The Consultative Committee for Space Data Systems (CCSDS) was formed in 1982 by letter of agreement, signed by responsible officials of the participating national and international space agencies
Since its formation, the CCSDS has developed and published many documents (“Recommendations for Space Data System Standards”, herein usually referred to as “CCSDS Standards”), the majority of which have become full international standards. Over 100 CCSDS documents are currently active and applicable in widespread use across the international space community. Note that CCSDS Recommended Standards may be adopted as the basis for international agreements, or they may be incorporated into local standards that form the controlling documentation for such agreements.
In 1990, Technical Committee 20 (TC 20) of the International Organization for Standardization (ISO) formed Subcommittee 13 (SC 13), Space Data and Information Transfer Systems. Recognizing CCSDS as a leading international authority in developing standards for space-related information technologies, ISO agreed that CCSDS has the primary responsibility for technical development of standards that are approved by ISO TC 20/SC 13.
The purposes of the CCSDS are contained in the Charter (above). Broadly, they are to provide an international forum in which the CCSDS agencies can discuss common space data communications and service-based needs and arrive through consensus at standard solutions to those needs, thereby increasing efficiency and interoperability among agencies, and decreasing costs
This Strategic Plan has been approved by the CCSDS Member Agencies. It is intended that the Strategic Plan should be updated whenever necessitated by changing events (or at least every 5 years) to redefine the organization’s current objectives, domains for standardization, and strategic goals. The Strategic Plan also serves to reaffirm the cooperative agreements entered into by the founding and continuing members of the CCSDS
CCSDS’ online Collaborative Work Environment (CWE) supports this Strategic Plan by providing organizational details, charters of each working group, project definitions and resource matrices, online polling, and a host of other collaborative tools designed to assist in document development and lead to better understanding of the CCSDS. The CWE is maintained by the CCSDS Engineering Steering Group, and is updated in real time as charters are approved.
In the process of developing CCSDS standards, the community
will, as a first priority, adopt existing standards and approaches rather than
developing something new. If an existing standard or innovative technical
approach cannot be adopted as is, the second priority is to adapt it to fit the
needs of the space community. As a final resort, when nothing exists that can
be adopted or adapted, the community will develop new technical approaches to
meet the needs of the spaceflight community. This is the basis of the CCSDS
mantra to “adopt/adapt/develop”, in that order.
Standardization is widely recognized as a vehicle to stimulate the development of world markets. To help develop space as an international marketplace, CCSDS standards aim to support the data information, communications, and service needs of a wide, but not totally inclusive, set of space missions. Primary CCSDS target missions include civilian spacecraft and landed vehicles operating in Earth orbit, within the Earth-Moon system, in deep space, and on and around other Solar System bodies.
While no kind of mission—civil, military, commercial, robotic, piloted—is specifically excluded from the interests of CCSDS, it is recognized that some spacecraft provide specialized data-handling services that are well supported by their own user communities or by other standardization bodies. For example, commercial voice, data, and video broadcasting satellites may use their own transponder data communications protocols, and commercial Earth-observing satellites may use their own private data distribution protocols, yet they both may use CCSDS standards to support other parts of their mission infrastructure—such as Tracking, Telemetry, and Command (TTC) functions. As a natural consequence, CCSDS is constantly motivated to consider the establishment of formal and technical liaisons with other organizations as a means for expanding space data systems standardization on a worldwide basis.
CCSDS therefore aims to perform the necessary outreach to seek the widest possible set of target missions. There are multiple interfaces at which “CCSDS conformance” may be achieved by following defined CCSDS interface standards, protocol/information proformas and profile requirements lists. However, conformance with a single particular standard will not necessarily result in interoperability unless both parties to the data exchange also agree to use the same “stack” of underlying standards.
The objective of the CCSDS is to harmonize and lead the worldwide standardization of space mission information and communication systems, thus promoting international cooperation and enabling these space systems to be effectively integrated with their terrestrial data communications and information systems counterparts.
CCSDS provides the means whereby space agencies can reach voluntary consensus on standardized solutions to common problems associated with the design of compatible space mission information and communication systems. The fruits of that consensus are made available across the space community in the form of new international standards, along with hardware and software (e.g., a future CCSDS Open Source Library) that facilitate their adoption. Standardization (through standardized products and COTS products) enhances the international exploration and exploitation of space by increasing the use and value of the information gathered, while simultaneously realizing significant savings in cost and development time for all participants.
