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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 667 records · Page 37
All sourcesNASA NTRSDOE OSTI
NASA NTRS1993

Clementine: Anticipated scientific datasets from the Moon and Geographos

The Clementine spacecraft mission is designed to test the performance of new lightweight and low-power detectors developed at the Lawrence Livermore National Laboratory (LLNL) for the Strategic Defense Initiative Office (SDIO). A secondary objective of the mission is to acquire useful scientific data, principally of the Moon and the near-Earth asteroid Geographos. The spacecraft will be in an elliptical polar orbit about the Moon for about 2 months beginning in February of 1994 and it will fly by Geographos on August 31. Clementine will carry seven detectors each weighing less than about 1 kg: two Star Trackers wide-angle uv/vis wide-angle Short Wavelength IR (SWIR) Long-Wavelength IR (LWIR) and LIDAR (Laser Image Detection And Ranging) narrow-angle imaging and ranging. Additional presentations about the mission detectors and related science issues are in this volume. If fully successful Clementine will return about 3 million lunar images, a dataset with nearly as many bits of data (uncompressed) as the first cycle of Magellan and more than 5000 images of Geographos. The complete and efficient analysis of such large data sets requires systematic processing efforts. Described below are concepts for two such efforts for the Clementine mission: global multispectral imaging of the Moon and videos of the Geographos flyby. Other anticipated datasets for which systematic processing might be desirable include multispectral observations of Earth; LIDAR altimetry of the Moon with high-resolution imaging along each ground track; high-resolution LIDAR color along each lunar ground track which could be used to identify potential titanium-rich deposits at scales of a few meters; and thermal IR imaging along each lunar ground track (including nighttime observations near the poles).

Mcewen, A. S.↗
NASA NTRS1992

MOSAIC: Software for creating mosaics from collections of images

We have developed a powerful, versatile image processing and analysis software package called MOSAIC, designed specifically for the manipulation of digital astronomical image data obtained with (but not limited to) two-dimensional array detectors. The software package is implemented using the Interactive Data Language (IDL), and incorporates new methods for processing, calibration, analysis, and visualization of astronomical image data, stressing effective methods for the creation of mosaic images from collections of individual exposures, while at the same time preserving the photometric integrity of the original data. Since IDL is available on many computers, the MOSAIC software runs on most UNIX and VAX workstations with the X-Windows or Sun View graphics interface.

Varosi, F.↗
NASA NTRS1992

SkICAT: A cataloging and analysis tool for wide field imaging surveys

We describe an integrated system, SkICAT (Sky Image Cataloging and Analysis Tool), for the automated reduction and analysis of the Palomar Observatory-ST ScI Digitized Sky Survey. The Survey will consist of the complete digitization of the photographic Second Palomar Observatory Sky Survey (POSS-II) in three bands, comprising nearly three Terabytes of pixel data. SkICAT applies a combination of existing packages, including FOCAS for basic image detection and measurement and SAS for database management, as well as custom software, to the task of managing this wealth of data. One of the most novel aspects of the system is its method of object classification. Using state-of-theart machine learning classification techniques (GID3* and O-BTree), we have developed a powerful method for automatically distinguishing point sources from non-point sources and artifacts, achieving comparably accurate discrimination a full magnitude fainter than in previous Schmidt plate surveys. The learning algorithms produce decision trees for classification by examining instances of objects classified by eye on both plate and higher quality CCD data. The same techniques will be applied to perform higher-level object classification (e.g., of galaxy morphology) in the near future. Another key feature of the system is the facility to integrate the catalogs from multiple plates (and portions thereof) to construct a single catalog of uniform calibration and quality down to the faintest limits of the survey. SkICAT also provides a variety of data analysis and exploration tools for the scientific utilization of the resulting catalogs. We include initial results of applying this system to measure the counts and distribution of galaxies in two bands down to Bj is approximately 21 mag over an approximate 70 square degree multi-plate field from POSS-II. SkICAT is constructed in a modular and general fashion and should be readily adaptable to other large-scale imaging surveys.

