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Vector Network Analyzer Calibration for Quasi-Optical Dual Ports

Goddard Space Flight Center, Greenbelt, Maryland It is desirable to measure the electromagnetic properties of devices and materials in the millimeter part of the spectrum. For guided wave-based devices and materials (waveguides, coaxial devices), a vector network analyzer (VNA) is an excellent tool for this purpose since it provides full reflection and transmission characterization at high precision.

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Optically Modulated Miniature Magnetometer

This instrument may replace two separate instruments that are often needed together to study magnetic fields. Goddard Space Flight Center, Greenbelt, Maryland The optically modulated miniature magnetometer (OMMM) is intended to replace two separate instruments (each with their respective mass and power allotments) that are commonly needed together for scientific studies of magnetic fields — a triaxial fluxgate vector magnetometer and an optically pumped alkali vapor scalar magnetometer. For all vector instruments, the scalar data is necessary for calibrating the vector data.

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Quantitative Analysis of Failure Mode in Adhesively Bonded Test Specimens

A fluorescence visualization technique is used. Langley Research Center, Hampton, Virginia After adhesively bonded mechanical test specimens have been tested to failure, the failure mode must be interpreted and quantified. Areas of the adherent that are bare (no residual adhesive remains) have undergone adhesive failure. The remainder of the surface has undergone cohesive failure. The ability to distinguish and accurately quantify the relative amounts of cohesive and adhesive failure on a failed bonding surface is of tremendous importance in the field of mechanical testing, and for the development of bonded assemblies. Some adhesives (and adherents) are fluorescent, meaning they re-emit light at a different wavelength after being irradiated by some lighting source. This property allows for quantitative analysis of the adhesive failure mode (adhesive and cohesive). A digital image of the fluorescing adhesive or adherent can be analyzed and quantified using publicly available software to determine the relative areas of exposed and covered adherent surface.

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Neutron Spectrometer for Inner Radiation Belt Studies

The instrument is inherently robust, cost-effective, compact, and modular. Goddard Space Flight Center, Greenbelt, Maryland The Earth’s magnetosphere offers a wealth of information on particle dynamics, acceleration, and trapping. Fast neutrons, produced in the Earth’s atmosphere by the impact of galactic cosmic rays (GCRs) and solar energetic particles (SEPs), are an important but poorly measured component of the radiation environment in the inner magnetosphere. Cosmic ray albedo neutron decay (CRAND), whereby atmospheric neutrons beta-decay into protons and electrons, is a significant source of energetic protons in the inner radiation belt. Current models of the inner proton belt rely heavily on Monte Carlo simulations for the CRAND component, validated primarily by a handful of single-point balloon measurements from the 1970s.

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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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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, Machinery & Automation, Monitoring

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