The NASA Space Physics Data System

Concept Document

		Space Physics Division
		Office of Space Science
		February 1993

Executive Summary

The prevailing data environment of the modern space physics community has three major features. First, a vast body of space physics data exists, some of which is not now adequately managed or not readily accessible to scientists. Second, the scientific maturity of the discipline is such that the science problems of the 1990’s require a greater ability for correlative analysis of multiple datasets. Third, the present and future fiscal climates are austere with the NASA Mission Operations and Data Analysis (MO&DA) funds available to meet these needs in greater demand than at any time in the recent history of space physics. Therefore, it is essential for the space physics community in general and the NASA Space Physics Division (SPD) in particular to address innovative and cost-efficient ways to preserve, exchange, and access science data. The Space Physics Data System (SPDS) presented in this Concept Document is designed to meet these needs within the fiscal constraints of present-day NASA budgets.

The purpose of this Concept Document is to present the initial findings of the SPDS Steering Committee to the potential system users, data suppliers and NASA management. It is critical to the short-term evolution of the system and the long-term success of SPDS that the system concept and evolving system plans reflect the views of the wider space physics community. The Steering Committee contemplates an SPDS “Community Workshop” for a mid-1993 time-frame as a forum for input and comments on the concept and to more precisely define the SPDS functional requirements by that wider community. As an aid in better understanding the intended concept and to stimulate interactions and discussion at that workshop, this Concept Document includes a strawman for an initial form and subsequent evolution of SPDS.

The SPDS is born from the recognition that the datasets derived from past, present and future SPD missions and from related activities of other national and international organizations are a capital asset, and that it is imperative to preserve, distribute and support the synergistic analysis of these data in concert with the overall NASA/SPD program. As knowledge of the Sun, Earth, planets, and the space that surrounds them and their governing physical laws increases, the space physics community requires increasingly sophisticated measurements and combinations of observations in order to continue its advance in understanding the wide range of interactions between regions as well as the collective roles of physics and chemistry in these regions. Therefore, it has become clear that new tools and approaches for managing relevant observational data and enabling the correlative analysis of SPD data are required in conjunction with relevant observations from non-SPD sources and physical models.

Currently, the relevant data are widely distributed and available in varying degrees of usefulness. Many of the datasets with the highest scientific potential are those located in the Principal Investigator institutions or in special data systems developed for specific missions, because data are generally archived where the scientific expertise necessary for their proper development and maintenance is located.

The experience of other Divisions of the Office of Space Science and Applications (OSSA) and the recommendation by the National Academy of Sciences (NAS) Committee on Data Management, Archiving, and Computing (CODMAC) suggests that one effective approach is a system of distributed data facilities and archives that can maximally exploit the dramatic new advances in information processing and network communications. This is the approach on which SPDS will be based. The fundamental objectives of SPDS will then be to:

The austere fiscal environment in which the space physics community exists and the need for a system that is highly responsive to the real needs of that community both strongly suggest that conventional system development, which are exclusively top-down and require a detailed initial design phase, cannot be effective. Although high-level functional requirements must be laid out and prioritized, and an overall system design defined, SPDS should evolve as much as possible incrementally from the grass roots. Such an approach will be less vulnerable to the shortcomings of a system specified by the global science community but developed and managed by others, and has been used with great success in the development of the Space Physics Analysis Network (SPAN).

Initially SPDS will use existing, project-specific data systems linked to each other and the user community by the NASA telecommunications infrastructure. Participation in the initial SPDS confederation will be driven from the grass roots and will be stimulated by the ability to perform correlative analysis. The SPDS will, in time, develop an architecture with nodes defined by science discipline and should become a common framework and common resource for other data systems subsequently developed by individual institutions, laboratories, universities and missions. As the scientific productivity of SPDS is demonstrated to a broader community with cost-effective access to more datasets, it can be expected that the future institution-level data systems will develop to be more readily compatible with SPDS. SPDS will also have a key role in working with future SPD flight projects to best assure their adequate and coordinated long-term data management planning.