Lunar electric power systems utilizing the SP-100 reactor coupled to dynamic conversion systems

Personal computers of the past were limited to running computational fluid dynamics codes in serial mode. With the advent of multicore technology and suitable compilers, personal computers nowadays can execute codes in a parallel fashion similar to that of supercomputers and cluster computer systems. This article investigated what performance can be achieved when executing an aerodynamic code on an Intel quad core based personal computer with an OpenMP compiler in a Windows environment. The code solved the Euler equations to find the flowfield around a NACA0012 aerofoil on an O-type boundary fitted structured grid system. A speedup of up to 350% was obtainable in double precision accuracy. The reduced computation time means that, for small scale problems, more accurate Euler codes can replace commonly used transonic small disturbance codes. For larger problems, this information serves as a reference for developers of hybrid MPI/OpenMP algorithms for cluster computer systems. References Advanced Micro Devices (AMD), AMD FireStream 9170: Industry's First GPU with Double-Precision Floating Point, 2007, http://ati.amd.com/products/streamprocessor/specs.html Allmaras, S. R., Venkatakrishnan, V., and Johnson, F. T., Farfield Boundary Conditions for 2-D Airfoils, AIAA Paper 2005-4711, AIAA, 2005. Bailey, D., Barszcz, E., Barton, J., Browning, D., Carter, R., Dagum, L., Fatoohi, R., Fineberg, S., Frederickson, P., Lasinski, T., Schreiber, R., Simon, H., Venkatakrishnan, V., and Weeratunga, S., The NAS Parallel Benchmarks, National Aeronautics and Space Administration (NASA), Contractor Report 203186, USA, 1994, http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19970014936_1997021577.pdf Dong, S., and Karniadakis, G. E., Dual-Level Parallelism for High-Order CFD Methods, Parallel Computing, 30, Jan. 2004, pp. 1--20. Hirsch, C., Numerical Computation of Internal and External Flows (Volume 2): Computational Methods for Inviscid and Viscous Flows, John Wiley and Sons, Great Britain, 1992. Hoffmann, K. A., Computational Fluid Dynamics for Engineers, Engineering Educational System, Texas, USA, 1989. Intel, Tera-scale Computing Research Program, c.2007, http://www.intel.com/research/platform/terascale/ Jin, H., Frumkin, M., and Yan, J., The OpenMP Implementation of NAS Parallel Benchmarks and its Performance, National Aeronautics and Space Administration (NASA), Technical Report NAS-99-011, Moffett Field, USA, 1999. Liu, Y., and Vinokur, M., Nonequilibrium Flow Computations 1: An Analysis of Numerical Formulations of Conservation Laws, National Aeronautics and Space Administration (NASA), Contractor Report 177489, California, USA, 1988, http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19880021000_1988021000.pdf Lock, R. C., Test Cases for Numerical Methods in Two-Dimensional Transonic Flows, Advisory Group for Aerospace Research and Development (AGARD), Report Number 575, 1970. Ly, E., Improved Approximate Factorisation Algorithm for the Steady Subsonic and Transonic Flow over an Aircraft Wing, Proceedings of the 21st Congress of the International Council of the Aeronautical Sciences (ICAS98), ICAS and AIAA, Melbourne, Australia, 1998, Paper A98-31699. Ly, E., and Gear, J. A., Time-Linearized Transonic Computations Including Shock Wave Motion Effects, Journal of Aircraft, 39, 6, Nov/Dec. 2002, pp. 964--972. Ly, E., and Nakamichi, J., Time-Linearised Transonic Computations Including Entropy, Vorticity and Shock Wave Motion Effects, The Aeronautical Journal, Nov. 2003, pp. 687--695. Ly, E., and Norrison, D., Automatic Elliptic Grid Generation by an Approximate Factorisation Algorithm, ANZIAM Journal, 48 (CTAC2006), pp. C188--C202, July 2007, http://anziamj.austms.org.au/ojs/index.php/ANZIAMJ/article/view/48. Ly, E., and Norrison, D., Generating Elliptic Grids in Three Dimensions by a Method of False Transients, ANZIAM Journal, 49 (EMAC2007), pp. C170--C183, Nov. 2007, http://anziamj.austms.org.au/ojs/index.php/ANZIAMJ/article/view/313. Nvidia, The Era of the Personal Supercomputer, 2007, http://www.nvidia.com/content/events/siggraph_2007/supercomputing.html Pope, S. B., A Perspective on Turbulence Modeling, Modeling Complex Turbulent Flows, Kluwer Academic Publishers, The Netherlands, 1999. Pulliam, T., Kutler, P., and Rossow, V., Harvard Lomax: His Quiet Legacy to Computational Fluid Dynamics, 14th AIAA Computational Fluid Dynamics Conference, Norfolk, VA, 28 June-1 July, 1999, http://people.nas.nasa.gov/ pulliam/mypapers/lomax_la.ps Steger, J. L., and Warming, R. F., Flux Vector Splitting of the Inviscid Gasdynamic Equations with Application to Finite Difference Methods, National Aeronautics and Space Administration (NASA) Technical Memorandum 78605, California, USA, 1979, http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19790020779_1979020779.pdf Thompson, J. R., Warsi, Z. U. A., and Mastin, C. W., Numerical Grid Generation: Foundations and Applications, Elsevier Science Publishing Co. Inc., New York, USA, 1985. Van Leer, B., Flux-Vector Splitting for the Euler Equations, Proceedings of the 8th International Conference on Numerical Methods in Fluid Dynamics, Aachen, West Germany, 1982.

