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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 559 records · Page 31
All sourcesNASA NTRSDOE OSTI
NASA NTRS2003

Performance of WPA Conductivity Sensor during Two-Phase Fluid Flow in Microgravity

The Conductivity Sensor designed for use in the Node 3 Water Processor Assembly (WPA) was based on the existing Space Shuttle application for the fuel cell water system. However, engineering analysis has determined that this sensor design is potentially sensitive to two-phase fluid flow (gadliquid) in microgravity. The source for this sensitivity is the fact that gas bubbles will become lodged between the sensor probe and the wall of the housing without the aid of buoyancy in l-g. Once gas becomes lodged in the housing, the measured conductivity will be offset based on the volume of occluded gas. A development conductivity sensor was flown on the NASA Microgravity Plan to measure the offset, which was determined to range between 0 and 50%. Based on these findings, a development program was initiated at the sensor s manufacturer to develop a sensor design fully compatible with two-phase fluid flow in microgravity.

Carter, Layne↗
NASA NTRSDate not supplied

Progress on the Development of a Step Height Sensor for the BOLT Flight Vehicle

This presentation will summarize progress on the development of a step height sensor for the BOLT flight vehicle. Two methods have been proposed to measure the step size in this effort.The first method involves the application of miniaturized camera embedded in the flight vehicle that views the step through a rearward-facing port (shown in Fig. 1a inset). The second method involves the application of a linear fiber optic array bundle to measure the intensity of light reflected back from the aft body step (concept shown in Fig. 1b). Preliminary testing with the miniaturized camera has been performed in the lab and shows that displacements of ≤10 μm can be measured using this method. Final testing with both methods will be performed on the test stand shown in Fig. 1a. This test stand will include a fine adjustment vertical translation stage that will be used to adjust the step height in steps of 1-2 μm. A high-magnification imaging system will also be used to verify the step height. The miniaturized camera and linear fiber optic array bundle will be mounted in one of several port holes with varying degrees of inclination relative to the top surface in the opposing aft-section slab. BOLT flight vehicle details and information on the steps can be found in Ref. [1].

BOLT↗
NASA NTRS2023

In Situ Sensors for Monitoring the Space Environment and Its Effect Upon Satellite Materials

Development of advanced materials for space requires both an understanding of the space environment and how a material might be affected by the environment. Despite a long history of space missions, we have insufficient knowledge to fully characterize the exposure that spacecraft materials experience over a mission lifetime, much less the effects that this exposure induces upon spacecraft materials. In addition, the physics of materials/environment interactions is less well understood than optimum owing to the complex nature of the space environment and the challenges in simulating this environment in the laboratory. Our understanding of both the environment and materials behavior in that environment would be advanced by the development of sensors that could be deployed on a variety of missions and collect sufficient data. In-situ environmental sensors would improve both our understanding of spacecraft materials environmental durability and lead to improved ground-laboratory investigations. There are a number of factors that have limited the development of a widespread network of space environmental sensors intended to fill this need. The cost of deploying space systems generally encourages system designers to minimize any functionality that is extraneous to the main mission of a space vehicle. Deploying additional sensors adds cost, size, weight, power and telemetry bandwidth that could interfere with mission goals. The complexity of the space environment makes it challenging to manufacture a sensor that provides a complete characterization of its environment, especially with a limited impact upon the host. Finally, such a hosted sensor could impact the security or reliability of the main mission.

Jim Barrie↗
NASA NTRS1987

A solid state laser development program for remote atmospheric sensors

The current status of NASA Langley efforts to develop solid-state lasers for use in the Lidar Atmospheric Sounder and Altimeter (LASA) of the Space Station Earth Observing System is surveyed. The types of observations to be performed with LASA are listed, and the parameters of presently available lasers are compared with the LASA baseline goals: 2 kW output power; 500 kg weight; tunability to 727, 760, and 943 nm to within 500 fm; high spectral purity; efficiency greater than 3 percent; energy about 1 J/pulse, pulse length less than 100 nsec, and lifetime greater than 108 shots. The use of sensitized flashlamp-pumped laser materials or diode-laser pumping to improve performance is discussed, and particular attention is given to materials research on Ti:sapphire lasers, studies of higher-efficiency detectors, and the LASE and LITE airborne lidar and DIAL experiments.

Newcomb, A. L.↗
NASA NTRS2006

Developing Multilayer Thin Film Strain Sensors With High Thermal Stability

A multilayer thin film strain sensor for large temperature range use is under development using a reactively-sputtered process. The sensor is capable of being fabricated in fine line widths utilizing the sacrificial-layer lift-off process that is used for micro-fabricated noble-metal sensors. Tantalum nitride films were optimized using reactive sputtering with an unbalanced magnetron source. A first approximation model of multilayer resistance and temperature coefficient of resistance was used to set the film thicknesses in the multilayer film sensor. Two multifunctional sensors were fabricated using multilayered films of tantalum nitride and palladium chromium, and tested for low temperature resistivity, TCR and strain response. The low temperature coefficient of resistance of the films will result in improved stability in thin film sensors for low to high temperature use.

