction, and quality annotation and accounting at data rates up to and beyond 150 Mbps.