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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 NTRS2007

Joint Test Report For Validation of Alternatives to Aliphatic Isocyanate Polyurethanes

National Aeronautics and Space Administration (NASA) and Air Force Space Command (AFSPC) have similar missions and therefore similar facilities and structures in similar environments. The standard practice for protecting metallic substrates in atmospheric environments is the application of an applied coating system. The most common topcoats used in coating systems are polyurethanes that contain isocyanates. Isocyanates are classified as potential human carcinogens and are known to cause cancer in animals. The primary objective of this effort was to demonstrate and validate alternatives to aliphatic isocyanate polyurethanes resulting in one or more isocyanate-free coatings qualified for use at AFSPC and NASA installations participating in this project. This joint Test Report (JTR) documents the results of the laboratory and field testing as well as any test modifications made during the execution of the testing. The technical stakeholders agreed upon test procedure modifications documented in this document. This JTR is made available as a reference for future pollution prevention endeavors by other NASA centers, the Department of Defense and commercial users to minimize duplication of effort. All coating system candidates were tested using approved NASA and AFSPC standard coating systems as experimental controls. This study looked at eight alternative coating systems and two control coating systems and was divided into Phase I Screening Tests, Phase II Tests, and Field Testing. The Phase I Screening Tests were preliminary tests performed on all the selected candidate coating systems. Candidate coating systems that did not meet the acceptance criteria of the screening tests were eliminated from further testing. Phase I Screening Tests included: Ease of Application, Surface Appearance, Dry-To-Touch (Sanding), Accelerated Storage Stability, Pot Life (Viscosity), Cure Time (Solvent Rubs), Cleanability, Knife Test, Tensile (pull-off) Adhesion, and X-Cut Adhesion by Wet Tape After a review of the Phase I test results, four of the alternative coating systems showed substandard performance in relation to the Control Systems and were eliminated from the Phase II testing. Due to the interest of stakeholders and time constraints, however, all eight alternatives were subjected to the following Phase II tests, along with field testing at Stennis Space Center (SSC), Mississippi: Hypergol Compatibility, Liquid Oxygen Compatibility, 18-Month Marine Exposure (Gloss Retention, Color Retention, Blistering, Visual Corrosion, Creepage from Scribe, Heat Adhesion), and Field Exposure (6- and 12-month Evaluation for Coating Condition, Color Retention, Gloss Retention). The remaining four alternative coating systems determined to be the best viable alternatives were carried on to Phase II testing that included: Removability, Repairability, Abrasion Resistance, Gravelometer, Fungus Resistance, Accelerated Weathering, Mandrel Bend Flexibility, and Cyclic Corrosion Resistance. Of the systems that continued to Phase II, three (3) alternative coating systems meet the performance requirements as identified by stakeholders. Two (2) other systems, that were not included in Phase II testing, performed well enough on the 18-Month Marine Exposure, the primary requirement for NASA technical standard NASA-STD-5008, Protective Coating of Carbon Steel, Stainless Steel, and Aluminum on Launch Structures, Facilities, and Ground Support Equipment, that they were also considered to be successful candidates. In total, five (5) alternative coating systems were approved for inclusion in the NASA-STD- 5008 Qualified Products List (QPL). The standard is intended to provide a common framework for consistent practices across NASA and is often used by other entities. The standard's QPL does not connote endorsement of the products by NASA, but lists those products that have been tested and meet the requirements as specified.

Lewis, Pattie↗
NASA NTRS1975

Investigation of land-use spectral signatures

A technique was developed to obtain bidirectional reflectance data from natural surfaces by using a folding mirror to transfer the reflected energy from the test surface to a spectroradiometer. The folding mirror was a first surface reflector made by stretching Mylar vacuum coated with aluminum over a light weight frame. The optically folding mirror was positioned over the test surfaces with a moveable platform for both laboratory and field tests. Field tests were conducted using a tethered balloon system to position the folding mirror. A spectroradiometer was designed and built specifically for this investigation. The spectroradiometer had an angular field of view of twenty-four minutes in one axis and ten minutes in the other axis. The radiometer was capable of detecting energies in small bandwidths throughout the electromagnetic spectrum from 0.3 microns to 3.0 microns. Bidirectional reflectance data and variations in the data with source angles were obtained for Saint Augustine grass, Bermuda grass, and a black alluvium soil from the Mississippi River delta.

