International Telemetering Conference Proceedings / October 20-23, 2003 / Riviera Hotel and Convention Center, Las Vegas, Nevada / This paper introduces the Reference Architecture for Space Data Systems (RASDS) that is being developed by CCSDS. RASDS uses five Views to describe architectures of space data systems. These Views are derived from the viewpoints of the Reference Model of Open Distributed Processing (RM-ODP), but they are slightly modified from the RM-ODP viewpoints so that they can better represent the concerns of space data systems.

International Telemetering Conference Proceedings / October 30-November 02, 1989 / Town & Country Hotel & Convention Center, San Diego, California / The Consultative Committee for Space Data Systems (CCSDS) is developing a set of communications protocols for Advanced Orbiting Systems (AOS). The National Aeronautics and Space Administration (NASA) and the European Space Agency (ESA) are cooperating in an effort to extensively validate these AOS protocols. This paper describes the techniques and facilities being used to perform this validation. Validation of the AOS protocols consists of (1) developing a formal specification of the protocols using a standard formal definition technique (FDT), (2) developing implementations of the protocols, and (3) remote testing of the implementations. From the FDT specifications, each agency is developing independent implementations which are consistent with the FDT specifications of the AOS protocols. Errors, omissions, or discrepancies detected during the development of the FDT specification and the implementation will be reported to the CCSDS and changes to the main specification will be suggested. The independent implementations will be extensively tested locally by the developing agency and then remotely tested through a cooperative test setup between the agencies. The implementations will interact to communicate between the agencies thus providing proof that the FDT specifications are sufficiently specific to be interpreted by everyone in the same way. Significant variations in the interpretations will result in feedback to the CCSDS and any needed changes to the main specification will be suggested. The AOS protocols are divided into four categories: Path, Space Link ARQ Protocol (SLAP), Space Link (SL), and Management. Each agency has agreed to be either the leader or support agency for each of the categories. NASA has agreed to be leader for the validation of the SLAP and SLS categories while ESA has agreed to lead in the validation of the Path and Management categories. Testbeds at the European Space Research and Technology Centre (ESTEC) in Noordwijk, Holland and at the MITRE Corporation in McLean, Virginia have been constructed for the development of FDT specifications and AOS protocol implementations. Communications facilities are being obtained which will connect these testbeds. This paper describes these testbeds, the AOS FDT specifications, the protocol implementations being developed, and the results expected from the tests performed.

International Telemetering Conference Proceedings / October 30-November 02, 1989 / Town & Country Hotel & Convention Center, San Diego, California / During the current decade, international cooperation in space projects has become more and more popular and this trend is increasing. Initially, this involved only single missions with agencies flying payloads on other agencies' spacecraft. Later, this trend continued with international ventures, involving different agencies. In the immediate future, even more challenging scenarios are foreseen. The best known example and prime driver for such sophisticated missions will be the Space Station Freedom and its participating partners' spacecraft. Some of the international missions (ESA missions) are described briefly in this paper, in order to set the scene for a better understanding of the complex needs for standards within advanced orbiting systems. These ventures call for efficient means for cooperation and interoperability. Part of these requirements can be met by following international standards for space communications and space data systems. The Consultative Committee for Space Data Systems (CCSDS) undertook the task of integrating the space data systems requirements and developing appropriate recommendations for data systems standards for these Advanced Orbiting Systems (AOS). All international partners in the Space Station Freedom Program participated in the definition, development, and review of the AOS recommendations. The need for better cooperation in space communications via data relay satellite prompted the formation of a three party international panel called the Space Network Interoperability Panel (SNIP). An important aspect is the need for verification and validation of the concept and of the detailed technical recommendations. For the immediate future, special compatibility campaigns, involving the international agencies are planned in order to ensure the smooth application and functioning of the AOS recommendations.

International Telemetering Conference Proceedings / October 17-20, 1994 / Town & Country Hotel and Conference Center, San Diego, California / The Consultative Committee for Space Data Systems (CCSDS) formulates and publishes recommendations for space data system standards. CCSDS Recommendations define a layered data communications network along the lines of the OSI model. In the space link layer (OSI Data Link layer) fixed length blocks of CCSDS Packets are generated and multiplexed into the data field of Virtual Channel Data Units (VCDUs) in the Virtual Channel Access Sublayer. VCDUs with error correction coding become CVCDUs (coded VCDUs). CVCDUs (or VCDUs) with an attached sync marker become Channel Access Data Units (CADUs) which are transmitted on the Physical Space Channel. This paper discusses AYDIN's DEC012 Data Unit Decoder, a VMEbus circuit card which recovers Virtual Channel Data Units (VCDUs) from corrupted Channel Access Data Units (CADUs) received on the Space Link Subnet of a CCSDS-compatible space datacomm link. The module's design and operation is described along with its use in the X-ray Timing Explorer (XTE) and Tropical Rainfall Measuring Mission (TRMM) science satellite programs run by NASA Goddard Space Flight Center.

International Telemetering Conference Proceedings / October 20-23, 2003 / Riviera Hotel and Convention Center, Las Vegas, Nevada / NASA and Lockheed Martin-CSOC have been supporting in the development of plans for the evolution of NASA’s Ground Network (GN) and Space Network (SN), and where possible, synchronizing those plans with plans for the evolution of the Deep Space Network (DSN). This paper describes a recommendation for a common ground system communication architecture based on the Consultative Committee for Space Data Systems (CCSDS) Space Link Extension (SLE).