HE ownership of resulting from T government financed research and development constitutes a very controversial problem. The federal government mainly the Department of Defense (DOD) has permitted industrial firms to obtain the patent rights to most of the inventions emerging from its contract research, under the so-called with the government acquiring royaltyfree licenses on the inventions. Our task here is an empirical investigation of one of the issues in the controversy over federal patent policy, namely, the concentration of resulting from the operation of the license policy. One of the strongest objections to the license policy rests on the belief that it causes undue concentration of economic power. The objection has been raised repeatedly by attorneys general, by legislators, and by economists who favor the so-called ' under which the government retains ownership of resulting from its contract research. From records of the United States Patent Office, we have compiled data for the period 1946 to 1962 on the numbers of assigned to business firms that have been the research and development (R and D) for the Atomic Energy Commission (AEC), the Department of Defense, and the National Aeronautics and Space Administration (NASA). The data are neither estimates nor samples; they are complete counts. The three agencies account for nearly all of the issued under the license policy to contractors. Henceforth, we shall refer to these as license-policy patents. We also have data on the private patents resulting from the company financed R and D of the same contractors. The major R and D contractors are 177 business firms that were among the first 100 of DOD in any fiscal year from 1955 to 1962, or who had contract awards of $2 million or more from the AEC or from NASA.2 Of these 177 firms, 40 are among the first 100 in Fortune's list for 1962. Another 49 are among Fortune's 500 companies. A further 36 have been officially stamped as small businesses. With the exception of a few of the bigger chemical and oil companies that have done little or no research for the federal government, the names of nearly all the Schumpeterian giants of American industry are on our list. By treating each firm and its subsidiaries as a unit, we overstate patent concen* The research underlying this article was supported by a grant (NsG 425) from the National Aeronautics and Space Administration to The George Washington University. 1 Department of Justice, Investigations of Government Patent Practices and Policies: Report and Recommendations of the Attorney General to the President 1 (Washington, D.C.: U.S. Government Printing Office, 1947), 37; Report of the Attorney General Pursuant to Section 708 (e) of the Defense Production Act of 1950, as Amended (Nov. 9, 1956, mimeo.); Clair Wilcox, Public Policies Toward Business (Homewood, Ill.: Richard D. Irwin, 1960), 191; Walter Adams and Horace M. Gray, Monopoly in America: The Government as Promotor (New York: Macmillan, 1955), 47, 94, and 148-152. Testimony against the license policy and in favor of the title policy was given to a Senate subcommittee in 1963 by Horace M. Gray, Robert F. Lanzillotti, Wassily W. Leontief, Richard R. Nelson, and Lee E. Preston. See Aspects of Government Patent Policies, Hearings before a Subcommittee of the Select Committee on Small Business, United States Senate, 88th Congress, First Session, Impact of Government Patent Policies on Economic Growth, Scientific and Technological Progress, Competition, and Opportunities for Small Business, March 7, 8, 13, and 14, 1963 (Washington, D.C.: U.S. Government Printing Office, 1963). Only Leontief (p. 236), however, addressed himself specifically to the question of concentration. 2 Department of Defense, 500 Contractors Listed According to Net Value of Military Prime Contract Awards for Experimental, Development Test and Research Work (Fiscal years 1955 through 1962, mimeo.); and Files of the Atomic Energy Commission and published reports of the National Aeronautics and Space Administration. 'Usually, government employees are required to assign title to the government. However, if a government employee, with his own resources, produces an invention that his agency wants, the government frequently files the patent application in exchange for a royalty-free license. Also, if an agency does not want a government financed invention made by an employee, the employee often is permitted to acquire title. Regulations governing employees were tightened in 1950. This fact and the relative growth of contract research are the causes of the decline in the number of licenses from employees after 1950.

