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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 73 records · Page 4
All sourcesNASA NTRSDOE OSTI
NASA NTRS2010

Stable Chlorine Isotope Study: Application to Early Solar System Materials

A significantly large mass fractionation between two stable chlorine isotopes is expected during planetary processes In addition, in view of the isotopic heterogeneity of other light elements, the chlorine isotopes can potentially be used as a tracer for the origins and evolutionary processes of early solar system materials. Due to analytical difficulties, however, current chlorine isotope studies on planetary materials are quite controversial among IRMS (gas source mass spectrometry) and/or TIMS (Thermal Ionization Mass Spectrometry) groups [i.e. 1-3]. Although a cross-calibration of IRMS and TIMS indicates that both techniques are sufficiently consistent with each other [4], some authors have claimed that the Cl-37/Cl-35 ratio of geological samples obtained by TIMS technique are, in general, misleadingly too high and variable compared to those of IRMS [3]. For example, almost no differences of Cl isotope composition were observed among mantle materials and carbonaceous meteorites by [3]. On the other hand, according to more recent IRMS work [2], significant Cl isotope variations are confirmed for mantle materials. Therefore, additional careful investigation of Cl isotope analyses are now required to confirm real chlorine isotope variations for planetary materials including carbonaceous chondrites [5]. A significantly large mass fractionation between two stable chlorine isotopes is expected during planetary processes In addition, in view of the isotopic heterogeneity of other light elements, the chlorine isotopes can potentially be used as a tracer for the origins and evolutionary processes of early solar system materials. Due to analytical difficulties, however, current chlorine isotope studies on planetary materials are quite controversial among IRMS (gas source mass spectrometry) and/or TIMS (Thermal Ionization Mass Spectrometry) groups [i.e. 1-3]. Although a cross-calibration of IRMS and TIMS indicates that both techniques are sufficiently consistent with each other [4], some authors have claimed that the 37Cl/35Cl ratio of geological samples obtained by TIMS technique are, in general, misleadingly too high and variable compared to those of IRMS [3]. For eample, almost no differences of Cl isotope composition were observed among mantle materials and carbonaceous meteorites by [3]. On the other hand, according to more recent IRMS work [2], significant Cl isotope variations are confirmed for mantle materials. Therefore, additional careful investigation of Cl isotope analyses are now required to confirm real chlorine isotope variations for planetary materials including carbonaceous chondrites [5]. In order to clarify the stable chlorine isotope features of early solar system materials, we have initiated development of the TIMS technique at NASA JSC applicable to analysis of small amounts of meteoritic and planetary materials. We report here the current status of chlorine isotope analysis at NASA JSC.

Mala,ira. M/↗
NASA NTRS2004

Transitsearch Workshop

The discovery of more than 100 planets around nearby solar-like stars that surpass Jupiter in size yet orbit their stars more quickly than Mercury has heralded a new era in astronomy. These enigmatic 'Hot-Jupiters' are large enough and close enough to their parent stars that their 'transits' can be captured by astronomers equipped with a small computer controlled telescope and a quality electronic CCD camera. The planet reveals its presence through the periodic decrease in brightness as it passes (or transits) in front of the star as seen from Earth. The first known transiting extrasolar planet HD 209458b, in the constellation Pegasus, has been the subject of hundreds of scientific papers since its discovery in 1999. The transit of 8th magnitude HD 209458 has been observed by at least a dozen non-professional astronomers using telescopes as small as 4 inches in aperture. Using equipment already in hand, and armed with target lists, transit time predictions, observing techniques and software procedures developed by astronomers at NASA's Ames Research Center and the University of California at Santa Cruz, non-professional astronomers can contribute significantly to the study of extrasolar planets by carefully measuring the brightness of stars with known Hot-Jupiters. In this way, we may resume (after a two century interruption!) the tradition of planetary discoveries by amateur astronomers begun with William Herschel's 1787 discovery of the 'solar' planet Uranus. In the few years transitsearch has been in existence, investigators Tim Castellano (NASA Ames) and Greg Laughlin (UCSC) have written articles for Sky and Telescope and Astronomy magazines, have been featured in stories by the Reuters News Service, Nature magazine, Science magazine, Space.com, the American Institute of Physics and others and received several hundred thousand total hits on their website www.transitsearch,org.

