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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 19 records
All sourcesNASA NTRSDOE OSTI
NASA NTRSDate not supplied

In-situ Testing to Acquire HR-EBSD and DIC Strain Data Within a Coincident Domain

For this project, an inked rubber stamp was applied to a small Inconel 625 specimen. The stamp transferred a thin pattern with microscale features for digital image correlation (DIC). The pattern is easily visible at lower voltages and thin enough to not obstruct backscattered electrons. The unique characteristics of the pattern enabled the concurrent acquisition of DIC and high-resolution electron backscatter diffraction (HR-EBSD) data while the specimen was loaded in-situ. The challenges of in-situ testing and combining EBSD with DIC measurements are discussed. By combining the elastic strains (from HR-EBSD) and total strains (from DIC) the result of this approach is an estimate of stress- strain behavior at points across the specimen surface. This combined dataset can then be used as higher-fidelity data in the calibration of crystal plasticity models.

Will Gilliland↗
NASA NTRS2017

Design and Development of a Rapid Research, Design, and Development Platform for In-Situ Testing of Tools and Concepts for Trajectory-Based Operations

To provide justification for equipping a fleet of aircraft with avionics capable of supporting trajectory-based operations, significant flight testing must be accomplished. However, equipping aircraft with these avionics and enabling technologies to communicate the clearances required for trajectory-based operations is cost-challenging using conventional avionics approaches. This paper describes an approach to minimize the costs and risks of flight testing these technologies in-situ, discusses the test-bed platform developed, and highlights results from a proof-of-concept flight test campaign that demonstrates the feasibility and efficiency of this approach.

Underwood, Matthew C.↗
NASA NTRS2007

In Situ Test Method for the Electrostatic Characterization of Lunar Dust

This paper serves to illustrate the testing methods necessary to classify the electrostatic properties of lunar dust using in situ instrumentation and the required techniques therein. A review of electrostatic classification of lunar simulant materials is provided as is its relevance to the success of future human lunar missions.

Buhler, C. R.↗
NASA NTRS2002

In situ testing of a satellite or other object prior to development

A method and system for testing a test object, such as a satellite, is disclosed. High energy acoustic testing is performed on the object by assembling an acoustical system about the test object rather than transporting the test object to a specially configured acoustic chamber. The acoustic system of the present invention preferably provides and directs acoustic energy directly to the surfaces of the test object rather than providing the test object in a high energy acoustic environment where a substantial amount of the acoustic energy is randomly directed within a chamber having the test object. Additionally, the present invention further provides for mechanical vibration tests concurrently or serially with acoustic testing, wherein the object is not required to be transported.

Eagen, James H.↗
NASA NTRS2020

In-Situ Testing Methods for Mixed-Mode Harsh Environments

Future NASA missions are driving a need for instrumentation and space electronics that will operate at extreme temperatures, with low mass and extended deployments. This need results in devices that will experience dose damage at both low and high temperatures that will suppress annealing and induce accelerated wear out issues. Therefore, the ability to perform radiation tests on devices at temperature is critical. This paper analyses the methods and process to enable these test as developed at the JPL Dynamitron Facility. Since electronics are the radiation source for this facility, the steps to ensure parity with cobalt-60 testing are discussed. Also discussed are the implications for system level testing and mixed radiation mode testing for highly integrated and scaled devices.

Scheick, Leif Z↗
NASA NTRS2020

In Situ Testing Methods for Mixed-Mode Harsh Environments

A review of the radiation effects investigation capabilities of the JPL Dynamitron Accelerator Facility are discussed. A process for its use in performing total ionizing dose (TID) studies are outlined. The results of radiation effects in complicated test systems where device effects may occur due to local system irradiation are also presented.