Hagewood, J. F.↗
NASA NTRS2004

Measurement of Turbulent Pressure and Temperature Fluctuations in a Gas Turbine Combustor

The report summarizes the results of the redesign efforts directed towards the gas-turbine combustor rapid-injector flow diagnostic probe developed under sponsorship of NASA-GRC and earlier reported in NASA-CR-2003-212540. Lessons learned during the theoretical development, developmental testing and field-testing in the previous phase of this research were applied to redesign of both the probe sensing elements and of the rapid injection device. This redesigned probe (referred to herein as Turboprobe) has been fabricated and is ready, along with the new rapid injector, for field-testing. The probe is now designed to capture both time-resolved and mean total temperatures, total pressures and, indirectly, one component of turbulent fluctuations.

Povinelli, Louis↗
NASA NTRS2017

NASA Handbook 7010: Direct Field Acoustic Testing

Instruments, spacecraft, antennas, reflectors, and other mechanical hardware have been undergoing acoustic qualification testing over the last decade using loudspeakers. This speaker-generated Direct Field Acoustic Test (DFAT) method offers cost, mobility, and schedule advantages over the conventional Reverberant Acoustic Field Test (RAFT) method. To develop most appropriate acoustic test program using the DFAT method for a flight project, flight project managers and their technical staffs will need overall guidance and technical rational for using DFAT to qualify flight hardware for acoustic environments. The NASA Chief Engineer Office had tasked JPL to prepare a NASA Handbook for DFAT Dynamics Testing. The handbook was completed and was released by NASA headquarters in 2015. The handbook provides advantages and disadvantages of such method of testing, key references and a series of recommended practices for test preparation and test performance. This paper will summarize key and important steps related to this method of acoustic testing.

Kolaini, Ali R↗
NASA NTRS2006

Desert Research and Technology Studies 2005 Report

During the first two weeks of September 2005, the National Aeronautics and Space Administration (NASA) Johnson Space Center (JSC) Advanced Extravehicular Activity (AEVA) team led the field test portion of the 2005 Research and Technology Studies (RATS). The Desert RATS field test activity is the culmination of the various individual science and advanced engineering discipline areas year-long technology and operations development efforts into a coordinated field test demonstration under representative (analog) planetary surface terrain conditions. The purpose of the RATS is to drive out preliminary exploration concept of operations EVA system requirements by providing hands-on experience with simulated planetary surface exploration extravehicular activity (EVA) hardware and procedures. The RATS activities also are of significant importance in helping to develop the necessary levels of technical skills and experience for the next generation of engineers, scientists, technicians, and astronauts who will be responsible for realizing the goals of the Constellation Program. The 2005 Desert RATS was the eighth RATS field test and was the most systems-oriented, integrated field test to date with participants from NASA field centers, the United States Geologic Survey (USGS), industry partners, and research institutes. Each week of the test, the 2005 RATS addressed specific sets of objectives. The first week focused on the performance of surface science astro-biological sampling operations, including planetary protection considerations and procedures. The second week supported evaluation of the Science, Crew, Operations, and Utility Testbed (SCOUT) proto-type rover and its sub-systems. Throughout the duration of the field test, the Communications, Avionics, and Infomatics pack (CAI-pack) was tested. This year the CAI-pack served to provide information on surface navigation, science sample collection procedures, and EVA timeline awareness. Additionally, 2005 was the first year since the Apollo program that two pressurized suited test subjects have worked together simultaneously. Another first was the demonstration of recharge of cryogenic life support systems while in-use by the suited test subjects. The recharge capability allowed the simulated EVA test duration to be doubled, facilitating SCOUT proto-type rover testing. This paper summarizes Desert RATS 2005 test hardware, detailed test objectives, test operations and test results.

