The study will develop a better understanding of the potential scientific and technological impact of high-end capability computing in four illustrative fields of science and engineering of interest to the Federal government. More specifically, the study will: (a) review the important scientific questions and technological problems identified for those fields in other sources (e.g., decadal surveys); (b) identify the subset of those important questions and problems for which an extraordinary advancement in understanding is difficult or impossible without high-end capability computing; (c) identify some of the likely impacts of making progress on as many of the scientific questions and technological problems identified in (b) as possible and the contribution that high-end capability computing can make to this progress; (d) discuss some of the most significant ramifications of postponing this use of high-end capability computing in order to capitalize on the decreasing cost of computing over time; (e) identify the numerical and algorithmic characteristics of the high-end capability computing requirements needed to address the scientific questions and technological problems identified in (b); and (f) categorize the numerical and algorithmic characteristics, specifically noting those categories that cut across disciplines. This task shall be done in a way that can later be used to inform design and procurements of high-end capability systems. This list of tasks is not in priority order. Tasks (a), (b), (e), and (f) are considered to be the most important and essential for the study’s success. "Note (12-28-2006): The Project Scope was revised to better define the committee’s tasks. The revised version of the Scope is as shown above."The project is sponsored by National Coordination Office for Networking and Information Technology Research and Development, Executive Office of the President.The approximate start date for the project is 12/6/2005 - 12/5/2007.A report will be issued at the end of the project in approximately 24 months.NOTE: The project duration has been extended. The report is expected to be issued by September 2008.