Wong, A. T.↗
NASA NTRS2024

The Active Volcanoes of Kamchatka as Suitable Terrestrial Analogs Within the AVENGERS Initiative: An Opportunity for In-Situ Operational Tests for Future Landing Venus Missions

The next decade will see the return to Venus thanks to a number of missions which have been recently selected and proposed for launch. The Roscosmos Venera-D mission, along with the NASA DAVINCI, NASA VERITAS, ESA EnVision, the ISRO Shukrayaan-1, and the CNSA VOICE missions will open a new era for the exploration of the Earth’s hellish twin planet. The next missions to Venus should be able to shed new light on the science questions such as: a) whether the volcanic activity on this planet is locally constrained, or volcanism acts on a global scale, b) the rate of the present-day volcanic activity, and c) the style of volcanism on Venus, whether it is predominantly effusive, or the occurrence of local episodes of pyroclastic volcanism is also possible. In preparation for the future missions to Venus, the Analogs for VENus’ Geologically Recent Surfaces (AVENGERS) initiative will select and analyze a number of active terrestrial volcanoes as suitable analogs for the identification and analysis of active volcanism on Venus. Among the future missions to Venus, the Roscosmos Venera-D is the only one to be equipped with a lander which will analyze the elemental and mineralogical composition of the surface. As the young topographic rises (areas characterized by recent volcano-tectonic activity) on Venus are being proposed as one of the possible terrain types for the Venera-D landing, it is crucial to look for volcanic areas on Earth where to perform operational tests such as surface drilling and in-situ elemental composition analysis. To this regard, we propose here the analysis of the active volcanoes of the Kamchatka Peninsula in Russia as a very suitable analog for the Venera-D mission, as well as for the analysis of surface change detection due to ongoing eruptions. The Kamchatka Peninsula is located on the eastern margin of the Eurasia plate, in proximity of the Kuril-Kamchatka subduction zone. The volcanoes of the Kamchatka Peninsula are among the most active volcanoes of the world, making them a suitable terrestrial analog in the search for active volcanism on Venus. Moreover, the volcanoes of Kamchatka are characterized by pyroclastic activity. Since the previous Soviet Venera and Vega missions landed over areas which elemental composition was most likely consistent with that of tholeiitic basalts, performing operational tests over areas characterized by pyroclastic activity also offers the unique opportunity to provide us the tools to potentially interpret the diverse output given by landing over portions of the surface of Venus possibly characterized by explosive volcanic products. Finally, the frequent eruptions characterizing the volcanoes of the Kamchatka Peninsula make them also a suitable terrestrial analog for the possible detection of ongoing eruptions on Venus by future missions, which can be achieved by comparing two (or more) radar images of the same volcano (and its surroundings) in two (or more) different moments of time.

Planetary Geology↗
NASA NTRS1992

NASA wind shear flight test in situ results

The main objectives in developing the NASA in situ windshear detection algorithm were to provide a measurement standard for validation of forward-look sensors under development, and to demonstrate the algorithm's ability to operate with a suitably low nuisance alert rate. It was necessary to know exactly how the algorithm was implemented and what parameters and filtering were used, in order to be able to fully test its effectiveness and correlate in situ results with forward-look sensor data.

Oseguera, Rosa M.↗
NASA NTRS1976

Mechanical testing - In situ fracture device for Auger electron spectroscopy

An in situ fracture device for Auger spectroscopy is described. The device is designed to handle small tensile specimens or small double-cantilever beam specimens and is fully instrumented with load and displacement transducers so that quantitative stress-strain measurements can be made directly. Some initial test results for specimens made from 4130 and 1020 steel are presented. Results indicate that impurity segregation at interfaces other than grain boundary may play a significant role in the mechanism of ductile fracture.

Moorhead, R. D.↗
NASA NTRS2004

Mechanism of Pinhole Formation in Membrane Electrode Assemblies for PEM Fuel Cells

The pinhole formation mechanism was studied with a variety of MEAs using ex-situ and in-situ methods. The ex-situ tests included the MEA aging in oxygen and MEA heat of ignition. In-situ durability tests were performed in fuel cells at different operating conditions with hydrogen and oxygen. After the in-situ failure, MEAs were analyzed with an Olympus BX 60 optical microscope and Cambridge 120 scanning electron microscope. MEA chemical analysis was performed with an IXRF EDS microanalysis system. The MEA failure analyses showed that pinholes and tears were the MEA failure modes. The pinholes appeared in MEA areas where the membrane thickness was drastically reduced. Their location coincided with the stress concentration points, indicating that membrane creep was responsible for their formation. Some of the pinholes detected had contaminant particles precipitated within the membrane. This mechanism of pinhole formation was correlated to the polymer blistering.

