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At least 127 records · Page 7
All sourcesNASA NTRSDOE OSTI
DOE OSTI2024

Where are the Data? Automating a Workflow for Carbon Storage Data Gap Analyses

This presentation demonstrates a spatial analysis workflow to assess data availability for the many components of geologic carbon storage technical viability. The workflow relies upon a knowledge-data framework that links the different components of GCS technical viability to the data types needed for evaluation. Using this contextual information, a combination of data science methods (e.g., natural language processing) and spatial analyses are applied to identify areas where sufficient data exists for a given component. The results are aggregated into maps illustrating data density and spatial gaps across all technical viability factors and data categories, as well as the individual component and category level for a more nuanced understanding. Presented at the Geological Society of America Connects 2024 Annual Meeting in Anaheim, California, 22-25 September 2024.

Creason, Christopher↗
DOE OSTI2024

Deep Learning-based Parameterization of Complex 3D CO2 Saturation Data in Large-scale Geological Carbon Storage

In deep learning (DL), dimension reduction plays a pivotal role in improving training efficiency and minimizing overfitting, especially when working with complex datasets like three-dimensional (3D) saturation data. In the context of geological carbon storage (GCS), 3D saturation data introduces unique challenges due to its sparse nature and sharp transitions at plume boundaries, known as shock fronts. To tackle these challenges, we developed a novel DL framework that combines dimension reduction with advanced 3D reconstruction techniques. Our approach utilizes latent variables derived from 2D average saturation fields to efficiently capture the essential features of high-dimensional data while reducing the number of variables. This enhances both the robustness and accuracy of DL models, making the framework more practical for real-world applications. By offering a tailored solution for modeling complex 3D saturation dynamics, this framework holds significant potential for environmental monitoring, energy storage, and other geological applications.

Wang, Hongsheng [University of Texas at Austin]↗
DOE OSTI2025

Transitioning CO2-EOR Field to Dedicated CO2 Storage: Risk Considerations and Quantifications

Presentation slides on “Transitioning CO2-EOR Field to Dedicated CO2 Storage: Risk Considerations and Quantifications” for the CCUS 2025 conference held in Houston, Texas March 3-5, 2025. CO2 injection wells for enhanced oil recovery (EOR) are currently regulated as Class II wells under the U.S. Environmental Protection Agency’s (EPA) Underground Injection Control (UIC) program, while dedicated geological CO2 storage (GCS) wells are considered Class VI wells. The UIC classification of wells for a transitioning CO2-EOR facility has the potential to substantially impact the feasibility of operations. This paper reports a case study of risk assessment of this transition, including areas review, plume stability and pressure transient and its impacts in dedicated CO2 storage.

carbon storage↗
DOE OSTI2026

A Play-Based Exploration of CO 2 Storage in the Illinois Basin (Final Technical Report)

This report documents the results of "A Play-Based Exploration of CO₂ Storage in the Illinois Basin" (DE-FE0032366), a project funded by the U.S. Department of Energy Office of Fossil Energy and Carbon Management and conducted by the Illinois State Geological Survey (ISGS) at the University of Illinois Urbana-Champaign in partnership with Visage Energy. The project adapted play-based exploration (PBE), a systematic basin-scale evaluation methodology from the petroleum industry, to screen areas of Illinois for commercial geologic carbon storage (GCS) in Cambro-Ordovician strata. The traditional play concept was expanded to encompass three play element groups, subsurface geologic factors, surface features, and societal factors, yielding 24 play elements with defensible suitability criteria applied through a five-tier classification scheme. An integrated geospatial database was assembled from ISGS, MGSC, MRCI, NATCARB, and public data sources, supported by significant data-improvement work including correction of legacy well locations, digitization of more than 1,300 well construction records using the DOE CATALOG team's OGRRE tool, compilation of a statewide 2D seismic database, and production of a refined fault and fold geodatabase.

58 GEOSCIENCES↗
DOE OSTI2026

Evidence for Environmental Stripping in the Coma Cluster

The stability and longevity of globular clusters (GCs) make them effective tracers of the dynamical histories of galaxies in cluster environments. We construct a catalog of 23,351 GC candidates in the Coma Cluster using imaging from the Hubble Space Telescope Advanced Camera for Surveys. We cross-match galaxy data from the SIMBAD, NASA/IPAC Extragalactic Database, and Sloan Digital Sky Survey archives to construct a galaxy sample and model their GC populations using the GC specific frequency. We find several galaxies with significantly smaller GC populations than expected from their luminosities, consistent with either tidal stripping or intrinsically low formation efficiencies. We analyze annular and Voronoi GC radial profiles of the two brightest cluster galaxies (BCGs), NGC 4874 and NGC 4889, as well as other Coma galaxies. A two-dimensional Voronoi density mapping reveals GC populations with marked deficits compared to our modeled expectations, including galaxies in proximity to the BCGs (e.g., IC 3998, NGC 4875, and NGC 4876) and others distributed across Coma (e.g., NGC 4908, NGC 4883, and IC 4042). Azimuthal symmetry testing suggests past dynamical interactions may have truncated GC systems in some galaxies, while intrinsic deficits are probable in others (e.g., IC 3973, IC 3976, IC 4040, and IC 4045). Our results show that GC deficits exist in several Coma galaxies and that the two-dimensional density structure reveals environmental signatures, with asymmetry statistics consistent with directional stripping. These findings highlight GC populations as powerful probes of environmental processing and the dynamical histories of galaxies in dense cluster environments.

