Data Management in Planetary Exploration and Space Physics

Planetary exploration and space physics approach data management in very different ways. In this talk we will compare the approaches in these two disciplines with emphasis on how each has dealt with the problems of locating and accessing distributed data. We also will outline the data management challenges each will face in the next decade. Sixteen years ago the NASA Solar System Exploration Division founded the Planetary Data System (PDS) to coordinate the data activities of planetary missions, provide the scientific community with access to planetary data and preserve the data from planetary missions for future analysis. PDS is organized into "nodes" by scientific sub-disciplines (Atmospheres, Geoscience, Plasma Interactions, Rings and Small Bodies) and experimental technique (Imaging and Radio Science). In addition the Navigation and Ancillary Information Facility (NAIF) addresses data issues involving navigation and instrument pointing. All planetary data from NASA missions are prepared to the same metadata standards that include a common data dictionary. Initially access to the data was by sub-discipline although within a sub-discipline the access was to all missions and instrument types. More recently planetary science has become more interdisciplinary and now PDS is moving toward a system that supports cross discipline access. Data are available either on online or on hard media (CDROM or DVD). In recent years space physics data access has been organized by missions. Some missions support data systems through which all of the data from the mission can be accessed while for others the data are available from individual principal investigator sites. In general the space physics missions support an open data policy and much of the data is available online. There are no discipline wide metadata standards. Different missions support different data dictionaries, schemas and interfaces. The data come in a variety of formats. In the near future both planetary science and space physics will be challenged with massive volumes of data from new missions (approximately 10¹⁵ bytes). In both disciplines the need for comparative research across missions or sub-disciplines is becoming more common. Both will have to support data structures that allow users to readily locate, access, and use data from distributed and diverse sources. Both disciplines must address the issue of how to distribute these massive data sets to the science community. Distributable media (DVD) are too expensive due to their limited storage capacity and the network bandwidth is unlikely to be able to support online distribution.