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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 19 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1997

Remote Sensing of Aircraft Contrails Using a Field Portable Digital Array Scanned Interferometer

With a Digital Array Scanned Interferometer (DASI), we have obtained proof-of-concept observations with which we demonstrate DASI capabilities for the determination of contrail properties. These include the measurement of the cloud and soot microphysical parameters, as well, the abundances of specific pollutant species such as SO(sub x) or NO(sub x). From high quality hyperspectral data and using radiative transfer methods and atmospheric chemistry analysis in the data reduction and interpretation, powerful inferences concerning cloud formation, evolution and dissipation can be made. Under this sub-topic, we will integrate DASI with computer controlled scanning of the field-of-view to direct the sensor towards contrails and exhaust plumes for tracking the emitting vehicles. The optimum DASI wavelength sensitivity range for sensing contrails is 0.35 - 2.5 micron. DASI deploys on the ground or from aircraft to observe contrails in the vicinity. This enables rapid, accurate measurement of the temporal, spatial, and chemical evolution of contrails (or other plumes or exhaust sources) with a low cost, efficient sensor.

Smith, William Hayden↗
NASA NTRS1993

Experimental comparison of time synchronization techniques by means of light signals and clock transport on the rotating earth

An experiment was conducted to investigate the equivalence of two methods of time transfer in a noninertial reference frame: by means of an electromagnetic signal using laser light pulses and by means of the slow ground transport of a hydrogen maser atomic clock. The experiment may also be interpreted as an investigation of whether the one-way speeds of light in the east-west and west-east directions on the rotating earth are the same. The light pulses were sent from a laser coupled to a telescope at the NASA Goddard Optical Research Facility (GORF) in Greenbelt, Maryland to the U.S. Naval Observatory (USNO) in Washington, DC. The optical path was made possible by a 30-cm flat mirror on a water tower near GORF and a 25-cm flat mirror on top of the Washington National Cathedral near USNO. The path length was 26.0 km with an east-west component of 20.7 km. The pulses were reflected back over the same path by a portable array of corner cube reflectors. The transmission and return times were measured with a stationary Sigma Tau hydrogen maser and a University of Maryland event timer at GORF, while the times of reflection were measured with a similar maser and event timer combination carefully transported to USNO. Both timekeeping systems were housed in highly insulated enclosures and were maintained at constant temperatures to within +/- 0.1 C by microprocessor controllers. The portable system was also protected from shock and vibration by pneumatic supports. The difference delta(T) between the directly measured time of reflection according to the portable clock and the time of reflection calculated from the light pulse signal times measured by the stationary clock was determined. For a typical trip delta(T) is less than 100 ps and the corresponding limit on an anisotropy of the one-way speed of light is delta(c/c) is less than 1.5 x 10(exp -6). This the only experiment to date in which two atomic clocks were calibrated at one location, one was slowly transported to the other end of a path, and the times of transmission, reflection, and return of short light pulses sent in different directions along the path were registered.

Nelson, R. A.↗
NASA NTRSDate not supplied

A Microphone Phased Array for Launch Acoustics Application

A new, portable, phased array of microphones is built at NASA Ames Research Center specifically for the harsh environment encountered in launch acoustics applications. It uses 70 rugged, piezo-electric, dynamic pressure sensors optimally distributed on a 10.5ft diameter open frame dome structure. The open frame is light yet robust to sustain the high wind load of typical seaside launch pads, and the blast and acoustic loads from the launch. A 200-ft long cable bundle carries the microphone signals to a weather-protected electronic cabinet containing the data acquisition system, computers, and other equipment. The array is equipped with an infra-red camera and a visible wavelength camera for imaging the launch site. The beamformed noise maps will be superimposed on the video footages collected by the cameras for correct identification of the noise sources. The array is tested with very loud noise sources to determine the beamforming ability. Multiple mathematical models, such as the conventional beamforming, functional beamforming, spectral element method etc. are used to determine the minimum spatial resolution of the sound sources that can be measured at different frequencies. Additionally, the array hardware is being tested for different environmental conditions and electro-magnetic compliance. The immediate goal is to use the array for NASA’s Artemis/SLS vehicle that will be launched from a newly built Mobile Launch platform and a modified launch pad.

