For example, a team of computational physics and engineering experts have been using NNSA supercomputers to better understand the impact of space debris. Working in collaboration with Los Alamos National Laboratory (LANL) and Sandia National Laboratories, the team developed a set of tools known as the Testbed for Space Situational Awareness (TESSA), they can simulate the position of objects in orbit and the detection of them by telescope and radar systems, helping to prevent a space disaster. In the future, the same technology can be used to enhance nuclear security by helping plan sensor operations and assessing the benefits of specific sensor systems, technologies, and data analysis techniques.
"NNSA's efforts to maintain the safety, security and effectiveness of the nuclear stockpile without underground testing have yielded solutions to some of the most challenging issues that face our country", stated Don Cook, NNSA's Deputy Administrator for Defense Programmes. "From space debris to medical work to climate change, even to understanding the damage that caused the breakup of the Space Shuttle Columbia, NNSA has been able to support many important issues that impact the nation while implementing President Obama's nuclear security agenda."
The development of the space debris modelling capability is one of many examples of the ways NNSA's supercomputers have enabled our laboratories to find solutions to broader national challenges.
At Los Alamos National Laboratory, ASC code is being used for medical physics. MCNPX, a general-purpose Monte Carlo radiation transport code for modelling the interaction of radiation with the things it comes into contact with, is ideally suited for use in medical applications because of the accuracy of its physics models, the unique set of clinically relevant features, and the responsive support provided by the developers and the user community. LANL has used MCNP code to calculate dose distributions for brain tumour therapy at the MIT Nuclear Reactor. MCNP is a 3D, parallel, internationally respected, particle transport code that is used in medical physics and radiation health protection.
Scientists were also able to help stabilize Roadrunner, an NNSA supercomputer at LANL, by running science-based applications before it was ready for use as part of the stockpile stewardship program. One application modelled HIV proteins, which led to a better understanding of how the AIDS virus replicates itself. That project could serve as the cornerstone to developing the first viable vaccine to protect people from HIV.
Also at LANL, research to understand the potential influenza pandemic sweeping across a continent has been conducted. This research, supported by the Department of Homeland Security and LANL supercomputer time provided by the Institutional Computing and ASC programmes, led to a cover article in theProceedings of the National Academy of Sciencesin April 2006 titled "Mitigation strategies for pandemic influenza in the United States".
Researchers at Sandia National Laboratories played a key role in helping NASA determine the cause of the space shuttle Columbia disaster. Sandia analyses and experimental studies supported the position that foam debris shed from the fuel tank and impacting the orbiter wing during launch was the most probable cause of the wing damage that led to the breakup the Columbia. Sandia researchers used a variety of internal and external computer codes to help in the analysis, including computational fluid dynamics analyses for the orbiter at various altitudes along the trajectory, heat transfer predictions, calculations of plumes that simulated hot gas entering the wing, and material-response calculations of possible damaged wing leading edge and tile materials.
Also, Sandia was recently selected as one of four institutions to develop new supercomputer prototype systems for the Defense Advanced Research Projects Agency (DARPA). To meet the increasing advanced computing needs for the Department of Defense, DARPA launched the Ubiquitous High Performance Computing (UHPC) programme.
NNSA's energy-efficient supercomputers are ranked in the most recent Green500 list. The work done on the supercomputers housed at NNSA's national laboratory are a critical part of President Obama's nuclear security agenda.
The two computers in the top 25 are housed at Los Alamos National Laboratory and six supercomputers housed at NNSA sites were also ranked in the Green500 list. Additionally, the top supercomputer at the IBM Thomas J. Watson Research Center in New York is based on NNSA's Blue Gene technology.
"Energy efficiency is vital to our enterprise as we invest in the future by building a modern infrastructure that is smaller, safer, more cost effective and more programmatically effective", stated Don Cook, NNSA's Deputy Administrator for Defense Programmes. "The work done by our supercomputer engineers and scientists is a reflection of their commitment in seeking ways to better do business while promoting energy awareness."
The purpose of the Green500 is to provide a ranking of the most energy-efficient supercomputers in the world. For decades, the notion of performance has been synonymous with speed. This particular focus has led to the emergence of supercomputers that consume large amounts of electrical power and produce heat that requires extravagant cooling facilities to ensure proper operation. The Green500 list encourages supercomputing stakeholders to create systems that are both cutting-edge and energy efficient.