Physical Sciences

Photogrammetric Recession Measurement

The testing of materials that ablate as a design function requires detailed time history of the ablation process. The rate at which the surface recedes during testing is a critically important measure of the performance of thermal protection system (TPS) materials like heat shields for aerospace vehicles. Photogrammetric recession measurement (PRM) meets these needs by recording the surface of the ablating model during heating in hyperthermal test facilities (arc-jets), using two high-resolution digital cameras capable of recording simultaneously. The cameras are calibrated to yield three-dimensional object space measurement for each stereo pair of images, producing surface recession data over the portion of the model for which both cameras share a view.

Posted in: Briefs, Physical Sciences, Test & Measurement, Failure modes and effects analysis, Optics, Optics, Protective structures, Thermal testing
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Tissue-Equivalent Radiation Dosimeteron-a-Chip with Plastic Scintillation Material

The complexity of spaceflight design requires reliable, fault-tolerant equipment capable of providing real-time dosimetry during a mission, which is not feasible with existing thermoluminescent dosimeter (TLD) technology. Real-time monitoring is important for low-Earth-orbiting spacecraft and interplanetary spaceflight to alert the crew when solar particle events (SPE) increase the particle flux of the spacecraft environment. In this innovation, the personal dosimeter is comprised of a tissue-equivalent scintillator coupled to a solid-state photomultiplier.

Posted in: Briefs, Physical Sciences, Test & Measurement, Plastics, Test equipment and instrumentation, Spacecraft
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Measurement of Cryogenic Fluid Level with Laser Propagation and Surface Floor Reflection

The risks associated with introducing new hardware and methods into an operational environment have in part prohibited cryogen level measurement technology from advancing. In prior art, measurements have been made with invasive probes immersed in the cryogenic fluid. Implementing this approach would require physical retrofitting, as well as requiring the measuring instrument to make contact with the harsh cryogen fluid environment. However, an externally mounted optical measurement system would mitigate these concerns. Therefore, an optical approach was developed that uses and augments existing validated technology in a manner that does not interfere with the current infrastructure.

Posted in: Briefs, Physical Sciences, Test & Measurement, Optics, Optics, Test equipment and instrumentation
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Video Acuity Measurement System

There is a widely acknowledged need for metrics to quantify the performance of video systems. Existing metrics are either difficult to measure or are largely theoretical. They do not reflect the full range of effects to which video may be subject, or do not relate easily to video performance in real-world tasks. The empirical Video Acuity metric is simple to measure and relates directly to task performance. Video acuity is determined by the smallest letters that can be automatically identified using a video system. It is expressed most conveniently in letters per degree of visual angle.

Posted in: Briefs, Physical Sciences, Test & Measurement, Mathematical analysis, Imaging, Imaging and visualization, Imaging, Imaging and visualization
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Heat-Flow Probe Design and Development

The lunar regolith exhibits extremely low conductivity. Penetrating the regolith presents problems if the geo-technical properties of the regolith are not well understood and accounted for.

Posted in: Briefs, Physical Sciences, Test & Measurement, Test equipment and instrumentation, Thermal testing
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Solar Pumped Fiber Laser for Solar Sail Propulsion and Remote Power Transfer

A new method has been developed to create coherent laser light efficiently with direct optical coupling of the Sun’s energy into the gain medium for multiple uses. New advances in solar cell photovoltaic (PV) technologies have greatly improved their efficiencies, mostly by improving their ability to convert many wavelengths or wider bands of the solar spectrum to electricity. New advances in actively doped fibers and optical glasses have been shown to produce very broad, multi-line absorption bands as well as stimulated emission lines, or laser lines. By designing the optical cavity system to feed back all emission bands into the gain media for amplification, a multi-wavelength source can be generated requiring no electronics.

Posted in: Tech Briefs, Briefs, Photonics, Physical Sciences, Electric power, Solar energy, Fibers
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Designing Smaller Magnets for the Large Hadron Collider

The European Organization for Nuclear Research (CERN) requires new magnets that are smaller than their predecessors to accommodate new instrumentation. Because of their size, these magnets need to generate a 24 percent stronger magnetic field and the structure must provide for near-zero deformation of the conductor. Even a small deformation could increase the electrical resistance and raise the temperature enough to cause the conductor to lose its superconducting state. Engineers addressed this challenge using ANSYS electromagnetic, thermal, and structural simulation tools. Coupling the multiphysics domains in the ANSYS® Workbench® environment allowed the team to optimize the design by simultaneously considering all of the physics.

Posted in: Briefs, Physical Sciences, Software, Computer simulation, Computer software / hardware, Computer software and hardware, Computer software / hardware, Computer software and hardware, Test equipment and instrumentation
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Electrical Calibration Source for Next-Generation Oscilloscope

Keysight Technologies (formerly Agilent Technologies) develops world-leading equipment for solving tough measurement challenges. The company’s Infiniium 90000 Q-Series oscilloscope is the first to reach the 60 GHz barrier, enabling engineers to make measurements on a new generation of fiber optic transponders and systems that provide higher levels of data communication speeds than previously possible.

Posted in: Briefs, Physical Sciences, Software, Computational fluid dynamics, Computer software / hardware, Computer software and hardware, Oscilloscopes, Computer software / hardware, Computer software and hardware, Oscilloscopes, Test equipment and instrumentation
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Integrated Space Weather Analysis System (iSWA)

The iSWA system is a Web-based dissemination framework for NASA-relevant space weather information that combines forecasts based on the most advanced space weather models with concurrent space environment information. A key design driver for the iSWA system is to generate and present vast amounts of space weather resources in an intuitive, user-configurable, and adaptable format, enabling users to respond to current and future space weather impacts, as well as enabling post-impact analysis.

Posted in: Briefs, Physical Sciences, Software, Computer simulation, Mathematical analysis, Mathematical models, Computer software / hardware, Computer software and hardware, Computer software / hardware, Computer software and hardware
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Automatic Localization of MSL Rover Mosaics in HiRISE Imagery

Mars Science Laboratory (MSL) surface operations require precise and accurate knowledge of rover position. A key means of establishing/verifying position is to match ortho-rectified mosaics from the MSL onboard cameras to orbital data. Manual localization by matching mosaics to HiRISE imagery can be laborious and somewhat subjective. Ortho-rectified mosaics and orbital images differ dramatically in appearance, due to the extreme viewpoint change as well as occlusions (i.e. objects must be in line of sight) in the mosaics. A straightforward intensity-based matcher using correlation or local feature descriptors cannot cope with this difference. Instead, an information theoretic matcher was used that measures the mutual information between the mosaic and trial positions in the HiRISE imagery.

Posted in: Briefs, Physical Sciences, Software, Computer software / hardware, Computer software and hardware, Imaging, Imaging and visualization, Computer software / hardware, Computer software and hardware, Imaging, Imaging and visualization, Autonomous vehicles, Spacecraft
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