microphone phased-array↗
NASA NTRSDate not supplied

A Microphone Phased Array for Launch Acoustics Application

A new, portable, phased array of microphones is built at NASA Ames Research Center specifically for the harsh environment encountered in launch pads of rocket vehicles. It uses 70 rugged, piezo-electric, dynamic pressure sensors optimally distributed on a 10.5ft diameter open frame dome structure. The open frame is light yet robust to sustain the high wind load of typical seaside launch pads, and the blast and acoustic loads from the launch. A 200-ft long cable bundle carries the microphone signals to a weather-protected electronic cabinet containing the data acquisition system, computers, and other equipment. The array is equipped with an infra-red camera and a visible wavelength camera for imaging the launch site. The beamformed noise maps will be superimposed on the video footages collected by the cameras for correct identification of the noise sources. The array is tested with very loud noise sources to determine the beamforming ability. Multiple mathematical models, such as the conventional beamforming, orthogonal-functional beamforming, spectral element method etc. are used to determine the minimum spatial resolution of the sound sources that can be measured at different frequencies. Additionally, the array hardware is being tested for different environmental conditions and electro-magnetic compliance. The goal is to use the array for NASA’s Artemis/SLS vehicle that will be launched from a newly built Mobile Launch platform and a modified launch pad. Data from a couple of validation tests will be presented in this paper. The first test involves an outdoor setup where the array was placed on a crane at several different heights and distances from a pair of very loud noise sources. The second test from the static firing of the RS25 engines in an outdoor test stand.

Acoustics↗
NASA NTRSDate not supplied

A Microphone Phased Array for Launch Acoustics Application

A new, portable, phased array of microphones is built at NASA Ames Research Center specifically for the harsh environment encountered in launch pads of rocket vehicles. It uses 70 piezoresistive, dynamic pressure sensors, optimally distributed on a 10.5ft diameter open frame dome structure. The open frame is light yet robust to sustain the high wind load of typical seaside launch pads, and the blast and acoustic loads from the launch. A 200-ft long cable bundle carries the microphone signals to a weather-protected cabinet containing the data systems, and allows for the placement of the array tall structures. The array is equipped with an infra-red camera and a visible wavelength camera for imaging the launch pad. The beamformed noise maps will be superimposed on the video footages collected by the cameras for correct identification of the noise sources. The array is tested with very loud speaker sources to determine the beamforming ability using different schemes, such as the conventional beamforming, orthogonal-functional beamforming, and spectral element methods. A comparative study was conducted to determine the minimum attainable spatial resolution. Data from a validation test in an outdoor setup, where the array was placed on a Telehandler at several different heights and distances from either a single or a pair of speakers, is presented in this paper. The final goal is to use the array during NASA’s Artemis-II launch to determine the distribution of noise sources on the Mobile Launcher.

Acoustics↗
NASA NTRS2019

Active Array Measurements using the Portable Laser Guided Robotic Metrology System

In this paper, we will discuss the impact of mounting structures on the installed performance of phased arrays. In particular, performance data for the Conformal, Lightweight Antennas for Aeronautical Communications Technology (CLAS-ACT) antenna will be presented. Performance data from a series of mounting configurations will show that null depth and location is particularly susceptible while the main beam steering angle remain relatively stable. In addition, the Portable Laser Guided Robotic antenna range (PLGR) will be discussed as a suitable instrument for measuring antenna patterns in complex or difficult locations that are challenging for traditional ranges. The PLGR antenna range was recently developed at the National Aeronautics and Space Administration's (NASA) Glenn Research Center (GRC) and deployed to measure in situ antenna patterns.

