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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 325 records · Page 18
All sourcesNASA NTRSDOE OSTI
NASA NTRS1992

Global distribution of hand-held photographs of ocean and coastal regions taken during space shuttle missions - 1981-1991

During the first 10 years of the US Space Shuttle program, 26,736 high-quality, hand-held photographs have been acquired of the earth's ocean and coastal areas from orbit by astronauts during 40 missions. The photographs are cataloged and stored in the Space Shuttle Earth Observations Project (SSEOP) database. While the majority of photographs are of tropical and subtropical coastal areas, many open-ocean and high-latitude areas have also been photographed. The majority of space shuttle missions have permitted photographing northern hemisphere areas in daylight. As a result, the latitudinal distribution of photographs is biased toward the northern hemisphere, particularly in high latitudes. Coastal areas and islands are most frequently photographed, while photographs of central ocean areas are either infrequent or nonexistent.

Ackleson, Steven G.↗
NASA NTRS1991

Applications of a hand-held GPS receiver in South American rain forests

A hand-held Global Positioning System receiver was used to determine the precise locations of villages, houses, gardens, and other cultural and environmental features in poorly mapped South American rain forests. The Magellan NAV 1000 unit profides extremely accurate latitude and longitude information, but determination of altitude is problematical. Overall, the receiver effectively allows anthropologists to obtain essential locational data useful for categorizing land uses, mapping tribal boundaries, and other applications in regions where environmental conditions are harsh and/or accessibility is difficult.

Baksh, Michael↗
NASA NTRS1993

A four-axis hand controller for helicopter flight control

A proof-of-concept hand controller for controlling lateral and longitudinal cyclic pitch, collective pitch and tail rotor thrust was developed. The purpose of the work was to address problems of operator fatigue, poor proprioceptive feedback and cross-coupling of axes associated with many four-axis controller designs. The present design is an attempt to reduce cross-coupling to a level that can be controlled with breakout force, rather than to eliminate it entirely. The cascaded design placed lateral and longitudinal cyclic in their normal configuration. Tail rotor thrust was placed atop the cyclic controller. A left/right twisting motion with the wrist made the control input. The axis of rotation was canted outboard (clockwise) to minimize cross-coupling with the cyclic pitch axis. The collective control was a twist grip, like a motorcycle throttle. Measurement of the amount of cross-coupling involved in pure, single-axis inputs showed cross coupling under 10 percent of full deflection for all axes. This small amount of cross-coupling could be further reduced with better damping and force gradient control. Fatigue was not found to be a problem, and proprioceptive feedback was adequate for all flight tasks executed.

Demaio, Joe↗
NASA NTRS1993

Investigation of hand capabilities under a variety of performance conditions and an attempt to explain performance differences

Human capabilities such as dexterity, manipulability, and tactile perception are unique and render the hands as a very versatile, effective and a multipurpose tool. This is especially true for environments such as the EVA environment. However, with the use of the protective EVA gloves, there is much evidence to suggest that human performance decreases. In order to determine the nature and cause of this performance decrement, several performance tests were run which studied the effects of gloves on strength, tactile feedback, and range of motion. Tactile sensitivity was measured as a function of grip strength, and the results are discussed. Equipment which was developed to measure finger range of motion along with corresponding finger strength values is discussed. The results of these studies have useful implications for improved glove design.

Bishu, Ram R.↗
NASA NTRS1993

Design and control of a hand exoskeleton for use in extravehicular activities

To counter problems inherent in extravehicular activities (EVA) and complex space operations, an exoskeleton, a unique adaptive structure, has been designed. The exoskeleton fits on the hand and powers the proximal and middle phalanges of the index finger, the middle finger, and the combined ring and little finger. A kinematic analysis of the exoskeleton joints was performed using the loop-closure method. This analysis determined the angular displacement and velocity relationships of the exoskeleton joints. This information was used to determine the output power of the exoskeleton. Three small DC motors (one for each finger) are used to power the exoskeleton. The motors are mounted on the forearm. Power is transferred to the exoskeleton using lead screws. The control system for the exoskeleton measures the contact force between the operator and the exoskeleton. This information is used as the input to drive the actuation system. The control system allows the motor to rotate in both directions so that the operator may close or open the exoskeleton.