Castellano, T.↗
DOE OSTI2025

Dual Readout in Homogenous Inorganic Scintillators for Precision Calorimeters

Homogeneous inorganic scintillator-based calorimeters are the gold standard for electromagnetic energy resolution, but often degrade the hadronic energy resolution achievable at colliders. By incorporating the dual readout technique, we seek to improve the hadronic energy resolution of these calorimeters through the measurement and separation of the scintillation and Cherenkov light in hadronic showers. In April 2024, CalVision performed single-crystal tests using the electron test beam at DESY. Using a single delay line technique for waveform analysis, sufficient cerenkov light can be extracted to fully capitalize on the dual readout technique. This talk will present the results of PWO, BGO, BSO, PbF2, and two novel scintillating glasses.

Anderson, Thomas [Virginia U.]↗
NASA NTRS2002

The Discovery of Extrasolar Planets by Backyard Astronomers

The discovery since 1995 of more than 80 planets around nearby solar-like stars and the photometric measurement of a transit of the jovian mass planet orbiting the solar-like star HD 209458 (producing a more than 1% drop in brightness that lasts 3 hours) has heralded a new era in astronomy. It has now been demonstrated that small telescopes equipped with sensitive and stable electronic detectors can produce fundamental scientific discoveries regarding the frequency and nature of planets outside the solar system. The modest equipment requirements for the discovery of extrasolar planetary transits of jovian mass planets in short period orbits around solar-like stars are fulfilled by commercial small aperture telescopes and CCD (charge coupled device) imagers common among amateur astronomers. With equipment already in hand and armed with target lists, observing techniques and software procedures developed by scientists at NASA's Ames Research Center and the University of California at Santa Cruz, non-professional astronomers can contribute significantly to the discovery and study of planets around others stars. In this way, we may resume (after a two century interruption!) the tradition of planet discoveries by amateur astronomers begun with William Herschel's 1787 discovery of the 'solar' planet Uranus.

Castellano, Tim↗
NASA NTRS2004

Metrology system for the Terrestrial Planet Finder Coronagraph

The Terrestrial Planet Finder (TPF) employs an aggressive coronagraph designed to obtain better than 1e-10 contrast inside the third Airy ring. Minute changes in low-order aberration content scatter significant light at this position. One implication is the requirement to control low-order aberrations induced by motion of the secondary mirror relative to the primary mirror; sub-nanometer relative positional stability is required. We propose a 6-beam laser truss to monitor the relative positions of the two mirrors. The truss is based on laser metrology developed for the Space Interferometry Mission.

Terrestrial Planet Finder (TPF)↗
NASA NTRS2005

Northeast Regional Planetary Data Center

In 1980, the Northeast Planetary Data Center (NEPDC) was established with Tim Mutch as its Director. The Center was originally located in the Sciences Library due to space limitations but moved to the Lincoln Field Building in 1983 where it could serve the Planetary Group and outside visitors more effectively. In 1984 Dr. Peter Schultz moved to Brown University and became its Director after serving in a similar capacity at the Lunar and Planetary Institute since 1976. Debbie Glavin has served as the Data Center Coordinator since 1982. Initially the NEPDC was build around Tim Mutch's research collection of Lunar Orbiter and Mariner 9 images with only partial sets of Apollo and Viking materials. Its collection was broadened and deepened as the Director (PHS) searched for materials to fill in gaps. Two important acquisitions included the transfer of a Viking collection from a previous PI in Tucson and the donation of surplused lunar materials (Apollo) from the USGS/Menlo Park prior to its building being torn down. Later additions included the pipeline of distributed materials such as the Viking photomosaic series and certain Magellan products. Not all materials sent to Brown, however, found their way to the Data Center, e.g., Voyager prints and negatives. In addition to the NEPDC, the planetary research collection is separately maintained in conjunction with past and ongoing mission activities. These materials (e.g., Viking, Magellan, Galileo, MGS mission products) are housed elsewhere and maintained independently from the NEPDC. They are unavailable to other researchers, educators, and general public. Consequently, the NEPDC represents the only generally accessible reference collection for use by researchers, students, faculty, educators, and general public in the Northeast corridor.