Piasecki, Marie↗
NASA NTRS2019

Active Array Measurements using the Portable Laser Guided Robotic Metrology System

In this paper, we will discuss the impact of mounting structures on the installed performance of phased arrays. In particular, performance data for the Conformal, Lightweight Antennas for Aeronautical Communications Technology (CLAS-ACT) antenna will be presented. Performance data from a series of mounting configurations will show that null depth and location is particularly susceptible to change while the main beam steering angle remains relatively stable. In addition, the Portable Laser Guided Robotic Metrology (PLGRM) system will be discussed as a suitable instrument for measuring antenna patterns in complex or difficult locations that are challenging for traditional ranges. The PLGRM system was recently developed at the National Aeronautics and Space Administration's (NASA) Glenn Research Center (GRC) and deployed to measure in situ antenna patterns.

Piasecki, Marie↗
NASA NTRSDate not supplied

Development of a Multi-Gas Microsensor Array for the Exploration Portable Life Support System

The Portable Life Support System (PLSS) of the Exploration Extravehicular Mobility Unit (xEMU) requires sensors capable of measuring the major constituents of the gas stream. These major constituents include oxygen, carbon dioxide, and water vapor. The sensors must operate across a wide range of flow and pressure conditions and introduce very low pressure drop in the ventilation loop. The sensors must operate with low power and occupy a small volume. This paper reports the development of a compact, low power, multi-parameter astronaut life support sensor (M-PALSS). M-PALSS consists of an array of low-power chemical microsensors for oxygen, carbon dioxide, water vapor, and pressure. M-PALSS includes custom electronics to control the sensors and is packaged in a custom housing that meets the volume and shape requirements for service in the PLSS.

James Makel↗
NASA NTRSDate not supplied

Development of a Multi-Gas Microsensor Array for the Exploration Portable Life Support System

The Portable Life Support System (PLSS) of the Exploration Extravehicular Mobility Unit (xEMU) requires sensors capable of measuring the major constituents of the gas stream. These major constituents include oxygen, carbon dioxide, and water vapor. The sensors must operate across a wide range of flow and pressure conditions and introduce very low pressure drop in the ventilation loop. The sensors must operate with low power and occupy a small volume. This paper reports the development of a compact, low power, multi-parameter astronaut life support sensor (M-PALSS). M-PALSS consists of an array of low-power chemical microsensors for oxygen, carbon dioxide, water vapor, and pressure. M-PALSS includes custom electronics to control the sensors and is packaged in a custom housing that meets the volume and shape requirements for service in the PLSS.

James Makel↗
NASA NTRSDate not supplied

Development of a Multi-Gas Microsensor Array for the Exploration Portable Life Support System

The Portable Life Support System (PLSS) of the Exploration Extravehicular Mobility Unit (xEMU) requires sensors capable of measuring the major constituents of the gas stream. These major constituents include oxygen, carbon dioxide, and water vapor. The sensors must operate across a wide range of flow and pressure conditions and introduce very low pressure drop in the ventilation loop. The sensors must operate with low power and occupy a small volume. This paper reports the development of a compact, low power, multi-parameter astronaut life support sensor (M-PALSS). M-PALSS consists of an array of low-power chemical microsensors for oxygen, carbon dioxide, water vapor, and pressure. M-PALSS includes custom electronics to control the sensors and is packaged in a custom housing that meets the volume and shape requirements for service in the PLSS.

James Makel↗
NASA NTRS2000

The Prediction and Observation of the 1997 July 18 Stellar Occultation by Triton: More Evidence for Distortion and Increasing Pressure in Triton's Atmosphere

We used CCD (charge coupled device) astrometric data to predict where the occultation path of the star Tr 176 was located, on July 18, 1997. It could be seen from northern Australia and the southern section of North America. We set up an array of portable and mixed telescopes which had high-speed photometric equipment to observe the occultation. Goals included the following: (1) mapping the central flash; (2) obtaining light curves for the signal-to-noise ratio; (3) acquiring light curves from Triton's disk. We combined these with data from others to find the radius and geometry of the half-light surface of the atmosphere, as well as the equivalent-isothermal temperature latitudes below the occultation on Triton.

