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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 307 records · Page 17
All sourcesNASA NTRSDOE OSTI
NASA NTRS1995

Flexible Multiplexed Surface Temperature Sensor

Unitary array of sensors measures temperatures at points distributed over designated area on surface. Useful in measuring surface temperatures of aerodynamic models and thermally controlled objects. Made of combination of integrated-circuit microchips and film circuitry. Temperature-sensing chips scanned at speeds approaching 10 kHz. Operating range minus 40 degrees C to 120 degrees C. Flexibility of array conforms to curved surfaces. Multiplexer eliminates numerous monitoring cables. Control of acquisition and recording of data effected by connecting array to microcomputers via suitable interface circuitry.

Daryabeigi, Kamran↗
NASA NTRS1977

Modification of os calcis bone mineral profiles during bedrest

The mineral content of the left central os calcis was determined using the photon absorptiometric technique modified for the space missions to permit area scanning, and was compared with total body calcium balance changes. The instrument consists of a rectilinear scanner that is programmed by a specially designed control module to move a low energy X-ray emitting radionuclide placed in opposition to a detector to scan the foot which is places between them. The foot is placed in a plexiglas box filled with water to provide tissue equivalence and to compensate for irregularities in thickness of tissue cover that surrounds the bone. The mineral content is obtained from basic attenuation equation.

Vogel, J. M.↗
NASA NTRS1973

Design and evaluation of controls for drift, video gain, and color balance in spaceborne facsimile cameras

The facsimile camera is an optical-mechanical scanning device which has become an attractive candidate as an imaging system for planetary landers and rovers. This paper presents electronic techniques which permit the acquisition and reconstruction of high quality images with this device, even under varying lighting conditions. These techniques include a control for low frequency noise and drift, an automatic gain control, a pulse-duration light modulation scheme, and a relative spectral gain control. Taken together, these techniques allow the reconstruction of radiometrically accurate and properly balanced color images from facsimile camera video data. These techniques have been incorporated into a facsimile camera and reproduction system, and experimental results are presented for each technique and for the complete system.

Katzberg, S. J.↗
NASA NTRS1976

Remote, unattended, forest fire detector

Instruments for land tract scanning and fire detection include: temperature sensor capable of detecting distant match flame; elevated television camera with automatic controls for light balance, position, filter, and focus; and scanner equipped with photocell to sense intensity of flying spot brought to it by sweep-and-scan mechanism.

Winslow, D. J.↗
NASA NTRS1985

Directivity optimization of a reflector antenna with cluster feeds - A closed-form solution

The directivity of a reflector antenna deteriorates as the feed moves away from the focal point for beam scanning. This deterioration can be substantially reduced if a cluster feed instead of single feed is used to control a beam. A closed-form solution is presented for the cluster excitation to achieve the optimum directivity. For an offset 108 lambda parabolic reflector scanning 10 beamwidths, the optimum directivity achieved by a 19-element (seven-element) cluster is 12 dB (8 dB) higher than that of a single element. Comparison of the optimum-directivity design and the popular conjugate field matching design is made. When the cluster spacing d is greater than 1 lambda, it is found that the optimum directivity is higher than that of conjugate field matching (CFM) scheme by an insignificant amount, although the excitations of two designs can be quite different. For d less than 0.5 lambda, the optimum design may exhibit the supergain phenomenon, namely extremely high directivities achieved by an oscillatory cluster excitation.

Lam, P. T.↗
NASA NTRS2024

Anthropometric Measurement Procedures at the Anthropometry and Biomechanics Facility

The Anthropometry and Biomechanics Facility (ABF) at NASA Johnson Space Center (JSC) is the centralized source of anthropometry data at NASA for use in requirement development, engineering design, and verification of human-system integrations such as spacesuits and vehicles. To ensure the collection of consistent, accurate, and valid anthropometry data, ABF has defined anthropometric measurements and anatomical landmarks which are generally based on the Anthropometric Survey for US Army Personnel (ANSUR), but with additional measurements which have been uniquely designed for spacesuit and hardware accommodation purposes. Unlike ANSUR, NASA anthropometry measurements primarily rely on 3D body scanning, a method which allows for explicitly defining the process of collecting measurements and the quality control methods used to ensure measurement reliability. In addition to ABF’s anthropometry measurement definitions and procedures, this presentation will also compare specifics of different measurement techniques ABF uses, for example, laser scanning versus manual measurement methods (e.g., tape measure or anthropometer-based), and the benefits and considerations of each method. The evolution of ABF’s measurement process will also be addressed, as new spaceflight programs have been introduced which have required unique measurements and the need to capture body shape changes over time was identified to be critical for spacesuit fit in some instances.