Shields, B.↗
NASA NTRS1995

Prepsolv (TM): The optimum alternative to 1,1,1-trichloroethane and methyl ethyl ketone for hand-wipe cleaning of aerospace materials

Engineers at Hercules Aerospace, a rocket motor manufacturer in Utah, have worked closely with chemists at Glidco Organics to study the feasibility of using terpenes for zero-residue wipe cleaning. The result of this work is a technological breakthrough, in which the barrier to ultra-low non-volatile residue formation has been broken. After 2 years of development and testing, SCM Glidco Organics has announced the availability of Glidsafe(registered trademark) Prepsolv(TM): a state-of-the-art ultra-low residue terpene wipe cleaning agent that does not require rinsing. Prepsolv(TM) can successfully be used in simple hand-wipe cleaning processes without fear of leaving surface residues. Industry testing has confirmed that Prepsolv(TM) is not only highly effective, but can even be less expensive to use than traditional cleaning solvents like methyl chloroform. This paper addresses the features and benefits of Prepsolv(TM), and presents performance and material compatibility data that characterizes this unique cleaning agent. Since its commercialization, Hercules Aerospace has chosen Prepsolv(TM) as the optimum cleaning agent to replace ozone-depleting solvents in their weapons factory in Magna, UT. Likewise, Boeing has approved Prepsolv(TM) for cleaning components in the manufacture of commercial aircraft at their facilities in Seattle, WA and Wichita, KS. Additional approvals are forthcoming for this uniquely safe and effective solvent.

Gallagher, R. Scott↗
NASA NTRS1995

Hand-portable gas chromatography-ion mobility spectrometer for the determination of the freshness of fish

A hand-held, portable gas chromatography-ion mobility spectrometer (GC-IMS) device was used to detect the presence of volatile amine compounds in the headspace of decomposing fish. The Food and Drug Administration (FDA) largely relies on olfactory discrimination with respect to fresh and spoiled, frozen and unfrozen fish. The fish are delivered at ship docks on pallets, and each pallet of fish can range from 30-40 thousand dollars in value. Fresh fish were placed in a teflon bag and the direct headspace was interrogated. In the first three days, only low molecular weight volatile amines were detected. On the fourth day, a number of spectral signatures were observed which indicated the presence of 1,5-diaminopentane, cadaverine. Analyses typically took from 0.5-1 minute.

Snyder, A. Peter↗
NASA NTRS1995

Hand-Operated Hydraulic Tube Expander

Hand-operated tool expands end portion of narrow metal or plastic tube to slightly larger diameter. Used on tubes with original inner diameters as small as 0.060 in. Includes replaceable tip comprising ferrule and tubular expansion sleeve sized for sliding fit into tube to be expanded. Expansion sleeve swells in response to internal hydraulic pressure generated by turning handle and thereby advancing piston.

Hagan, David W.↗
NASA NTRS1995

Prosthetic Hand For Holding Rods, Tools, And Handles

Prosthetic hand with quick-grip/quick-release lever broadens range of specialized functions available to lower-arm amputee by providing improved capabilities for gripping rods, tools, handles, and like. Includes two stationary lower fingers opposed by one pivoting upper finger. Lever operates in conjunction with attached bracket.

Belcher, Jewell G., Jr.↗
NASA NTRS1996

InfraCAM (trade mark): A Hand-Held Commercial Infrared Camera Modified for Spaceborne Applications

In 1994, Inframetrics introduced the InfraCAM(TM), a high resolution hand-held thermal imager. As the world's smallest, lightest and lowest power PtSi based infrared camera, the InfraCAM is ideal for a wise range of industrial, non destructive testing, surveillance and scientific applications. In addition to numerous commercial applications, the light weight and low power consumption of the InfraCAM make it extremely valuable for adaptation to space borne applications. Consequently, the InfraCAM has been selected by NASA Lewis Research Center (LeRC) in Cleveland, Ohio, for use as part of the DARTFire (Diffusive and Radiative Transport in Fires) space borne experiment. In this experiment, a solid fuel is ignited in a low gravity environment. The combustion period is recorded by both visible and infrared cameras. The infrared camera measures the emission from polymethyl methacrylate, (PMMA) and combustion products in six distinct narrow spectral bands. Four cameras successfully completed all qualification tests at Inframetrics and at NASA Lewis. They are presently being used for ground based testing in preparation for space flight in the fall of 1995.