The National Aeronautics and Space Administration (NASA) has initiated a technology program to establish the readiness of nuclear propulsion technology for the Space Exploration Initiative (SEI). This program was initiated in the past fiscal year with a very modest effort identified with nuclear thermal propulsion (NTP); however, nuclear electric propulsion (NEP) is also an integral part of this program and builds upon NASA’s Base Research and Technology Program in power and electric propulsion as well as the SP‐100 space nuclear power program. Although the Synthesis Group On America’s Space Exploration Initiative has identified NEP only as an option for cargo missions, recent studies conducted by NASA Lewis show that NEP offers the potential for the early manned Mars missions as well. Lower power NEP is also of current interest for outer planetary robotic missions. This paper reviews current plans for the overall nuclear propulsion project, with emphasis on NEP and those elements of NTP program which have synergism with NEP.

The National Aeronautics and Space Administration has formed the Advanced Space Transportation Program (ASTP) at the Marshall Space Flight Center to address advanced space transportation technologies. The main focus of the ASTP Office is directed to those technologies that will be needed to reduce the cost of both Earth-toorbit and in-space transportation. The current focus of the advanced reusable technologies (ART) Project is the development of those critical technologies required to enable a rocket-based combined-cycle (RBCC) engine and ultimately an RBCC-based reusable launch vehicle. Additional effort is also being expended to address those associated technologies that would be required to not only support an RBCC-based vehicle but other advanced reusable transportation systems as well. This paper will describe the work that has been performed since the last project status was presented to the 1997 Joint Propulsion Conference.' Currently, NASA and its industry partners are performing ground testing of hydrogen-fueled rocketbased combined-cycle flowpaths. Successful ramjet and scramjet testing at Mach 6 and scramjet testing at Mach 8 have been performed. Cold flow mixing tests have also been successfully performed as have inlet operability tests. Additional testing of RBCC flowpaths at air augmented rocket and rocket only modes is underway. Additional work will be performed on technologies that will support an RBCC-powered launch vehicle and will be focused in the following areas: structures and materials; avionics and operations; propulsion turbomachinery; and thermal protection systems. Chief Engineer, Advanced Reusable Technologies Project, NASA/ MSFC, Senior Member AIAA Project Manager, Advanced Reusable Technologies Project, NASA/MSFC, Member AIAA Copyright © 1998 by the American Institute of Aeronautics and Astronautics, Inc. No copyright is asserted in the United States under Title 17, U.S. Code. The U.S. Government has a royalty-free license to exercise all rights under the copyright claimed herein for Governmental Purposes. All other rights are reserved by the copyright owner. Introduction The National Aeronautics and Space Administration (NASA) Advanced Space Transportation Program (ASTP), part of the Space Transportation Program (STP) Office at the Marshall Space Flight Center (MSFC), is focusing on those technologies that will be needed to reduce the cost of both Earth-to-orbit and in-space transportation. NASA's strategy is to advance innovative space transportation technology development through the X-33, X-34, ASTP, and the Future-X programs to enable reduction of these costs. The ASTP consists of three major technology areas: focused, core, and research technologies. The ART project currently manages the work that is covered under NASA Research Announcements 8-16 and 8-21. The project's primary focus over the last 2 years has been on rocket-based combined-cycle (RBCC) technology development activities awarded under NRA 8-16. The current aerospace and academic organizations listed in Figure 1 are performing testing and analysis supporting the RBCC propulsion activities. The engine contractors, Aerojet, Pratt & Whitney, and Rocketdyne are currently either testing or preparing to test their RBCC engine flowpaths. Direct connect testing has been performed at Mach 6 flight conditions in both ramjet and scramjet modes and at Mach 8 flight conditions in the scramjet mode. Testing has also been performed at sealevel static conditions and at Mach 3.4 ramjet conditions.