Wrbanek, John D.↗
NASA NTRS1980

Progress report on the ATMOS sensor - Design description and development status

The Atmospheric Trace Molecule Spectroscopy program is a multiflight shuttle borne investigation designed to determine, on a global scale, the compositional structure and spatial variability of the upper atmosphere using the technique of high resolution infrared absorption spectroscopy. The measurement approach is based on an advanced Fourier Transform Spectrometer capable of obtaining high sensitivity spectral measurements of the atmosphere over a wide spectral region (625-5000 kaysers; 2-16 microns) at high spectral resolution (0.01 kaysers) and vertical height spatial resolution (2 km). Additional elements of the sensor system include a suntracker, a telescope, a mechanically cooled (Hg,Cd)Te detector, and a data handling subsystem with a 16 Mbit/s PCM output. A description is given of the sensor design, including performance predictions, followed by a brief summary of the current technical status of the development effort.

Morse, P. G.↗
NASA NTRS2002

Advanced Microgravity Acceleration Measurement Systems Being Developed

The Advanced Microgravity Acceleration Measurement Systems (AMAMS) project at the NASA Glenn Research Center is part of the Instrument Technology Development program to develop advanced sensor systems. The primary focus of the AMAMS project is to develop microelectromechanical (MEMS) acceleration sensor systems to replace existing electromechanical-sensor-based systems presently used to assess relative gravity levels aboard spacecraft. These systems are used in characterizing both vehicle and payload responses to low-gravity vibroacoustic environments. The collection of microgravity acceleration data has cross-disciplinary utility to the microgravity life and physical sciences and the structural dynamics communities. The inherent advantages of semiconductor-based systems are reduced size, mass, and power consumption, while providing enhanced stability.

Sicker, Ronald J.↗
NASA NTRS1981

Development of a Shuttle Infrared Telescope Facility /SIRTF/ fine guidance sensor

Fine guidance technology development for the Shuttle Infrared Telescope Facility (SIRTF) centers upon the use of a single multiple-star-tracking sensor to provide the position information necessary to produce three-axis attitude control signals for precision payload pointing. The effort described in this paper is concerned with the development of a fine guidance sensor that employs a high-density charge-coupled imaging device for producing position information signals by using star fields. Multiple star position information produces three-axis position error signals that are used to update inertial reference gyros. The sensor employs advanced position interpolation algorithms to enhance field-of-view resolution and to correct for optical aberrations inherent in spatially chopped star images resulting from the telescope's movable secondary mirror. Operation of the sensor is under the control of a high-performance microcomputer that provides both autonomy and flexibility in a guidance application.

Salomon, P. M.↗
DOE OSTI2019

SBIR Phase II Final Report - A Robust Wireless Communication System for Harsh Environments Including Nuclear Facilities

This is the Final Report for the DOE Phase II SBIR project “A Robust Wireless Communication System for Harsh Environments Including Nuclear Facilities.” The topics covered herein include technical progress made, progress against the planned milestones and deliverables, project outcomes, and a discussion on future expectations of deployment and impacts of the results of this work. In brief, all planned work for the project was successfully completed, on or ahead of schedule and on budget. The major accomplishment was the successful development of new sensor/communications systems with wideband (WB)/ultra-wideband (UWB) communications based on the software-defined-radio (SDR) technology to improve sensing and control in nuclear power plants and then a broad range of similar sensing applications. The impacts of these disciplines/focuses of this SBIR include: A new multi-frequency SDR-based architecture with WB/UWB communications integrated with sensors was developed, utilizing 310 MHz, 450 MHz, 915 MHz, and 5 GHz frequencies; Secure communications using Advanced Encryption Standard (AES) algorithm; Sensing possibilities not effectively addressed by previous technologies was addressed; and, The newly developed wireless sensor communications system can adapt its communications parameters to its operational environment for optimal performance. The performance of this system has been evaluated by systematic laboratory and field testing. The field testing was conducted at Massachusetts Institute of Technology (MIT)’s Nuclear Test Reactor, and the McClellan Nuclear center at the University of California Davis (UC Davis), as well as at Oak Ridge National Laboratory (ORNL). The success in this project resulted in DSI being awarded “The DOE’s 2018 SBIR/STTR Small Business of the Year”. This technology has attracted interest from The Rolls Royce company with ongoing discussions under NDA for potential strategic partnership between DSI and Rolls Royce in providing wireless sensor communications in nuclear facilities. Furthermore, the success of this project has attracted significant interest from the United Nations International Atomic Agency (IAEA) in Vienna, Austria, as well as other DOE and DOD offices. Currently, per request from IAEA, DOE’s office of International Safeguards has funded DSI to develop a WB/UWB wireless communication system for real-time transmission of images from IAEA’s safeguards cameras in various nuclear facilities. DSI also has received a Phase II and Phase II.5 SBIR awards from ARMY and NAVY for wireless communications capability for various DOD aircraft.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
NASA NTRS2008

