NOST News: Results of Spring 2002 International Standards Workshop

By John Garrett and Donald Sawyer

Panel 2 of the Consultative Committee for Space Data Systems (CCSDS) held its spring 2002 workshop from 8-12 April 2002. The prior week from 3-5 April, 2002, a cross-panel group of interested CCSDS participants held a workshop looking at the use of XML in the Space domain. Both these events were hosted by the British National Space Centre (BNSC) at the Rutherford Appleton Laboratory (RAL) near Oxford, England.

The CCSDS XML Workshop that preceded the Panel 2 Workshop was a follow on to the CCSDS XML workshop hosted by NOST and Raytheon during the summer of 2001 (see article at http://nssdc.gsfc.nasa.gov/nssdc_news/sept01/xml_nost.html). The workshop was motivated by the possibility of leveraging the existing and in process XML and related standards to supplement and extend existing CCSDS Panel 2 standards and Panel 3 Space Link Extensions (SLE) standards to provide interoperability and cross-support. These methods could provide a significant positive impact on the cross-support interfaces which now typically use manual interfaces and interchange of unstructured information. The workshop resulted in a resolution asking the CCSDS Management Council to create a new formal work item to address the use of XML and related technologies. The workshop participants also suggested the development of an incremental prototype to demonstrate space mission interoperability and cross-support function. The prototype would help drive the development of future standards.

The XML workshop also allowed the Panel 2 participants to report on their status and plan of action on XML Packaging Standards. During the CCSDS Panel 2 meeting, significant progress since the last workshop (see article at http://nssdc.gsfc.nasa.gov/nssdc_news/dec01/nost.html) was made on a number of standards efforts. The first two days of the meeting incorporated the ISO TC20/SC13 archiving session and included participants both from within and outside of the space community.

The updated "Reference Model for an Open Archival Information System (OAIS)" has completed both the CCSDS and ISO reviews. Pending the inclusion of a few editorial updates, this document has been approved as a standard by both groups. The final version is in the process of being published.

An early draft standard entitled "Producer-Archive Interface Methodology" lays out a set of steps for the interaction between the data producer and the archive. It is intended to be relevant to all science and project archives having multiple submitters of information. This document was reviewed and draft updates and additions were identified. It is expected that we will produce another internal draft and then by the 2002 fall meeting the document will be ready for a formal public review as a CCSDS draft standard (Red Book). We encourage all archives and projects to review the document and provide comments. It can be found at http://ssdoo.gsfc.nasa.gov/nost/isoas/CCSDS-651.0-W-1.pdf.

There is still a significant interest in developing a document addressing the certification of a archive. Several CCSDS members are continuing to explore the possibilities of supporting this activity.

Archiving activities within members respective countries and organizations remain at a high level. BNSC expects to be holding a Preservation Workshop later this year possibly at the e-Science Center in Edinburgh. The French Space Agency, Centre National d'Etude Spatiales (CNES), is sponsoring the Ensuring Long-Term Preservation and Adding Value to Scientific and Technical Data Symposium from 5-7 November 2002. The Research Libraries Group continues to support our efforts and has set up mailing lists and http://ssdoo.gsfc.nasa.gov/nost/isoas/us/overview.html.

In the remainder of the CCSDS Panel 2 Workshop, the focus was primarily on extending the XML Packaging concepts discussed the previous week. There was also reporting on the progress of documents moving through the standards approval process. The Data Entity Dictionary Specification Language (DEDSL) set of standards- DEDSL - Abstract Syntax, DEDSL - PVL Syntax, and DEDSL - XML/DTD Syntax have all now been published as CCSDS Standards. They are now under review to also become ISO Standards. These documents provide a standard way to express the semantics of data such as names, definitions, data types used, and other attributes. They also allow for users to extend the attributes available for descriptions of data.

For further information on any of these topics, contact Donald Sawyer at Donald.Sawyer@gsfc.nasa.gov or John Garrett at John.Garrett@gsfc.nasa.gov.