Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “solid Earth”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 721 records · Page 40

Bombardment History of the Moon: What We Think We Know and What We Don't Know

The absolute impace history of the moon and inner solar system can in principle be derived from the statistics of radiometric ages of shock-heated planetary samples (lunar or meteoritic), from the formation ages of specific impact craters on the moon or Earth; and from agedating samples representing geologic surface units on the moon (or Mars) for which crater densities have been determined. This impact history, however, is still poorly defined. The heavily cratered surface of the moon is a testimony to the importance of impact events in the evolution of terrestrial planets and satellites. Lunar impacts range in scale from an early intense flux of large objects that defined the surface geology of the moon, down to recent, smaller impacts that continually generate and rework the lunar regolith. Densities of larger craters on lunar surface units of dated age define a projectile flux over time that serves as the basis for estimating surface ages on other solid bodies, particularly Mars. The lunar cratering history may address aspects of Earth s evolution, such as the possible role of early intense impacts on the atmosphere and early life and possible periodicity in large impact events in the more recent past. But, much about the lunar impact history remains unknown.. On Earth approximately 172 impact craters up to ~300 km in diameter and up to ~2 Gyr in age are recognized. Although these data suggest greater relative numbers of younger craters, possibly suggesting a recent increase in projectile flux, both the diameters and especially the ages of most terrestrial crates are so poorly known that the differential terrestrial impact flux over time is uncertain. For the moon, densities of craters on some mare surfaces and crater ejecta deposits, for which we have measured or estimated formation ages, suggest an approximately constant lunar impact rate of larger projectiles over the past ~3.5 Gyr. However, the data are cumulative in nature and limited. Questions exist as to how accurately dated samples correlate with surfaces having measured crater densities. Studies of ages of many tiny impact-melt beads from Apollos 12 and 14 soils show a decrease in the number of beads with age from ~4 Gyr ago to ~0.4 Gyr ago, followed by a significant increase in beads with age <0.4 Gyr (2). These authors concluded that the projectile flux had decreased over time, followed by a significant flux increase more recently.

Bogard, Donald↗

A possible mechanism for the capture of microparticles by the earth and other planets of the solar system

By application of Lyttleton's theory for the formation of comets, it is shown that a possible mechanism for the origin and formation of a concentration of cosmic particles around the earth and the other planets of the solar system exists. In the vicinity of the neutral point, where the velocity of colliding particles is not greater than 6 km/s, it is found that if the solid particles after collision must remain in a solid state, there can be no possibility of accretion for Mercury, Mars, and the Moon, where the maximum value of the distance of the center of the planet to the asymptotic trajectory is less than the radius of the planet. On the other hand, the capture radii of microparticles in solid form varies from a minimum of 2.95 planetary radii for Venus and 3.47 for the Earth, to about 986 for Jupiter.

Dibenedetto, F.↗

Growth Strategy of a Hybrid Yb3Rh4Sn13/LaRuSn3 Structure Type: Integrating Thermal Analysis, In Situ Diffraction, and Geometric Descriptors

Remeika phases form a versatile family of cage like intermetallics built from transition metal–centered trigonal prisms linked into three dimensional frameworks that generate two characteristic voids: a large [AX₁₂] cuboctahedral cage hosting the rare earth ion and an [XX′₁₂] icosahedral cage accommodating the tetrel atom. In this work, we present a tool driven approach for targeted solid state synthesis of Remeika phases, integrating differential scanning calorimetry, in situ neutron diffraction, and a geometric tolerance factor that quantifies rare earth size compatibility within these polyhedral cages. When combined with arc melting and metallic flux crystal growth, this framework enables prediction, verification, and isolation of specific Remeika phases. Applying this strategy, we obtain single crystals of the predicted pseudo-perovskite Fe based Remeika compound Yb0.9FeGe3.1. More broadly, this perspective highlights how coupling real time structural probes with simple geometric descriptors provides a general pathway for designing synthesis conditions and accessing potentially metastable structure types in complex intermetallic systems.