Pomeroy, Richard T. [University of Texas Rio Grand↗
DOE OSTI2026

The Kinematically Hot, Extremely Metal-poor C-19 Stellar Stream in DESI DR2

Stellar streams are the result of a host galaxy’s gravitational potential tidally disrupting satellite dwarf galaxies and globular clusters (GCs), causing them to grow leading and trailing tidal tails. The C-19 stellar stream is an extremely metal-poor stellar population, showing chemical abundance patterns characteristic of a GC. However, its large velocity dispersion is difficult to reconcile with a conventional, purely baryonic, disrupting-GC progenitor. Current techniques for stream characterization are primarily applied to Gaia DR3, relying heavily on proper-motion measurements. Using the Dark Energy Spectroscopic Instrument (DESI), which provides radial velocities and metallicities for over 10 million stars and reaches significantly fainter magnitudes than comparable surveys, we employ a mixture model approach to jointly characterize stream populations in proper motions, radial velocities, and metallicities against a Milky Way halo background. By applying this framework to the C-19 stellar stream, we identify a total of 47 spectroscopically confirmed member stars, of which 41 are newly identified and only 6 were previously reported in the literature. In this work, we measure a velocity dispersion of $7.8^{+1.5}_{-1.3}$km s −1 and a mean metallicity of [Fe/H] = $-3.36^{+0.12}_{-0.10}$. We further identify a novel “spur” feature within the stream. We conclude that our measurements are in line with previous works identifying C-19 as a “hot,” metal-poor stream. In forthcoming work, we will apply this approach to many more streams in the DESI footprint, enabling population-level comparisons with predictions from simulations.

Mohammed, Nasser [University of Toronto; Dunlap In↗
NASA NTRS1981

Overview

The creation of a spherical model in cylindrical geometry is discussed. The model requires a radial body force to simulate gravity. This force is achieved by dielectric effects on a liquid in the presence of a large voltage, but in the terrestrial laboratory it cannot be made large enough to overwhelm gravity. However, in an orbiting vehicle like Spacelab, this dielectric force will dominate. The behavior of a stripped down general circulation system (GCS) is a salient omission of GCM. It is suggested that the system will contribute to global weather and climate studies.

Fowlis, W. W.↗
NASA NTRS1983

Application of the Hardman methodology to the Army Remotely Piloted Vehicle (RPV)

The application of the HARDMAN Methodology to the Remotely Piloted Vehicle (RPV) is described. The methodology was used to analyze the manpower, personnel, and training (MPT) requirements of the proposed RPV system design for a number of operating scenarios. The RPV system is defined as consisting of the equipment, personnel, and operational procedures needed to perform five basic artillery missions: reconnaissance, target acquisition, artillery adjustment, target designation and damage assessment. The RPV design evaluated includes an air vehicle (AV), a modular integrated communications and navigation system (MICNS), a ground control station (GCS), a launch subsystem (LS), a recovery subsystem (RS), and a number of ground support requirements. The HARDMAN Methodology is an integrated set of data base management techniques and analytic tools, designed to provide timely and fully documented assessments of the human resource requirements associated with an emerging system's design.

Source record↗
NASA NTRS1989

Software reliability studies

The longterm goal of this research is to identify or create a model for use in analyzing the reliability of flight control software. The immediate tasks addressed are the creation of data useful to the study of software reliability and production of results pertinent to software reliability through the analysis of existing reliability models and data. The completed data creation portion of this research consists of a Generic Checkout System (GCS) design document created in cooperation with NASA and Research Triangle Institute (RTI) experimenters. This will lead to design and code reviews with the resulting product being one of the versions used in the Terminal Descent Experiment being conducted by the Systems Validations Methods Branch (SVMB) of NASA/Langley. An appended paper details an investigation of the Jelinski-Moranda and Geometric models for software reliability. The models were given data from a process that they have correctly simulated and asked to make predictions about the reliability of that process. It was found that either model will usually fail to make good predictions. These problems were attributed to randomness in the data and replication of data was recommended.