The National Aeronautics and Space Administration (NASA) ‐ Lewis Research Center has the responsibility to develop power technologies that have the potential of satisfying anticipated future space mission power requirements. The Free‐Piston Stirling Power Converter (FPSPC) is one of the power technologies being evaluated and developed by NASA. FPSPC's have the potential to provide high reliability, long life, efficient operation, and can be coupled with all potential heat sources, various heat input and heat rejection systems, and various power management and distribution systems. FPSPC's can compete favorably with alternative power conversion systems over a range of tens of watts to hundreds of kilowatts. Mechanical Technology Incorporated (MTI) is developing FPSPC technology under contract to NASA‐Lewis Research Center (NASA‐LeRC). This paper will discuss progress toward developing the technology required for a 1050 K Stirling Space Power Converter with a review of the design and also the tested performance of a full scale, full space temperature environment Stirling power converter designated the Component Test Power Converter (CTPC). Initial tests of the CTPC have achieved all performance goals established at the initiation of the program.

The National Aeronautics and Space Administration (NASA) carries out a variety of cooperative programs with African countries, the most extensive being the Landsat data analysis projects begun in 1972. Other programs include television broadcasts via satellite to Africa and use of meteorological satellites. All of NASA’s cooperative programs in Africa are run on a no-exchange-of-funds basis, with each nation bearing its own costs. Hence, no NASA funds are transferred to Africa in connection with cooperative activities. In NASA’s Office of International Affairs, the staff of twenty-five persons spends somewhat less than ten per cent of their time on African matters.

الأرشفة الإلكترونية | إدارة الوثائق | البيانات الضخمة | الإدارة الوطنية للملاحة الجوية والفضاء | وكالة ناسا الفضائية | الوثائق | الأرشيف | Electronic Archiving | Records Management | Big Data | National Aeronautics and Space Administration | NASA Space Agency | Records | Archive

The mission risk results reported in the Ulysses Final Safety Analysis Report (FSAR) issued on March 14, 1990, were based on initiating accident probabilities the National Aeronautics and Space Administration (NASA) provided to the Department of Energy (DOE) on July 13, 1988. These probabilities were provided in terms of ranges; the geometric mean of these ranges were used in the development and presentation of the results in the FSAR for source terms, radiological consequences and risks. Subsequent to the issuance of the FSAR, DOE received a revised set of probabilities from NASA. These probabilities were presented in terms of distributions for each initiating accident and characterized by a mean and cumulative percentile values. NASA recommended that DOE use the updated probabilities to update the Ulysses FSAR results. Accordingly, at the request of DOE, this letter report has been prepared to evaluate the changes in the Ulysses FSAR results when the updated mean probabilities are used.

The National Aeronautics and Space Administration (NASA) is conducting far-term research into a proposed concept for gate-to-gate national airspace system (NAS) operations called Distributed Air/Ground Traffic Management (DAG-TM) in which flight deck crews, air traffic service providers and aeronautical operational control facilities use distributed decision-making. In this study we estimate the benefits of En Route Free Maneuvering and En Route Trajectory Negotiation in off-nominal conditions using empirical data. Specifically, the benefits we measure are the avoided disruption costs under inclement weather conditions due to the implementation of the two en route concept elements. The random nature of inclement weather makes the measurement of its impact on aviation a challenge. Since June 2003, the Department of Transportation's Airline Service Quality Performance (ASQP) data reports the major airlines' schedule/operation disruptions, in terms of flight cancellations, delays, and diversions, allocated to five cause categories, including extreme weather and non-extreme weather conditions. We extract the inclement weather- caused disruptions from the one-year period of July 2003 through June 2004 from the ASQP data. In developing the benefits pool, we recognize that these two concept elements' functionalities and capabilities could not eliminate all disruptions caused by weather conditions. We estimate the percentage of weather caused disruptions that can be helped by the two concept elements based on expert opinion. We estimate the NAS-wide benefits for year 2004 by extending the ASQP results to the non-ASQP carriers via linear extrapolation. We also extrapolate current NAS benefits to the projected benefits in year 2015, the target year of DAG-TM deployment, by developing and applying forecast parameters to year 2004 benefits based on the traffic forecast. Finally, we translate the operational performance benefits of reduced delay and avoided diversions/cancellations into economic benefits using FAA and other published cost factors. I. Introduction HE National Aeronautics and Space Administration (NASA) is conducting far-term research into a proposed concept for gate-to-gate national airspace system (NAS) operations called Distributed Air/Ground Traffic Management (DAG-TM). DAG-TM is based on distributed decision making between flight deck crews, air traffic service providers (ATSP) and aeronautical operational control (AOC) personnel. The goal of DAG-TM is to increase system capacity/throughput, enable user preferences, and provide greater flexibility and efficiency, while meeting air traffic management (ATM) requirements and maintaining system safety and user accessibility to the NAS. DAG-TM will be accomplished with a human-centered operational paradigm enabled by procedural and technological innovations. These innovations include automation aids, information sharing and Communication, Navigation, and Surveillance (CNS) / ATM technologies. The total DAG-TM concept is intended to address all user classes (commercial carriers, general aviation, etc.) with an emphasis towards ensuring access to airspace resources

