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The Mars Hopper: a radioisotope powered, impulse driven, long-range, long-lived mobile platform for exploration of Mars (open access)

The Mars Hopper: a radioisotope powered, impulse driven, long-range, long-lived mobile platform for exploration of Mars

Planetary exploration mission requirements are becoming more demanding. Due to the increasing cost, the missions that provide mobile platforms that can acquire data at multiple locations are becoming more attractive. Wheeled vehicles such as the MER rovers have proven extremely capable but have very limited range and cannot traverse rugged terrain. Flying vehicles such as balloons and airplanes have been proposed but are problematic due to the very thin atmospheric pressure and the strong, dusty winds present on Mars. The Center for Space Nuclear Research has designed an instrumented platform that can acquire detailed data at hundreds of locations during its lifetime - a Mars Hopper. The Mars Hopper concept utilizes energy from radioisotopic decay in a manner different from any existing radioisotopic power sources—as a thermal capacitor. By accumulating the heat from radioisotopic decay for long periods, the power of the source can be dramatically increased for short periods. The platform will be able to "hop" from one location to the next every 5-7 days with a separation of 5-10 km per hop. Preliminary designs show a platform that weighs around 52 kgs unfueled which is the condition at deployment. Consequently, several platforms may be deployed on a single …
Date: February 1, 2011
Creator: Howe, Steven D.; O'Brien, Robert C.; Taitano, William; Crawford, Doug; Jerred, Nathan; Cooley, Spencer et al.
Object Type: Article
System: The UNT Digital Library
Thermal-hydraulics Analysis of a Radioisotope-powered Mars Hopper Propulsion System (open access)

Thermal-hydraulics Analysis of a Radioisotope-powered Mars Hopper Propulsion System

Thermal-hydraulics analyses results produced using a combined suite of computational design and analysis codes are presented for the preliminary design of a concept Radioisotope Thermal Rocket (RTR) propulsion system. Modeling of the transient heating and steady state temperatures of the system is presented. Simulation results for propellant blow down during impulsive operation are also presented. The results from this study validate the feasibility of a practical thermally capacitive RTR propulsion system.
Date: February 1, 2011
Creator: O'Brien, Robert C.; Klein, Andrew C.; Taitano, William T.; Gibson, Justice; Myers, Brian & Howe, Steven D.
Object Type: Article
System: The UNT Digital Library
SURFACE GEOPHYSICAL EXPLORATION - COMPENDIUM DOCUMENT (open access)

SURFACE GEOPHYSICAL EXPLORATION - COMPENDIUM DOCUMENT

This report documents the evolution of the surface geophysical exploration (SGE) program and highlights some of the most recent successes in imaging conductive targets related to past leaks within and around Hanford's tank farms. While it is noted that the SGE program consists of multiple geophysical techniques designed to (1) locate near surface infrastructure that may interfere with (2) subsurface plume mapping, the report will focus primarily on electrical resistivity acquisition and processing for plume mapping. Due to the interferences from the near surface piping network, tanks, fences, wells, etc., the results of the three-dimensional (3D) reconstruction of electrical resistivity was more representative of metal than the high ionic strength plumes. Since the first deployment, the focus of the SGE program has been to acquire and model the best electrical resistivity data that minimizes the influence of buried metal objects. Toward that goal, two significant advances have occurred: (1) using the infrastructure directly in the acquisition campaign and (2) placement of electrodes beneath the infrastructure. The direct use of infrastructure was successfully demonstrated at T farm by using wells as long electrodes (Rucker et al., 2010, 'Electrical-Resistivity Characterization of an Industrial Site Using Long Electrodes'). While the method was capable …
Date: October 4, 2011
Creator: Rucker, D. F. & Myers, D. A.
Object Type: Report
System: The UNT Digital Library
Development of a propulsion system and component test facility for advanced radioisotope powered Mars Hopper platforms (open access)

Development of a propulsion system and component test facility for advanced radioisotope powered Mars Hopper platforms

Verification and validation of design and modeling activities for radioisotope powered Mars Hopper platforms undertaken at the Center for Space Nuclear Research is essential for proof of concept. Previous research at the center has driven the selection of advanced material combinations; some of which require specialized handling capabilities. The development of a closed and contained test facility to forward this research is discussed within this paper.
Date: February 1, 2011
Creator: O'Brien, Robert C.; Jerred, Nathan D. & Howe, Steven D.
Object Type: Article
System: The UNT Digital Library
Ongoing Space Nuclear Systems Development in the United States (open access)