Elliot, J. L.↗
NASA NTRS2016

Mechanical Prototyping and Manufacturing Internship

The internship was located at the Johnson Space Center (JSC) Innovation Design Center (IDC), which is a facility where the JSC workforce can meet and conduct hands-on innovative design, fabrication, evaluation, and testing of ideas and concepts relevant to NASA's mission. The tasks of the internship included mechanical prototyping design and manufacturing projects in service of research and development as well as assisting the users of the IDC in completing their manufacturing projects. The first project was to manufacture hatch mechanisms for a team in the Systems Engineering and Project Advancement Program (SETMAP) hexacopter competition. These mechanisms were intended to improve the performance of the servomotors and offer an access point that would also seal to prevent cross-contamination. I also assisted other teams as they were constructing and modifying their hexacopters. The success of this competition demonstrated a proof of concept for aerial reconnaissance and sample return to be potentially used in future NASA missions. I also worked with Dr. Kumar Krishen to prototype an improved thermos and a novel, portable solar array. Computer-aided design (CAD) software was used to model the parts for both of these projects. Then, 3D printing as well as conventional techniques were used to produce the parts. These prototypes were then subjected to trials to determine the success of the designs. The solar array is intended to work in a cluster that is easy to set up and take down and doesn't require powered servomechanisms. It could be used terrestrially in areas not serviced by power grids. Both projects improve planetary exploration capabilities to future astronauts. Other projects included manufacturing custom rail brackets for EG-2, assisting engineers working on underwater instrument and tool cases for the NEEMO project, and helping to create mock-up parts for Space Center Houston. The use of the IDC enabled efficient completion of these projects at significantly reduced cost. I acquired and improved manufacturing and prototyping skills during my tour including learning about a CAD (Computer-Aided Design) program called Creo (Creo Parametric; design software), gaining valuable conventional machining experience with lathes, CNC (Computer Numerical Control) milling machines and various other tools, and improving my engineering project communication and collaboration skills. The internship also allowed me to better understand operations at NASA. I plan to work in the aerospace industry or do academic research benefitting space science and exploration, and this internship experience will enable me to have insight into manufacturing processes for research and development.

Grenfell, Peter↗
NASA NTRS2007

First Results from the Washington D.C. Metropolitan Area Lighting Map Demonstration Project

An experimental portable lightning mapping array (LMA) operating in the upper VHF TV band (Channels 7-13; 174-216 MHz) was deployed in the Washington DC Metropolitan area during the summer 2006 to locate and monitor the overall lightning activity. The LMA network provides total lightning data to support lightning research as well as proxy data to benefit the development of applications for planned observing systems such as the GOES-R Geostationary Lightning Mapper. The portable LMA hardware is a compactly-housed, easily deployed version of the LMA stations installed North Alabama, Oklahoma, and New Mexico, which operate in the lower VHF TV band (Channels 2-6,54-88 MHz). Real-time LMA data products are provided to the National Weather Service Weather Forecast Office (WFO) in Sterling, VA to aid in their forecast and warning operations. Forecasters at WFO Sterling have already found the lightning data from the Washington DC demonstration network to be very useful in assessing the development of storm systems. On July 4,2006, data from the LMA aided forecasters as they monitored an area of convection that later developed into a line of severe storms that moved southward through the Washington DC metropolitan area across the Washington Mall. Additional applications of lightning mapping data in the Baltimore-Washington DC urban environment will be discussed.

Goodman, Steven J.↗
NASA NTRS2001

Cyrano "Nose" The Smell of Success

Cyrano Sciences, Inc. has commercialized a simple, accurate, non- invasive tool that enables "machines to smell". The Cyranose 320 is used for quality control purposes in the food and chemical industries. Using a sensor array and onboard pattern recognition algorithms, the lightweight, portable device works by exposing an array of polymer composite sensors to the chemical components in a vapor. When the sensors come in contact with the vapor, the polymer expands like a sponge, changing the resistance of the composites. The change in resistance is measured, and from that measurement, the presence of a pre-trained substance is determined with a quick and accurate diagnosis. This real-time, portable device enables food companies to spot test raw materials for batch-to-batch consistency, spoilage, or contamination. The Cyranose 320 is also used by chemical and petrochemical companies for quick assessment of the chemical status associated with various industrial processes. Profiling a chemical environment in a hazardous materials situation allows emergency crews to accurately select fire retardants, containment strategies, and protective gear. Future applications for the Cyranose 320 are fast growing and other uses of this technology are on the horizon.

