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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 217 records · Page 12
All sourcesNASA NTRSDOE OSTI
NASA NTRS1993

ATM technology and beyond

Networks based on Asynchronous Transfer Mode (ATM) are expected to provide cost-effective and ubiquitous infrastructure to support broadband and multimedia services. In this paper, we give an overview of the ATM standards and its associated physical layer transport technologies. We use the experimental HIPPI-ATM-SONET (HAS) interface in the Nectar Gigabit Testbed to illustrate how one can use the SONET/ATM public network to provide transport for bursty gigabit applications.

Cheung, Nim K.↗
NASA NTRS1993

Overview of NASA's Adaptive Structures program

NASA's recent progress in Adaptive Structures is reviewed using results from both experimental and flight hardware test programs. Particular attention is given to testbeds, structural deployment/assembly, structural linearization, static shape/position adjustment, on-orbit system identification, and vibration suppression. It is concluded that a very rapid transition of research in Adaptive Structures to applications has occurred in the past five years. Adaptive Structures provide tools for increasing the robustness of structural design.

Venneri, S. L.↗
NASA NTRS1996

Performance Evaluation in Network-Based Parallel Computing

Network-based parallel computing is emerging as a cost-effective alternative for solving many problems which require use of supercomputers or massively parallel computers. The primary objective of this project has been to conduct experimental research on performance evaluation for clustered parallel computing. First, a testbed was established by augmenting our existing SUNSPARCs' network with PVM (Parallel Virtual Machine) which is a software system for linking clusters of machines. Second, a set of three basic applications were selected. The applications consist of a parallel search, a parallel sort, a parallel matrix multiplication. These application programs were implemented in C programming language under PVM. Third, we conducted performance evaluation under various configurations and problem sizes. Alternative parallel computing models and workload allocations for application programs were explored. The performance metric was limited to elapsed time or response time which in the context of parallel computing can be expressed in terms of speedup. The results reveal that the overhead of communication latency between processes in many cases is the restricting factor to performance. That is, coarse-grain parallelism which requires less frequent communication between processes will result in higher performance in network-based computing. Finally, we are in the final stages of installing an Asynchronous Transfer Mode (ATM) switch and four ATM interfaces (each 155 Mbps) which will allow us to extend our study to newer applications, performance metrics, and configurations.

Dezhgosha, Kamyar↗
NASA NTRS2002

An Experimental Framework for Executing Applications in Dynamic Grid Environments

The Grid opens up opportunities for resource-starved scientists and engineers to harness highly distributed computing resources. A number of Grid middleware projects are currently available to support the simultaneous exploitation of heterogeneous resources distributed in different administrative domains. However, efficient job submission and management continue being far from accessible to ordinary scientists and engineers due to the dynamic and complex nature of the Grid. This report describes a new Globus framework that allows an easier and more efficient execution of jobs in a 'submit and forget' fashion. Adaptation to dynamic Grid conditions is achieved by supporting automatic application migration following performance degradation, 'better' resource discovery, requirement change, owner decision or remote resource failure. The report also includes experimental results of the behavior of our framework on the TRGP testbed.

Huedo, Eduardo↗
DOE OSTI2025

TRUST Sensors in Environments: Accelerometers (SE-A) Report Release FY25

The objective of the Delivery Environments (DE) Testbeds to Reduce Uncertainty in Simulations and Tests (TRUST) project is to quantify and help increase confidence in specific areas of computa tional and experimental capabilities that are applicable to the development, on-target assessment, and qualification of current and future delivery environments. The TRUST project consists of five "low-complexity", single-feature testbeds used to conduct experiments with accompanying models and simulations. Each of the five single feature testbeds aims to isolate an engineering feature or behavior of interest, then work towards improving the fundamental engineering understanding of that feature. Additionally, the single feature testbeds are used to identify capability development needs that can help reduce model and experimental uncertainty.