Stanic, Vesna↗
NASA NTRSDate not supplied

In-Situ Ice Adhesion Testing using the Deformed Skin Adhesion Test

There exists a plethora of ice adhesion testing methods such as centrifuge-based methods, push/pull methods, and lap joint shear tests. However, these methods often cannot be done in-situ during an icing spray and require researcher handling/preparation prior to testing. Additionally, many of these methods test ice accretions that are not representative of the ice shapes that grow on airframes which can have unintended consequences such as edge or corner stress concentrations. In order to mitigate the issues present with other ice adhesion tests a novel, hands-free, in-situ test method imbedded into the leading edge of the airfoil has been developed and tested in the NASA Glenn Research Center Icing Research Tunnel. The mechanics of the new test method are discussed with finite element simulations being used to highlight the fundamental mechanics of this test method. The testing procedures used during the experimental test campaign are discussed along with the icing cloud test matrix. Analysis of the force-displacement results highlights the repeatability of the test method with regards to both sample behavior across several days of testing and different ice shapes. The results from first run of the day showed a significant discrepancy from subsequent runs and differential image analysis was used to determine differences in the interfacial bonding states between runs.

Ice Adhesion↗
NASA NTRSDate not supplied

In-Situ Ice Adhesion Testing using the Deformed Skin Adhesion Test

There exists a plethora of ice adhesion testing methods such as centrifuge-based methods, push/pull methods, and lap joint shear tests. However, these methods often cannot be done in-situ during an icing spray and require researcher handling/preparation prior to testing. Additionally, many of these methods test ice accretions that are not representative of the ice shapes that grow on airframes which can have unintended consequences such as edge or corner stress concentrations. In order to mitigate the issues present with other ice adhesion tests a novel, hands-free, in-situ test method imbedded into the leading edge of the airfoil has been developed and tested in the NASA Glenn Research Center Icing Research Tunnel. The mechanics of the new test method are discussed with finite element simulations being used to highlight the fundamental mechanics of this test method. The testing procedures used during the experimental test campaign are discussed along with the icing cloud test matrix. Analysis of the force-displacement results highlights the repeatability of the test method with regards to both sample behavior across several days of testing and different ice shapes. The results from first run of the day showed a significant discrepancy from subsequent runs and differential image analysis was used to determine differences in the interfacial bonding states between runs.

Ice Adhesion↗
NASA NTRS1992

Microstructure-failure mode correlations in braided composites

Explication of the fracture processes of braided composites is needed for modeling their behavior. Described is a systematic exploration of the relationship between microstructure, loading mode, and micro-failure mechanisms in carbon/epoxy braided composites. The study involved compression and fracture toughness tests and optical and scanning electron fractography, including dynamic in-situ testing. Principal failure mechanisms of low sliding, buckling, and unstable crack growth are correlated to microstructural parameters and loading modes; these are used for defining those microstructural conditions which are strength limiting.

Filatovs, G. J.↗
NASA NTRS1978

Voyager electronic parts radiation program. Volume 2: Test requirements and procedures

Documents are presented outlining the conditions and requirements of the test program. The Appendixes are as follows: appendix A -- Electron Simulation Radiation Test Specification for Voyager Electronic Parts and Devices, appendix B -- Electronic Piece-Part Testing Program for Voyager, appendix C -- Test Procedure for Radiation Screening of Voyager Piece Parts, appendix D -- Boeing In Situ Test Fixture, and appendix E -- Irradiate - Anneal (IRAN) Screening Documents.

Stanley, A. G.↗
NASA NTRS2002

Characterization of the Twelve Channel 100/140 Micron Optical Fiber, Ribbon Cable and MTP Array Connector Assembly for Space Flight Environments

Presented here is the second set of testing conducted by the Technology Validation Laboratory for Photonics at NASA Goddard Space Flight Center on the 12 optical fiber ribbon cable with MTP array connector for space flight environments. In the first set of testing the commercial 62.5/125 cable assembly was characterized using space flight parameters. The testing showed that the cable assembly would survive a typical space flight mission with the exception of a vacuum environment. Two enhancements were conducted to the existing technology to better suit the vacuum environment as well as the existing optoelectronics and increase the reliability of the assembly during vibration. The MTP assembly characterized here has a 100/140 optical commercial fiber and non outgassing connector and cable components. The characterization for this enhanced fiber optic cable assembly involved vibration, thermal and radiation testing. The data and results of this characterization study are presented which include optical in-situ testing.

Ott, Melanie N.↗