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NASA NTRS1994

The development and operation of the international solar-terrestrial physics central data handling facility

The National Aeronautics and Space Administration (NASA) Goddard Space Flight Center (GSFC) International Solar-Terrestrial Physics (ISTP) Program is committed to the development of a comprehensive, multi-mission ground data system which will support a variety of national and international scientific missions in an effort to study the flow of energy from the sun through the Earth-space environment, known as the geospace. A major component of the ISTP ground data system is an ISTP-dedicated Central Data Handling Facility (CDHF). Acquisition, development, and operation of the ISTP CDHF were delegated by the ISTP Project Office within the Flight Projects Directorate to the Information Processing Division (IPD) within the Mission Operations and Data Systems Directorate (MO&DSD). The ISTP CDHF supports the receipt, storage, and electronic access of the full complement of ISTP Level-zero science data; serves as the linchpin for the centralized processing and long-term storage of all key parameters generated either by the ISTP CDHF itself or received from external, ISTP Program approved sources; and provides the required networking and 'science-friendly' interfaces for the ISTP investigators. Once connected to the ISTP CDHF, the online catalog of key parameters can be browsed from their remote processing facilities for the immediate electronic receipt of selected key parameters using the NASA Science Internet (NSI), managed by NASA's Ames Research Center. The purpose of this paper is twofold: (1) to describe how the ISTP CDHF was successfully implemented and operated to support initially the Japanese Geomagnetic Tail (GEOTAIL) mission and correlative science investigations, and (2) to describe how the ISTP CDHF has been enhanced to support ongoing as well as future ISTP missions. Emphasis will be placed on how various project management approaches were undertaken that proved to be highly effective in delivering an operational ISTP CDHF to the Project on schedule and within budget. Examples to be discussed include: the development of superior teams; the use of Defect Causal Analysis (DCA) concepts to improve the software development process in a pilot Total Quality Management (TQM) initiative; and the implementation of a robust architecture that will be able to support the anticipated growth in the ISTP Program science requirements with only incremental upgrades to the baseline system. Further examples include the use of automated data management software and the implementation of Government and/or industry standards, whenever possible, into the hardware and software development life-cycle. Finally, the paper will also report on several new technologies (for example, the installation of a Fiber Data Distribution Interface network) that were successfully employed.

Lehtonen, Kenneth↗

NASA NTRS1994

Performance evaluation of the NASA/KSC CAD/CAE and office automation LAN's

This study's objective is the performance evaluation of the existing CAD/CAE (Computer Aided Design/Computer Aided Engineering) network at NASA/KSC. This evaluation also includes a similar study of the Office Automation network, since it is being planned to integrate this network into the CAD/CAE network. The Microsoft mail facility which is presently on the CAD/CAE network was monitored to determine its present usage. This performance evaluation of the various networks will aid the NASA/KSC network managers in planning for the integration of future workload requirements into the CAD/CAE network and determining the effectiveness of the planned FDDI (Fiber Distributed Data Interface) migration.

Zobrist, George W.↗

NASA NTRS1994

Scalability study of parallel spatial direct numerical simulation code on IBM SP1 parallel supercomputer

The implementation and the performance of a parallel spatial direct numerical simulation (PSDNS) code are reported for the IBM SP1 supercomputer. The spatially evolving disturbances that are associated with laminar-to-turbulent in three-dimensional boundary-layer flows are computed with the PS-DNS code. By remapping the distributed data structure during the course of the calculation, optimized serial library routines can be utilized that substantially increase the computational performance. Although the remapping incurs a high communication penalty, the parallel efficiency of the code remains above 40% for all performed calculations. By using appropriate compile options and optimized library routines, the serial code achieves 52-56 Mflops on a single node of the SP1 (45% of theoretical peak performance). The actual performance of the PSDNS code on the SP1 is evaluated with a 'real world' simulation that consists of 1.7 million grid points. One time step of this simulation is calculated on eight nodes of the SP1 in the same time as required by a Cray Y/MP for the same simulation. The scalability information provides estimated computational costs that match the actual costs relative to changes in the number of grid points.