42 ENGINEERING↗
DOE OSTI2026

Validation of an integrated modeling framework for investigating 3D plasma responses in tokamak plasmas

As contemporary experimental tokamaks are pushed toward reactor-relevant operation, they provide essential testbeds for demonstrating and exploring ELM control strategies for deployment in future fusion pilot plants. Accurate predictions of full plasma responses are essential to guide and optimize these demonstrations. This paper introduces and validates an integrated modeling framework over a historical range of DIII-D operational space. The integrated modeling framework uses only scalar plasma parameters and optional reference boundary to self-consistently and flexibly scan through tokamak operational space and estimate the corresponding ELM-suppression relevant plasma response over 3D coil phase space. The framework generates tightly converged equilibria that satisfy a target set of plasma parameters (I p , β N , l i ), with kinetic profiles constrained by an EPED(NN)-computed pedestal and empirical core model. The plasma response of these modeled equilibria is calculated with GPEC. Validated against 55 distinct DIII-D equilibria, the framework consistently reproduces experimentally constrained equilibrium pressure, q, and other representative profiles using the time-varying information from only evolving scalar plasma parameters; plasma response validation is performed for the n=3 perturbation. In particular, the plasma response of a DIII-D discharge scanning q 95 in search of ELM suppression windows is quantitatively reproduced. By accurately reproducing experimental equilibria and plasma responses across wide parameter variation, the framework supports potential for synthetic parameter scans in key operational, stability, and plasma response dimensions to investigate RMP ELM-suppression experiments and inform predictive RMP scenario optimization.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
NASA NTRS1996

Experimental Validation of an Integrated Controls-Structures Design Methodology

The first experimental validation of an integrated controls-structures design methodology for a class of large order, flexible space structures is described. Integrated redesign of the controls-structures-interaction evolutionary model, a laboratory testbed at NASA Langley, was described earlier. The redesigned structure was fabricated, assembled in the laboratory, and experimentally tested against the original structure. Experimental results indicate that the structure redesigned using the integrated design methodology requires significantly less average control power than the nominal structure with control-optimized designs, while maintaining the required line-of-sight pointing performance. Thus, the superiority of the integrated design methodology over the conventional design approach is experimentally demonstrated. Furthermore, amenability of the integrated design structure to other control strategies is evaluated, both analytically and experimentally. Using Linear-Quadratic-Guassian optimal dissipative controllers, it is observed that the redesigned structure leads to significantly improved performance with alternate controllers as well.

Maghami, Peiman G.↗
NASA NTRS1979

Progress on Variable Cycle Engines

Progress in the development and future requirements of the Variable Stream Control Engine (VSCE) are presented. The two most critical components of this advanced system for future supersonic transports, the high performance duct burner for thrust augmentation, and the low jet coannular nozzle were studied. Nozzle model tests substantiated the jet noise benefit associated with the unique velocity profile possible with a coannular nozzle system on a VSCE. Additional nozzle model performance tests have established high thrust efficiency levels only at takeoff and supersonic cruise for this nozzle system. An experimental program involving both isolated component and complete engine tests has been conducted for the high performance, low emissions duct burner with good results and large scale testing of these two components is being conducted using a F100 engine as the testbed for simulating the VSCE. Future work includes application of computer programs for supersonic flow fields to coannular nozzle geometries, further experimental testing with the duct burner segment rig, and the use of the Variable Cycle Engine (VCE) Testbed Program for evaluating the VSCE duct burner and coannular nozzle technologies.

Westmoreland, J. S.↗
DOE OSTI2025

Medium Voltage Testbed for Comparing Advanced Power Line Sensors vs. Transformers with Electrical Grid Events

Electrical utilities have relied upon potential transformers (PTs) and current transformers (CTs) for very accurate metering and to provide reliable signals for protective relays. These devices measure phase voltages and currents and are commissioned by electrical engineers. PTs/CTs can detect and react to various electrical anomalies that could adversely affect electrical grid operations. Less expensive alternative sensing technologies offer the possibility of wider deployment, particularly in grids that employ distributed energy resources. In this work, the performance of an advanced medium-voltage sensor is compared with that of a reference PT and a CT and experimentally evaluated for different power grid scenarios on an advanced outdoor power line sensor testbed at the U.S. Department of Energy’s Oak Ridge National Laboratory. The sensor is based on a capacitive divider for voltage monitoring and a Rogowski coil with an integrator for current monitoring. This study simulated a power grid model based on a utility circuit at the Riverside EPB of Chattanooga. The simulation circuit was created with MATLAB/Simulink software and was integrated into an RT-LAB project to run with the OP4510 real-time simulator at the OPLST. During the tests, the real-time simulations were run for 40 s, and the signal to record the test event with the power meter was set at 30 s for the event-trigger circuit. The advanced outdoor power line sensor testbed has a real-time simulator that is used to generate transient scenarios (e.g., electrical faults, capacitor bank operation, and service restoration), while the analog signals are recorded by the same high-resolution power meter. The behaviors of analog signals, harmonic components, total harmonic distortion, and crest factors are assessed for this power line sensor and compared with those of the reference PT/CT because of the absence of testing standards for advanced outdoor power line sensors. The results showed that this OPLS technology responded identically to the PT and CT under all conditions.

