As the space age evolved in the 1960's and 1970's, there was increasing interest in stimulating international cooperation
as a way to enhance space exploration. In particular, since many space agencies had invested large sums of money in the development of space mission support
infrastructure on the ground, the concept of “cross support” emerged whereby one Agency could offer its data handling services to another and thus enhance
the opportunities for conducting international missions. During those early days, in the absence of any internationally agreed space data standards,
cross support was generally handled by the introduction of "black box" adapters to forge compatibility at the interfaces between agencies. These black boxes
were uniquely configured for each individual case.
As space exploration moved along into the 1980's, technological advances in spacecraft computation, memory and communications
capabilities made it feasible to start standardizing the ways in which spacecraft and ground data systems exchanged information. At the same time, the costs
of implementing and operating these more capable space missions were increasing significantly. To take advantage of the opportunities presented by the
technological advances and to meet the fiscal challenges, some initial steps were taken which ultimately lead to the formation of Consultative Committee for
Space Data Systems (CCSDS).
In March 1981, the NASA-ESA Working Group (NEWG) held its first meeting to address cooperative development of space data
standards, initially in the areas of spacecraft “packet telemetry” and then in “packet telecommand”. In January 1982, at an International Workshop on Space
Data Systems held in Washington, DC, USA, this bilateral activity was broadened and many of the world's space agencies met to begin discussing common problems
relative to space information and data systems. At that meeting, the final steps were taken to formalize international space data standardization activities by
creating the CCSDS, which then had its inaugural meeting at CNES in Toulouse, France on 04-08 October 1982.
The CCSDS was chartered to study the problems of cross support and, through the collective efforts of its international
experts, to develop advanced standardized solutions to these challenges of exchanging space mission data. These solutions, called CCSDS Recommendations,
were the primary products of the CCSDS for most of its first twenty years. Draft CCSDS Recommendations were created, reviewed by CCSDS participating agencies
and were subsequently adopted by the CCSDS participating agencies as final CCSDS Recommendations that served to guide the internal development of standards
by each of the members. These early CCSDS activities significantly enhanced the planning and execution of cooperative space missions flown by the
The initial structure of CCSDS, adopted in 1982, centered around technical “panels” to develop standard Recommendations in
various space data system areas. The initial structure was:
- Panel 1 - Telemetry, Tracking, and Command,
- Panel 2 - Information Interchange Processes,
- Panel 3 - Cross Support Operations, and
- Panel 4 - Radio-metric and Orbit Data
The space-to-ground data link was the first part of the data system to be addressed by CCSDS, primarily because it is unique
to space missions and is constrained by the stressed communications environment. Based on the precursor work by NASA and ESA, CCSDS Panel 1 soon presented
concrete results in the form of two final CCSDS Recommendations, one for “Packet Telemetry” and one for "Telemetry Channel Coding". Panel 1 quickly followed
through with standards for space channel modulation, packet telecommand, time code formats and – by the end of the 1980’s – with the “advanced orbiting
systems” standards that became the data communications baseline for the International Space Station. Meanwhile, Panel 2 rapidly developed new standards
for exchanging information among scientific and engineering users, Panel 3 began developing the “space link extension” standards that could allow one
agency’s control center to connect to another agency’s ground station, and Panel 4 developed standards for exchanging radio metric information.
In 1991, the CCSDS entered into a cooperative arrangement with the International Organization for Standardization (ISO).
Under this arrangement, CCSDS Recommendations were advanced to Subcommittee 13 within Technical Committee 20 (Aircraft and Space Vehicles) where, via the
normal ISO procedures of review and voting, they are progressed into full International Standards.
In 2003, after twenty years of success and recognizing the need to streamline and broaden its processes, CCSDS re-engineered
the organization using a working model that was used so successfully by the Internet Engineering Task Force (IETF) to develop the terrestrial Internet.
Within the new CCSDS organization, six broad discipline “Areas” were created:
Within each of these Areas, specialized Working Groups were chartered to develop “Recommended Standards”. Additional
categories of “Recommended Practices” and “Experimental” standards were also added to the specification hierarchy.
Although the growing acceptance of CCSDS Recommendations
is testimony to the quality of its
work, there remains much to be done. Not only must we continue to maintain the current recommendations, but we must also address new areas of standardization.
And our initial problems of advancing technology and increasing budgetary pressures continue to challenge us.
Credit for the emerging success of the CCSDS must be given to many people in many places: the fine technical staffs of the
member agencies who form the core of the activity, the flight project managers who showed fairness in their analysis and acceptance of the CCSDS products,
and the management of the member agencies who support the CCSDS by each contributing their unique human resources. Through all of the people who work in
CCSDS, the worldwide space agencies continue to work together towards cooperative solutions to common space data handling problems that will allow us to fly
international space missions for the benefit of all humankind.
Largely excerpted from articles by:
- Dr. Horst Kummer (formerly of ESA)
- Mr. Robert Stephens (formerly of NASA)
- Mr. Edward Greene (formerly CCSDS Secretariat and formerly of NASA)