36 MATERIALS SCIENCE↗

Bacterial Biomining Rare Earth Elements in Abandoned Coal Mine Drainage: Solubilization and Sequestration

Bacteria can be used to biomine rare earth elements (REEs) domestically from abandoned coal-mine drainage (AMD) solids. Pennsylvania has ~11,000 abandoned mines, with ~500 AMD passive remediation systems that precipitate AMD REE rich solids onsite. In passive systems, REEs, co-precipitate with manganese (Mn), accumulating as solids that can produce a valuable leachate when resolubilized. REEs like lanthanum (La) are used in battery technology. Microbial metabolic changes that co-resolubilize Mn and REEs could result in an affordable release process that does not require chemical additives and the select sequestering of REEs like La allow for the selective purification from a mixed REE composition. Currently, the microbial mechanisms that contribute to mass REE resolubilization and selective sequestration are poorly understood. We have isolated bacteria (Bacillus mycoides JR07 and Bacillus pseudomycoides KB7) that solubilize Mn oxide, La oxide, and AMD solids by acidogenesis. We have determined that isolates JR07 and KB7 solubilize the La from AMD PRS solids by their production of organic acids. Preliminary results show methylotrophic bacterial isolate B3 can take up soluble La(III), giving an avenue to purification of La from a rich REE leachate. Determining the microbial metabolism and genes involved in the mass resolubilization of REEs and selective biomining of La(III) is crucial to optimize the biomining of AMD solids. Our work addresses the growing need to develop novel REE recovery methods from domestic sources.

microbiology↗

Microstructure and composition of InSb-GaSb ingots directionally solidified aboard Skylab

InSb-GaSb solid solution ingots prepared by directional solidification aboard Skylab and on earth consist of twins with (111) twin planes parallel to the direction of solidification and growth directions that lie along 211, 110, or 321 crystallographic directions. Significant fractions of several ingots prepared aboard Skylab were solidified from melts that were not in contact with container walls, resulting in convection driven by surface tension gradients in the melt and corresponding radially-symmetric composition variations in the ingot. In these regions, adjacent twins exhibit marked differences in indium content, indicating a substantial dependence of composition on crystallographic orientation.

Lefever, R. A.↗

The Cambridge photographic atlas of the planets

The origin of the solar systems is considered along with the formation of the planets, the evolution of the planets, the surfaces of solid planets, and the atmosphere of the planets. A description is provided of the various planets of the solar system. It is pointed out that Mercury was little known until March 1974 when the Mariner 10 spacecraft made the first of its three flybys of that body. In the case of Venus, the Pioneer mission to Venus by NASA in 1978 provided a breakthrough concerning a knowledge of the solid body hidden beneath the clouds. The characteristics of the planet earth are discussed together with information about the moon. A shaded relief map of Mars illustrates the geographic features of this planet. The map was produced with the aid of Mariner 9 photographs. Maps of the Jovian system based on photographs provided by space missions are also presented, and the Saturnian system is discussed, taking into account major satellites and rings of Saturn.

Briggs, G.↗

Coordinate systems

Jovian coordinate systems are different from those employed in the case of the earth. Latitude and longitude coordinates are usually established relative to some solid surface. Because Jupiter does not have a solid surface (at least none which is visible through the clouds), arbitrary, but convenient, coordinate grids have been prescribed. A spin equator is made out from observations of cloud motion, and the direction of the planetary spin axis is, therefore, determined with relatively good accuracy. The problem in establishing a Jupiter longitude system is that the mean rotation period of the clouds is a function of latitude. The solution selected was to define two separate longitude grids. A third longitude system became necessary with the detection of radio signals which gave evidence for a rotating planetary magnetic field. Attention is also given to orbital phase angle and longitude conventions for satellites, and two latitude systems for Jupiter

Dessler, A. J.↗

Planetary environments and the conditions of life

Geophysical models of the first 600 Ma ofthe earth's history following accretion and core formation point to a period of great environmental disequilibrium. In such an environment, the passage of energy from the earth's interior and from the sun through gas-liquid-solid domains and their boundaries with each other generated a dynamically interacting, complex hierarchy of self-organized structures ranging from bubbles at the sea-air interface to tectonic plates. The ability of a planet to produce such a hierarchy is speculated to be a prerequisite to the origin and sustenance of life. The application of this criterion to Mars argues against the origin of Martian life.