Ross, Amy J.↗
DOE OSTI2024

MODELING, IMPLEMENTATION AND CONTROL OF A CVT BASED PTO FOR A SMALL SCALE MHK-TURBINE IN LOW FLOW SPEED OPERATION

Modeling, implementation, field testing and control of a power takeoff (PTO) device equipped with a ball-type continuously variable transmission (B-CVT) for a small marine hydrokinetic (MHK) turbine deployed from a floating unmanned autonomous mobile catamaran platform is described. The turbine is a partially submerged multi-blade undershot waterwheel (USWW). A validated numerical torque model for the MHK turbine has been derived and a speed controller has been developed, implemented and tested in the field. The dependance of the power generated as a function of number and submergence level of turbine blades has been investigated and the number of blades that maximizes power production is determined. Bench and field testing in support of characterizing the power conversion capabilities of MHK turbine and PTO are described. Detailed results of the final torque and power coefficient models, the controls architecture, and the MHK turbine performance with varying numbers of blades are provided.

Pimentel, Hugo↗
DOE OSTI2025

Reinforcement Learning-Based Oscillation Dampening: Scaling Up Single-Agent Reinforcement Learning Algorithms to a 100-Autonomous-Vehicle Highway Field Operational Test

In this article, we explore the technical details of the reinforcement learning (RL) algorithms that were deployed in the largest field test of automated vehicles designed to smooth traffic flow in history as of 2023, uncovering the challenges and breakthroughs that come with developing RL controllers for automated vehicles. We delve into the fundamental concepts behind RL algorithms and their application in the context of self-driving cars, discussing the developmental process from simulation to deployment in detail, from designing simulators to reward function shaping. We present the results in both simulation and deployment, discussing the flow-smoothing benefits of the RL controller. From understanding the basics of Markov decision processes to exploring advanced techniques such as deep RL, our article offers a comprehensive overview and deep dive of the theoretical foundations and practical implementations driving this rapidly evolving field. We also showcase real-world case studies and alternative research projects that highlight the impact of RL controllers in revolutionizing autonomous driving. From tackling complex urban environments to dealing with unpredictable traffic scenarios, these intelligent controllers are pushing the boundaries of what automated vehicles can achieve. Furthermore, we examine the safety considerations and hardware-focused technical details surrounding deployment of RL controllers into automated vehicles. As these algorithms learn and evolve through interactions with the environment, ensuring their behavior aligns with safety standards becomes crucial. Here, we explore the methodologies and frameworks being developed to address these challenges, emphasizing the importance of building reliable control systems for automated vehicles.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
NASA NTRS2011

HDU Deep Space Habitat (DSH) Overview

This paper gives an overview of the National Aeronautics and Space Administration (NASA) led multi-center Habitat Demonstration Unit (HDU) project Deep Space Habitat (DSH) analog that will be field-tested during the 2011 Desert Research and Technologies Studies (D-RATS) field tests. The HDU project is a technology pull project that integrates technologies and innovations from multiple NASA centers. This project will repurpose the HDU Pressurized Excursion Module (PEM) that was field tested in the 2010 D-RATS, adding habitation functionality to the prototype unit. The 2010 configuration of the HDU-PEM consisted of a lunar surface laboratory module that was used to bring over 20 habitation-related technologies together in a single platform that could be tested as an advanced habitation analog in the context of mission architectures and surface operations. The 2011 HDU-DSH configuration will build upon the PEM work, and emphasize validity of crew operations (habitation and living, etc), EVA operations, mission operations, logistics operations, and science operations that might be required in a deep space context for Near Earth Object (NEO) exploration mission architectures. The HDU project consists of a multi-center team brought together in a skunkworks approach to quickly build and validate hardware in analog environments. The HDU project is part of the strategic plan from the Exploration Systems Mission Directorate (ESMD) Directorate Integration Office (DIO) and the Exploration Mission Systems Office (EMSO) to test destination elements in analog environments. The 2011 analog field test will include Multi Mission Space Exploration Vehicles (MMSEV) and the DSH among other demonstration elements to be brought together in a mission architecture context. This paper will describe overall objectives, various habitat configurations, strategic plan, and technology integration as it pertains to the 2011 field tests.

Kennedy, Kriss J.↗
NASA NTRS2006

Automated objective characterization of visual field defects in 3D

A method and apparatus for electronically performing a visual field test for a patient. A visual field test pattern is displayed to the patient on an electronic display device and the patient's responses to the visual field test pattern are recorded. A visual field representation is generated from the patient's responses. The visual field representation is then used as an input into a variety of automated diagnostic processes. In one process, the visual field representation is used to generate a statistical description of the rapidity of change of a patient's visual field at the boundary of a visual field defect. In another process, the area of a visual field defect is calculated using the visual field representation. In another process, the visual field representation is used to generate a statistical description of the volume of a patient's visual field defect.