Motivated by the Electronic Geophysical Year (eGY; www. egy.org), which is one of four international celebrations of the 50th anniversary of the International Geophysical Year which occurred in 1957–1958, the first ever conference devoted to Virtual Observatories in Geosciences (VOiG) was held in Denver, Colorado, USA between June 11 and 14, 2007. The conference was sponsored by National Aeronautics and Space Administration (NASA), United States Geological Survey (USGS), eGY, National Center for Atmospheric Research (NCAR), and National Science Foundation (NSF), and was attended by 74 people from nine countries. Of the many contributed presentations from the conference, initially six were reviewed and selected to appear in this volume of Earth Science Informatics. These contributions are clustered under the broad discipline of space physics and largely sponsored by the innovative Virtual Observatories for Heliophysics Data program from the U.S. National Aeronautical and Space Administration. As is noted in all the contributed papers, the virtual observatory paradigm which was originated in the astronomy and astrophysics community, was quickly adopted into solar physics and space physics. More recently, other fields such as environmental science, aeronomy, oceanography, seismology, volcanology, hydrology, and ecology are embracing the paradigm to serve their diverse community needs. The papers represent an excellent cross-section of the developments that have taken place for solar and space physics virtual observatories, and the needs that have emerged and the developed solutions. Modern data frameworks involve multi-tiered architecture (King et al.) and the new virtual observatories are no exception. Deciding on topologies for how best to update loose federations of VOs so that accuracy, currency, relevance and scalability are satisfied is one of the present challenges. How do virtual observatories communicate their holdings to each other? For space physics, the Developing a Space Physics Archive Search and Extract (SPASE) Query Language contribution (Narock et al.) indicates how a community vocabulary, and existing standards developed in the astronomy community, are being brought together to solve the exchange problem in three space physics virtual observatories. In contrasting the differences between astronomical VO needs and those of solar and space physics (Harvey et al.), another contribution lays out the categories of VO participants and their characteristics which drive the interoperability needs of VOs and in particular, the development of the aforementioned, community-based SPASE effort. The practical implementation of the SPASE vocabulary (Merka et al.) in a modern data framework setting, so that users can query and access interdisciplinary data sources via distributed searches from both web portals and web services, demonstrates the substantial and science-relevant application of virtual observatories to space science. In assessing the relevance of searches returned from the “Brave New World” of VOs being implemented (King et al.), it is clear that while some of the techniques for ranking used in general internet searches apply, many do not, and new scoring methods are required, in addition to the importance of faceted search, in order to lead the user to the accurate source of information. The paper on the Virtual Earth–Sun Observatory describes Earth Sci Inform (2008) 1:3–4 DOI 10.1007/s12145-008-0001-8