Hanebutte, Ulf R.↗

NASA NTRS1994

ASF archive issues: Current status, past history, and questions for the future

The Alaska SAR Facility (ASF) collects, processes, archives, and distributes data from synthetic aperture radar (SAR) satellites in support of scientific research. ASF has been in operation since 1991 and presently has an archive of over 100 terabytes of data. ASF is performing an analysis of its magnetic tape storage system to ensure long-term preservation of this archive. Future satellite missions have the possibility of doubling to tripling the amounts of data that ASF acquires. ASF is examining the current data systems and the high volume storage, and exploring future concerns and solutions.

Goula, Crystal A.↗

NASA NTRS1994

Magnetite: What it reveals about the origin of the banded iron formations

Magnetite, Fe3O4 is produced abiotically and biotically. Abiotically, magnetite is a late magmatic mineral and forms as a consequence of the cooling of iron rich magma. Biotically, magnetite is produced by several organisms, including magnetotactic bacteria. Hematite, Fe2O3, is also produced abiotically and biotically. Abiotically, hematite rarely occurs as a primary mineral in igneous rocks, but is common as an alteration product, fumarole deposit, and in some metamorphosed Fe-rich rocks. Biotically, hematite is produced by several types of microorganisms. Biologically-produced magnetite and hematite are formed under the control of the host organism, and consequently, have characteristics not found in abiotically produced magnetite and hematite crystals. To determine if the magnetite and hematite in the Banded Iron Formation was biologically or abiotically produced, the characteristics of biologically-produced magnetite and hematite (concentrated from Aquaspirillum magnetotacticum) and abiotically-produced magnetite and hematite obtained from Wards Scientific Supply Company, were compared with characteristics of magnetite and hematite concentrated from the Gunflint Banded Iron Formation (Ontario, Canada) using thermal and crystallographic analytical techniques. Whole rock analysis of the Gunflint Banded Iron Formation by x-ray diffraction (XRD) and differential thermal analysis (DTA) revealed the presence of quartz, hematite, siderite and dolomite as the major minerals, and magnetite, greenalite, pyrite, pyrrhotite and apatite as the minor minerals. Analysis of a crude magnetic fraction of the Gunflint showed the minerals quartz, hematite, siderite, dolomite, and magnetite. Analysis of the crude magnetic fraction from Aquaspirillum magnetotacticum revealed organic compounds plus hematite and magnetite. The mineral identification and particle size distribution data obtained from the DTA along with XRD data indicate that the magnetite and hematite from the Gunflint BIF share some similarities with biologically formed magnetite and hematite.

Schwartz, D. E.↗

NASA NTRS1993

R and T report: Goddard Space Flight Center

The 1993 Research and Technology Report for Goddard Space Flight Center is presented. Research covered areas such as (1) flight projects; (2) space sciences including cosmology, high energy, stars and galaxies, and the solar system; (3) earth sciences including process modeling, hydrology/cryology, atmospheres, biosphere, and solid earth; (4) networks, planning, and information systems including support for mission operations, data distribution, advanced software and systems engineering, and planning/scheduling; and (5) engineering and materials including spacecraft systems, material and testing, optics and photonics and robotics.

Soffen, Gerald A.↗

NASA NTRS1996

Fifth NASA Goddard Conference on Mass Storage Systems and Technologies.

This document contains copies of those technical papers received in time for publication prior to the Fifth Goddard Conference on Mass Storage Systems and Technologies. As one of an ongoing series, this conference continues to serve as a unique medium for the exchange of information on topics relating to the ingestion and management of substantial amounts of data and the attendant problems involved. This year's discussion topics include storage architecture, database management, data distribution, file system performance and modeling, and optical recording technology. There will also be a paper on Application Programming Interfaces (API) for a Physical Volume Repository (PVR) defined in Version 5 of the Institute of Electrical and Electronics Engineers (IEEE) Reference Model (RM). In addition, there are papers on specific archives and storage products.