Wilson, Larry W.↗
NASA NTRS1991

An evaluation of a DO-178A software development process

The guidance and control software (GCS) experiment is an effort to generate realistic software failure data by developing three implementations of a guidance and control software application according to the Radio Technical Commission for Aeronautics RTCA/DO-178A guidelines. The authors describe their approach for evaluating the DO-178A guidelines and give results from the development and verification process for the Pluto implementation. The other names are Mercury and Earth. The preliminary analysis of the Pluto implementation has already yielded some results that will be interesting to track for the other implementations.

Shagnea, Anita M.↗
NASA NTRS1992

Statistical modeling of software reliability

This working paper discusses the statistical simulation part of a controlled software development experiment being conducted under the direction of the System Validation Methods Branch, Information Systems Division, NASA Langley Research Center. The experiment uses guidance and control software (GCS) aboard a fictitious planetary landing spacecraft: real-time control software operating on a transient mission. Software execution is simulated to study the statistical aspects of reliability and other failure characteristics of the software during development, testing, and random usage. Quantification of software reliability is a major goal. Various reliability concepts are discussed. Experiments are described for performing simulations and collecting appropriate simulated software performance and failure data. This data is then used to make statistical inferences about the quality of the software development and verification processes as well as inferences about the reliability of software versions and reliability growth under random testing and debugging.

Miller, Douglas R.↗
NASA NTRS1990

Autonomous control

KSC has been developing the Knowledge-Based Autonomous Test Engineer (KATE), which is a tool for performing automated monitoring, diagnosis, and control of electromechanical devices. KATE employs artificial intelligence computing techniques to perform these functions. The KATE system consists of a generic shell and a knowledge base. The KATE shell is the portion of the system which performs the monitoring, diagnosis, and control functions. It is generic in the sense that it is application independent. This means that the monitoring activity, for instance, will be performed with the same algorithms regardless of the particular physical device being used. The knowledge base is the portion of the system which contains specific functional and behavorial information about the physical device KATE is working with. Work is nearing completion on a project at KSC to interface a Texas Instruments Explorer running a LISP version of KATE with a Generic Checkout System (GCS) test-bed to control a physical simulation of a shuttle tanking system (humorously called the Red Wagon because of its color and mobility). The Autonomous Control System (ACS) project supplements and extends the KATE/GCS project by adding three other major activities. The activities include: porting KATE from the Texas Instruments Explorer machine to an Intel 80386-based UNIX workstation in the LISP language; rewriting KATE as necessary to run on the same 80386 workstation but in the Ada language; and investigating software and techniques to translate ANSI Standard Common LISP to Mil Standard Ada. Primary goals of this task are as follows: (1) establish the advantages of using expert systems to provide intelligent autonomous software for Space Station Freedom applications; (2) determine the feasibility of using Ada as the run-time environment for model-based expert systems; (3) provide insight into the advantages and disadvantagesof using LISP or Ada in the run-time environment for expert systems; and (4) compare the performance of the 80386 processor to a symbolic processor as a delivery vehicle for expert systems.

Brown, Barbara↗
NASA NTRS2001

The Discovery of a Second Luminous Low Mass X-ray Binary in the Globular Cluster M15

We report an observation by the Chandra X-ray Observatory of 4U2127+119, the X-ray source identified with the globular cluster M15. The Chandra observation reveals that 4U2127+119 is in fact two bright sources, separated by 2.7". One source is associated with AC21 1, the previously identified optical counterpart to 4U2127+119, a low mass X-ray binary (LMXB). The second source, M15-X2, is coincident with a 19th U magnitude blue star that is 3.3" from the cluster core. The Chandra count rate of M15-X2 is 2.5 times higher than that of AC211. Prior to the 0.5" imaging capability of Chandra the presence of two so closely separated bright sources would not have been resolved, The optical counterpart, X-ray luminosity and spectrum of M15-X2 are consistent with it also being an LMXB system. This is the first time that two LMXBS have been seen to be simultaneously active in a globular cluster. The discovery of a second active LMXB in M15 solves a long standing puzzle where the properties of AC211 appear consistent with it being dominated by an extended accretion disk corona, and yet 4U2127+119 also shows luminous X-ray bursts requiring that the neutron star be directly visible. The resolution of 4U2127+119 into two sources suggests that the X-ray bursts did not come from AC211, but rather from M15X2. We discuss the implications of this discovery for understanding the origin and evolution of LMXBs in GCs as well as X-ray observations of globular clusters in nearby galaxies.

