CCSDS – 20 Years of Success
For 20 years, the Consultative Committee for Space Data Systems (CCSDS) has
been developing the standard space communication protocols used by space
agencies from North America, South America, Europe, Asia, Africa, and
Australia. From the initial development of the packet telemetry standard to
the protocols that will be used for the Mars communications infrastructure,
CCSDS has developed and published 30 Recommendations for Space Data Systems
Standards. CCSDS attributes its success to the cooperation among its diverse
membership.
The 2002 Space Ops conference has noted this special milestone by scheduling
a special plenary session titled “CCSDS; 20 Years in Review” on October 9.
SpaceOps is an international spacecraft operations conference that promotes
continuous technical interchange for all aspects of space mission operations
and ground data systems.
To date more than 200 satellite missions have elected to fly using CCSDS
protocols. The majority of these missions utilize the CCSDS Recommendations
for Packet Telemetry and Telecommand data formats and Radio Frequency
Modulation Systems. Many of these missions also follow recommendations for
data archiving, Space Link Extension (SLE) services, Time Code Formats, and
Lossless Data Compression.
Recent accomplishments of CCSDS include the development of protocols that
adapt new communication technologies for use in space. The CCSDS File
Delivery Protocol is slated for use in future missions to Mars. This
standard will facilitate interoperability between rovers, landers, and
orbiters that will be launched by different international space agencies.
Commercial product developments are also using new CCSDS networking
protocols that allow spacecraft and their instruments to operate like nodes
on the Internet.
The CCSDS was formed in 1982 by the major space agencies of the world to
provide a forum for discussion of common problems in the development and
operation of space data systems. Its mission is to provide the means
whereby space agencies can reach voluntary consensus on standard techniques
for handling space data that enhance cross support, interoperability, and
science information interchange. These standards reduce operations costs by
sharing facilities, and eliminating unjustified project-unique design and
development. Since its inception, participation in the CCSDS has steadily
increased and it is currently composed of ten member agencies and
twenty-four observer agencies. The member space agencies represent the US,
Europe, Japan, UK, France, Germany, Italy, Europe, Brazil, Russia, and
Canada. Additionally, over 100 worldwide industrial associates participate
in CCSDS and have developed compatible products to meet the requirements of
missions and ground-support complexes.
CCSDS products are data- and information-systems Recommendations called Blue
Books. These Recommendations, developed jointly by the experts of the
member agencies with contributions from the observer agencies and industry,
serve as baseline documents for the applicable standards of the
participating agencies. CCSDS Recommendations are routinely submitted to
the International Organization for Standardization (ISO) for adoption as
international standards. CCSDS also publishes Reports (Green Books), which
provide additional material to support the implementation of
Recommendations. CCSDS Recommendations and Reports are available free of
charge on the web at www.ccsds.org.
CCSDS History
As the space age evolved in the 1960s and 1970s, space agencies grew
increasingly interested in international cooperative activities for space
science. This gradually led to a desire for cross support between the
respective communications and space data systems of the agencies. During
those early days, in the absence of any internationally agreed space data
standards, cross support was generally handled by the introduction of “black
boxes” to establish compatibility at the interfaces. These “black boxes”
were uniquely designed for each individual case.
As the space program moved into the 1980s, technological advances in onboard
computation and memory made available new capabilities for space data
systems. At the same time, the costs of implementing and operating these
systems were increasing significantly.
In the autumn of 1982, the CCSDS with its panel structure was formally
established at a meeting in Toulouse, France. Technical panels were formed
to develop Recommendations in various space data system areas. The following
structure was adopted:
The space-ground link was the first part of the data system to be addressed
by CCSDS, primarily because it was unique to space activities and was
constrained by rather severe problems. CCSDS Panel 1 soon presented concrete
results in the form of a CCSDS Recommendation on Packet Telemetry. This
document contains recommendations on telemetry data structures for what has
been called “conventional spacecraft,” and these recommendations have
subsequently been used to produce agency telemetry standards for application
to a number of flight projects. The quick production of the completed
Recommendation was in a large part due to the great progress made in this
field prior to 1982 by NASA and the European Space Agency (ESA).
Around 1990, the CCSDS entered into a cooperative arrangement with
Sub-Committee 13 under Technical Committee 20 of ISO. Under this
arrangement, CCSDS-developed Recommendations are advanced to SC-13 where
they are progressed, via the normal ISO procedures of review and voting,
into ISO/CCSDS Standards. Additionally, CCSDS technical panels have become
more involved with other Standards Developing Organizations through liaison
activities. Typical of these are Committee for Earth Observing Systems
(CEOS), US Department of Defense (DoD), and others.
Although the growing acceptance of CCSDS Recommendations is testimony to the
quality of the work, there remains much to be done.
Credit for the success of the CCSDS must be given to many people in many
places: the fine technical staffs of the member agencies which form the core
of the activity, the flight project managers who showed fairness in their
analysis and acceptance of the CCSDS products, and management of the member
agencies who support the CCSDS efforts. Through the CCSDS, space agencies
worldwide continue to work for cooperative solutions to the space data
problems that allow us to do more in better and cheaper ways for the benefit
of all humankind.