Ongoing Space Nuclear Systems Development in the United States

Reliable, long-life power systems are required for ambitious space exploration missions. Nuclear power and propulsion options can enable a bold, new set of missions and introduce propulsion capabilities to achieve access to science destinations that are not possible with more conventional systems. Space nuclear power options can be divided into three main categories: radioisotope power for heating or low power applications; fission power systems for non-terrestrial surface application or for spacecraft power; and fission power systems for electric propulsion or direct thermal propulsion. Each of these areas has been investigated in the United States since the 1950s, achieving various stages of development. While some nuclear systems have achieved flight deployment, others continue to be researched today. This paper will provide a brief overview of historical space nuclear programs in the U.S. and will provide a summary of the ongoing space nuclear systems research, development, and deployment in the United States.
Date: October 1, 2011
Creator: Bragg-Sitton, S.; Werner, J.; Johnson, S.; Houts, Michael G.; Palac, Donald T.; Mason, Lee S. et al.
Object Type: Article
System: The UNT Digital Library
Highly Integrated Quality Assurance – An Empirical Case (open access)

Highly Integrated Quality Assurance – An Empirical Case

Highly Integrated Quality Assurance – An Empirical Case Drake Kirkham1, Amy Powell2, Lucas Rich3 1Quality Manager, Radioisotope Power Systems (RPS) Program, Idaho National Laboratory, P.O. Box 1625 M/S 6122, Idaho Falls, ID 83415-6122 2Quality Engineer, RPS Program, Idaho National Laboratory 3Quality Engineer, RPS Program, Idaho National Laboratory Contact: Voice: (208) 533-7550 Email: Drake.Kirkham@inl.gov Abstract. The Radioisotope Power Systems Program of the Idaho National Laboratory makes an empirical case for a highly integrated Quality Assurance function pertaining to the preparation, assembly, testing, storage and transportation of 238Pu fueled radioisotope thermoelectric generators. Case data represents multiple campaigns including the Pluto/New Horizons mission, the Mars Science Laboratory mission in progress, and other related projects. Traditional Quality Assurance models would attempt to reduce cost by minimizing the role of dedicated Quality Assurance personnel in favor of either functional tasking or peer-based implementations. Highly integrated Quality Assurance adds value by placing trained quality inspectors on the production floor side-by-side with nuclear facility operators to enhance team dynamics, reduce inspection wait time, and provide for immediate, independent feedback. Value is also added by maintaining dedicated Quality Engineers to provide for rapid identification and resolution of corrective action, enhanced and expedited supply chain interfaces, improved bonded storage …
Date: February 1, 2011
Creator: Kirkham, Drake; Powell, Amy & Rich, Lucas
Object Type: Article
System: The UNT Digital Library
Integrating Online Discussion Forums into the Foreign Language Curriculum: A Case Study of Advanced Learners of French (open access)

Integrating Online Discussion Forums into the Foreign Language Curriculum: A Case Study of Advanced Learners of French

This exploratory case study aims to develop a set of best practices for integrating online discussion forums into the foreign language curriculum, focusing specifically on a group of learners in an advanced French grammar course at a large, public U.S. university. During a period of two months, 26 participants completed a series of tasks designed to provide three different types of data: 1) exploration and analysis of interactional, linguistic, and social features of Web forum discourse; 2) participation in Web forums; and 3) feedback from students. Since the feedback received from two questionnaires was ultimately the most consistent and reliable type of data collected, this study focuses on students' participation patterns and their perceptions of Web forums as a communication space having the potential to provide opportunities for learning French. Although some students indicated that they would neither consider visiting a French-language Web forum nor actually visit one, in both cases, more than half of the participants who completed these questionnaires indicated that they would both consider visiting a French-language Web forum and might actually visit one. Since encouraging students to use French beyond the classroom and to engage in the lifelong use of French for personal enrichment (following the …
Date: May 2011
Creator: Mbuye, Kanku Lisette
Object Type: Thesis or Dissertation
System: The UNT Digital Library
NASA: Assessments of Selected Large-Scale Projects (open access)