Garima Gupta↗
NASA NTRS2024

Anthropometric Measurement Procedures at the Anthropometry and Biomechanics Facility

The Anthropometry and Biomechanics Facility (ABF) at NASA Johnson Space Center (JSC) is the centralized source of anthropometry data at NASA for use in requirement development, engineering design, and verification of human-system integrations such as spacesuits and vehicles. To ensure the collection of consistent, accurate, and valid anthropometry data, ABF has defined anthropometric measurements and anatomical landmarks which are generally based on the Anthropometric Survey for US Army Personnel (ANSUR), but with additional measurements which have been uniquely designed for spacesuit and hardware accommodation purposes. Unlike ANSUR, NASA anthropometry measurements primarily rely on 3D body scanning, a method which allows for explicitly defining the process of collecting measurements and the quality control methods used to ensure measurement reliability. In addition to ABF’s anthropometry measurement definitions and procedures, this presentation will also compare specifics of different measurement techniques ABF uses, for example, laser scanning versus manual measurement methods (e.g., tape measure or anthropometer-based), and the benefits and considerations of each method. The evolution of ABF’s measurement process will also be addressed, as new spaceflight programs have been introduced which have required unique measurements and the need to capture body shape changes over time was identified to be critical for spacesuit fit in some instances.

Garima Gupta↗
NASA NTRSDate not supplied

STARscan: Spatial Targeting and Alignment Rig for Scanning

The Spatial Targeting and Alignment Rig for Scanning (STARScan) is a 3D photogrammetry system developed at NASA Ames Research Center to address bottlenecks in pre/post-test scanning of arcjet test articles. It reduces scan time from 15 minutes with handheld laser scanners to under 2 minutes, while maintaining high accuracy (±0.2-0.5 mm). STARScan integrates an array of cameras, a 3D-printed rack, turntable, and LED light panels, all controlled via a user-friendly graphical user interface (GUI). The system offers tools for scan visualization, mesh analysis, and data export, automating tasks such as alignment of pre/post-test scans, material recession measurements, surface roughness assessment, and curvature analysis. By integrating scanning, imaging, and post-processing into one application, STARScan significantly improves efficiency in scanning and analyzing arcjet test samples.

Ablation↗
NASA NTRS1994

Design and implementation of a beam-waveguide mirror control system for vernier pointing of the DSS-13 antenna

The design and implementation of an antenna beam-waveguide (BWG) mirror position control system at the DSS-13 34-m antenna is presented. While it has several potential applications, a positioner on the last flat-plate BWG mirror (M6) at DSS 13 is installed to demonstrate the conical scan (conscan) angle-tracking technique at the Ka-band (32-GHz) operating frequency. Radio frequency (RF) beam-scanning predictions for the M6 mirror, computed from a diffraction analysis, are presented. From these predictions, position control system requirements are then derived. The final mechanical positioner and servo system designs, as implemented at DSS 13, are illustrated with detailed design descriptions given in the appendices. Preliminary measurements of antenna Ka-band beam scan versus M6 mirror tilt made at DSS 13 in December 1993 are presented. After reduction, the initial measurements are shown to be in agreement with the RF predicts. Plans for preliminary conscan experimentation at DSS 13 are summarized.

Alvarez, L. S.↗
NASA NTRS2014

Phase Change Material for Temperature Control of Imager or Sounder on GOES Type Satellites in GEO

This paper uses phase change material (PCM) in the scan cavity of an imager or sounder on satellites in geostationary orbit (GEO) to maintain the telescope temperature stable. When sunlight enters the scan aperture, solar heating causes the PCM to melt. When sunlight stops entering the scan aperture, the PCM releases the thermal energy stored to keep the components in the telescope warm. It has no moving parts or bimetallic springs. It reduces heater power required to make up the heat lost by radiation to space through the aperture. It is an attractive thermal control option to a radiator with a louver and a sunshade.

phase change material↗
NASA NTRS1972

Comparison of two sensors for outer planet mission onboard navigation.

Onboard instruments have been shown to be an effective aid to navigation on missions to the outer planets. The relationship of two possible candidate navigation instruments, an image tube (television) and a scanning photometer, with other systems such as data processing and attitude control is discussed. Certain key problem areas relating to the design of each sensor are considered, and the scientific uses of each sensor are examined. The navigational efficacy of both instruments is illustrated by some selected results from a navigation and guidance simulation of outer planet missions. It is concluded that both devices are viable alternatives for onboard outer planet navigation.

Malchow, H. L.↗
NASA NTRS1972

Experimental study of spectral and spatial distribution of solar X-rays

The study of the physical conditions within the solar corona and the development of instrumentation and technical expertise necessary for advanced studies of solar X-ray emission are reported. Details are given on the Aerobee-borne-X-ray spectrometer/monochromator and also on the observing program. Preliminary discussions of some results are presented and include studies of helium-like line emission, mapping O(VII) and Ne(IX) lines, survey of O(VII) and Ne(IX) lines, study of plage regions and small flares, and analysis of line emission from individual active regions. It is concluded that the use of large-area collimated Bragg spectrometers to scan narrow wavelength intervals and the capability of the SPARCS pointing control to execute a complex observing program are established.