Schultz, Peter H.↗
NASA NTRS2016

Design and Experimental Evaluation of Flextensional-Cantilever Based Piezoelectric Transducers for Flow Energy Harvesting

Cantilever type piezoelectric harvesters, such as bimorphs, are typically used for vibration induced energy harvesting. However, a major drawback of a piezoelectric bimorph is its brittle nature in harsh environments, resulting in short life-times as well as output power degradation. The emphasis in this work is to design robust, highly efficient piezoelectric harvesters that are capable of generating electrical power in the milliwatt range. Various harvesters have been modeled, designed and prototyped, and the flextensional actuator based harvester, where the metal cantilever is mounted and coupled between two flextensional actuators, was found to be a viable alternative to the cantilever type piezoelectric harvesters. Preliminary tests showed that these devices equipped with 5x5x36 mm two piezoelectric PZT stacks can produce greater than 50 mW of power under air flow induced vibrations.

fluid structure interaction↗
NASA NTRS1993

Repeater For A Digital-Communication Bus

Digital repeater circuit designed to extend range of communication on MIL-STD-1553 bus beyond original maximum allowable length of 300 ft. Circuit provides two-way communication, one way at time, and conforms to specifications of MIL-STD-1553. Crosstalk and instability eliminated.

Torres-Guzman, Esteban↗
NASA NTRS1991

A space transfer vehicle for lunar missions

Two 'low profile' strategies for supporting the lunar outpost concept developed by NASA-JSC Planetary Surface Systems are examined. The first strategy involves the design of missions that require only a single launch of a derivative 'National Launch System' (NLS) vehicle. The launch capacity of the derivatives range from 80 to 140 percent of the Apollo/Saturn capacity and use only conventional cryogenic or stable chemical propulsion. The second strategy involves the design of missions that only require the currently planned NASA NLS vehicle to be built. This strategy uses either one or two launches with an earth and/or lunar orbit rendezvous for stage assembly. Advance propulsion concepts, in addition to cryogenics, for the translunar injection stage are addressed.

Andrews, Dana↗
NASA NTRS2004

JWST ISIM Primary Structure and Kinematic Mount Configuration

In this presentation we will review the evolution of the ISIM primary structure tube topology and kinematic mount configuration to the current baseline concept. We will also show optimization procedures used and challenges resulting from complex joints under launch loads. Two additional key ISIM structure challenges of meeting thermal distortion and stability requirements and metal-composite bonded joint survivability at cryogenic temperatures are covered in other presentations.

Bartoszyk, Andrew↗
NASA NTRS2003

Long Term Performance Retention Test Using High Power COTS NiCd and NiMH Cells

This slide presentation reviews the tests and results for performance retention of high powered commercial off the shelf (COTS) NiCd, and NiMH cells. Electromechanical actuators for space flight requires short duration high power batteries. The concern is that NiCd battery designs demonstrate an unfavorable power degradation after long periods of inactivity. Cycling can recover some of the decay, but this reduces the readiness that these batteries must have. Two 5-cell SubC stick test batteries ere chosen using NiCd and NiMH were tested and then the differences for charge maintenance were compared.

Hall, Dan↗
NASA NTRSDate not supplied

TPSAS-NF1676L-27431-DND

The Protocol Actions for Astronaut Dose Calculations were developed to provide participating agencies an opportunity to compare results best on their best practices. The results presented here were calculated using the HZETRN space radiation transport code and human response models developed for the On-Line Tool for the Assessment of Radiation in Space (OLTARIS). Two sets of results are presented: - The first set, labelled TARIS 4.0, were calculated using the latest version of the space radiation analysis tools developed for OLTARIS, but not yet incorporated into OLTARIS. - The second set, labelled OLTARIS (TARIS version 3.5), were calculated with the current version of OLTARIS and TIM participants should be able to reproduce these results.