Chang, S.↗

Current trajectory options for a comet nucleus sample return mission

A summary of the current trajectory options available for the ESA comet nucleus sample return mission, Rosetta, is presented. These options include direct trajectories, delta-V-EGA trajectories using a Titan IV/Centaur launch vehicle with upgraded solid rocket motors, a trajectory involving a gravity assist of the earth (VEGA) prior to comet rendezvous, and one involving an additional gravity assist of the earth (VEEGA). Other propulsion options proposed and discussed are solar electric propulsion/ballistic trajectory modes and nuclear electric propulsion trajectory modes. Tables of performance data for each of these trajectory options are given.

Sauer, Carl G., Jr.↗

Characterization of surfaces

Low gravity biotechnology experiments indicate a need to better understand and control a host of liquid-solid interfacial phenomena which reduce the efficiency of bioseparations methods on earth as well as in space. We have improved and utilized polymeric and silane derivatives, developed in association with MSFC, in order to control such phenomena. The objectives of the proposed research have been obtained. They were to improve NASA-patented coatings capable of controlling macromolecular adsorption, electroosmosis, and particle electrophoresis over a wide range of pH, and to further characterize the ability of polymeric coatings to control wall wetting interactions. To date this research has resulted in six publications and four abstracts. It has also aided researchers at MSFC with studies on the electrophoresis of large DNA molecules in free solution. It will continue to enhance NASA's efforts to exploit the space environment to enhance knowledge of phenomena relevant to biotechnology, and obtain bioseparations currently unobtainable on Earth. Abstracts from the 1994 ACS Meeting in Birmingham are attached.

Vanalstine, James M.↗

Status of the Direct Data Distribution (D(exp 3)) Experiment

NASA Glenn Research Center's Direct Data Distribution (D3) project will demonstrate an advanced, high-performance communications system that transmits information from an advanced technology payload carried by a NASA spacecraft in low Earth orbit (LEO) to a small receiving terminal on Earth. The space-based communications package will utilize a solid-state, K-band phased-array antenna that electronically steers the radiated energy beam toward a low-cost, tracking ground terminal, thereby providing agile, vibration-free, electronic steering at reduced size and weight with increased reliability. The array-based link will also demonstrate new digital processing technology that will allow the transmission of substantially increased amounts of latency-tolerant data collected from the LEO spacecraft directly to NASA field centers, principal investigators, or into the commercial terrestrial communications network. The technologies demonstrated by D3 will facilitate NASA's transition from using Government-owned communication assets to using commercial communication services. The hardware for D3 will incorporate advanced technology components developed under the High Rate Data Delivery (HRDD) Thrust Area of NASA's Office of Aerospace Technology Space Base Program at Glenn's Communications Technology Division. The flight segment components will include the electrically steerable phased-array antenna, which is being built by the Raytheon System Corporation and utilizes monolithic microwave integrated circuit (MMIC) technology operating at 19.05 GHz; and the digital encoder/modulator chipset, which uses four-channel orthogonal frequency division multiplexing (OFDM). The encoder/modulator will use a chipset developed by SICOM, Inc., which is both bandwidth and power efficient. The ground segment components will include a low-cost, open-loop tracking ground terminal incorporating a cryoreceiver to minimize terminal size without compromising receiver capability. The project is planning to hold a critical design review in the second quarter of fiscal year 2002.

