Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “Geophysics for exploration”

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 55 records · Page 3
All sourcesNASA NTRSDOE OSTI
NASA NTRS1992

The NASA-LaRC Controls-Structures Interaction (CSI) technology program

One of the main difficulties encountered in the design and implementation of control systems for spacecraft is the interaction between the control system and the flexibility of the vehicle. This difficulty has resulted in problems for a multitude of spacecraft including the earliest U.S. spacecraft, Explorer I; the Orbiting Geophysical Observatory III; Mariner 10; Galileo; and the Hubble Telescope. Recognizing the importance of the issue, NASA has an ongoing Controls-Structures Interaction (CSI) technology program to develop the methodology to design optimally and simultaneously both the control system and the structure. The CSI program is a multicenter program involving research teams from NASA's Langley Research Center (LaRC), Jet Propulsion Laboratory (JPL), and Marshall Space Flight Center (MSFC). JPL's area of interest is in optics-class vehicles and MSFC's in astrophysics vehicles. The aim of this paper is to explain the ongoing activities at LaRC, which are of a theoretical, ground test, and flight test nature, with focus on applications to spacecraft with multiple experiment-pointing mounts, large space radiometers, Space Station Freedom (SSF), and the Space Shuttle Remote Manipulator System (RMS).

Anderson, Willard W.↗
NASA NTRS1993

Modelling the gravity and magnetic field anomalies of the Chicxulub crater

The approximately 180-km-diameter Chicxulub crater lies buried by approximately 1 km of sediment on the northwestern corner of the Yucatan Peninsula, Mexico. Geophysical, stratigraphic and petrologic evidence support an impact origin for the structure and biostratigraphy suggests that a K/T age is possible for the impact. The crater's location is in agreement with constraints derived from proximal K/T impact-wave and ejecta deposits and its melt-rock is similar in composition to the K/T tektites. Radiometric dating of the melt rock reveals an age identical to that of the K/T tektites. The impact which produced the Chicxulub crater probably produced the K/T extinctions and understanding the now-buried crater will provide constraints on the impact's lethal effects. The outstanding preservation of the crater, the availability of detailed gravity and magnetic data sets, and the two-component target of carbonate/evaporites overlying silicate basement allow application of geophysical modeling techniques to explore the crater under most favorable circumstances. We have found that the main features of the gravity and magnetic field anomalies may be produced by the crater lithologies.

Aleman, C. Ortiz↗
NASA NTRS1993

Terrestrial case studies of ilmenite exploration and lunar implications

The Space Exploration Initiative (SEI) includes space resource utilization as one of the four architectures to achieve U.S. goals in space. Space resource utilization will make use of lunar resources to support long term activities on the lunar surface. Lunar ilmenite and regolith are two of the materials that can be mined and processed for lunar oxygen production. During this investigation, several sources were reviewed to assess terrestrial exploration methods used for locating ilmenite resources. These sources included published reports on terrestrial ilmenite exploration methods, analytical methods, case histories, chemical and physical properties, and associations with other minerals. Using a terrestrial analog and considering the differences between terrestrial and lunar environmental conditions, rocks, and minerals, exploration methods and analytical instruments can be recommended for a lunar orbiter and lander for assessing lunar resources. Twelve terrestrial case histories were reviewed to gain insight into ilmenite exploration on the Moon. All exploration case histories follow the same pattern. They begin with a model, use remote geophysical techniques, define regional sampling sites from the model and geophysics, narrow down the area of exploration based on the preceding work, collect more samples and cores, and perform laboratory analyses of samples. An important part of this process is the collection of samples to determine the correctness of the model. Surface and core samples are collected in areas expected to contain both high and low concentration of the commodity to test the model. After samples are analyzed and the area of mineralization is defined, reserves are calculated to determine the cost/benefit ratio, the necessary capacity of the processing plant, and the life of the mine. The exploration methods used for locating terrestrial ilmenite resources are reviewed with respect to the petrology, chemistry, and mineral associations of the terrestrial and lunar environments.

Feldman, S. C.↗
NASA NTRS1984

A bibliography of planetary geology and geophysics principal investigators and their associates, 1983 - 1984

A compilation is given of selected bibliographic data specifically relating to recent publications submitted by principle investigators and their associates, supported through NASA's Office of Space Science and Applications, Solar System Exploration Division, Planetary Geology and Geophysics Program. Topics include the solar system, asteroids, volcanoes, stratigraphy, remote sensing, and planetary craters.