NASA: Assessments of Selected Large-Scale Projects

A letter report issued by the Government Accountability Office with an abstract that begins "GAO's work has shown that the National Aeronautics and Space Administration's (NASA) large-scale projects, while producing groundbreaking research and advancing our understanding of the universe, tend to cost more and take longer to develop than planned, and are often approved without evidence of a sound business case. Although space development is complex and diffi cult by nature, GAO has found that inherent risks are compounded by the need for better management and oversight practices. GAO has designated NASA's acquisition management a high risk area. This report provides a snapshot of how well NASA is planning and executing its acquisition of selected large-scale projects. It also provides observations about the performance of NASA's major projects and project management, outlines steps NASA is taking to improve its acquisitions, identifi es challenges that contribute to cost and schedule growth, and assesses 21 NASA projects, each with an estimated life-cycle cost of over $250 million."
Date: March 3, 2011
Creator: United States. Government Accountability Office.
Object Type: Report
System: The UNT Digital Library
The Future of NASA: Space Policy Issues Facing Congress (open access)

The Future of NASA: Space Policy Issues Facing Congress

This report addresses a number of cross-cutting issues, such as NASA's interactions with ither federal agencies and the growing role of the commercial space industry.
Date: January 27, 2011
Creator: Morgan, Daniel
Object Type: Report
System: The UNT Digital Library
Space and Missile Defense Acquisitions: Periodic Assessment Needed to Correct Parts Quality Problems in Major Programs (open access)

Space and Missile Defense Acquisitions: Periodic Assessment Needed to Correct Parts Quality Problems in Major Programs

A letter report issued by the Government Accountability Office with an abstract that begins "Quality is key to success in U.S. space and missile defense programs, but quality problems exist that have endangered entire missions along with less-visible problems leading to unnecessary repair, scrap, rework, and stoppage; long delays; and millions in cost growth. For space and missile defense acquisitions, GAO was asked to examine quality problems related to parts and manufacturing processes and materials across DOD and NASA. GAO assessed (1) the extent to which parts quality problems affect those agencies' space and missile defense programs; (2) causes of any problems; and (3) initiatives to prevent, detect, and mitigate parts quality problems. To accomplish this, GAO reviewed all 21 systems with mature designs and projected high costs: 5 DOD satellite systems, 4 DOD missile defense systems, and 12 NASA systems. GAO reviewed existing and planned efforts for preventing, detecting, and mitigating parts quality problems. Further, GAO reviewed regulations, directives, instructions, policies, and several studies, and interviewed senior headquarters and contractor officials."
Date: June 24, 2011
Creator: United States. Government Accountability Office.
Object Type: Report
System: The UNT Digital Library
The Colony Courier-Leader (The Colony, Tex.), Vol. 30, No. 34, Ed. 1 Thursday, September 22, 2011 (open access)

The Colony Courier-Leader (The Colony, Tex.), Vol. 30, No. 34, Ed. 1 Thursday, September 22, 2011

Weekly newspaper from The Colony, Texas that includes local, state, and national news along with advertising.
Date: September 22, 2011
Creator: Mann, Rick
Object Type: Newspaper
System: The Portal to Texas History
Deep Water: the Gulf Oil Disaster and the Future of Offshore Drilling (open access)

Deep Water: the Gulf Oil Disaster and the Future of Offshore Drilling

On May 22, 2010, President Barack Obama announced the creation of the National Commission on the BP Deepwater Horizon Oil Spill and Offshore Drilling: an independent,nonpartisan entity, directed to provide a thorough analysis and impartial judgment. The President charged the Commission to determine the causes of the disaster, and to improve the country’s ability to respond to spills, and to recommend reforms to make offshore energy production safer. This report is the result of an intense six-month effort to fulfill the President’s charge. The Commission’s report offers the President, policymakers, industry, and the American people the fullest account available of the largest oil spill in U.S history: the context for the well itself, how the explosion and spill happened, and how industry and government scrambled to respond to an unprecedented emergency.
Date: January 2011
Creator: National Commission on the BP Deepwater Horizon Oil Spill and Offshore Drilling (U.S.)
Object Type: Book
System: The UNT Digital Library
The Express-Star (Chickasha, Okla.), Ed. 1 Friday, June 10, 2011 (open access)

The Express-Star (Chickasha, Okla.), Ed. 1 Friday, June 10, 2011

Daily newspaper from Chickasha, Oklahoma that includes local, state, and national news along with advertising.
Date: June 10, 2011
Creator: DeSilver, Debi
Object Type: Newspaper
System: The Gateway to Oklahoma History
StarDate, Volume 39, Number 4, July/August 2011 (open access)

