Tech Briefs

Dual-Cavity Rayleigh Scattering Measurement System

A method and apparatus were developed for simultaneous measurement of velocity, density, temperature, and their spatial and temporal derivatives in gas flow. Langley Research Center, Hampton, Virginia Molecular-based optical diagnostics techniques capable of obtaining simultaneous measurements of multiple fluid properties are critically important for characterizing hypersonic air-breathing engines, such as scramjet engines and scramjet-rocket combined cycle engines. Correlations between those properties lead to a more detailed understanding of complex flow behavior, and aid in the development of multiparameter turbulence models required for supersonic combustion engine flow path predictions.

Posted in: Briefs, TSP, Optics, Measuring Instruments

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Miniature Laser Magnetometer

This conceptual design includes three key innovations future space science requires while minimizing size, mass, and power. Goddard Space Flight Center, Greenbelt, Maryland Space missions using magnetometers have been very successful. However, science missions now require higher levels of accuracy and stability in order to refine existing understanding and improve modeling. In most space missions that require high-accuracy vector measurement of magnetic fields, a separate scalar magnetometer must also be included in order to calibrate the vector measurements. The miniature laser magnetometer (MLM) addresses the need for a single, high-stability magnetometer instrument that provides both scalar and vector measurements for future space science needs while minimizing size, mass, and power.

Posted in: Briefs, TSP, Lasers & Laser Systems, Measuring Instruments

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Cryogenic Slosh Apparatus

John F. Kennedy Space Center, Florida Commercially available components are integrated into an assembly that can be used to measure the slosh dynamics of cryogenic liquids. The apparatus consists of a linear motion table that is properly instrumented to record highfidelity position, force, and acceleration measurements of all linear and rotation responses of the cryogenic liquid.

Posted in: Briefs, Measuring Instruments

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Negative-Ion Time Projection Chamber Polarimeter for Measuring Polarization of Bright Transient Astrophysical Sources

Goddard Space Flight Center, Greenbelt, Maryland A negative ion time projection chamber (NI-TPC) was developed that is suitable for measuring the polarization of bright transient events. The polarization of the astrophysical source is determined by imaging photoelectron tracks created by incident x-rays interacting in a gas. The tracks drift through the gas under a uniform electric field to the readout electronics. The initial photoelectron direction is correlated with the polarization of the incident x-ray, and therefore by imaging many tracks, one can determine the polarization magnitude and direction of the incident x-rays.

Posted in: Briefs, TSP, Measuring Instruments

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A Large-Eddy Simulation Model of the Atmospheric Boundary Layer

The model includes the interaction of various physical processes, including turbulence, clouds, precipitation, and radiation. NASA’s Jet Propulsion Laboratory, Pasadena, California The atmospheric boundary layer is the lowermost layer of the atmosphere and is host to a plethora of physical processes that significantly affect weather, climate, and air quality. In many applications, detailed information about the boundary layer is required at high temporal and spatial resolution. The main purpose of the current model is to provide accurate and finely resolved inspace and time predictions of the atmospheric boundary layer. High-resolution predictions of the boundary layer are typically pertinent in the development and evaluation of weather and climate models, in fundamental studies of atmospheric dynamics including clouds and precipitation, the dispersion of pollutants, and the development of remote sensing instruments.

Posted in: Briefs, Electronics & Computers, Simulation Software

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Hydrogen Peroxide for Microbial Growth Control in Space Potable Water Systems

This on-demand generator can provide the needed hydrogen peroxide levels for microbial growth control in potable water holding tanks and waterlines. Marshall Space Flight Center, Alabama NASA uses a biocide to prevent contamination of astronaut drinking water with harmful microorganisms. Concerns have arisen over existing biocides — that they’re inadequately effective, and may have toxic side effects when consumed. New microbial control methods are a priority. This need is addressed by using an electrochemical reactor for on-demand generation of hydrogen peroxide (H2O2) solutions. The device uses onboard resources only. The method eliminates the need for resupply items (reducing launch costs), and reduces toxicity risk.

Posted in: Briefs

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Nonlinear Swept Frequency Technique for CO2 Measurements Using a CW Laser System

The measurements would be used to significantly reduce the uncertainties in global estimates of CO2, improve climate models, and close the carbon budget for improved forecasting and policy decisions. Langley Research Center, Hampton, Virginia The U.S. National Research Council recently identified the need for a near-term space mission of Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS). The primary objective of the ASCENDS mission is to make CO2 column measurements across the troposphere during the day and night over all latitudes and all seasons, and in the presence of scattered clouds. These measurements would be used to significantly reduce the uncertainties in global estimates of CO2 sources and sinks, provide an increased understanding of the connection between climate and CO2 exchange, improve climate models, and close the carbon budget for improved forecasting and policy decisions.

Posted in: Briefs, TSP, Greenhouse Gases, Lasers & Laser Systems

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