Kobler, Benjamin↗

NASA NTRS1996

Fifth NASA Goddard Conference on Mass Storage Systems and Technologies

This document contains copies of those technical papers received in time for publication prior to the Fifth Goddard Conference on Mass Storage Systems and Technologies held September 17 - 19, 1996, at the University of Maryland, University Conference Center in College Park, Maryland. As one of an ongoing series, this conference continues to serve as a unique medium for the exchange of information on topics relating to the ingestion and management of substantial amounts of data and the attendant problems involved. This year's discussion topics include storage architecture, database management, data distribution, file system performance and modeling, and optical recording technology. There will also be a paper on Application Programming Interfaces (API) for a Physical Volume Repository (PVR) defined in Version 5 of the Institute of Electrical and Electronics Engineers (IEEE) Reference Model (RM). In addition, there are papers on specific archives and storage products.

Kobler, Benjamin↗

NASA NTRS1995

NAS Experiences of Porting CM Fortran Codes to HPF on IBM SP2 and SGI Power Challenge

Current Connection Machine (CM) Fortran codes developed for the CM-2 and the CM-5 represent an important class of parallel applications. Several users have employed CM Fortran codes in production mode on the CM-2 and the CM-5 for the last five to six years, constituting a heavy investment in terms of cost and time. With Thinking Machines Corporation's decision to withdraw from the hardware business and with the decommissioning of many CM-2 and CM-5 machines, the best way to protect the substantial investment in CM Fortran codes is to port the codes to High Performance Fortran (HPF) on highly parallel systems. HPF is very similar to CM Fortran and thus represents a natural transition. Conversion issues involved in porting CM Fortran codes on the CM-5 to HPF are presented. In particular, the differences between data distribution directives and the CM Fortran Utility Routines Library, as well as the equivalent functionality in the HPF Library are discussed. Several CM Fortran codes (Cannon algorithm for matrix-matrix multiplication, Linear solver Ax=b, 1-D convolution for 2-D datasets, Laplace's Equation solver, and Direct Simulation Monte Carlo (DSMC) codes have been ported to Subset HPF on the IBM SP2 and the SGI Power Challenge. Speedup ratios versus number of processors for the Linear solver and DSMC code are presented.

Saini, Subhash↗

NASA NTRS1996

An Acoustic Emission and Acousto-Ultrasonic Analysis of Impact Damaged Composite Pressure Vessels

The research presented herein summarizes the development of acoustic emission (AE) and acousto-ultrasonic (AU) techniques for the nondestructive evaluation of filament wound composite pressure vessels. Vessels fabricated from both graphite and kevlar fibers with an epoxy matrix were examined prior to hydroburst using AU and during hydroburst using AE. A dead weight drop apparatus featuring both blunt and sharp impactor tips was utilized to produce a single known energy 'damage' level in each of the vessels so that the degree to which the effects of impact damage could be measured. The damage levels ranged from barely visible to obvious fiber breakage and delamination. Independent neural network burst pressure prediction models were developed from a sample of each fiber/resin material system. Here, the cumulative AE amplitude distribution data collected from low level proof test (25% of the expected burst for undamaged vessels) were used to measure the effects of the impact on the residual burst pressure of the vessels. The results of the AE/neural network model for the inert propellant filled graphite/epoxy vessels 'IM7/3501-6, IM7/977-2 and IM7/8553-45' demonstrated that burst pressures can be predicted from low level AE proof test data, yielding an average error of 5.0%. The trained network for the IM7/977-2 class vessels was also able to predict the expected burst pressure of taller vessels (three times longer hoop region length) constructed of the same material and using the same manufacturing technique, with an average error of 4.9%. To a lesser extent, the burst pressure prediction models could also measure the effects of impact damage to the kevlar/epoxy 'Kevlar 49/ DPL862' vessels. Here though, due to the higher attenuation of the material, an insufficient amount of AE amplitude information was collected to generate robust network models. Although, the worst case trial errors were less than 6%, when additional blind predictions were attempted, errors as high as 50% were produced. An acousto-ultrasonic robotic evaluation system (AURES) was developed for mapping the effects of damage on filament wound pressure vessels prior to hydroproof testing. The AURES injects a single broadband ultrasonic pulse into each vessel at preprogrammed positions and records the effects of the interaction of that pulse on the material volume with a broadband receiver. A stress wave factor in the form of the energy associated with the 750 to 1000 kHz and 1000 to 1250 kHz frequency bands were used to map the potential failure sites for each vessel. The energy map associated with the graphite/epoxy vessels was found to decrease in the region of the impact damage. The kevlar vessels showed the opposite trend, with the energy values increasing around the damage/failure sites.