StarDate, Volume 39, Number 4, July/August 2011

This is a bimonthly publication of the McDonald Observatory discussing research, news, and other topics of interest related to astronomy and science. The publication offers key featured articles, miscellaneous astronomy information, a a current star chart, a calendar of astronomical events, and a Q&A titled Dear Merlin.
Date: July 2011
Creator: McDonald Observatory
Object Type: Journal/Magazine/Newsletter
System: The Portal to Texas History
Financial Management: NOAA Needs to Better Document Its Policies and Procedures for Providing Management and Administration Services (open access)

Financial Management: NOAA Needs to Better Document Its Policies and Procedures for Providing Management and Administration Services

A letter report issued by the Government Accountability Office with an abstract that begins "The National Oceanic and Atmospheric Administration (NOAA) is a bureau within the Department of Commerce (Commerce). To help achieve NOAA's program goals, it relies on management and administration (M&A) services, such as legal support and information technology. In response to the fiscal year 2010 Consolidated Appropriations Act Conference Report, GAO (1) examined how NOAA's M&A services are funded, (2) assessed the extent to which NOAA's policies and procedures for M&A services conform to applicable standards, and (3) estimated salaries and expenses for NOAA's budget for fiscal year 2009. Among other things, GAO reviewed documents on M&A services and data on M&A costs from NOAA officials for its headquarters; line offices, which are responsible for executing NOAA's programs; and a subset of financial management centers (FMC) within the line offices, which manage specific programs and projects."
Date: January 31, 2011
Creator: United States. Government Accountability Office.
Object Type: Report
System: The UNT Digital Library
The Baytown Sun (Baytown, Tex.), Vol. 91, No. 113, Ed. 1 Friday, June 10, 2011 (open access)

The Baytown Sun (Baytown, Tex.), Vol. 91, No. 113, Ed. 1 Friday, June 10, 2011

Daily newspaper from Baytown, Texas that includes local, state, and national news along with advertising.
Date: June 10, 2011
Creator: Gray, Janie
Object Type: Newspaper
System: The Portal to Texas History
StarDate, Volume 39, Number 3, May/June 2011 (open access)

StarDate, Volume 39, Number 3, May/June 2011

This is a bimonthly publication of the McDonald Observatory discussing research, news, and other topics of interest related to astronomy and science. The publication offers key featured articles, miscellaneous astronomy information, a a current star chart, a calendar of astronomical events, and a Q&A titled Dear Merlin.
Date: June 2011
Creator: McDonald Observatory
Object Type: Journal/Magazine/Newsletter
System: The Portal to Texas History
NASA Needs to Better Assess Contract Termination Liability Risks and Ensure Consistency in Its Practices (open access)

NASA Needs to Better Assess Contract Termination Liability Risks and Ensure Consistency in Its Practices

Correspondence issued by the Government Accountability Office with an abstract that begins "The National Aeronautics and Space Administration (NASA) procures most of its goods and services through contracts, and it terminates very few of them. In fiscal year 2010, for example, NASA's procurements, ranging from small contracts for human resources consulting services to multimillion dollar contracts to build and operate spacecraft, totaled approximately $17.4 billion, representing about 83.4 percent of the agency's obligations that year. That same year, it terminated 28 of 16,343 active contracts and orders--a termination rate of about .17 percent. This rate is about the same--less than 0.2 percent--for each of the past 5 fiscal years. NASA contract terminations--the complete or partial cancellation of work under a contract before the contract's period of performance ends--are rare but could become more common in the future. The federal government is facing real fiscal limitations and will have to make difficult choices about upcoming priorities. This reality makes it more important than ever that NASA manage its projects as efficiently and effectively as possible and within its budget. This is a struggle for NASA. Our work has shown that NASA's large-scale projects tend to cost more and take longer to …
Date: July 12, 2011
Creator: United States. Government Accountability Office.
Object Type: Text
System: The UNT Digital Library
Conceptual Design of a CERMET NTR Fission Core Using Multiphysics Modeling Techniques (open access)

Conceptual Design of a CERMET NTR Fission Core Using Multiphysics Modeling Techniques