Witbeck, N. E.↗
NASA NTRS1985

Lunar bases and space activities of the 21st century

The present conference gives attention to such major aspects of lunar colonization as lunar base concepts, lunar transportation, lunar science research activities, moon-based astronomical researches, lunar architectural construction, lunar materials and processes, lunar oxygen production, life support and health maintenance in lunar bases, societal aspects of lunar colonization, and the prospects for Mars colonization. Specific discussions are presented concerning the role of nuclear energy in lunar development, achromatic trajectories and the industrial scale transport of lunar resources, advanced geologic exploration from a lunar base, geophysical investigations of the moon, moon-based astronomical interferometry, the irradiation of the moon by particles, cement-based composites for lunar base construction, electrostatic concentration of lunar soil minerals, microwave processing of lunar materials, a parametric analysis of lunar oxygen production, hydrogen from lunar regolith fines, metabolic support for a lunar base, past and future Soviet lunar exploration, and the use of the moons of Mars as sources of water for lunar bases.

Mendell, W. W.↗
NASA NTRS1986

Thermospheric nitric oxide and its role in thermospheric dynamics and composition

The global distribution of thermospheric nitric oxide has been measured under different geophysical conditions by the Atmosphere Explorer (AE) and Solar Mesosphere Explorer (SME) satellites. These observations show a great variability in the NO concentration but the existence of a latitudinal gradient is clearly evidenced by statistical maps of the NO meridional distribution. A two dimensional zonally averaged chemical-dynamical model was used to investigate the importance of nitric oxide 5.3 micrometer cooling and its role on thermospheric temperature, dynamics and major gas composition. For this purpose, a 2-D background atmosphere code and an odd nitrogen code were coupled and run to steady state. The NO distribution obtained is in good agreement with the AE-D global picture calculated at solstice for solar minimum activity. The importance of each term in the thermodynamic equation was studied spatially. It is found that the NO I.R. cooling term competes with conduction in the upper thermosphere and reaches its maximum value near 200 km at high summer latitudes. The primary effect of including the NO cooling term is to increase the temperature in the upper winter thermosphere and decrease it in the other hemisphere, if the global average temperature is fixed. In general, the strength of the circulation is decreased and the thermal gradient is smoother. As a consequence of these changes in the wind and temperature fields, the O2, N2 and O densities also react to the effect of the NO cooling. The importance of this process depends on the level of solar activity which controls the NO distribution.

Gerard, J. C.↗
NASA NTRS1985

The handling of data in solar-terrestrial and in planetary physics

The evolution of data handling systems for solar-terrestrial and planetary physics applications is discussed. The main elements of data management systems for scientific satellites are described, including: command and control; data transmission; prioritization of data users; and data reduction and analysis. The design approaches incorporated into the data management systems of the Interplanetary Monitoring Platform (IMP), International Sun Earth Explorer (ISEE), and the Orbiting Geophysical Observatory, (OGO) spacecraft, are discussed. Emphasis is given to classical, centralized, and hybrid system designs. The report of the Committee on Data Management and Computation (CODMAC) concerning concepts for new data management systems is briefly summarized.

Vette, J. I.↗
NASA NTRS1967

1967 Aeronautics and Space Report

This document includes Surveyor, Lunar Orbiter, Apollo 4, Biosatellite, Orbiting Geophysical Observatory, Orbiting Solar Observatory, Explorers, Applications Technology satellites, operational satellites, Mariner to Venus, San Marco, sounding rockets, and aeronautical research.

Source record↗
NASA NTRS2011

Vostok Subglacial Lake: A Review of Geophysical Data Regarding Its Discovery and Topographic Setting

Vostok Subglacial Lake is the largest and best known sub-ice lake in Antarctica. The establishment of its water depth (>500 m) led to an appreciation that such environments may be habitats for life and could contain ancient records of ice sheet change, which catalyzed plans for exploration and research. Here we discuss geophysical data used to identify the lake and the likely physical, chemical, and biological processes that occur in it. The lake is more than 250 km long and around 80 km wide in one place. It lies beneath 4.2 to 3.7 km of ice and exists because background levels of geothermal heating are sufficient to warm the ice base to the pressure melting value. Seismic and gravity measurements show the lake has two distinct basins. The Vostok ice core extracted >200 m of ice accreted from the lake to the ice sheet base. Analysis of this ice has given valuable insights into the lake s biological and chemical setting. The inclination of the ice-water interface leads to differential basal melting in the north versus freezing in the south, which excites circulation and potential mixing of the water. The exact nature of circulation depends on hydrochemical properties, which are not known at this stage. The age of the subglacial lake is likely to be as old as the ice sheet (approx.14 Ma). The age of the water within the lake will be related to the age of the ice melting into it and the level of mixing. Rough estimates put that combined age as approx.1 Ma.