In order to maximize the benefits of standardization, CCSDS has as an objective to disseminate the results of its standardization activities and promote their worldwide adoption. This includes promotion of CCSDS standards within the member organizations’ programs and outreach towards other space communities. Tracking and reporting the infusion of the standards in space programs within member organizations also serves this purpose
CCSDS shall promote:
In order to increase the productivity and impact of the standardization activities, it is important to increase the number of agencies that actively contribute to the development of new standards in CCSDS by leveraging the agencies’ resources and expertise.
CCSDS will continue its strong relationships and ties with ISO to further the stature and pre-eminence of CCSDS standards in the international community
CCSDS has achieved greater international visibility by responding to requests for support to other governing and coordinating bodies on the topic of spaceflight. An example of this is the report that CCSDS provided to the United Nations Committee on the Peaceful Uses of Outer Space; the Working Group on the Long-term Sustainability of Outer Space Activities. CCSDS shall continue to provide responses to such requests, and will further seek out additional opportunities for similar outreach
In order to extend the CCSDS body of standards with sufficient lead time to keep pace with the new requirements of space missions to be flown in the coming decades, CCSDS shall conduct continuing outreach that will build liaisons with CCSDS stakeholders (space missions and space mission support organizations) as well as with other standardization organizations and with other space communities. The new requirements include:
CCSDS exists to develop the necessary agreements that allow standard communications data-handling services to be exposed at the major interfaces between participating organizations. When such a standard service is offered by one organization and is used by another, an instance of CCSDS cross support has occurred. When information flows automatically across the interface so created in accordance with standard data exchanges or protocols under well-defined interoperable profiles, an instance of CCSDS interoperability has occurred.
It is a CCSDS core requirement that recommended standards and practices must be developed to facilitate interoperability and cross support.
In order to satisfy this requirement, CCSDS establishes technical areas for standardization. Although they are intended to be relatively stable entities, areas may be added or deleted in response to a changing space mission environment.
As shown in Figure 1, six technical areas form the current working structure of CCSDS. Each area contains narrowly chartered working groups (not shown here) that concentrate on the production of specific recommended standards and practices within the theme of that parent area.
The overall goal as expressed in the CCSDS Charter is the enabling of interoperable spaceflight missions by producing standards in the communications and data systems area. The strategic goals that follow are intended to be unique approaches to better enable that charter
The objective of the Systems Engineering Area (SEA) is to address system-wide architectural and engineering topics that are so pervasive that they span over all, or several, other CCSDS areas. This work includes development of specific standards and guidelines, development of system architectures and models, coordination/collaboration with other areas, and otherwise supporting CCSDS and CMC engineering and operational goals.
The SEA system architecture tasks include end-to-end reference architecture, architecture analysis and description methods, and related cross cutting terminology topics. The SEA security architecture and standards are to be used by other CCSDS areas requiring security guidance and services. The Delta-DOR services touch upon the Cross Support Services (CSS) and Space Link Services (SLS) areas, and Mission Operations and Information Management Services (MOIMS) may be involved in planning for use of these services. The information architecture and registry services also cross cut MOIMS, CSS, Space Internetworking (SIS), and other Services. Extensible Markup Language (XML) standards and guidelines and other special cross-cutting topics that are guided by SEA affect all of the other areas. As system or information architecture standards are developed, SEA will coordinate with the other CCSDS areas and working groups to develop approaches that align with CCSDS goals for interoperability and cross support. The strategic goals of the SEA are listed below.
The CSS area addresses how the services of an agency’s TTC network are made available to another agency’s mission spacecraft. This includes addressing data transfer services and their management. The data transfer services involve both space link (to/from TTC network ground station to mission spacecraft) and terrestrial link (to/from TTC network ground station to the mission ground data system). The space link data transfer encoding/protocol schemes are subject to the SLS area and are not defined by the CSS area. The terrestrial data transfer services, with regard to transfer mission data and observations such as ground station tracking data, are addressed by the CSS area. The management of both the space link and data transfer services is also addressed by the CSS area. Proper definitions of the services and management of these services depends on a reference architecture definition and also agreed, internationally recognized terms for the functional components of this architecture. The terrestrial data transfer services and management data format definitions may be incorporated into mission operations end-to-end recommendations of the MOIMS area. The strategic goals of the CSS area are presented below.
