Physical Sciences

Photogrammetric Recession Measurement

This method can be used to measure the recession of ablative materials in insulation coatings, ceramics and composites, arc-jet systems, and soil erosion. Ames Research Center, Moffett Field, California 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: Physical Sciences, Test & Measurement, Briefs

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Tissue-Equivalent Radiation Dosimeteron-a-Chip with Plastic Scintillation Material

This innovation uses solid-state technology to create a compact, lightweight, personal space radiation monitor. Lyndon B. Johnson Space Center, Houston, Texas 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: Physical Sciences, Test & Measurement, Briefs

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Measurement of Cryogenic Fluid Level with Laser Propagation and Surface Floor Reflection

The current float sensing system can be augmented with this new development. Stennis Space Center, Mississippi 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: Physical Sciences, Test & Measurement, Briefs

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Video Acuity Measurement System

The smallest letters that can be automatically identified are used to rate the video system. Ames Research Center, Moffett Field, California 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: Physical Sciences, Test & Measurement, Briefs

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Heat-Flow Probe Design and Development

Applications include measuring heat flow on Earth, where optimal thermal isolation of heaters/temperature sensors is important. Marshall Space Flight Center, Alabama 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: Physical Sciences, Test & Measurement, Briefs

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Solar Pumped Fiber Laser for Solar Sail Propulsion and Remote Power Transfer

The photovoltaic capability of any instrument can be enhanced by delivering extra power via a space-based, broadband laser beam. Goddard Space Flight Center, Greenbelt, Maryland 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, Physical Sciences, Photonics, Briefs

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Designing Smaller Magnets for the Large Hadron Collider

CERN designs a smaller and more powerful superconducting accelerator magnet using ANSYS multiphysics tools. FEAC Engineering, Ioannina, Greece 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: Physical Sciences, Software, Briefs

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