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Noncontact DC and AC Magnetostrictive Current Sensor

John H. Glenn Research Center, Cleveland, Ohio At the time of this reporting, there have been no effective methods of monitoring current in conductors in space without breaking the circuit or making contact with the conductor. In space, reliability rules all designs, and breaking a circuit to insert a sensor to monitor current would reduce reliability of the system. Hall effect sensors provide a noncontact DC measurement technique, but they are relatively expensive and not rugged enough for the space environment.

Posted in: Physical Sciences, Briefs

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Method and Apparatus for Determining Propellant Mass in Microgravity by Capacitance Measurements

The method is relatively insensitive to propellant orientation. Marshall Space Flight Center, Alabama Propellant mass gauging in microgravity has posed a challenge for decades. Various methods have been applied, including ultrasonic, capacitance probes, point level sensors, thermal detectors (thermistors, thermocouples, etc.), Michelson interferometry, and nuclear devices. All have problems in terms of how to provide accurate measurements irrespective of the fluid orientation in the tank.

Posted in: Physical Sciences, Briefs

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Preparation, Planning, and Concept Demo of a Technique to Find ≈7-to-10-m Near Earth Asteroids

A paper describes a new technique designed to increase significantly the sensitivity for finding and tracking small, dim, and fast-moving near Earth asteroids (NEAs). The technique relies on a combined use of a novel data processing approach and a new generation of high-speed CCD cameras. These new cameras have very low readout noise (≈le–) and allow taking short exposures of moving objects at high frame rates, effectively “freezing” their motion on the CCD. A long-exposure image is synthetically created as if the telescope were tracking the object with a significantly higher SNR — an approach called “synthetic tracking.” By changing the shift/add vector, multiple dim objects moving in different directions can be detected in the same data set.

Posted in: Physical Sciences, Briefs, TSP

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Strobing to Mitigate Vibration for Display Legibility

Blur is eliminated with appropriate strobing frequency. Ames Research Center, Moffett Field, California This method mitigates the motion blur introduced when a display, and/or the operator reading it, is undergoing vibration (e.g. during the launch phase of spaceflight). If both the operator and the display are undergoing vibration, their respective impulses need not be in phase. This mitigation occurs when the display is illuminated at a strobing rate that corresponds with the frequency of the vibration. This can be done either by strobing the ambient illumination in the environment (e.g., if the operator is reading a reflective surface display), or by strobing the display itself (e.g., strobing the LED backlighting of an electronic display).

Posted in: Physical Sciences, Imaging, Briefs, TSP

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Imaging Space System Architectures Using a Granular Medium as a Primary Concentrator

Higher-resolution optics provide improved hyperspectral imaging for ocean and land monitoring, as well as exoplanet detection. NASA’s Jet Propulsion Laboratory, Pasadena, California Typically, the cost of a space observatory is driven by the size and mass of the primary aperture. Generally, a monolithic aperture is much heavier and complex to fabricate (hence, more costly) than an aperture of the same size but composed of much smaller units. Formation flying technology, as applied to swarm systems in space, is an emerging discipline.

Posted in: Physical Sciences, Imaging, Briefs, TSP

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Image Processing Method To Determine Dust Optical Density

John F. Kennedy Space Center, Florida Image processing techniques for determining dust optical density in Apollo videos have been developed. The software generates histograms, and calculates the mean and standard deviation, which are then used to match dusty and clear images for the purpose of estimating an effective optical density. A dust thickness model, based on the tilt of the camera and increasing thickness of the dust layer towards the top of the image, is used to account for the distance light travels through dust.

Posted in: Physical Sciences, Imaging, Briefs, TSP

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Vibration and Thermal Cycling Apparatus for Cryogenic Tanks

Key design characteristics can be reliably and repeatedly tested together or separately as required by the design requirements. John F. Kennedy Space Center, Florida Understanding thermal and mechanical behaviors and their inter-dependencies of complex tank systems is crucial to making proper design decisions. Low-maintenance, high-performance systems are becoming more important as global energy demands and efficiency requirements increase.

Posted in: Physical Sciences, Briefs, TSP

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