Hot dust-obscured galaxies (hot DOGs), selected from Wide-Field Infrared Survey Explorer’s all-sky infrared
\nsurvey, host some of the most powerful active galactic nuclei known and may represent an important stage in the
\nevolution of galaxies. Most known hot DOGs are located at z > 1.5, due in part to a strong bias against identifying
\nthem at lower redshift related to the selection criteria. We present a new selection method that identifies 153 hot
\nDOG candidates at z ~ 1, where they are significantly brighter and easier to study. We validate this approach by
\nmeasuring a redshift z = 1.009 and finding a spectral energy distribution similar to that of higher-redshift hot
\nDOGs for one of these objects, WISE J1036+0449 ( LBol ~= 8 x 10^46 erg s^-1). We find evidence of a broadened
\ncomponent in Mg II, which would imply a black hole mass of MBH ~= 2 x 10^8 M(solar) and an Eddington ratio of
\nLambdaEdd ~= 2.7. WISE J1036+0449 is the first hot DOG detected by the Nuclear Spectroscopic Telescope Array, and
\nobservations show that the source is heavily obscured, with a column density of NH = 2-15 x 10^23 cm^-2 . The
\nsource has an intrinsic 2–10 keV luminosity of ~ 6 x 10^44 erg s^-1, a value significantly lower than that expected
\nfrom the mid-infrared/X-ray correlation. We also find that other hot DOGs observed by X-ray facilities show a
\nsimilar deficiency of X-ray flux. We discuss the origin of the X-ray weakness and the absorption properties of hot
\nDOGs. Hot DOGs at z ~< 1 could be excellent laboratories to probe the characteristics of the accretion flow and of
\nthe X-ray emitting plasma at extreme values of the Eddington ratio.

Abstract20 July 1969: approximately 240 000 mi away from Earth, two astronauts named Neil Armstrong and Edwin E. Aldrin Jr. landed on the moon. 20 October 2020: approximately 200 million miles away from Earth, the National Aeronautics and Space Administration (NASA) managed to land a spacecraft on an asteroid named Bennu and collect a sample from its surface. Sometime 2030s: approximately 34 million miles away from Earth, NASA is looking to successfully send humans to Mars. So, why is all this important? The effects of climate change are apparent on Earth today—temperatures around the world higher than normal, a rising sea level, natural disasters increasing in frequency and strength—and these effects continue to become ever more apparent as time goes on; thus, there is a need for solutions, which outer space has become one that is simultaneously grown in seriousness over the years. Colonizing space, traveling to distant planets and inhabiting them, these are definite possibilities for humans, as evidenced above by the remarkable progress NASA has made; however, one of the biggest obstacles NASA is dealing with in bringing those possibilities into fruition is their food system—all the actors and interactions within a food chain, meaning those who grow the food, those who process the food, those who transport the food, those who sell the food and finally, those who consume and dispose of the food. The shelf life of NASA's current food system will not last past 18 months in the unique environment of space, where there are the hazards of galactic cosmic rays, solar radiation and microgravity. Recognizing this—essentially recognizing that achieving such aforementioned feats would require a food system that can last much longer—NASA and others have constantly been researching and experimenting with their food system, ranging from how its food is grown, processed and preserved to the focus of this literature review: how it is packaged. Henceforth, the purpose of this literature review is to chronologically look at and discuss the major materials and technologies used in NASA's space food packaging of the past—the 1960s–1970s—look at and discuss those of the present—the 1980s–2000s—and finally, look ahead and discuss those of the future, entailing materials and technologies currently being worked on or considered for future use in NASA space missions. At that, here's to 60 years of activity in space.

Free‐piston Stirling power converters have the potential to meet the many future space power requirements for a wide variety of applications with less mass, better efficiency, and less total area (collector and radiator) than other power converter options. These benefits result in significant dollar savings over the projected mission lifetime. The National Aeronautics and Space Administration (NASA)—Lewis Research Center (LeRC), which has the responsibility to evaluate and develop power technologies that can satisfy anticipated future space mission power requirements, has been developing free‐piston Stirling power converters and is bringing the Stirling technology to readiness. As the principal contractor to NASA‐LeRC, Mechanical Technology Incorporated (MTI) is under contract to develop the necessary space Stirling technology but also demonstrate the readiness of the technology in two generations of full‐scale power converters. The first generation Stirling power converter, the component test power converter (CTPC), initiated cold end testing at the end of 1991, with hot testing scheduled during 1992. This paper reviews test progress of the CTPC including the initial hot engine test results. Modifications incorporated into the CTPC from the earlier space power demonstrator engine are reviewed as well.