Fink, Wolfgang↗
NASA NTRS1976

Optical guidance vidicon test program

A laboratory and field test program was conducted to quantify the optical navigation parameters of the Mariner vidicons. A scene simulator and a camera were designed and built for vidicon tests under a wide variety of conditions. Laboratory tests characterized error sources important to the optical navigation process and field tests verified star sensitivity and characterized comet optical guidance parameters. The equipment, tests and data reduction techniques used are described. Key test results are listed. A substantial increase in the understanding of the use of selenium vidicons as detectors for spacecraft optical guidance was achieved, indicating a reduction in residual offset errors by a factor of two to four to the single pixel level.

Eiseman, A. R.↗
NASA NTRS2015

Real-time Terrain Relative Navigation Test Results from a Relevant Environment for Mars Landing

Terrain Relative Navigation (TRN) is an on-board GN&C function that generates a position estimate of a spacecraft relative to a map of a planetary surface. When coupled with a divert, the position estimate enables access to more challenging landing sites through pin-point landing or large hazard avoidance. The Lander Vision System (LVS) is a smart sensor system that performs terrain relative navigation by matching descent camera imagery to a map of the landing site and then fusing this with inertial measurements to obtain high rate map relative position, velocity and attitude estimates. A prototype of the LVS was recently tested in a helicopter field test over Mars analog terrain at altitudes representative of Mars Entry Descent and Landing conditions. TRN ran in real-time on the LVS during the flights without human intervention or tuning. The system was able to compute estimates accurate to 40m (3 sigma) in 10 seconds on a flight like processing system. This paper describes the Mars operational test space definition, how the field test was designed to cover that operational envelope, the resulting TRN performance across the envelope and an assessment of test space coverage.

Pin-point Landing↗
NASA NTRS1976

Magnetic pulsations as a probe of the interplanetary magnetic field - A test of the Borok B index

A magnetic pulsation index based on the periods of Pc 2-4 pulsations as recorded in earth current measurements at the Borok Geophysical Observatory has been claimed to be a measure of the interplanetary field. Tests of this index for the period 1972 to June 1974 show only a 27% success rate. However, a simple recalibration of the index improves the success rate to 51%. The success of the index indicates that the source of many terrestrial magnetic pulsations is external to the magnetosphere.

Russell, C. T.↗
NASA NTRS2002

Apolipoprotein E expression and behavioral toxicity of high charge, high energy (HZE) particle radiation

Apolipoprotein E (apoE) is a lipid binding protein that plays an important role in tissue repair following brain injury. In the present studies, we have investigated whether apoE affects the behavioral toxicity of high charge, high energy (HZE) particle radiation. METHODS: Sixteen male apoE knockout (KO) mice and sixteen genetically matched wild-type (WT) C57BL mice were used in this experiment. Half of the KO and half of the WT animals were irradiated with 600 MeV/amu iron particles (2 Gy whole body). The effect of irradiation on motor coordination and stamina (Rotarod test), exploratory behavior (open field test), and spatial working and reference memory (Morris water maze) was assessed. ROTAROD TEST: Performance was adversely affected by radiation exposure in both KO and WT groups at 30 d after irradiation. By 60 d after radiation, the radiation effect was lost in WT, but still apparent in irradiated KO mice. OPEN FIELD TEST: Radiation reduced open field exploratory activity 14, 28, 56, 84, and 168 d after irradiation of KO mice, but had no effect on WT mice. MORRIS WATER MAZE: Radiation adversely affected spatial working memory in the KO mice, but had no discernible effect in the WT mice as assessed 180 d after irradiation. In contrast, irradiated WT mice showed marked impairment of spatial reference memory in comparison to non-irradiated mice, while no effect of radiation was observed in KO mice. CONCLUSIONS: These studies show that apoE expression influences the behavioral toxicity of HZE particle radiation and suggest that apoE plays a role in the repair/recovery from radiation injury of the CNS. ApoE deficiency may exacerbate the previously reported effects of HZE particle radiation in accelerating the brain aging process.