Wald, Lawrence↗

High-Efficiency Ka-Band Waveguide Two-Way Asymmetric Power Combiner

NASA is planning a number of Space Exploration, Earth Observation and Space Science missions where Ka-band solid-state power amplifiers (SSPAs) could have a role. Monolithic microwave integrated circuit (MMIC) based SSPAs with output powers on the order of 10 W at Ka-band frequencies would be adequate to satisfy the data transmission rate requirements at the distances involved. MMICs are a type of integrated circuit fabricated on a GaAs wafer, which operates at micro wave frequencies and performs the function of signal amplification. The highest power Ka-band (31.8 to 32.3 GHz) SSPA to have flown in space had an output power of 2.6 W with an overall efficiency of 14.3 percent. This SSPA was built around discrete GaAs pHEMT (high electron mobility transistor) devices and flew aboard the Deep Space One spacecraft. State-of-the-art GaAs pHEMT-based MMIC power amplifiers (PAs) can deliver RF power at Ka-band frequencies anywhere from 3 W with a power added efficiency (PAE) of 32 percent to 6 W with a PAE of 26 percent. However, to achieve power levels higher than 6 W, the output of several MMIC PAs would need to be combined using a high-efficiency power combiner. Conventional binary waveguide power combiners, based on short-slot and magic-T circuits, require MMIC PAs with identical amplitude and phase characteristics for high combining efficiency. However, due to manufacturing process variations, the output powers of the MMIC PAs tend to be unequal, and hence the need to develop unequal power combiners. A two-way asymmetric magic-T based power combiner for MMIC power amplifiers, which can take in unequal inputs, has been successfully designed, fabricated, and characterized over NASA s Deep Space Network (DSN) frequency range of 31.8 to 32.3 GHz. The figure is a transparent view of the a sym - metric combiner that shows the 4-port configuration and the internal structure. The rod, post, and iris are positioned by design to achieve the desired asymmetric power ratio, phase equality, and port isolation. Although the combiner was designed for an input power ratio of 2:1, it can be custom-designed for any arbitrary power ratio and frequency range. The manufactured prototype combiner was precision machined from aluminum and is less than 2 in.3 (32.8 cm3). Previously investigated rectangular waveguide unequal power combiners were based on shunt/series coupling slots, E-plane septums, or H-plane T-junctions. All the prior art unequal power combiners operated at or below X-band (10 GHz) frequencies and were primarily used in the feed network of antenna arrays. The only reported asymmetric magic-T was developed as a 2:1 power divider for operation at a much lower frequency, around 500 MHz. The measured power ratio when tested as a power divider was very close to 2 and the phase balance was within 2.6, resulting in near ideal performance. When tested as a combiner using two MMIC SSPAs with a 2:1 power output ratio, an efficiency greater than 90 percent was demonstrated over the 500 MHz DSN frequency range. The return loss at the combiner output port (1) was greater than 18 dB and the input port (2 and 3) isolation was greater than 22 dB. The results show the asymmetric combiner to be a good candidate for high-efficiency power combining of two or more SSPAs needed to achieve the 6 to 10 W required by space communications systems of future NASA missions.

Wintucky, E. G.↗

Submillimeter Source Needs for NASA Missions

Submillimeter source needs for the NASA astrophysics Submillimeter Intermediate Mission (SMIM) and the Earth Observing System Microwave Limb Sounder (EOS MLS) instrument are presented. Solid state local oscillators using planar devices are planned. State-of-the-art performance for these components is reviewed

Submillimeter↗

Delta II Geotail -- 1st Stage and Solid Motor Booster Erection

The Geotail mission's goal was to investigate the structure and dynamics of the geomagnetic tail that extends on the nightside of the Earth. The launch date was July 24, 1992. This video shows the Delta II on the pad, being prepared for the launch. The first stage and the solid motor booster are shown being moved into place on the rocket.