The objective of the Spacecraft Onboard
Interface Services (SOIS) area is to address the services and protocols used by
communication networks within a spacecraft and within close proximity of the
spacecraft. These are applicable to the core spacecraft platform as well as to
the interfaces with both internal and external payloads and extra-vehicular
activities. SOIS also covers the use of wireless technology for ground, space
and planetary surface communication within the spacecraft and within close
proximity to the spacecraft.
The long-term goal of the SOIS area is to encourage the standardization of interfaces and on-board data exchange mechanisms such that spacecraft building blocks, which may range from individual sensors and actuators to complete units, may be developed and utilized with minimum or no change.
As part of this objective, the way in which spacecraft device and interface information is presented is being analyzed and standards are being proposed for specifying such information in electronic, machine-readable format. This aspect is intended to reduce the effort required for spacecraft development and testing by automating the process of code generation and database import. The area will also evaluate other opportunities which may benefit from international standards.
The SOIS area needs to coordinate the following:
The strategic goals of the SOIS area are presented below.
The objective of the SLS area is to address all of the point-to-point communications links and protocols that interconnect a spacecraft with its ground-support system, or with another spacecraft, by developing standards for efficient and reliable space link communications systems addressing nominal as well as emergency scenarios. Specific attention is given by SLS to needs for higher data rates and better link performances, a standard security mechanism, and lower cost, mass, and power.
SLS area objectives focus on Layers 1 & 2 (of the Open Systems Interconnection [OSI] protocol stack)—i.e., the Physical Layer and the Data Link Layer. This means that SLS concentrates in particular on radio-frequency and optical systems, modulation, synchronization and channel coding, and
data link protocols, for both long-haul (e.g., spacecraft-to-ground) and proximity links (e.g., orbiter-to-lander). Moreover SLS concentrates also on two additional functions essential on the space link: data compression for end-to-end data transfer optimization, and ranging for accurate orbit determination.
The SLS area needs to coordinate:
The strategic goals of the SLS area are presented below.
The objective of the SIS area is to address the communications services and protocols supporting end-to-end communications among applications, particularly where those communications may span multiple heterogeneous physical and data link technologies. Areas addressed by SIS include the networking infrastructure to support application-to-application communication onboard a single spacecraft, communications among multiple spacecraft, and communications between space-based applications and their counterparts on Earth and/or other planetary bodies.
Specifically, note that the Service Catalog 2 of the Interagency Operations Advisory Group (IOAG) "identifies the cross-support service types that should be provided by the ground tracking assets operated by the IOAG member agencies participating in the Solar System Internetworking (SSI) based on DTN [Delay-Tolerant Networking] and / or IP [Internet Protocol] technologies." The SIS area focuses on these service types and related services.
As such, the SIS area deals with communication services and protocols that are independent of specific link technology (as a lower layer bound) and independent of application-specific semantics (as an upper bound). Thus the SIS area covers essentially the Network through Transport Layers of the OSI reference model. The SIS area also develops application support protocols where the services provided are intended to operate over an internetworked infrastructure. An example of such an application support protocol is the Asynchronous Messaging Service (AMS), which is intended to be invoked by applications to effect message exchange.
The Bundle Protocol, a central element of DTN, uses the underlying communication and infrastructure services provided by the SLS and SOIS areas and any other onboard networks, and provides the networked connectivity needed by applications developed in other CCSDS areas such as MOIMS and SOIS. This enables the SIS services to provide hardware-independent mechanisms for identifying end systems and to provide communications services that allow users to operate the same way whether communication is over a single data link layer or over multiple hops. The suite of capabilities developed by the SIS area, centered on the DTN architecture, accommodates all ranges of delay, interactivity, and directionality, although not all protocols are appropriate for all environments.
SIS area needs to coordinate the following:
The objective of the CCSDS Management Council (CMC) is to provide the executive management oversight of the organization. The CMC is responsible for staying technically and politically informed about important long-term issues in the field of international space mission cross support and for keeping an eye on the “big picture” of the CCSDS program of work. The CMC provides oversight for the whole CCSDS technical organization and of support organizations like the Secretariat and the SANA. The technical work of the SANA is specifically guided by the SANA Steering Group (SSG).