Piesciorovsky, Emilio [ORNL]↗
NASA NTRS2026

Experimental Study of Aeropropulsive Interactions for Electric Ducted Fans on a Wing

The Adaptable Distributed Electric Propulsion Testbed (ADEPT)Wing was tested in the NASA Langley 12-Foot Low-Speed Tunnel to investigate electric propulsion technologies for commercial transport aircraft. The purpose of the test was to study the aeropropulsive effects across angle of attack and fan speed variations for several propulsor placements and array sizes, and to investigate how distributed electric propulsion (DEP) can be leveraged for augmented lift and vehicle control. Six electric ducted fan (EDF) array placements were tested by positioning the fans along the leading and trailing edges on the top and bottom surfaces, as well as centered on the chord line in front of and behind the wing. Each fan placement configuration was tested with an array of one, three, and five EDFs to characterize an aeropropulsive extrapolation effect, and the bare wing was tested separately to provide baseline aerodynamic measurements. The results compare the longitudinal forces and moments for each configuration by analyzing the combined aeropropulsive interaction effects, and offer valuable insight into considerations for fan placement along a wing to enable the benefits of DEP integration.

Rose Weinstein↗
DOE OSTI2025

Modular Autonomous Experimentation for Biological Applications (Full Report)

The Modular Autonomous Research System (MARS) was developed to address the pressing need for faster, more reliable, and more adaptable scientific discovery. Traditional experimentation is limited by manual labor, long cycle times, and fragmented data streams, which constrain the ability to explore complex chemical and materials design spaces. To overcome these limitations, we created an integrated, modular platform that combines laboratory robotics, diverse measurement instruments, and a central data infrastructure with artificial intelligence–driven decision-making. The system links liquid handling robots, robotic arms, and optical plate readers into a closed loop where experiments are executed automatically, data is analyzed in real time, and subsequent experimental conditions are adaptively chosen to maximize information gain. Over the course of the project, MARS was validated on two primary test cases—spectroscopic metal–ligand binding assays and peptide-directed mineralization—which highlighted the system’s ability to handle uncertainty and variability in experimental measurements. To further demonstrate modularity and extensibility, we also established additional testbeds in electrochemistry for catalyst discovery and electrolyte formulation for advanced batteries. The results show that MARS can reliably conduct autonomous campaigns with minimal human intervention, adapt to distinct scientific domains, and provide a scalable model for future self-driving laboratories. This work establishes new capabilities for modular, uncertainty-aware automation and directly supports the need for advanced, data-driven research platforms capable of accelerating discovery across a wide range of scientific and national security missions.

59 BASIC BIOLOGICAL SCIENCES↗
NASA NTRS1992

Vibration isolation technology development to demonstration

The main thrust of these studies has resulted in an active inertial feedforward/feedback isolation system. This prototype magnetic suspension system has been demonstrated in a laboratory setting in six degrees-of-freedom and has been preliminarily characterized in its isolation performance with favorable results. This isolation system consists of a closed loop digital control system referencing a platform around six relative and six inertial sensors. These sensors control the isolated mass through nine attractive electromagnetic actuators with a system capability of +/- three-tenths of an inch travel in three dimensions. The development of a prototype system from design to fabrication leads directly into the demonstration phase of the project which will attempt a low gravity environmental demonstration of engineering hardware for the isolation of a scientific payload. The demonstration phase of the project will use an aircraft low gravity maneuver to establish a research testbed for the study of isolation hardware and control strategies in an off-loaded environment. In developing this demonstration capability the Lewis Learjet aircraft has been characterized through its parabolic flight maneuvers and a trunnioned experimental volume has been designed for the test of both active and passive isolation packages. This vibration isolation testbed is operational and has two data acquisition systems available for both autonomous and interactive operation, with a combined input capability of 32 channels.