Martha Clowdsley↗
NASA NTRS2011

Multi-Wavelength, Multi-Beam, and Polarization-Sensitive Laser Transmitter for Surface Mapping

A multi-beam, multi-color, polarized laser transmitter has been developed for mapping applications. It uses commercial off-the-shelf components for a lowcost approach for a ruggedized laser suitable for field deployment. The laser transmitter design is capable of delivering dual wavelengths, multiple beams on each wavelength with equal (or variable) intensities per beam, and a welldefined state of polarization. This laser transmitter has been flown on several airborne campaigns for the Slope Imaging Multi-Polarization Photon Counting Lidar (SIMPL) instrument, and at the time of this reporting is at a technology readiness level of between 5 and 6. The laser is a 1,064-nm microchip high-repetition-rate laser emitting energy of about 8 microjoules per pulse. The beam was frequency-doubled to 532 nm using a KTP (KTiOPO4) nonlinear crystal [other nonlinear crystals such as LBO (LiB3O5) or periodically poled lithium niobiate can be used as well, depending on the conversion efficiency requirements], and the conversion efficiency was approximately 30 percent. The KTP was under temperature control using a thermoelectric cooler and a feedback monitoring thermistor. The dual-wavelength beams were then spectrally separated and each color went through its own optical path, which consisted of a beam-shaping lens, quarterwave plate (QWP), and a birefringent crystal (in this case, a calcite crystal, but others such as vanadate can be used). The QWP and calcite crystal set was used to convert the laser beams from a linearly polarized state to circularly polarized light, which when injected into a calcite crystal, will spatially separate the circularly polarized light into the two linear polarized components. The spatial separation of the two linearly polarized components is determined by the length of the crystal. A second set of QWP and calcite then further separated the two beams into four. Additional sets of QWP and calcite can be used to further split the beams into multiple orders of two. The spatially separated beams had alternating linearly polarization states; a half-wave plate (HWP) array was then made to rotate the alternating states of A multi-beam, multi-color, polarized laser transmitter has been developed for mapping applications. It uses commercial off-the-shelf components for a lowcost approach for a ruggedized laser suitable for field deployment. The laser transmitter design is capable of delivering dual wavelengths, multiple beams on each wavelength with equal (or variable) intensities per beam, and a welldefined state of polarization. This laser transmitter has been flown on several airborne campaigns for the Slope Imaging Multi-Polarization Photon Counting Lidar (SIMPL) instrument, and at the time of this reporting is at a technology readiness level of between 5 and 6. The laser is a 1,064-nm microchip high-repetition-rate laser emitting energy of about 8 microjoules per pulse. The beam was frequency-doubled to 532 nm using a KTP (KTiOPO4) nonlinear crystal [other nonlinear crystals such as LBO (LiB3O5) or periodically poled lithium niobiate can be used as well, depending on the conversion efficiency requirements], and the conversion efficiency was approximately 30 percent. The KTP was under temperature control using a thermoelectric cooler and a feedback monitoring thermistor. The dual-wavelength beams were then spectrally separated and each color went through its own optical path, which consisted of a beam-shaping lens, quarterwave plate (QWP), and a birefringent crystal (in this case, a calcite crystal, but others such as vanadate can be used). The QWP and calcite crystal set was used to convert the laser beams from a linearly polarized state to circularly polarized light, which when injected into a calcite crystal, will spatially separate the circularly polarized light into the two linear polarized components. The spatial separation of the two linearly polarized components is determined by the length of the crystal. A cond set of QWP and calcite then further separated the two beams into four. Additional sets of QWP and calcite can be used to further split the beams into multiple orders of two. The spatially separated beams had alternating linearly polarization states; a half-wave plate (HWP) array was then made to rotate the alternating states of

Yu, Anthony W.↗
NASA NTRS2015

Thermal Interface Materials Selection and Application Guidelines: In Perspective of Xilinx Virtex-5QV Thermal Management