Walker, James L.↗

NASA NTRS1994

Microstructure and Mechanical Properties of Reaction-Formed Silicon Carbide (RFSC) Ceramics

The microstructure and mechanical properties of reaction-formed silicon carbide (RFSC) ceramics fabricated by silicon infiltration of porous carbon preforms are discussed. The morphological characterization of the carbon preforms indicates a very narrow pore size distribution. Measurements of the preform density by physical methods and by mercury porosimetry agree very well and indicate that virtually all of the porosity in the preforms is open to infiltrating liquids. The average room temperature flexural strength of the RFSC material with approximately 8 at.% free silicon is 369 +/- 28 MPa (53.5 +/- 4 ksi). The Weibull strength distribution data give a characteristic strength value of 381 MPa (55 ksi) and a Weibull modulus of 14.3. The residual silicon content is lower and the strengths are superior to those of most commercially available reaction-bonded silicon carbide materials.

Singh, M.↗

NASA NTRS1998

Comparison of Continuous-Wave CO2 Lidar Calibration by use of Earth-Surface Targets in Laboratory and Airborne Measurements

Backscatter of several Earth surfaces was characterized in the laboratory as a function of incidence angle with a focused continuous-wave 9.1 micro meter CO2 Doppler lidar for use as possible calibration targets. Some targets showed negligible angular dependence, while others showed a slight increase with decreasing angle. The Earth-surface signal measured over the complex Californian terrain during a 1995 NASA airborne mission compared well with laboratory data. Distributions of the Earth's surface signal shows that the lidar efficiency can be estimated with a fair degree of accuracy, preferably with uniform Earth-surface targets during flight for airborne or space-based lidar.

Jarzembski, Maurice A.↗

NASA NTRS1998

Atmospheric and Spectroscopic Research in the Far Infrared

The spectroscopic measurements of molecular parameters constitute one of the major areas of our research program. This part of our program has been conducted in close collaboration with Smithsonian Astrophysical Observatory (SAO) and National Institute of Standards and Technology (NIST). The references on HO2, OH, and O2 that appear on the publication list are examples of this type of work completed during the grant period. These pressure-broadening studies have provided the kind of improvements needed in the database for retrieving atmospheric profiles from far infrared limb sensing data. Authors summarized the laboratory spectroscopic studies conducted during the grant period. We attempted to measure the pressure broadening coefficients of the O2 lines in the 50 and 117/ cm regions. An accurate characterization of these lines using the IBEX detector system was needed to analyze the flight data. These are difficult lines to measure because they arise from weak magnetic dipole transitions. We used a 4-meter absorption cell to obtain the pressure broadening coefficients for the 50 and 83 /cm lines. We also completed the pressure broadening studies including the temperature dependence of two lines of OH at 83 and 118 /cm. These two lines are important not only for the balloon data retrieval work but also for the future project proposals.Another area of focus in our program is the far infrared detector research. The third area of focus deals with data distribution and dissemination.