Development and Evaluation of Sensor Concepts for Ageless Aerospace Vehicles: Report 3 - Design of the Concept Demonstrator

This report provides an outline of the essential features of a Structural Health Monitoring Concept Demonstrator (CD) that will be constructed during the next eight months. It is emphasized that the design cannot be considered to be complete, and that design work will continue in parallel with construction and testing. A major advantage of the modular design is that small modules of the system can be developed, tested and modified before a commitment is made to full system development. The CD is expected to develop and evolve for a number of years after its initial construction. This first stage will, of necessity, be relatively simple and have limited capabilities. Later developments will improve all aspects of the functionality of the system, including sensing, processing, communications, intelligence and response. The report indicates the directions this later development will take.

Abbott, David↗
DOE OSTI2019

Status of Mock-up and Integration for Ultrasonic Deformation Sensor for TREAT Experiments

Fuel deformation (both axial and radial) information provides insights into fuel performance and failure limits. Traditionally, fuel deformation has been quantified using post-irradiation examinations due to the lack of an appropriate sensor for monitoring deformation in situ. Recent developments in sensor and instrumentation design have led to the use of linear variable differential transducers (LVDT) for monitoring axial strain in fuel during irradiation. Size and operational constraints limit the use of LVDT sensors for radial deformation monitoring, and alternatives are needed. One possible alternative to LVDT sensors is an ultrasonic sensor. Ultrasonic sensors monitor the interaction of high-frequency stress waves with the test object. The resulting response may be analyzed to determine the properties of the material, including stress, strain, microstructure, presence of defects, and the elastic constants. While ultrasonic measurements have been successfully applied for monitoring strain in a number of applications, their use for in-core measurements has been limited. Largely, the limitations are due to the challenges associated with designing sensors that can operate under typical in-core conditions. This report documents progress to date toward planning, construction, and testing of a mock-up test capsule/facility to be used for in-lab testing of ultrasonic displacement sensor designs and toward integration of the sensor into prototypic TREAT experiment designs.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2019

Integration Testing of Ultrasonic Deformation Sensor for TREAT Experiments

Fuel deformation (both axial and radial) information provides insights into fuel performance and failure limits. Traditionally, fuel deformation has been quantified using post-irradiation examinations due to the lack of an appropriate sensor for monitoring deformation in situ. Recent developments in sensor and instrumentation design have led to the use of linear variable differential transformers (LVDT) for monitoring axial strain in fuel during irradiation. Size and operational constraints limit the use of LVDT sensors for radial deformation monitoring, and alternatives are needed. One possible alternative to LVDT sensors is an ultrasonic sensor. Ultrasonic sensors monitor the interaction of high-frequency stress waves with the test object. The resulting response may be analyzed to determine the properties of the material, including stress, strain, microstructure, presence of defects, and the elastic constants. While ultrasonic measurements have been successfully applied for monitoring strain in a number of applications, their use for in-core measurements has been limited. Largely, the limitations are due to the challenges associated with designing sensors that can operate under typical in-core conditions. This report documents testing performed to confirm that the prototypic ultrasonic deformation sensor can be integrated into TREAT irradiation experiments using the SETH capsule.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2019

Second Annual Progress Report on Ultrasonic Sensors for TREAT Fuel Condition Measurement and Monitoring

Fuel deformation (both axial and radial) information provides insights into fuel performance and failure limits. Traditionally, fuel deformation has been quantified using post-irradiation examinations due to the lack of an appropriate sensor for monitoring deformation in situ. Recent developments in sensor and instrumentation design have led to the use of linear variable differential transformers (LVDT) for monitoring axial strain in fuel during irradiation. Size and operational constraints limit the use of LVDT sensors for radial deformation monitoring, and alternatives are needed. One possible alternative to LVDT sensors is an ultrasonic sensor. Ultrasonic sensors monitor the interaction of high-frequency stress waves with the test object. The resulting response may be analyzed to determine the properties of the material, including stress, strain, microstructure, presence of defects, and the elastic constants. While ultrasonic measurements have been successfully applied for monitoring strain in a number of applications, their use for in-core measurements has been limited. Largely, the limitations are due to the challenges associated with designing sensors that can operate under typical in-core conditions. The overall objective of this work is to design an ultrasonic sensor capable of rapid in-situ measurements of fuel rodlet dimensional changes during TREAT transient irradiation testing. This report summarizes the activities and research findings through the end of Year 2 of this three-year project.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
NASA NTRS1972

Aerodynamic properties of spherical balloon wind sensors.