Source record↗
NASA NTRS2003

Semiselective Optoelectronic Sensors for Monitoring Microbes

Sensor systems are under development for use in real-time detection and quantitation of microbes in water without need for sampling. These systems include arrays of optical sensors; miniature, portable electronic data-acquisition circuits; and optoelectronic interfaces between the sensor arrays and data-acquisition circuits. These systems are intended for original use in long-term, inline monitoring of waterborne micro-organisms in water-reclamation systems aboard future spacecraft. They could also be adapted to similar terrestrial uses with respect to municipal water supplies, stored drinking water, and swimming water; for detecting low-level biological contamination in biotechnological, semiconductor, and pharmaceutical process streams; and in verifying the safety of foods and beverages. In addition, they could be adapted to monitoring of airborne microbes and of surfaces (e.g., to detect and/or quantitate biofilms). The designs of the sensors in these systems are based partly on those of sensors developed previously for monitoring airborne biological materials. The designs exploit molecular- recognition and fluorescence-spectroscopy techniques, such that in the presence of micro-organisms of interest, fluorescence signals change and the changes can be measured. These systems are characterized as semiselective because they respond to classes of micro-organisms and can be used to discriminate among the classes. This semiselectivity is a major aspect of the design: It is important to distinguish between (1) the principle of detection and quantitation of classes of micro-organisms by use of these sensors and (2) the principle of detection and quantitation of individual microbiological species by means of prior immuno-diagnostic and/or molecular-biology techniques. Detection of classes (in contradistinction to species) is particularly valuable when the exact nature of a contaminant is unknown.

Tabacco, Mary Beth↗
NASA NTRS1993

Specular scattering on a terrestrial playa and implications for planetary surface studies

Multiangle Advanced Solid State Array Spectroradiometer (ASAS) and Portable Apparatus for Rapid Acquisition of Bidirectional Observations of Land and Atmosphere (PARABOLA) visible and near infrared reflectance data covering the Lunar Lake playa, Nevada, were modeled using specular and volume scattering theory. The volume component used to model the data was based on the Hapke (1986) model and the specular scattering component was based on Fresnel reflection from surface facets with a distribution of tilts. Specular scattering was needed to explain the several-fold increase in reflectance observed at high phase angles in the solar principal plane. Results imply single scattering albedos of approximately 0.93 to 0.95, a real index of refraction value of approximately 1.52 (at a wavelength of 0.66 micron), a small imaginary index of refraction and an exponential facet tilt probability function for the playa. Electron micrographs showed th playa surface to consist of ensembles of smooth, micrometer-scale ellipsoidal particles on gently undulating topography at the millimeter to centimeter scale. The exponential probability function is consistent with this observation. Mars and the icy satellites are discussed as possible places to look for a significant specular scattering component.

Shepard, Michael K.↗
NASA NTRS1993

Preliminary results from the portable standard satellite laser ranging intercomparison with MOBLAS-7

Conventional Satellite Laser Ranging (SLR) instrumentation has been configured and successfully used to provide high-accuracy laboratory measurements on the LAGEOS-2 and TOPEX cube-corner arrays. The instrumentation, referred to as the Portable Standard, has also been used for field measurements of satellite ranges in tandem with MOBLAS-7. Preliminary results of the SLR measurements suggest that improved range accuracy can be achieved using this system. Results are discussed.

Selden, Michael↗
NASA NTRS1992

Portable Power And Digital-Communication Units

Conceptual network of electronic-equipment modules provides electrical power and digital radio communications at multiple sites not served by cables. System includes central communication unit and portable units powered by solar photovoltaic arrays. Useful to serve equipment that must be set up quickly at remote sites or buildings that cannot be modified to provide cable connections.

Levin, Richard R.↗