Manitakos, Daniel↗
NASA NTRS1995

Hand-held terminal antennas for personal satellite communications

This paper deals with two hand-held antenna types operating with geostationary and medium earth orbit (GEO and MEO) satellite systems. They could be applied to the low earth orbit (LEO) and highly elliptical orbit (HEO) systems respectively doing the appropriate frequency scale designs. The first one is a lambda/2 (1/2 turn) quadrifilar helix (quasi-hemispherical coverage), and the second one is a self-diplexed antenna made of a circular patch and a short-circuited ring patch in stacked configuration (zenithal coverage).

Caballero, J. E.↗
NASA NTRS1996

Virtual Keyboard for Hands-Free Operations

The measurement of direction of gaze (d.o.g.) has been used for clinical purposes to detect illness, such as nystagmus, unusual fixation movements and many others. It also is used to determine the points of interest in objects. In this study we employ a measurement of d.o.g. as a computer interface. The interface provides a full keyboard as well as a mouse function. Such an interface is important to computer users with paralysis or in environments where hand-free machine interface is required. The study utilizes the commercially available (ISCAN Model RK426TC) headset which consists of an InfraRed (IR) source and an IR camera to sense deflection of the illuminating beam. It also incorporates image processing package that provides the position of the pupil as well as the pupil size. The study shows the ability of implementing a full keyboard, together with some control functions, imaged on a head mounted monitor screen. This document is composed of four sections: (1) The Nature of the Equipment; (2) The Calibration Process; (3) Running Process; and (4) Conclusions.

Abou-Ali, Abdel-Latief↗
NASA NTRS1996

Long-Wavelength 256 x 256 QWIP Hand-Held Camera

In this paper, we discuss the development of very sensitive long wavelength infrared (LWIR) GaAs/Al(x)Ga(l-x)As quantum well infrared photodetectors (QWIPs), fabrication of random reflectors for efficient light coupling, and the demonstration of the first hand-held long-wavelength 256 x 256 QWIP focal plane array camera. Excellent imagery, with a noise equivalent differential temperature (NE Delta T) of 25 mK has been achieved.

Gunapala, S. D.↗
NASA NTRS1999

S-Wave Dispersion Relations: Exact Left Hand E-Plane Discontinuity from the Born Series

We show, for a superposition of Yukawa potentials, that the left hand cut discontinuity in the complex E plane of the (S-wave) scattering amplitude is given exactly, in an interval depending on n, by the discontinuity of the Born series stopped at order n. This also establishes an inverse and unexpected correspondence of the Born series at positive high energies and negative low energies. We can thus construct a viable dispersion relation (DR) for the partial (S-) wave amplitude. The high numerical precision achievable by the DR is demonstrated for the exponential potential at zero scattering energy. We also briefly discuss the extension of our results to Field Theory.

Bessis, D.↗
NASA NTRS1999

In Situ Identification of Mineral Resources with an X-Ray-Optical "Hands-Lens" Instrument

