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Technical Paper

The Applicability of Past Innovative Concepts to the Technology for New Extremely Large Space Antenna/Telescope Structures

2006-07-17
2006-01-2063
Early development of concepts for space structures up to 1000 meters in size was initiated in the early 1960's and carried through the 1970's. The enabling technologies were self-deployables, on-orbit assembly, and on-orbit manufacturing. Because of the lack of interest due to the astronomical cost associated with advancing the on-orbit assembly and manufacturing technologies, only self-deployable concepts were subsequently pursued. However, for over 50 years, potential users of deployable antennas for radar, radiometers, planar arrays, VLBF and others, are still interested and constantly revising the requirements for larger and higher precision structures. This trend persists today. An excellent example of this trend is the current DARPA/SPO ISAT Program that applies self-deployable structures technology to a 300 meter long active planar array radar antenna. This ongoing program has created a rare opportunity for innovative advancement of state-of-the-art concepts.
Technical Paper

HELS Based Acoustic Holographic Measurements to Evaluate Structure-Borne Noise

2007-05-15
2007-01-2281
General Motors (GM) recently purchased an acoustic holography system based on the Helmholtz Equation Least Squares (HELS) methodology. Typically acoustic holography has utilized planar transformation of the Fourier acoustic equations. General Motors conducted a variety of experiments on a simple well understood structure. This enabled us to understand the setup parameters and confirm the manufacturer's claims for accuracy. Measurements on the structure were taken using the HELS based equipment and a laser vibrometer. Conclusions are drawn on how to set up the equipment for future testing on vehicles.
Technical Paper

Development of the Surface Thermal Environment for the Mars Scout Phoenix Mission

2007-07-09
2007-01-3239
Phoenix is NASA's first Mars Scouts Mission that will place a soft-lander on the Martian surface at a high northern latitude. Much of the Mars surface environmental flight data from landed missions pertains to the near-equatorial regions. However, orbital observations have yielded very useful data about the surface environment. These data along with a simple, but highly effective one-dimensional atmospheric model was used to develop the Phoenix surface thermal environment. As candidate landing sites were identified, parametric studies including statistical variations were conducted to prescribe minimum nighttime and maximum daytime temperature design Sols (a Martian day). Atmospheric effects such as clouds and ice were considered. Finally, recent candidate landing site imaging conducted by the Mars Reconnaissance Orbiter revealed that the prime site contained a much higher rock density than first thought.
Technical Paper

Fabrication of laterally coupled InGaAsSb-GaSb-AlGaAsSb DFB laser structures

2000-07-10
2000-01-2305
The development of tunable diode laser systems in the 2 - 5 μm spectral region will have numerous applications for trace gas detection. To date, the development of such systems has been hampered by the difficulties of epitaxial growth, and device processing in the case of the Sb-based materials system. One of the compounding factors in this materials system is the use of aluminum containing compounds in the laser diode cladding layers. This makes the regrowth steps used in traditional lasers very difficult. As an alternative approach we are developing laterally coupled antimonide based lasers structures that do not require the regrowth steps. In this paper, the materials growth, device processing and development of the necessary drive electronics for an antimony based tunable diode laser system are discussed.
Technical Paper

Experimental Characterization of the Unsteady Flow Field behind Two outside Rear View Mirrors

2008-04-14
2008-01-0476
The unsteady flow fields behind two different automobile outside side rear view mirrors were examined experimentally in order to obtain a comprehensive data base for the validation of the ongoing computational investigation effort to predict the aero-acoustic noise due to the outside rear view mirrors. This study is part of a larger scheme to predict the aero-acoustic noise due to various external components in vehicles. To aid with the characterization of this complex flow field, mean and unsteady surface pressure measurements were undertaken in the wake of two mirror models. Velocity measurements with particle image velocimetry were also conducted to develop the mean velocity field of the wake. Two full-scale mirror models with distinctive geometrical features were investigated.
Technical Paper