Source record↗

Suborbital Testing of the OSCAR Trash-to-Gas System

With the sustained human exploration of nearby celestial bodies on the horizon, a renewed outlook on crew waste management must be realized. Current waste management strategies aboard the International Space Station become impractical as we venture beyond low Earth orbit. Furthermore, for future exploration missions, extracting resources from various waste streams becomes increasingly advantageous. One method of combatting the long-duration waste management problem is by thermally degrading solid and liquid crew waste items into a chemically inert, ventable gas stream, a process known as Trash-to-Gas. The Orbital Syngas/Commodity Augmentation Reactor (OSCAR) is the state-of-the-art Trash-to-Gas system which has been designed to explore microgravity Trash-to-Gas concepts for improved mass/volume reduction and resource recovery from waste. OSCAR is a subscale testbed design that supports the NASA Logistics Reduction project under the Advanced Exploration Systems Program and Space Technology Mission Directorate Flight Opportunities Program to determine the feasibility of Trash-to-Gas technology for future use on long duration space missions. OSCAR has flown on two suborbital flight demonstrations aboard Blue Origin’s New Shepard launch vehicle. This paper presents a high-level comparative analysis of these microgravity test campaigns with Earth gravity laboratory experiments. Solid-to-gas conversion, gas production & composition, and reactor temperature & pressure are compared to highlight the operational factors and performance differences within the microgravity environment for future optimization.

Ray P Pitts↗

Earth imaging results from Galileo's second encounter

The recent flyby of the Galileo spacecraft en route to Jupiter contributes a unique perspective to our view of our home planet. Imaging activities conducted during the second Earth encounter provide an important opportunity to assess new methods and approaches on familiar territory. These include unique multispectral observations, low light-level imaging (searches for aurorae, lightning and artificial lights on the nightside) and experiments with multiple exposure times to extend the effective radiometric resolution and dynamic range of the camera system. Galileo imaging data has the potential to make important contributions to terrestrial remote sensing. This is because the particular set of filters included in the Solid State Imaging system are not presently incorporated in any currently operating Earth-orbiting sensor system. The visible/near-infrared bandpasses of the SSI filters are well suited to remote sensing of geological, glaciological, botanical, and meteorological phenomena. Data from this and the previous Earth encounter may provide an extremely valuable reference point in time for comparison with similar data expected from EOS or other systems in the future, contributing directly to our knowledge of global change. The highest resolution imaging (0.2 km/pixel) during the December, 1992 encounter occurred over the central Andes; a five filter mosaic of visible and near infrared bands displays the remarkable spectral heterogeneity of this geologically diverse region. As Galileo departed the Earth, cooperative imaging with the Near Infrared Mapping Spectrometer (NIMS) instrument targeted Antarctica, Australia, and Indonesia at 1.0 to 2.5 km/pixel resolutions in the early morning local times near the terminator. The Antarctic data are of particular interest, potentially allowing ice grain size mapping using the 889 and 968 nm filters and providing an important means of calibrating the technique for application to the Galilean satellites. As the spacecraft receded further, regional scale imaging provided data which, along with data from the previous encounter, will enable the production of global multispectral mosaics of Earth in each of the SSI filters.

Greenberg, R.↗

Technical issues in focal plane development for terrestrial resource observations

Performance goals for solid-state detector arrays operating in the pushbroom scan mode for the high-resolution, high-accuracy remote sensing of earth resources from space are discussed and some of the focal plane and system trades involved are identified. Issues in the development of solid-state pushbroom arrays with radiometric calibration to 0.5% precision detector-to-detector over a dynamic range of 1000:1 are considered, with calibration, temporal stability and spectral response conditions noted. Factors influencing the geometric precision of satellite-borne pushbroom scan mode sensors are then examined, including satellite orbit track and attitude errors, and geometric and radiometric correlation between information in the various spectral bands. Approaches to the alignment of linear arrays of thousands of detectors are then discussed that take into account tradeoffs between fabrication and test complexity and ground processing requirements. Continuing science experiments are indicated as necessary to establish tolerances on performance goals.

Thompson, L. L.↗