The Visible Infrared Imaging Radiometer Suite (VIIRS) is a key instrument onboard the Suomi NPP (S-NPP) and the NOAA-20 satellites that provides state-of-the-art Earth observations for ocean, land, aerosol, and cloud applications. VIIRS Reflective Solar Band (RSB) Sensor Data Records (SDR, or Level 1b products) are calibrated and produced independently by The National Oceanic and Atmospheric Administration (NOAA) and the National Aeronautics and Space Administration (NASA) VIIRS science teams. Multiple versions of S-NPP and NOAA-20 VIIRS SDRs are available to date. This study evaluates the long-term calibration stability, biases, and inter-channel consistency of S-NPP and NOAA-20 VIIRS SDRs generated by NOAA and NASA over Deep Convective Clouds (DCC) to support downstream applications, especially climate data record studies. Five VIIRS RSB SDRs were analyzed in this study: (1) NOAA version 2 S-NPP VIIRS reprocessed SDRs (NOAA-NPP-V2, 2012–2020), (2) NASA Collection 1 S-NPP VIIRS SDRs (NASA-NPP-C1, 2012–2021), (3) NASA Collection 2 S-NPP VIIRS SDRs (NASA-NPP-C2, 2012–2021), (4) NOAA constant F-factor calibrated NOAA-20 VIIRS SDRs (NOAA-N20-ConstF, 2018–2021), and (5) NASA Collection 2 NOAA-20 VIIRS SDRs (NASA-N20-C2, 2018–2021). The DCC time series analysis results indicate that the calibrations of the three S-NPP VIIRS RSB SDRs are generally stable, with trends within ±0.1%/year for all RSBs, except for M3–M4 (all three S-NPP SDRs) and I3 (NASA-NPP-C1 only). The calibration of NASA-NPP-C2 SDRs is more uniform at individual detector levels. NOAA-NPP-V2 and NASA-NPP-C1 SDRs exhibit non-negligible time-dependent detector level degradation in M1–M4 (up to 1.5% in 2020–2021), causing striping in the SDR imagery. The biases between NOAA and NASA S-NPP VIIRS RSB SDRs are from 0.1% to 2.4%. The calibrations of the two NOAA-20 VIIRS RSB SDRs are also generally stable, with trends within ±0.16%/year. Small downward trends were observed in the visible and near-infrared (VIS/NIR) bands, and small upward trends were observed in the shortwave infrared (SWIR) bands for both NOAA and NASA NOAA-20 SDRs. The biases between NOAA and NASA NOAA-20 VIIRS RSB SDRs are nearly constant over time and within ±0.2% for VIS/NIR bands and ±0.7% for SWIR bands. There exists large inter-satellite biases between S-NPP and NOAA-20 VIIRS SDRs, especially in the VIS/NIR bands (up to 4.5% for NOAA SDRs and up to 7% for NASA SDRs). In addition, the DCC reflectance of S-NPP VIIRS RSB spectral bands is more consistent with that of the SCanning Imaging Absorption SpectroMeter for Atmospheric CHartographY (SCIAMACHY) than that of NOAA-20. Bands M4 and M9 seem out of family in all five S-NPP and NOAA-20 RSB SDRs evaluated.

National Aeronautics and Space Administration Office of the Administrator Washington DC May 24, 2006 Dear Dr. Chang Diaz, We have followed, with interest, the privatization of the Variable Specific Impulse Magnetoplasma Rocket (VASIMR) project and are pleased with the success of our collaboration as defined in the Space Act Agreement signed June 26, 2005, between the National Aeronautics and Space Administration (NASA) and the Ad Astra Rocket Company. We have monitored your progress in the development of this technology with private funds and believe that your company’s initiative could one day be applicable to NASA’s exploration goals. We fully endorse such private efforts, and consistent with our Agency’s needs, will consider using these capabilities when they come to fruition. More specifically, we understand that one of your company’s near-term objectives is the development of a 100 kilowatt VASIMR engine, together with a space power and propulsion test facility, to be installed on the International Space Station (ISS). Such capability might be useful in providing drag compensation for the orbital complex or might evolve into a test bed for advanced electric plasma rockets in the future. NASA is interested in these concepts and willing to explore the feasibility of an addendum to the Space Act Agreement between NASA and your company. In order to determine if such an addendum is warranted, we should first collaboratively define the physical and functional interfaces required for the integration of such a system on the ISS, as well as your company’s ability to sustain the development and operation phases. In the long term, technologies such as VASIMR, once successfully demonstrated, could play a role in the evolving space exploration architecture. I am directing William H. Gerstenmaier, Associate Administrator for Space Operations, to assign someone to work with your team on the potential for expanding our collaborative framework. I look forward to the continuation of a very productive relationship. Sincerely Michael D. Griffin Administrator