The recognition of material resources on a planetary surface requires exploration strategies not dissimilar to those employed by early field geologists who searched for ore deposits primarily from surface clues. In order to determine the location of mineral ores or other materials, it will be necessary to characterize host terranes at regional or subregional scales. This requires geographically broad surveys in which statistically significant numbers of samples are rapidly scanned from a roving platform. To enable broad-scale, yet power-conservative planetary-surface exploration, we are developing an instrument that combines x-ray diffractometry (XRD), x-ray fluorescence spectrometry (XRF), and optical capabilities; the instrument can be deployed at the end of a rover's robotic arm, without the need for sample capture or preparation. The instrument provides XRD data for identification of mineral species and lithological types; diffractometry of minerals is conducted by ascertaining the characteristic lattice parameters or "d-spacings" of mineral compounds. D-spacings of 1.4 to 25 angstroms can be determined to include the large molecular structures of hydrated minerals such as clays. The XRF data will identify elements ranging from carbon (Atomic Number = 6) to elements as heavy as barium (Atomic Number = 56). While a sample is being x-rayed, the instrument simultaneously acquires an optical image of the sample surface at magnifications from lx to at least 50x (200x being feasible, depending on the sample surface). We believe that imaging the sample is extremely important as corroborative sample-identification data (the need for this capability having been illustrated by the experience of the Pathfinder rover). Very few geologists would rely on instrument data for sample identification without having seen the sample. Visual inspection provides critical recognition data such as texture, crystallinity, granularity, porosity, vesicularity, color, lustre, opacity, and so forth. These data can immediately distinguish sedimentary from igneous rocks, for example, and can thus eliminate geochemical or mineral ambiguities arising, say between arkose and granite. It would be important to know if the clay being analyzed was part of a uniform varve deposit laid down in a quiescent lake, or the matrix of a megabreccia diamictite deposited as a catastrophic impact ejecta blanket. The unique design of the instrument, which combines Debye-Scherrer geometry with elements of standard goniometry, negates the need for sample preparation of any kind, and thus negates the need for power-hungry and mechanically-complex sampling systems that would have to chip, crush, sieve, and mount the sample for x-ray analysis. Instead, the instrument is simply rested on the sample surface of interest (like a hand lens); the device can interrogate rough rock surfaces, coarse granular material, or fine rock flour. A breadboard version of the instrument has been deployed from the robotic arm of the Marsokhod rover in field trials at NASA Ames, where large vesicular boulders were x-rayed to demonstrate the functionality of the instrument design, and the ability of such a device to comply with constraints imposed by a roving platform. Currently under development is a flight prototype concept of this instrument that will weigh 0.3 kg, using about 4500 J of energy per sample analysis. It requires about 5 min. for XRD analysis, and about 30 min. for XRF interrogation. Its small mass and rugged design make it ideal for deployment on small rovers of the type currently envisaged for the exploration of Mars (e.g., Sojourner-scale platforms). The design utilizes a monolithic P-N junction photodiode pixel array for XRD, a Si PIN photodiode/avalanche photodiode system for XRF, and an endoscopic imaging camera system unobtrusively embedded between the detectors and the x-ray source (the endoscope with its board-mounted camera can be adapted for IR light in addition to visible wavelenths. A rugged, miniature (7 cu cm) x-ray source for the instrument has already been breadboarded.

Marshall, J.↗
NASA NTRS2000

Exploring the Solar System in the Classroom: A Hands-On Approach

This final report discusses the development and implementation of several educational products for K-16 teachers and students. Specifically, I received support for: (A) three K-12 Teacher workshops, Exploring the Solar System in the Classroom: A Hands-On Approach, and minimal Support to finish two computer-based tutorials. (B) Contact Light: An Interactive CD-ROM, and (C) Another Look at Taurus Littrow: An Interactive GIS Database. Each of these projects directly supports NASA's Strategic Plan to: "Involve the education community in our endeavors to inspire America's students, create learning opportunities, enlighten inquisitive minds", and, to "communicate widely the content, relevancy, and excitement of NASA's missions and discoveries to inspire and to increase understanding and the broad application of science and technology." Attachment: Appendix A. And also article: "Aristarchus plateau: as potential lunar base site."

Coombs, Cassandra R.↗
NASA NTRS1999

Experiments in Aligning Threaded Parts Using a Robot Hand

Techniques for determining and correcting threaded part alignment using force and angular position data are developed to augment currently limited techniques for align- ing threaded parts. These new techniques are based on backspinning a nut with respect to a bolt and measuring the force change that occurs when the bolt "falls" into the nut. Kinematic models that describe the relationship between threaded parts during backspinning are introduced and are used to show how angular alignment may be determined. The models indicate how to distinguish between the aligned and misaligned cases of a bolt and a nut connection by using axial force data only. In addition, by tracking the in-plane relative attitude of the bolt during spinning, data can be obtained on the direction of the angular misalignment which, in turn, is used to correct the misalignment. Results from experiments using a bolt held in a specialized fixture and a three fingers Stanford/JPL hand are presented.

Diftler, M. A.↗