Thermal Vacuum Testing of the Moon Mineralogy Mapper Instrument

2008-06-29
2008-01-2037
The Moon Mineralogy Mapper (M3) instrument is scheduled for launch in 2008 onboard the Indian Chandrayaan-1 spacecraft. The mission is managed by the Indian Space Research Organization (ISRO) in Bangalore, India and is India's first flight to the Moon. M3 is being developed for NASA by the Jet Propulsion Laboratory under the Discovery Program Office managed by Marshall Space Flight Center. M3 is a state-of-the-art instrument designed to fulfill science and exploratory objectives. Its primary science objective is to characterize and map the lunar surface composition to better understand its geologic evolution. M3's primary exploration goal is to assess and map the Moon mineral resources at high spatial resolution to support future targeted missions. M3 is a cryogenic near infrared imaging spectrometer with spectral coverage of 0.4 to 3.0 μm at 10 nm resolution with high signal to noise ratio, spatial and spectral uniformity.
Technical Paper

Characterization of Methanol and Ethanol Sprays from Different DI Injectors by Using Mie-scattering and Laser Induced Fluorescence at Potential Engine Cold-start Conditions

2010-04-12
2010-01-0602
A laser sheet imaging system with Mie-scattering and Laser Induced Fluorescence (LIF) was used to investigate the spray characteristics of gasoline, methanol and ethanol fuels. A range of conditions found in today's gasoline engines were investigated including that observed during engine cold-start. Both a swirl injector and a multi-hole fuel injector were examined for each of the three fuels. A combination of the second harmonic (532 nm) and the fourth harmonic (266 nm) was generated simultaneously using a Nd:YAG laser system to illuminate the spray. The Mie-scattering technique was used to characterize the liquid phase of the spray while the LIF technique was used to detect a combination of liquid and vapor phases. While gasoline naturally fluoresced, the dopant TEA was added to the methanol and ethanol fuels as a fuel tracer. The Mie-scattering and LIF signals were captured simultaneously using a CCD camera along with an image doubler.
Technical Paper

On-Orbit Performance of the TES Loop Heat Pipe Heat Rejection System

2008-06-29
2008-01-2000
Launched on NASA's Aura spacecraft on July 15, 2004, JPL's Tropospheric Emission Spectrometer (TES) has been operating successfully for over three years in space. TES is an infrared high resolution, imaging fourier transform spectrometer with spectral coverage of 3.3 to 15.4 μm to measure and profile essentially all infrared-active molecules present in the Earth's lower atmosphere. It measures the three-dimensional distribution of ozone and its precursors in the lower atmosphere on a global scale. The Aura spacecraft was successfully placed in a sun-synchronous near-circular polar orbit with a mean altitude of 705 km and 98.9 minute orbit period. The observatory is designed for a nominal 5 year mission lifetime. The instrument thermal design features include four temperature zones needed for efficient cryogenic staging to provide cooling at 65 K, 180 K, 230 K and 300 K.
Technical Paper

Mid-IR Semiconductor Lasers for Chemical Sensing

2003-07-07
2003-01-2551
The development of mid-IR semiconductor diode lasers based on type-II interband cascade structures is presented. How these diode lasers can be developed to meet the requirements in chemical sensing applications is discussed.
Technical Paper

A Study on the Camshaft Lobe Microstructure Obtained by Different Processing

2012-10-02
2012-36-0499
The present work aims to characterize the microstructure of valvetrain camshaft lobes that are currently applied in the automotive industry, obtained by different processing routes. The cam lobe microstructure has been assessed by microscopy, whereas the mechanical properties by hardness profile measurements on the surface region. Microconstituents type and form, composing the final microstructure at the cam lobe work region, are defined by the casting route and/or post-heat treatment process other than alloy chemical composition, so that knowledge and control of processing route is vital to assure suitable valvetrain system assembly performance and durability. Most of the mechanical solicitations on the part occur at the interface between cam and follower; the actual contact area is significantly smaller than the apparent area. As a result, the microstructure at and near the surface performs a direct role on the performance of the valvetrain, cam lobe and its counterpart.
Journal Article