Weir, N.↗
NASA NTRS1994

Self-calibrating models for dynamic monitoring and diagnosis

The present goal in qualitative reasoning is to develop methods for automatically building qualitative and semiquantitative models of dynamic systems and to use them for monitoring and fault diagnosis. The qualitative approach to modeling provides a guarantee of coverage while our semiquantitative methods support convergence toward a numerical model as observations are accumulated. We have developed and applied methods for automatic creation of qualitative models, developed two methods for obtaining tractable results on problems that were previously intractable for qualitative simulation, and developed more powerful methods for learning semiquantitative models from observations and deriving semiquantitative predictions from them. With these advances, qualitative reasoning comes significantly closer to realizing its aims as a practical engineering method.

Kuipers, Benjamin↗
NASA NTRS1994

Simulation of arthroscopic surgery using MRI data

With the availability of Magnetic Resonance Imaging (MRI) technology in the medical field and the development of powerful graphics engines in the computer world the possibility now exists for the simulation of surgery using data obtained from an actual patient. This paper describes a surgical simulation system which will allow a physician or a medical student to practice surgery on a patient without ever entering an operating room. This could substantially lower the cost of medial training by providing an alternative to the use of cadavers. This project involves the use of volume data acquired by MRI which are converted to polygonal form using a corrected marching cubes algorithm. The data are then colored and a simulation of surface response based on springy structures is performed in real time. Control for the system is obtained through the use of an attached analog-to-digital unit. A remote electronic device is described which simulates an imaginary tool having features in common with both arthroscope and laparoscope.

Heller, Geoffrey↗
NASA NTRS1993

Nonlinear unstable auroral-arc driven thermospheric winds in an ionosphere-magnetosphere coupled model

The nonlinear evolution of thermospheric winds in an ionosphere-magnetosphere coupled model has been studied for the first time for a dynamic unstable auroral-arc environment. We treat the problem using a multi-layer, quasi-three-dimensional model which averages in altitude the thermospheric dynamics over each layer. For the upper thermosphere, we find that (1) the thermosphere can respond to the ionospheric Kelvin-Helmholtz (KH) instability on temporal scales on the order of an hour, depending on ambient conditions, and on spatial scales of tens to hundreds of kilometers, (2) strong thermospheric meridional and zonal vortical flows with embedded nonlinear jet-like structures can be generated by the ionospheric/magnetospheric KH instability and (3) neutral thermospheric winds, vortices, and associated power spectra develop in a distinctly different manner in the presence of magnetospheric coupling effects. Comparison with recent observations is made.

Keskinen, M. J.↗
NASA NTRS1994

Dual-Use Space Technology Transfer Conference and Exhibition, Volume 1

This document contains papers presented at the Dual-Use Space Technology Transfer Conference and Exhibition held at the Johnson Space Center February 1-3, 1994. Possible technology transfers covered during the conference were in the areas of information access; innovative microwave and optical applications; materials and structures; marketing and barriers; intelligent systems; human factors and habitation; communications and data systems; business process and technology transfer; software engineering; biotechnology and advanced bioinstrumentation; communications signal processing and analysis; new ways of doing business; medical care; applications derived from control center data systems; human performance evaluation; technology transfer methods; mathematics, modeling, and simulation; propulsion; software analysis and decision tools systems/processes in human support technology; networks, control centers, and distributed systems; power; rapid development perception and vision technologies; integrated vehicle health management; automation technologies; advanced avionics; ans robotics technologies. More than 77 papers, 20 presentations, and 20 exhibits covering various disciplines were presented b experts from NASA, universities, and industry.

Kumar Krishen↗
NASA NTRS1994

Dual-Use Space Technology Transfer Conference and Exhibition

This is the second volume of papers presented at the Dual-Use Space Technology Transfer Conference and Exhibition held at the Johnson Space Center February 1-3, 1994. Possible technology transfers covered during the conference were in the areas of information access; innovative microwave and optical applications; materials and structures; marketing and barriers; intelligent systems; human factors and habitation; communications and data systems; business process and technology transfer; software engineering; biotechnology and advanced bioinstrumentation; communications signal processing and analysis; medical care; applications derived from control center data systems; human performance evaluation; technology transfer methods; mathematics, modeling, and simulation; propulsion; software analysis and decision tools; systems/processes in human support technology; networks, control centers, and distributed systems; power; rapid development; perception and vision technologies; integrated vehicle health management; automation technologies; advanced avionics; and robotics technologies.

