Test & Measurement

High-Energy Instrumentation for Small Satellite Platforms

A key asset of the instrument design is the ability to measure a broad range of radiation. Goddard Space Flight Center, Greenbelt, Maryland Given the increased availability of small satellite opportunities either through CubeSats or the Air Force’s University Nanosat program, and the limited availability of larger platforms, it is challenging to develop new instrumentation that not only fits within the envelope of small satellites, but also addresses the diverse science applications available in low Earth orbit (LEO). While small-platform instrumentation is limited in sensitivity, the ability to populate LEO with a fleet of instruments opens new science objectives not available with larger standalone payloads. Furthermore, coordinated observations of a variety of radiation species that either enter LEO from the Sun or heliosphere directly, or that reside within the radiation belts themselves, are necessary to fully reach closure on complex processes that govern particle acceleration and transport.

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Variable Acceleration Force Calibration System

Langley Research Center, Hampton, Virginia A variable acceleration calibration system combines an innovative mechanical system and a statistical design of experiments to calibrate multi-axis force transducers. This system can reduce calibration time, allow for improved calibration of large-scale transducers, provide mobility for on-site calibrations, allow multiple transducers to be calibrated simultaneously, and accommodate dynamic force calibration.

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A Synthetic Quadrature Phase Detector/ Demodulator for Fourier Transform Spectrometers

This method makes it possible to use simple, low-cost, high-resolution audio digitizers. Langley Research Center, Hampton, Virginia Fourier transform spectroscopy works by measuring a spectral/light signal through a Michelson interferometer. In order to know the wavelength of the signal, one must use a stable reference, which is typically a metrology laser. In a standard Fourier transform spectrometer (FTS) system, the laser signal also runs through the interferometer and the laser beam is guided to a separate detector that is then used to trigger an analog-to-digital converter, which then captures the spectral signal.

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Device for Direct Measurement of the Diffusivity and Molecular Release Through Membranes and Filters

Controlled-release systems for drug delivery, molecular sieving, and single-molecule detection use micro and nano structures. Lyndon B. Johnson Space Center, Houston, Texas Concentration-driven molecular diffusion is a fundamental phenomenon essential for the transport of nutrients in cells, for oxygen exchange in the lungs, and mating of chemicals in industrial reactors and the food industry. Thus, diffusion plays a key role in a variety of disciplines. The concentration-driven diffusive transport is commonly described by Fick’s laws of diffusion. It is most often approximated by the Stokes-Einstein equation, which assumes a rigid solute sphere diffusing in a continuum of solvent at a low Reynolds number and infinite dilution.

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Magnetic Encoders

POSITAL (Hamilton, NJ) introduced new models of IXARC magnetic encoders that combine incremental and absolute rotation measurement capabilities in a single, compact package. Absolute encoders provide a control system with a report of the rotational angle and rotation count at a specific point in time; incremental encoders provide a signal pulse each time the encoder shaft rotates by a specified angle. The hybrid encoders are based on the company’s magnetic measurement technology, and offer shock, dust, and moisture resistance. The hybrid incremental and absolute rotary encoders have communications interfaces that support both measurement modes: RS-422, HTL, or TTL for incremental readings; and SSI for absolute measurements. Available multi-turn versions can count up to 64,000 revolutions, while incremental measurements have resolutions as high as 16,384 pulses per revolution. For Free Info Visit http://info.hotims.com/55588-300

Posted in: Products, Manufacturing & Prototyping, Mechanical Components, Motion Control, Measuring Instruments

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Emily Wilson, Scientist, Goddard Space Flight Center, Greenbelt, MD

Emily Wilson developed a miniaturized laser heterodyne radiometer (mini-LHR) to measure the emissions of carbon dioxide and methane from melting permafrost. Wilson’s technology will be one of several NASA instruments sent to Alaska in June to analyze trace gases in the region’s atmosphere.

Posted in: Who's Who, Environmental Monitoring, Greenhouse Gases, Lasers & Laser Systems, Measuring Instruments, Monitoring

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Sampling Mechanism for a Comet Sample Return Mission

A similar sampling mechanism could be deployed in dangerous situations on Earth. Goddard Space Flight Center, Greenbelt, Maryland Sample return missions have the ability to vastly increase scientific understanding of the origin, history, current status, and resource potential of solar system objects including asteroids, comets, Mars, and the Moon. However, to make further progress in understanding such bodies, detailed analyses of samples are needed from as many bodies as possible. A standoff sample collection system concept has been developed that would quickly obtain a sample from environments as varied as comets, asteroids, and permanently shadowed craters on the Moon, using vehicles ranging from traditional planetary spacecraft to platforms such as hovering rotorcraft or balloons on Mars, Venus, or Titan. The depth of penetration for this harpoon- based hollow collector was experimentally determined to be proportional to the momentum of the penetrator in agreement with earlier work on the penetration of solid projectiles. A release mechanism for the internal, removable sample cartridge was tested, as was an automatic closure system for the sample canister.

Posted in: Briefs, TSP, Aerospace, Data Acquisition, Mechanical Components, Machinery & Automation, Monitoring

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