Grodsinsky, Carlos↗
NASA NTRS1995

Structural Analysis and Testing of an Erectable Truss for Precision Segmented Reflector Application

This paper describes analysis and test results obtained at Langley Research Center (LaRC) on a doubly curved testbed support truss for precision reflector applications. Descriptions of test procedures and experimental results that expand upon previous investigations are presented. A brief description of the truss is given, and finite-element-analysis models are described. Static-load and vibration test procedures are discussed, and experimental results are shown to be repeatable and in generally good agreement with linear finite-element predictions. Truss structural performance (as determined by static deflection and vibration testing) is shown to be predictable and very close to linear. Vibration test results presented herein confirm that an anomalous mode observed during initial testing was due to the flexibility of the truss support system. Photogrammetric surveys with two 131-in. reference scales show that the root-mean-square (rms) truss-surface accuracy is about 0.0025 in. Photogrammetric measurements also indicate that the truss coefficient of thermal expansion (CTE) is in good agreement with that predicted by analysis. A detailed description of the photogrammetric procedures is included as an appendix.

Collins, Timothy J.↗
NASA NTRSDate not supplied

Laboratory Demonstration of High Contrast with the PIAACMC Coronagraph on an Obstructed and Segmented Aperture

Coronagraphs (together with starshades) are an important tool to directly image and characterize exoplanets, and enable the search for biomarkers in reflected light on potentially habitable worlds. Their performance and efficiency has steadily been improving over the past several decades, but has not yet reached performance limits. In particular, the expected exoplanet yield for missions such as the Astro2020-recommended “IR/O/UV Flagship” can still be improved by factors of at least 2-3, simply by continued improvements in coronagraph performance, before they plateau due to physics limits. One possible architecture that can enable at least a part of this improvement is the Phase-Induced Amplitude Apodization Complex Mask Coronagraph (PIAACMC). Itoffersthe advantages of high throughput, small inner working angle (IWA),and almost noloss inPSF sharpness, and natively supports obstructed and segmented apertures, which is essential to the Astro2020 “IR/O/UV Flagship”mission. Historically, key disadvantages of PIAA have been poor tolerance to stellar angular sizes and maturity, but latest designs and demonstrations have made significant strides in this respect.In this paper, we present the current status and overview of our program to mature the PIAACMC technology. We first review PIAACMC designs for LUVOIR-A and B, which resultedin improved expected yield of Exo-Earths relative tothe baselines for both mission concepts. In particular, for LUVOIR-B, the yield improves from 28 to 42due to improvedtolerance to stellar angular size in our design. The improvement in yield is marginal for LUVOIR-A, but our design enables detecting planets around smaller diameter stars (nearby K-dwarfs and/or farther FG stars). We also describe our modeling and vacuum demonstrationsfor the LUVOIR-A aperture(which is more challengingthan LUVOIR-B due to the central obstruction).The demonstration included a LUVOUR-A pupil mask, an on-axis PIAA set of 2 mirrors with central holes, a Boston Micromachines DM, a patterned CMC mask, Lyot stop, and supporting masks and optics. Demonstrations were conducted at JPL’s High Contrast Imaging Testbed (HCIT) using several characterization andwavefront control techniques (primarily standard EFC, several experimental techniques were attempted, as well as speckle nulling). So far, our results include 1.9e-8 raw contrast in 10% broadband light between 3.5 and 8 l/D; 4.1e-8 and 1.6e-9 coherent contrasts in monochromatic light between 2-4 and 4-8 l/D, respectively. We also present measurements and analysis of sensitivity to tip/tilt jitter and stellar angular size. Finally, we compare our test results to models, present an analysis of our limiting factors, and explorefuture prospectsfor improvement based on validated models.