Park, Kwangjai↗

NASA NTRS1998

Ultrasonic Velocity Variations with Soil Composition for Moisture Measurement

Soil moisture content may be measured by many methods, but the presently available techniques all have drawbacks when used in ground truth measurements for remote sensing. Ultrasonic velocity varies with soil moisture content, and may be used as the basis of a new measurement technique. In order to characterize a sensor capable of field use, soil particle size distribution data are compared to ultrasonic velocity in a variety of soils over a wide moisture range.

Metzl, R.↗

NASA NTRS2000

Eighth Goddard Conference on Mass Storage Systems and Technologies in Cooperation with the Seventeenth IEEE Symposium on Mass Storage Systems

This document contains copies of those technical papers received in time for publication prior to the Eighth Goddard Conference on Mass Storage Systems and Technologies which is being held in cooperation with the Seventeenth IEEE Symposium on Mass Storage Systems at the University of Maryland University College Inn and Conference Center March 27-30, 2000. As one of an ongoing series, this Conference continues to provide a forum for discussion of issues relevant to the management of large volumes of data. The Conference encourages all interested organizations to discuss long term mass storage requirements and experiences in fielding solutions. Emphasis is on current and future practical solutions addressing issues in data management, storage systems and media, data acquisition, long term retention of data, and data distribution. This year's discussion topics include architecture, future of current technology, new technology with a special emphasis on holographic storage, performance, standards, site reports, vendor solutions. Tutorials will be available on stability of optical media, disk subsystem performance evaluation, I/O and storage tuning, functionality and performance evaluation of file systems for storage area networks.

Kobler, Benjamin↗

NASA NTRS1999

Geometric Representations of Condition Queries on Three-Dimensional Vector Fields

Condition queries on distributed data ask where particular conditions are satisfied. It is possible to represent condition queries as geometric objects by plotting field data in various spaces derived from the data, and by selecting loci within these derived spaces which signify the desired conditions. Rather simple geometric partitions of derived spaces can represent complex condition queries because much complexity can be encapsulated in the derived space mapping itself A geometric view of condition queries provides a useful conceptual unification, allowing one to intuitively understand many existing vector field feature detection algorithms -- and to design new ones -- as variations on a common theme. A geometric representation of condition queries also provides a simple and coherent basis for computer implementation, reducing a wide variety of existing and potential vector field feature detection techniques to a few simple geometric operations.

Henze, Chris↗

NASA NTRS1999

HPF Implementation of ARC3D

We present an HPF (High Performance Fortran) implementation of ARC3D code along with the profiling and performance data on SGI Origin 2000. Advantages and limitations of HPF as a parallel programming language for CFD applications are discussed. For achieving good performance results we used the data distributions optimized for implementation of implicit and explicit operators of the solver and boundary conditions. We compare the results with MPI and directive based implementations.

Frumkin, Michael↗

NASA NTRS2001

NASA IVHM Technology Experiment for X-vehicles (NITEX)

The purpose of the NASA IVHM Technology Experiment for X-vehicles (NITEX) is to advance the development of selected IVHM technologies in a flight environment and to demonstrate the potential for reusable launch vehicle ground processing savings. The technologies to be developed and demonstrated include system-level and detailed diagnostics for real-time fault detection and isolation, prognostics for fault prediction, automated maintenance planning based on diagnostic and prognostic results, and a microelectronics hardware platform. Complete flight The Evolution of Flexible Insulation as IVHM consists of advanced sensors, distributed data acquisition, data processing that includes model-based diagnostics, prognostics and vehicle autonomy for control or suggested action, and advanced data storage. Complete ground IVHM consists of evolved control room architectures, advanced applications including automated maintenance planning and automated ground support equipment. This experiment will advance the development of a subset of complete IVHM.

Sandra, Hayden↗