Non-NASA Center↗
NASA NTRS2009

Desert Research and Technology Studies 2008 Report

During the last two weeks of October 2008, the National Aeronautics and Space Administration (NASA) Johnson Space Center (JSC) Advanced Extravehicular Activity (AEVA) team led the field test portion of the 2008 Desert Research and Technology Studies (D-RATS) near Flagstaff, AZ. The Desert RATS field test activity is the year-long culmination of various individual science and advanced engineering discipline areas technology and operations development efforts into a coordinated field test demonstration under representative (analog) planetary surface terrain conditions. The 2008 Desert RATS was the eleventh RATS field test and was the most focused and successful test to date with participants from six NASA field centers, three research organizations, one university, and one other government agency. The main test objective was to collect Unpressurized Rover (UPR) and Lunar Electric Rover (LER) engineering performance and human factors metrics while under extended periods of representative mission-based scenario test operations involving long drive distances, night-time driving, Extravehicular Activity (EVA) operations, and overnight campover periods. The test was extremely successful with all teams meeting the primary test objective. This paper summarizes Desert RATS 2008 test hardware, detailed test objectives, test operations, and test results.

Romig, Barbara↗
DOE OSTI2024

Energy performance evaluation of the ASHRAE Guideline 36 control and reinforcement learning–based control using field measurements

This study evaluates the energy performance of ASHRAE Guideline 36–compliant control (ASHRAE 36 control) and reinforcement learning (RL)–based control through experimental field tests and a simulation study. Three field tests were conducted at Oak Ridge National Laboratory’s commercial building test facility in Oak Ridge, Tennessee: a baseline with a baseline conventional control, a test with ASHRAE 36 control, and a test with RL-based control. The selected ASHRAE 36 controls were trim and respond control, as well as variable air volume (VAV) box control. We compared the measured supply air temperature of the rooftop unit, VAV box supply air temperature, and VAV box supply airflow rate across the three test cases. The field data indicated that ASHRAE 36 controls operated as specified by ASHRAE Guideline 36. Based on these data, ASHRAE 36 control achieved a 45 % reduction in hourly averaged HVAC energy consumption compared with the baseline, and RL-based control achieved a 66 % reduction. These potential annual energy savings were confirmed using a calibrated whole-building energy model. Compared with the baseline, ASHRAE 36 control reduced HVAC energy consumption by 42 %, and RL-based control achieved a 54 % reduction. Furthermore, RL-based control reduced total HVAC energy consumption by 21 % more than ASHRAE 36 control.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
NASA NTRS1993

Active Hydrazine Vapor Sampler (AHVS)

The Active Hydrazine Vapor Sampler (AHVS) was developed to detect vapors of hydrazine (HZ) and monomethylhydrazine (MMH) in air at parts-per-billion (ppb) concentration levels. The sampler consists of a commercial personal pump that draws ambient air through paper tape treated with vanillin (4-hydroxy-3-methoxybenzaldehyde). The paper tape is sandwiched in a thin cardboard housing inserted in one of the two specially designed holders to facilitate sampling. Contaminated air reacts with vanillin to develop a yellow color. The density of the color is proportional to the concentration of HZ or MMH. The AHVS can detect 10 ppb in less than 5 minutes. The sampler is easy to use, low cost, and intrinsically safe and contains no toxic material. It is most beneficial for use in locations with no laboratory capabilities for instrumentation calibration. This paper reviews the development, laboratory test, and field test of the device.

Young, Rebecca C.↗
NASA NTRS2010

Distributed Impact Detector System (DIDS) Health Monitoring System Evaluation

Damage due to impacts from micrometeoroids and orbital debris is one of the most significant on-orbit hazards for spacecraft. Impacts to thermal protection systems must be detected and the damage evaluated to determine if repairs are needed to allow safe re-entry. To address this issue for the International Space Station Program, Langley Research Center and Johnson Space Center technologists have been working to develop and implement advanced methods for detecting impacts and resultant leaks. LaRC funded a Small Business Innovative Research contract to Invocon, Inc. to develop special wireless sensor systems that are compact, light weight, and have long battery lifetimes to enable applications to long duration space structures. These sensor systems are known as distributed impact detection systems (DIDS). In an assessment, the NASA Engineering and Safety Center procured two prototype DIDS sensor units to evaluate their capabilities in laboratory testing and field testing in an ISS Node 1 structural test article. This document contains the findings of the assessment.

Prosser, William H.↗