An initial pre-conceptual CERMET Nuclear Thermal Propulsion reactor system is investigated within this paper. Reactor configurations are investigated where the fuel consists of 60 vol.% UO2 and 40 vol.% W where the UO2 consists of Gd2O3 concentrations of 5 and 10 mol.%.Gd2O3. The fuel configuration consisting of 5 mol.% UO2 was found to have a total mass of 2761 kg and a thrust to weight ratio of 4.10 and required a coolant channel surface area to fueled volume ratio of approximately 15.0 in order to keep the centerline temperature below 3000 K. The configuration consisting of 10 mol.% Gd2O3 required a surface area to volume ratio of approximately 12.2 to cool the reactor to a peak temperature of 3000 K and had a total mass of 3200 kg and a thrust to weight ratio of 3.54. It is not known yet what concentration of Gd2O3 is required to maintain fuel stability at 3000 K; however, both reactors offer the potential for operations at 25,000 lb, and at a specific impulse which may range from 900 to 950 seconds.
Date: August 1, 2011
Creator: Webb, Jonathan A.; Gross, Brian J. & Taitano, William T.
Object Type: Article
System: The UNT Digital Library
Sapulpa Daily Herald (Sapulpa, Okla.), Vol. 96, No. 119, Ed. 1 Wednesday, March 2, 2011 (open access)

Sapulpa Daily Herald (Sapulpa, Okla.), Vol. 96, No. 119, Ed. 1 Wednesday, March 2, 2011

Daily newspaper from Sapulpa, Oklahoma that includes local, state, and national news along with advertising.
Date: March 2, 2011
Creator: Harmon, C. L.
Object Type: Newspaper
System: The Gateway to Oklahoma History
The Muon Collider (open access)

The Muon Collider

We describe the scientific motivation for a new type of accelerator, the muon collider. This accelerator would permit an energy-frontier scientific program and yet would fit on the site of an existing laboratory. Such a device is quite challenging, and requires a substantial R&D program. After describing the ingredients of the facility, the ongoing R&D activities of the Muon Accelerator Program are discussed. A possible U.S. scenario that could lead to a muon collider at Fermilab is briefly mentioned.
Date: January 5, 2011
Creator: Zisman, Michael S.
Object Type: Article
System: The UNT Digital Library
Assessing the cleanliness of surfaces: Innovative molecular approaches vs. standard spore assays (open access)

Assessing the cleanliness of surfaces: Innovative molecular approaches vs. standard spore assays

A bacterial spore assay and a molecular DNA microarray method were compared for their ability to assess relative cleanliness in the context of bacterial abundance and diversity on spacecraft surfaces. Colony counts derived from the NASA standard spore assay were extremely low for spacecraft surfaces. However, the PhyloChip generation 3 (G3) DNA microarray resolved the genetic signatures of a highly diverse suite of microorganisms in the very same sample set. Samples completely devoid of cultivable spores were shown to harbor the DNA of more than 100 distinct microbial phylotypes. Furthermore, samples with higher numbers of cultivable spores did not necessarily give rise to a greater microbial diversity upon analysis with the DNA microarray. The findings of this study clearly demonstrated that there is not a statistically significant correlation between the cultivable spore counts obtained from a sample and the degree of bacterial diversity present. Based on these results, it can be stated that validated state-of-the-art molecular techniques, such as DNA microarrays, can be utilized in parallel with classical culture-based methods to further describe the cleanliness of spacecraft surfaces.
Date: April 1, 2011
Creator: Cooper, Moogega; La Duc, Myron T.; Probst, Alexander; Vaishampayan, Parag; Stam, Christina; Benardini, James N. et al.
Object Type: Article
System: The UNT Digital Library
Laboratory Directed Research and Development FY-10 Annual Report (open access)

Laboratory Directed Research and Development FY-10 Annual Report

The FY 2010 Laboratory Directed Research and Development (LDRD) Annual Report is a compendium of the diverse research performed to develop and ensure the INL's technical capabilities can support the future DOE missions and national research priorities. LDRD is essential to the INL -- it provides a means for the laboratory to pursue novel scientific and engineering research in areas that are deemed too basic or risky for programmatic investments. This research enhances technical capabilities at the laboratory, providing scientific and engineering staff with opportunities for skill building and partnership development.
Date: March 1, 2011
Creator: Tomchak, Dena
Object Type: Report
System: The UNT Digital Library
Sweetwater Reporter (Sweetwater, Tex.), Vol. 113, No. 211, Ed. 1 Thursday, July 21, 2011 (open access)

Sweetwater Reporter (Sweetwater, Tex.), Vol. 113, No. 211, Ed. 1 Thursday, July 21, 2011

Daily newspaper from Sweetwater, Texas that includes local, state, and national news along with advertising.
Date: July 21, 2011
Creator: unknown
Object Type: Newspaper
System: The Portal to Texas History