Acton, L. W.↗
NASA NTRS1979

An electric propulsion long term test facility

An existing test facility was modified to provide for extended testing of multiple electric propulsion thruster subsystems. A program to document thruster subsystem characteristics as a function of time is currently in progress. The facility is capable of simultaneously operating three 2.7-kW, 30-cm mercury ion thrusters and their power processing units. Each thruster is installed via a separate air lock so that it can be extended into the 7m x 10m main chamber without violating vacuum integrity. The thrusters exhaust into a 3m x 5m frozen mercury target. An array of cryopanels collect sputtered target material. Power processor units are tested in an adjacent 1.5m x 2m vacuum chamber or accompanying forced convection enclosure. The thruster subsystems and the test facility are designed for automatic unattended operation with thruster operation computer controlled. Test data are recorded by a central data collection system scanning 200 channels of data a second every two minutes. Results of the Systems Demonstration Test, a short shakedown test of 500 hours, and facility performance during the first year of testing are presented.

Trump, G.↗
NASA NTRS1984

Incoherent scatter observations of an artificially modified ionosphere

The 'experiment of opportunity' to test incoherent scatter radar techniques for the diagnostic study of a chemically induced modification of the ionosphere occasioned by the launch of the HEAO-C satellite is described. The optimal utilization of a steerable incoherent scatter radar for a short duration event is examined. The choice of keeping the antenna fixed to obtain good control data and excellent time resolution along a given direction versus scanning the antenna to obtain mixed spatial and temporal morphologies is discussed. Results for fixed position measurements, elevation scans, ion-drift, and total electron content are presented. The first unambiguous observations of a gas expansion 'snowplow effect' is reported along with the derivation of local and height-integrated plasma recombination rates and the full spatial, temporal, and dynamical morphologies of a large-scale ionospheric hole.

Wand, R. H.↗
NASA NTRS1987

Effects of combining vertical and horizontal information into a primary flight display

A ground-based aircraft simulation study was conducted to determine the effects of combining vertical and horizontal flight information into a single display. Two display configurations were used in this study. The first configuration consisted of a Primary Flight Display (PFD) format and a Horizontal Situation Display (HSD) with the PFD displayed conventionally above the HSD. For the second display configuration, the HSD format was combined with the PFD format. Four subjects participated in this study. Data were collected on performance parameters, pilot-control inputs, auditory evoked response parameters (AEP), oculometer measurements (eye-scan), and heart rate. Subjective pilot opinion was gathered through questionnaire data and scorings for both the Subjective Workload Assessment Technique (SWAT) and the NASA Task Load Index (NASA-TLX). The results of this study showed that, from a performance and subjective standpoint, the combined configuration was better than the separate configuration. Additionally, both the eye-transition and eye-dwell times for the separate HSD were notably higher than expected, with a 46% increase in available visual time when going from double to single display configuration.

Abbott, Terence S.↗
NASA NTRS1991

Ruling Blazed, Aberration-Corrected Diffraction Gratings

Proposed optoelectromechanical apparatus that functions partly as ruling engine and partly as pantograph rules blazed, aberration-corrected diffraction gratings. Makes possible to combine precision of aberration-corrected, holographically produced grating with diffraction efficiency of blazed grating by using holographically produced grating as model or master pattern that controls ruling engine making blazed grating. Surface of model holographic grating scanned by sensing head mounted on pantographic arm. Ruling stylus mounted on other end of pantographic arm with tip in grating blank.

Leviton, Douglas B.↗
NASA NTRS1992

A combined Earth scanner and momentum wheel for attitude determination and control of small spacecraft

In order to satisfy the stringent cost and power requirements of small satellites, an advanced SCANWHEEL was designed, built, and qualified by ITHACO, Inc. The T-SCANWHEEL is a modular momentum/reaction wheel with an integral conical Earth scanner. The momentum wheel provides momentum bias and control torques about the pitch axis of a spacecraft. An angled scan mirror coupled to the rotating shaft of the momentum wheel provides a conical scan of the field-of-view of an infrared sensor to provide pitch-and-roll attitude information. By using the same motor and bearings for the momentum wheel and Earth scanner, the overall power consumption is reduced and the system reliability is enhanced. The evolution of the T-SCANWHEEL is presented, including design ground rules, tradeoff analyses, and performance results.

Bialke, Bill↗
NASA NTRS1992

The NASA/NSO spectromagnetograph

The Kitt Peak Vacuum Telescope's spectromagnetograph features real-time digital analysis of long-slit spectra formed on a 2D CCD detector, and is located at an exit port of a Littrow spectrograph. Commercial video processing boards are used to digitize the spectral images at video rates and to separate, accumulate, and buffer the spectra in the two polarization states. A processor removes fixed-pattern bias and gain from the spectra in cadence with spatial scanning of the image across the entrance slit; a data-control computer conducts position and width analysis of the line profiles and records line-of-sight magnetic field, Doppler shift, and other computed parameters, as demonstrated by the early observations presented.

Jones, Harrison P.↗