Tensile Deformation and Fracture of TRIP590 Steel from Digital Image Correlation

2010-04-12
2010-01-0444
Quasi-static tensile properties of TRIP590 steels from three different manufacturers were investigated using digital image correlation (DIC). The focus was on the post-uniform elongation behavior which can be very different for steels of the same grade owing to different manufacturing processes. Miniature tensile specimens, cut at 0°, 45°, and 90° relative to the rolling direction, were strained to failure in an instrumented tensile stage. True stress-true strain curves were computed from digital strain gages superimposed on digital images captured from one gage section surface during tensile deformation. Microstructural phases in undeformed and fracture specimens were identified with optical microscopy using the color tint etching process. Fracture surface analyses conducted with scanning electron microscopy and energy dispersive spectroscopy were used to investigate microvoids and inclusions in all materials.
Technical Paper

Extended Temperature Range Studies for Dry Heat Microbial Reduction

2005-07-11
2005-01-3096
Dry heat microbial reduction is an approved method to reduce the microbial bioburden on space-flight hardware prior to launch to meet flight project planetary protection requirements. Microbial bioburden reduction also occurs if a spacecraft enters a planetary atmosphere (e.g., Mars) and is heated by frictional forces. However, without further studies, administrative credit for this reduction cannot be applied. The killing of Bacillus subtilis var. niger spores has been examined and lethality data has been collected by placing spores in a vacuum oven or thermal spore exposure vessels (TSEV) in a constant temperature bath. Using this lethality data, a preliminary mathematical model is being developed that can be used to predict spore killing at different temperatures. This paper will present the lethality data that has been collected at this time and the planned future studies.
Technical Paper

Implications of the VBNC State of B. cepacia and S. maltophilia on Bioreduction and Microbial Monitoring of ISS Potable Waters

2005-07-11
2005-01-2933
Certain Eubacteria enter a viable but nonculturable (VBNC) state upon encountering unfavorable environmental conditions. VBNC cells do not divide on conventional media yet remain viable and in some cases retain virulence. Here, we describe the VBNC state of two opportunistic pathogens previously isolated from ISS potable waters, Burkholderia cepacia and Stenotrophomonas maltophilia. Artificially inoculated microcosms were exposed to the biocidal agents copper (CuSO4) and iodine (I2) in an attempt to induce nonculturablility. Viability was assessed via fluorescent microscopy (direct viable count assay coupled with BacLight™ staining) and metabolic activity was monitored by quantifying both intracellular ATP and transcribed rRNA (reverse transcriptase quantitative PCR). Culturablility was lost in both B. cepacia and S. maltophilia within two days of exposure to copper or high concentrations of iodine (6 or 8 ppm).
Technical Paper

Solar Proton Event Observations at Mars with MARIE

2003-07-07
2003-01-2329
The 2001 Mars Odyssey spacecraft Martian Radiation Environment Experiment (MARIE) is a solid-state silicon telescope high-energy particle detector designed to measure galactic cosmic radiation (GCR) and solar particle events (SPEs) in the 20 – 500 MeV/nucleon energy range. In this paper we discuss the instrument design and focus on the observations and measurements of SPEs at Mars. These are the first-ever SPE measurements at Mars. The measurements are compared with the geostationary GOES satellite SPE measurements. We also discuss some of the current interplanetary particle propagation and diffusion theories and models. The MARIE SPE measurements are compared with these existing models.
Journal Article

On-Orbit Performance of the Moon Mineralogy Mapper Instrument

2009-07-12
2009-01-2390
Launched on India's Chandrayaan-1 spacecraft on October 22, 2008, JPL's Moon Mineralogy Mapper (M3) instrument has successfully completed over six months of operation in space. M3 is one in a suite of eleven instruments, six of which are foreign payloads, flying onboard the Indian spacecraft. Chandrayaan-1, managed by the Indian Space Research Organization (ISRO) in Bangalore, is India's first deep space mission. Chandrayaan-1 was launched on the upgraded version of India's Polar Satellite Launch Vehicle (PSLV-XL) from the Satish Dhawan Space Centre, SHAR, Sriharikota, India. The primary science objective of the M3 instrument is the characterization and mapping of the lunar surface composition in the context of its geologic evolution. Its primary exploration goal is to assess and map the Moon mineral resources at high spatial resolution to support future targeted missions.
Journal Article