Krishen, Kumar↗
NASA NTRS1985

Development of an Expert System for Representing Procedural Knowledge

A high level of automation is of paramount importance in most space operations. It is critical for unmanned missions and greatly increases the effectiveness of manned missions. However, although many functions can be automated by using advanced engineering techniques, others require complex reasoning, sensing, and manipulatory capabilities that go beyond this technology. Automation of fault diagnosis and malfunction handling is a case in point. The military have long been interested in this problem, and have developed automatic test equipment to aid in the maintenance of complex military hardware. These systems are all based on conventional software and engineering techniques. However, the effectiveness of such test equipment is severely limited. The equipment is inflexible and unresponsive to the skill level of the technicians using it. The diagnostic procedures cannot be matched to the exigencies of the current situation nor can they cope with reconfiguration or modification of the items under test. The diagnosis cannot be guided by useful advice from technicians and, when a fault cannot be isolated, no explanation is given as to the cause of failure. Because these systems perform a prescribed sequence of tests, they cannot utilize knowledge of a particular situation to focus attention on more likely trouble spots. Consequently, real-time performance is highly unsatisfactory. Furthermore, the cost of developing test software is substantial and time to maturation is excessive. Significant advances in artificial intelligence (AI) have recently led to the development of powerful and flexible reasoning systems, known as expert or knowledge-based systems. We have devised a powerful and theoretically sound scheme for representing and reasoning about procedural knowledge.

Georgeff, Michael P.↗
NASA NTRS1998

A Review of Recent Thermophotovoltaic Energy Conversion Technology Development at NASA Lewis Research Center

NASA Lewis Research Center (LeRC) has had an ongoing research program in TPV since the late 1980's. This effort has included both in-house research programs on critical components such as photovoltaic cells (PV) and emitter materials, as well as an active contracting effort directed toward system, and component development. Of particular note is the in-house development of thin film selective emitters fabricated from rare-earth yttrium aluminum garnets (YAG). Also developed at LeRC is a Monolithic Interconnect Module (MIM) consisting of many small InGaAs cells series interconnected on a single InP substrate. An infrared reflector placed on the rear surface of the substrate returns unabsorbed photons to the emitter for recycling. The current contracted efforts include two TPV system developments by Tecogen, Inc., a solar powered TPV system development, a GaInAsSb cell development and several emitter development efforts (plasma-sprayed selective emitters, flexible SiC and a selective emitting light pipe).

Wilt, David M.↗
NASA NTRS1998

The Development of Kolmogoroff-Like Power Spectra in the Expanding Solar Wind

Power spectra of the solar wind fluctuations consistently exhibit a -5/3 power-law slope consistent with the idea that the medium is undergoing a turbulent cascade as seen in ordinary fluids. This is surprising both because the radial streams and the magnetic field threading the plasma will induce anisotropies and because the expansion of the wind will tend to lead to the suppression of nonlinear cascades. These conditions violate the assumptions used by Kolmogoroff to derive the -5/3 law. We have studied this issue using a compressible IMHD code in spherical coordinates and have shown that a -5/3 spectrum results from a broad-band flat-spectrum input condition that is sheared and distorted by a current sheet as the wind expands. We determine spectra from time series taken at selected points in the domain as is done with observational spacecraft data. The spectra are very like those we have seen in nonexpanding runs and exhibit evolution and compressive characteristics very similar to those seen in observations. We will report on these results in addition to a new set of runs intended to constrain the necessary and sufficient conditions for the spectra to have this form. The simulation also allows us to examine the anisotropy for the spectra to attempt to determine why the result of an isotropic magnetofluid is obtained in a highly anisotropic situation.