Coronagraph↗
NASA NTRS2003

Robot Tracking of Human Subjects in Field Environments

Future planetary exploration will involve both humans and robots. Understanding and improving their interaction is a main focus of research in the Intelligent Systems Branch at NASA's Johnson Space Center. By teaming intelligent robots with astronauts on surface extra-vehicular activities (EVAs), safety and productivity can be improved. The EVA Robotic Assistant (ERA) project was established to study the issues of human-robot teams, to develop a testbed robot to assist space-suited humans in exploration tasks, and to experimentally determine the effectiveness of an EVA assistant robot. A companion paper discusses the ERA project in general, its history starting with ASRO (Astronaut-Rover project), and the results of recent field tests in Arizona. This paper focuses on one aspect of the research, robot tracking, in greater detail: the software architecture and algorithms. The ERA robot is capable of moving towards and/or continuously following mobile or stationary targets or sequences of targets. The contributions made by this research include how the low-level pose data is assembled, normalized and communicated, how the tracking algorithm was generalized and implemented, and qualitative performance reports from recent field tests.

Graham, Jeffrey↗
NASA NTRSDate not supplied

System Identification of Flexible Aircraft: Lessons Learned from the X-56A Phase 1 Flight Tests

The X-56A Multi-Utility Technology Testbed (MUTT) is a subscale airplane that was de-signed as an experimental flight research platform for improving aeroelastic modeling and control technologies. The Phase 1 flight tests, conducted from 2017 to 2019 at the NASA Arm-strong Flight Research Center (AFRC), included 39 flights and approximately 1000 research maneuvers, some of which demonstrated stable closed-loop flight beyond the open-loop flutter speed. This paper summarizes the system identification effort to extract nondimensional stability and control derivatives from the flight test data for constructing aeroelastic models of the flight dynamics. Topics discussed include instrumentation, experiment design, model postulation and reduction, parameter estimation, and others. Throughout the paper, unique challenges for the identification of flexible aircraft, practical aspects of the analysis, and lessons learned are presented.

Jared A Grauer↗
NASA NTRSDate not supplied

High-Altitude ADS-B/GPS LPV Flight Tests on a NASA ER-2 Research Airplane

The research presented in this paper describes the conceptual design of a system architecture that integrates Automatic Dependent Surveillance-Broadcast (ADS-B) and Global Positioning System (GPS) Localizer Performance Vertical (LPV) guidance technology onto a unique high-altitude research airplane: a United States Air Force (USAF) / Lockheed Martin (Bethesda, Maryland) Aeronautics U-2S airplane. The design features modern display capabilities to provide air-to-air surveillance and precision navigation, to adhere to Federal Aviation Administration (FAA) certification standards for operations in upper Class E airspace. The National Aeronautics and Space Administration (NASA) variant of the U-2S, now called the Earth Resources (ER-2) airplane, remains unrivaled in the art of sustained high-altitude flight for scientific expeditions. Capable of routinely cruising above flight level (FL) 650 that had been considered, at inception, the domain of only the most elite experimental research aircraft types. Nicknamed the Dragon Lady, this U-2S research testbed is still one of the most advanced aircraft in the world. The exceptional military design of the vehicle, security guidelines, and the performance envelope of the ER-2 posed unique challenges to the integration of modern civilian avionics. ADS-B epitomizes the next generation of surveillance technology, incorporating both air and ground aspects. ADS-B provides air traffic control (ATC) with a more accurate picture of the three-dimensional positioning of aircraft in various phases of flight, including en route, terminal, approach, and ground operations. The airborne surveillance system broadcasts its identification, position, altitude, velocity, and other information. GPS LPV represents a significant advancement in aviation technology, emphasizing the pivotal role that GPS and Performance-Based Navigation concepts will play in the foreseeable future. This technology represents a shift from sensor-based navigation to performance-based navigation, allowing for more flexible and efficient use of airspace. This research described herein is structured as follows: Section II, “Systems Background,” provides a systems background and description of an ADS-B and GPS LPV system equipped on the high-altitude ER-2 research airplane to satisfy the FAA airworthiness requirements for high-altitude flight operations. Section III, “Flight Test System,” describes the flight-test airplane systems. Section IV, “Analysis of GPS SBAS, Safety, and Ground Tests,” provides an overview of the GPS Satellite-Based Augmentation System (SBAS) and an analysis of the GPS LPV metrics, safety, and ground tests. Section V, “High-Altitude Flight Tests,” describes the high-altitude flight tests, including 3 flight-test results, analysis, human factors, and lessons learned. Section VI, the conclusion, draws insights from the lessons learned, discusses the design challenges associated with ADS-B and GPS LPV, and showcases the paramount significance of these pivotal technologies in aircraft surveillance and navigation.

Ricardo A. Arteaga↗