Siegert, Martin J.↗
NASA NTRS2006

ARPS Enabled Titan Rover Concept with Inflatable Wheels

The Decadal Survey identified Titan as one of the top priority science destinations in the large moons category, while NASA's proposed Design Reference Mission Set ranked a Titan in-situ explorer second, after a recommended Europa Geophysical Observer mission. This paper discusses a Titan rover concept, enabled by a single advanced Radioisotope Power System that could provide about 110We (BOL). The concept targets the smaller Flagship or potentially the New Frontiers mission class. This MSL class rover would traverse on four 1.5 m diameter inflatable wheels during its 3 years mission duration and would use as much design and flight heritage as possible to reduce mission cost. Direct to Earth communication would remove the need for a relay orbiter. Details on the strawman instrument payload, and rover subsystems are given for this science driven mission concept. In addition, power system trades between Advanced RTG, TPV, and Advanced Stirling and Brayton Radioisotope Power Systems (RPS) are outlined. While many possible approaches exist for Titan in-situ exploration, the Titan rover concept presented here could provide a scientifically interesting and programmatically affordable solution.

Radioisotope Power System (RPS)↗
NASA NTRS1990

Evaluation of geophysical properties of the lunar regolith for the design of precursor scientific missions for the space exploration initiative

The following topics are addressed: (1) the frequency of encountering boulders that represent hazards to lunar operations; (2) the ease of lunar soil excavation; (3) the use of explosives in excavation operation; (4) the trafficability of the regolith; (5) problems encountered in mining (probably strip mining) of the regolith; (6) the stable angle(s) of repose in excavation of the regolith; (7) the layering to be encountered in the subsurface; (8) knowledge of the regolith site and the possibility of its general application to any site on the lunar surface; (9) the data needed to characterize a site for a lunar base; (10) the influence of regolith properties on the design of geophysical experiments from the lunar base; and (11) terrestrial analogues for the geophysical properties of the lunar regolith.

Morgan, Paul↗
NASA NTRS1982

The reduction, verification and interpretation of MAGSAT magnetic data over Canada

Research into an approach for altitude adjustments for MAGSAT or similar data acquired over a range of altitudes is progressing. The technique shows promise not only in the production of refined anomaly maps but also in the derivation of regional charts of the magnetic elements from satellite and ground data. Correlations between MAGSAT anomalies and other geophysical and geological data are being explored further and quantitative modelling of some features has begun. The form of some anomalies may change as the maps are refined by the technique being developed. Emphasis is being given to the Canadian regions, although analogous features elsewhere are being considered.

Coles, R. L.↗
NASA NTRS1969

Aeronautics and Space Report: Highlights 1968

These highlights include the end of the Surveyor Program, planetary studies, Pioneers, Orbiting Geophysical Observatory, sounding rockets, radio astronomy Explorer, Orbiting Astronomical Observatory, Nimbus, lifting bodies, X-15 Program, XB-70, V/TOL, model research, jet noise reduction, flight safety, nuclear engines, Project Apollo (testing and training), and Apollo 5, 6, 7, and 8.

Source record↗
NASA NTRS2002

The Impact of Land Initialization and Assimilation on Climate Predictability and Prediction

Analysis will be presented which explores the impact of land conditions on monthly to seasonal climate simulations in a variety of atmospheric general circulation models (AGCMs). In one set of experiments, the Geophysical Fluid Dynamics Laboratory (GDFL) AGCM is used to explore the nature of soil-moisture predictability and associated climate predictability as an initial value problem. For another set of experiments, the Center for Ocean Land Atmosphere (COLA) and the Goddard Earth Observing System 2 (GEOS-2) AGCMs are used to investigate the impact of realistic snow initialization and assimilation in retrospective climate forecasts for the northern hemisphere spring (March-June).

Schlosser, C. Adam↗