Thermal Design Trade Study for the Mars Science Laboratory ChemCam Body Unit

2009-07-12
2009-01-2462
The Mars Science Laboratory will be the next Martian mobility system that is scheduled to launch in the fall of 2011. The ChemCam Instrument is a part of the MSL science payload suite. It is innovative for planetary exploration in using a technique referred to as laser breakdown spectroscopy to determine the chemical composition of samples from distances of up to about 9 meters away. ChemCam is led by a team at the Los Alamos National Laboratory and the Centre d'Etude Spatiale des Rayonnements in Toulouse, France. The portion of ChemCam that is located inside the Rover, the ChemCam Body Unit contains the imaging charged-coupled device (CCD) detectors. Late in the design cycle, the ChemCam team explored alternate thermal design architectures to provide CCD operational overlap with the Rover's remote sensing instruments. This operational synergy is necessary to enable planning for subsequent laser firings and geological context.
Journal Article

On-Orbit Thermal Performance of the TES Instrument-Three Years in Space

2008-06-29
2008-01-2118
The Tropospheric Emission Spectrometer (TES), launched on NASA's Earth Observing System Aura spacecraft on July 15, 2004 has successfully completed over three years in space and has captured a number of important lessons. The instrument primary science objective is the investigation and quantification of global climate change. TES measures the three-dimensional distribution of ozone and its precursors in the lower atmosphere on a global scale. It is an infrared (IR) high resolution, imaging Fourier Transform Spectrometer (FTS) with a 3.3 to 15.4 μm spectral coverage required for space-based measurements to profile essentially all infrared-active molecules present in the Earth's lower atmosphere. The nominal on-orbit mission lifetime is 5 years. The Aura spacecraft flies in a sun-synchronous near-circular polar orbit with 1:38 pm ascending node.
Journal Article

Thermal Control System of the Moon Mineralogy Mapper Instrument

2008-06-29
2008-01-2119
The Moon Mineralogy Mapper (M3) instrument is one in a suite of twelve instruments which will fly onboard the Indian Chandrayaan-1 spacecraft scheduled for launch in 2008. Chandrayaan-1 is India's first mission to the Moon and is being managed by the Indian Space Research Organization (ISRO) in Bangalore, India. Chandrayaan-1 overall scientific objective is the photo-selenological and the chemical mapping of the Moon. The primary science objective of the M3 instrument is the characterization and mapping of the lunar surface composition in the context of its geologic evolution. Its primary exploration goal is to assess and map the Moon mineral resources at high spatial resolution to support future targeted missions. It is a “push-broom” near infrared (IR) imaging spectrometer with spectral coverage of 0.4 to 3.0 μm at 10 nm resolution with high signal to noise ratio, spatial and spectral uniformity.
Technical Paper

Thermal Design and On-Orbit Performance of the Multi-Angle Imaging SpectroRadiometer

2001-07-09
2001-01-2262
The Multi-angle Imaging SpectroRadiometer (MISR) instrument was launched aboard NASA’s Earth Observing System (EOS) Terra spacecraft on December 18, 1999. The overall mission design lifetime for the instrument is 6 years. The EOS Terra spacecraft was placed in a sun-synchronous near-circular polar orbit with an inclination of 98.3 degrees and a mean altitude of 705 km. The overall objective of MISR is to provide a means to study the ecology and climate of Earth through the acquisition of global multiangle imagery on the daylit side of Earth. MISR views the sunlit Earth simultaneously at nine widely spaced angles, collects global images with high spatial detail in four colors at every angle. The images acquired, once calibrated, provide accurate measurements of brightness, contrast and color of reflected sunlight.
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