THE SMITHSONIAN/NASA ASTROPHYSICS DATA SYSTEM (ADS) IS A CORE COMPONENT OF THE SCHOLARLY INFRASTRUCTURE OF ASTRONOMY AND ALSO FINDS SUBSTANTIAL USE IN THE PHYSICS AND GEOPHYSICS COMMUNITIES. TODAY THE ADS IS BEST DESCRIBED AS A DISCIPLINARY REPOSITORY FOR BIBLIOGRAPHIC CONTENT IN ASTRONOMY AND ASTROPHYSICS. IN ADDITION TO ITS SEARCH CAPABILITIES ADS TRACKS CITATIONS BETWEEN PAPERS LINKS TO DATASETS ASSOCIATED WITH THE PUBLICATIONS PROVIDES ARTICLE-LEVEL METRICS AND FEATURES PERSONALIZED NOTIFICATION SERVICES.THE ADS LITERATURE DATABASE CONTAINS ENTRIES FOR MORE THAN ELEVEN MILLION ITEMS AND INCLUDES THE FULL-TEXT FOR APPROXIMATELY FOUR MILLION OF THEM. NEARLY EVERY MODERN REFEREED ARTICLE IN PHYSICS ASTRONOMY OR GEOPHYSICS IS IN THE ADS FULL-TEXT COLLECTION. THE ADS IS MORE THAN JUST A PROTOTYPICAL BIBLIOGRAPHIC DATABASE BUT RATHER IT ACTS AS AN AGGREGATOR OF SCHOLARLY RESOURCES RELEVANT TO NASA ASTROPHYSICS RESEARCH. IN ADDITION TO INDEXING CONTENT FROM A VARIETY OF PUBLISHERS THE ADS PROVIDES A NUMBER OF VALUE ADDED SERVICES WHICH ENRICH ITS COLLECTIONS IN MANY DIFFERENT WAYS. WE HARVEST AND MERGE BIBLIOGRAPHIC DATA FROM MULTIPLE SOURCES (ARXIV CROSSREF A NUMBER OF PUBLISHERS AND ASTROPHYSICS ARCHIVES) CROSS-CORRELATING CONTENT ACROSS THEM (ARXIV E-PRINTS AND PUBLISHED PAPERS DATA CATALOGS OBSERVING AND FUNDING PROPOSALS AND THEIR PAPERS). WE COLLECT AND EXPOSE LINKS TO EXTERNAL RESOURCES SUCH AS PUBLISHERS AND NASA DATA ARCHIVES. WE ENRICH ARTICLE METADATA VIA TEXT-MINING OF FULL-TEXT SOURCES (EXTRACTING REFERENCES ACKNOWLEDGMENTS KEYWORDS). WE INCORPORATE BIBLIOGRAPHIES FROM INSTITUTES AND ARCHIVES. AND WE GENERATE AND MAINTAIN CITATION AND CO-READERSHIP NETWORKS TO SUPPORT DISCOVERY AND BIBLIOMETRIC SERVICES.ROUGHLY 50 000 SCIENTISTS USE THE ADS ALMOST DAILY INCLUDING ESSENTIALLY EVERY WORKING ASTRONOMER AND A FEW TENS OF THOUSANDS OF PHYSICISTS AND GEOPHYSICISTS. ABOUT 250 000 SCIENTISTS USE IT TO DOWNLOAD A COUPLE OF ARTICLES PER WEEK OR MONTH AND A FEW MILLION INDIVIDUALS USE IT OCCASIONALLY OFTEN VIA GOOGLE OR WIKIPEDIA LINKS. THE ADS IS ALSO USED BY DOZENS OF DATA ARCHIVISTS AND LIBRARIANS WHO USE IT AS THE REFERENCE BIBLIOGRAPHIC SYSTEM CONNECTING PUBLICATIONS WITH THE DIGITAL RESOURCES WHICH THEY CURATE. IN THIS PROPOSAL WE DESCRIBE IN DETAIL THE SCIENTIFIC AND TECHNICAL CONTRIBUTIONS THAT ADS ACTIVITIES PROVIDE TO NASA AND THE RESEARCH COMMUNITY. THE TECHNICAL AND BUDGET SECTION DISCUSS IN DETAIL THE EFFORT REQUIRED TO SUPPORT OUR PROJECT PRIORITIES NAMELY: TO CONTINUE OPERATING THE ADS SERVICES EFFECTIVELY AND EFFICIENTLY; TO PROVIDE STABILITY TO THE ADS PROJECT AND TO ITS SERVICES; AND TO ENSURE THE ONGOING RELEVANCE OF ADS TO NASA S MISSION IN THE FAST-CHANGING WORLD OF SCHOLARLY COMMUNICATIONS