White, Nicholas E.↗
NASA NTRS2004

X-Ray Emission from the Halo of M31

Our goal was to use short (10 ksec) observations of selected fields in the halo of M31, to determine the size and characteristics of its X-ray population and to study the connection between globular clusters and X-ray sources. The program of observations has yet to be successfully completed. We received acceptable data from just 2 of the 5 approved fields. Nevertheless, the results were intriguing and we have submitted a paper based on this data to Nature. We find that the X-ray source density is significantly enhanced in the vicinity of one GC, providing the first observational evidence supporting the ejection hypothesis. We also find additional X-ray sources, including some which are very soft, in large enough numbers to suggest that not all could have been formed in GCs. That is, some must be descended from the same primordial halo population that produced any compact stars comprising part of the halo's dark matter. Extrapolating fiom the X-ray source population, we estimate that stellar remnants and dim old stars in the halo could comprise as much as 25% of the estimated mass (approx. 10(exp 12) Solar Mass) of the halo. These results suggest that the other approved fields should be observed soon and also provide strong motivation for the future XMM-Newton programs.

Mushotzky, Richard↗
NASA NTRS2007

Ikhana: A NASA UAS Supporting Long Duration Earth Science Missions

The NASA Ikhana unmanned aerial vehicle (UAV) is a General Atomics Ae ronautical Systems Inc. (San Diego, California) MQ-9 Predator-B modif ied to support the conduct of Earth science missions for the NASA Sci ence Mission Directorate and, through partnerships, other government agencies and universities. It can carry over 2000 lb of experiment p ayloads in the avionics bay and external pods and is capable of missi on durations in excess of 24 hours at altitudes above 40,000 ft. The aircraft is remotely piloted from a mobile ground control station (GC S) that is designed to be deployable by air, land, or sea. On-board s upport capabilities include an instrumentation system and an Airborne Research Test System (ARTS). The Ikhana project will complete GCS d evelopment, science support systems integration, external pod integra tion and flight clearance, and operations crew training in early 2007 . A large-area remote sensing mission is currently scheduled for Summ er 2007.

Cobleigh, B.↗
NASA NTRS2006

Earth Science Capability Demonstration Project

A viewgraph presentation reviewing the Earth Science Capability Demonstration Project is shown. The contents include: 1) ESCD Project; 2) Available Flight Assets; 3) Ikhana Procurement; 4) GCS Layout; 5) Baseline Predator B Architecture; 6) Ikhana Architecture; 7) UAV Capability Assessment; 8) The Big Picture; 9) NASA/NOAA UAV Demo (5/05 to 9/05); 10) NASA/USFS Western States Fire Mission (8/06); and 11) Suborbital Telepresence.

Cobleigh, Brent↗
NASA NTRS2006

Notional Airspace Operations Demonstration Plan

The airspace operations demonstration (AOD) is intended to show that the Access 5 Step 1 functional requirements can be met. The demonstration will occur in two phases. The initial on-range phase will be carried out in restricted airspace to demonstrate the cooperative collision avoidance (CCA) functional requirements and to provide risk-reduction for the AOD by allowing the test team to rehearse some elements of the demonstration mission. The CCA system to be used in these flights is based on Automatic Dependent Surveillance-Broadcast (ADS-B) which is a commercially-available system by which airplanes constantly broadcast their current position and altitude to other aircraft and ground resources over a dedicated radio datalink. The final phase will occur in the national airspace (NAS) and will be the formal demonstration of the remainder of the proposed functional requirements. The general objectives of the AOD are as follows: (1) Demonstrate that the UAS can aviate in the NAS (2) Demonstrate that the UAS can navigate in the NAS (3) Demonstrate that the UAS can communicate with the NAS (4) Demonstrate that the UAS can perform selected collision avoidance functions in the NAS (5) Demonstrate that the UAS can evaluate and avoid weather conflicts in the NAS (6) Demonstrate that the UAS can provide adequate command and control in the NAS In addition to the stated objectives, there are a number of goals for the flight demonstration. The demo can be accomplished successfully without achieving these goals, but these goals are to be used as a guideline for preparing for the mission. The goals are: (1) Mission duration of at least 24 hours (2) Loiter over heavy traffic to evaluate the data block issue identified during the Access 5 Airspace Operations Simulations (3) Document the contingency management process and lessons learned (4) Document the coordination process for Ground Control Stations (GCS) handoff (5) Document lessons learned regarding the process of flying in the NAS Preliminary planning for a notional mission to achieve the objectives and goals has been prepared. The planning is intended to serve as a guide for detailed planning of the AOD.

Trongale, Nicholas A.↗
NASA NTRS2008

2007 Western States Fire Mission

A general overview of the Ikhana Uninhabited Air System (UAS) is presented. The contents include: 1) Ikhana UAS; 2) Ikhana UAS / Ground Control Station (GCS); 3) Ikhana UAS / Antennas; 4) Western States Fire Mission 2007 Partners; 5) FAA Certificate of Authorization (COA); 6) Western States Fire Missions (WSFM) 2007; 7) WSFM 1-4 2007; 8) California Wildfire Emergency Response 2007; 9) WSFM 5-8 Emergency Response 2007; 10) WSFM Achievements; and 11) WSFM Challenges.

Howell, Kathleen↗