Goldstein, M. L.↗
NASA NTRS1999

MABVAP: One Step Closer to an Aerobot Mission to Mars

Lighter-than-air planetary missions continued attract growing interest in Mars exploration due to unique combination of proximity to the surface and mobility that far surpasses capability of surface vehicles. Following the experience with the Sojourner rover and subsequent development of powerful rovers for Mars 2003 and 2005 missions it became clear that on Mars surface rover mobility is quite restricted. Realistic travel distances may be limited to tens of kilometers per year on relatively obstacle-free plains and a few kilometers or less on the more rugged terrains. Many areas on Mars will be inaccessible to rovers. Several concepts for a Mars aerobot (robotic balloon) mission have been pursued in the last decade. Additional information is contained in the original extended abstract.

Kerzhanovich, V. V.↗
NASA NTRS2001

Image2000: A Free, Innovative, Java Based Imaging Package

The National Aeronautics and Space Administration (NASA) Goddard Space Flight Center's (GSFC) Scientific and Educational Endeavors (SEE) and the Center for Image Processing in Education (CIPE) use satellite image processing as part of their science lessons developed for students and educators. The image processing products that they use, as part of these lessons, no longer fulfill the needs of SEE and CIPE because these products are either dependent on a particular computing platform, hard to customize and extend, or do not have enough functionality. SEE and CIPE began looking for what they considered the "perfect" image processing tool that was platform independent, rich in functionality and could easily be extended and customized for their purposes. At the request of SEE, NASA's GSFC, code 588 the Advanced Architectures and Automation Branch developed a powerful new Java based image processing endeavors.

Pell, Nicholas↗
NASA NTRS2004

Progress in Low-Power Digital Microwave Radiometer Technologies

Three component technologies were combined into a digital correlation microwave radiometer. The radiometer comprises a dual-channel X-band superheterodyne receiver, low-power high-speed cross-correlator (HSCC), three-level ADCs, and a correlated noise source (CNS). The HSCC dissipates 10 mW and operates at 500 MHz clock speed. The ADCs are implemented using ECL components and dissipate more power than desired. Thus, a low-power ADC development is underway. The new ADCs arc predicted to dissipated less than 200 mW and operate at 1 GSps with 1.5 GHz of input bandwidth. The CNS provides different input correlation values for calibration of the radiometer. The correlation channel had a null offset of 0.0008. Test results indicate that the correlation channel can be calibrated with 0.09% error in gain.

Piepmeier, Jeffrey R.↗
NASA NTRS2005

Next Generation Millimeter-Wave Radar for Safe Planetary Landing

Safe, precise landing on planetary bodies requires knowledge of altitude and velocity, and may require active detection and avoidance of hazardous terrain. Radar offers a superior solution to both problems due to its ability to operate at any time of day, through dust and engine plumes, and ability to detect velocity coherently. While previous efforts have focused on providing near term solutions to the safe landing problem, we are designing radar velocimeters and radar imagers for missions beyond the next decade. In this paper we identify the fundamental issues within each approach, at arrive at strawman sensor designs at a center frequency at or around 160 GHz (Gband). We find that a G-band radar velocimeter design is capable of sub-10 cm/s accuracy, and a G-band imager is capable of sub-0.5 degree resolution over a 28 degree field of view. From those designs, we arrive at the key technology requirements for the development of power and low noise amplifiers, signal distribution methods, and antenna arrays that enable the construction of these next generation sensors.

radar velocimetry↗
NASA NTRS2006

Lithium-Ion Cell Charge Control Unit

Life-test data of Lithium-Ion battery cells is critical in order to establish their performance capabilities for NASA missions and Exploration goals. Lithium-ion cells have the potential to replace rechargeable alkaline cells in aerospace applications, but they require a more complex charging scheme than is typically required for alkaline cells. To address these requirements in our Lithium-Ion Cell Test Verification Program, a Lithium-Ion Cell Charge Control Unit was developed by NASA Glenn Research Center (GRC). This unit gives researchers the ability to test cells together as a pack, while allowing each cell to charge individually. This allows the inherent cell-to-cell variations to be addressed on a series string of cells and results in a substantial reduction in test costs as compared to individual cell testing. The Naval Surface Warfare Center at Crane, Indiana developed a power reduction scheme that works in conjunction with the Lithium-Ion Cell Charge Control Unit. This scheme minimizes the power dissipation required by the circuitry to prolong circuit life and improve its reliability.

Reid, Concha↗