The heat from high-power microdevices for space, such as Xilinx Virtex 4 and 5 (V4 and V5), has to be removed mainly through conduction in the space vacuum environment. The class-Y type packages are designed to remove the heat from the top of the package, and the most effective method to remove heat from the class-Y type packages is to attach a heat transfer device on the lid of the package and to transfer the heat to frame or chassis. When a heat transfer device is attached to the package lid, the surfaces roughness of the package lid and the heat transfer device reduces the effective contact area between the two. The reduced contact area results in increased thermal contact resistance, and a thermal interface material is required to reduce the thermal contact resistance by filling in the gap between the surfaces of the package lid and the heat transfer device. The current report describes JPL's FY14 NEPP task study on property requirements of TIM and impact of TIM properties on the packaging reliability. The current task also developed appratuses to investigate the performances of TIMs in the actual mission environment.

Suh, Jong-ook↗
NASA NTRS2004

Project Golden Gate: towards real-time Java in space missions

This paper describes the problem domain and our experimentation with the first commercial implementation of the Real Time Specification for Java. The two main issues explored in this report are: (1) the effect of RTSJ's non-heap memory on the programming model, and (2) performance benchmarking of RTSJ/Linux relative to C++/VxWorks.

lander↗
NASA NTRS2015

A Sinuous Tumulus over an Active Lava Tube at Klauea Volcano: Evolution, Analogs, and Hazard Forecasts

Inflation of narrow tube-fed basaltic lava flows (tens of meters across), such as those confined by topography, can be focused predominantly along the roof of a lava tube. This can lead to the development of an unusually long tumulus, its shape matching the sinuosity of the underlying lava tube. Such a situation occurred during Klauea Volcanos (Hawaii, USA) ongoing East Rift Zone eruption on a lava tube active from July through November 2010. Short-lived breakouts from the tube buried the flanks of the sinuous, ridge-like tumulus, while the tumulus crest, its surface composed of lava formed very early in the flows emplacement history, remained poised above the surrounding younger flows. At least several of these breakouts resulted in irrecoverable uplift of the tube roof. Confined sections of the prehistoric Carrizozo and McCartys flows (New Mexico, USA) display similar sinuous, ridge-like features with comparable surface age relationships. We contend that these distinct features formed in a fashion equivalent to that of the sinuous tumulus that formed at Kīlauea in 2010. Moreover, these sinuous tumuli may be analogs for some sinuous ridges evident in orbital images of the Tharsis volcanic province on Mars. The short-lived breakouts from the sinuous tumulus at Kīlauea were caused by surges in discharge through the lava tube, in response to cycles of deflation and inflation (DI events) at Kīlauea's summit. The correlation between DI events and subsequent breakouts aided in lava flow forecasting. Breakouts from the sinuous tumulus advanced repeatedly toward the sparsely populated Kalapana Gardens subdivision, destroying two homes and threatening others. Hazard assessments, including flow occurrence and advance forecasts, were relayed regularly to the Hawaiʻi County Civil Defense to aid their lava flow hazard mitigation efforts while this lava tube was active.

volcanic hazards↗
NASA NTRSDate not supplied

Electrical Discharge Machining of Additively Manufactured Superalloys Containing Oxide Dispersions

Superalloys can be strengthened by oxide dispersions to potentially improve their mechanical properties at high temperatures. Additive manufacturing has opened new paths for introducing oxide particles into superalloys with increased processing flexibility, to potentially provide oxide dispersion strengthening. Numerically controlled electrical discharge machining (EDM) has often been used as a machining process for initial sectioning, detailed roughing, and even finishing operations of conventional superalloys. The objective of this study was to examine how additively manufactured superalloys containing oxide dispersions respond when sectioned using EDM. Consistent sections of several superalloys, two containing an oxide dispersion, were sliced using a typical EDM machine with standard brass wire and a typical roughing condition set. Roughness, microstructure, and residual stress at the EDM surfaces were compared for the varied superalloys.

superalloys↗