A first-order theory of the fluctuating lift and drag coefficients associated with the aerodynamically induced motions of rising and falling spherical wind sensors is developed. The equations of motion of a sensor are perturbed about an equilibrium state in which the buoyancy force balances the mean vertical drag force. It is shown that, to within first order in perturbation quantities, the aerodynamic lift force is confined to the horizontal, and the fluctuating drag force associated with fluctuations in the drag coefficient acts along the vertical. The perturbation equations are transformed with Fourier-Stieltjes integrals. The resulting equations lead to relationships between the power spectra of the aerodynamically induced velocity components and the spectra of the fluctuating lift and drag coefficients.

Fichtl, G. H.↗
NASA NTRS1991

Avoiding space robot collisions utilizing the NASA/GSFC tri-mode skin sensor

Sensor based robot motion planning research has primarily focused on mobile robots. Consider, however, the case of a robot manipulator expected to operate autonomously in a dynamic environment where unexpected collisions can occur with many parts of the robot. Only a sensor based system capable of generating collision free paths would be acceptable in such situations. Recently, work in this area has been reported in which a deterministic solution for 2DOF systems has been generated. The arm was sensitized with 'skin' of infra-red sensors. We have proposed a heuristic (potential field based) methodology for redundant robots with large DOF's. The key concepts are solving the path planning problem by cooperating global and local planning modules, the use of complete information from the sensors and partial (but appropriate) information from a world model, representation of objects with hyper-ellipsoids in the world model, and the use of variational planning. We intend to sensitize the robot arm with a 'skin' of capacitive proximity sensors. These sensors were developed at NASA, and are exceptionally suited for the space application. In the first part of the report, we discuss the development and modeling of the capacitive proximity sensor. In the second part we discuss the motion planning algorithm.

Prinz, F. B.↗
NASA NTRS2005

USE OF THE SDO POINTING CONTROLLERS FOR INSTRUMENT CALIBRATION MANEUVERS

During the science phase of the Solar Dynamics Observatory mission, the three science instruments require periodic instrument calibration maneuvers with a frequency of up to once per month. The command sequences for these maneuvers vary in length from a handful of steps to over 200 steps, and individual steps vary in size from 5 arcsec per step to 22.5 degrees per step. Early in the calibration maneuver development, it was determined that the original attitude sensor complement could not meet the knowledge requirements for the instrument calibration maneuvers in the event of a sensor failure. Because the mission must be single fault tolerant, an attitude determination trade study was undertaken to determine the impact of adding an additional attitude sensor versus developing alternative, potentially complex, methods of performing the maneuvers in the event of a sensor failure. To limit the impact to the science data capture budget, these instrument calibration maneuvers must be performed as quickly as possible while maintaining the tight pointing and knowledge required to obtain valid data during the calibration. To this end, the decision was made to adapt a linear pointing controller by adjusting gains and adding an attitude limiter so that it would be able to slew quickly and still achieve steady pointing once on target. During the analysis of this controller, questions arose about the stability of the controller during slewing maneuvers due to the combination of the integral gain, attitude limit, and actuator saturation. Analysis was performed and a method for disabling the integral action while slewing was incorporated to ensure stability. A high fidelity simulation is used to simulate the various instrument calibration maneuvers.

Vess, Melissa F.↗
NASA NTRS2007

The Sensor Management for Applied Research Technologies (SMART) Project

NASA seeks on-demand data processing and analysis of Earth science observations to facilitate timely decision-making that can lead to the realization of the practical benefits of satellite instruments, airborne and surface remote sensing systems. However, a significant challenge exists in accessing and integrating data from multiple sensors or platforms to address Earth science problems because of the large data volumes, varying sensor scan characteristics, unique orbital coverage, and the steep "learning curve" associated with each sensor, data type, and associated products. The development of sensor web capabilities to autonomously process these data streams (whether real-time or archived) provides an opportunity to overcome these obstacles and facilitate the integration and synthesis of Earth science data and weather model output.

Goodman, Michael↗
NASA NTRS2011

Characterizing Weak-Link Effects in Mo/Au Transition-Edge Sensors

We are developing Mo/Au bilayer transition-edge sensors (TESs) for applications in X-ray astronomy. Critical current measurements on these TESs show they act as weak superconducting links exhibiting oscillatory, Fraunhofer-like, behavior with applied magnetic field. In this contribution we investigate the implications of this behavior for TES detectors, under operational bias conditions. This includes characterizing the logarithmic resistance sensitivity with temperature, (alpha, and current, beta, as a function of applied magnetic field and bias point within the resistive transition. Results show that these important device parameters exhibit similar oscillatory behavior with applied magnetic field, which in turn affects the signal responsivity, noise and energy resolution.

Smith, Stephen↗