The restructuring of the ADS is necessitated by continued budgetary pressures within NASA. The availability of alternative distributed data access mechanisms allows the ADS Project to phase out the proprietary software that was used by the project in favor of WWW based protocols while still maintaining some of the infrastructure that is a key component of this distributed information system. Our objective is to provide complete support for the existing ADS Abstract Service and to maintain access to as much of the existing ADS data assets as possible within the constraints of our resources. We will continue to operate the "classical" ADS for as long as possible during this transition to WWW services. However, we will not be able to provide high levels of user or node support with our reduced resources.
Development work will include cooperation with the publishers of astronomical literature to provide access to the original author abstracts. We will also work on providing access to the full articles in bitmapped form. As a first step in this direction we plan to provide links to the bitmaps of journal articles that were produced by the STELAR project. User response to having full journal articles available and linked with the abstracts will be evaluated. If it proves to be a valuable service, we will work with publishers to digitize more of the old literature and to see whether we can provide access to electronic forms of new articles.
Recently it has become possible to "publish" electronically, data tables from a journal article. We have started work on linking these data tables to the abstracts of the articles. We are making use of the on-line data currently available through the CDS in Strasbourg. Our objective is to provide access to these data from the abstracts that refer to them.
The efforts described above will extend the scope of the abstract service and expand it into a wide ranging Digital Library service with greatly enhanced utility for the astronomical community.
The central location service provided by the ADS helps to deal with the general problem of how the user community can know about the existence of valuable data. We plan to continue to provide this important (and unique) function through our Web Catalog Server. Similarly, we are working on a prototype WWW server for archival data. Our initial effort is to provide access to the Einstein Observatory data set maintained at SAO. We plan to work with our current ADS data providers to help in the transition from ADS servers using our proprietary protocol to servers based on WWW protocols. We will also include links within the ADS WWW Services HomePage to other sources of astronomical data so that users can have a single starting point for finding these resources.