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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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NASA NTRS1991

Spectral types of stars in the SMC associations NGC456, NGC460a, b and NGC465

Spectral types of stars for an extended area (1200 sq arcmin) of the SMC, containing the associations NGC456, NGC460 a, b and NGC465 have been derived here. High-quality UJ and YJ film copies of objective prism plates taken with the 1.2-m UK Schmidt telescope were used. The medium dispersion spectral (830 A/mm) were digitized with a PDS microdensitometer and spectra types of stars were obtained down to about 16.5 mag. A computer interactive method of reduction has been developed, and the spectral types obtained are accurate to 0.3 spectral subtypes. Spectral classification for the low (2440 A/mm) dispersion spectra down to 18.5 mag was carried out visually using a binocular microscope. The frequency distributions of stars in the associations region, after subtracting the field stars, have revealed that only blue main sequence stars are their members.

Dapergolas, A.↗
NASA NTRS1991

The discovery of a long H I plume near the peculiar galaxy NGC 2782 (ARP 215)

The peculiar starburst galaxy NGC 2782 (Arp 215) is mapped in the 21-cm H I line using the VLA, and a massive H I plume extending about 5 arcmin toward the northwest is discovered which contains 1.4 x 10 to the 9th solar mass of atomic hydrogen (about 40 percent of the total H I mass of the system). There is also a shorter H I structure extending toward the east, which contains 6.6 x 10 to the 8th solar mass of H I. In the Arp Atlas photograph, NGC 2782 has a disturbed body with bright arcs, possibly ripples, throughout the disk, and a pronounced stellar tail extending 2.7 arcmin toward the east. The eastern H I structure is associated with the beginning of this stellar tail. PDS scanning of the Palomar plates in the vicinity of NGC 2782 reveals a low surface-brightness counterpart to the long HI plume in the northwest. The most likely formation scenario for NGC 2782 is a merger, possibly of unequal mass galaxies, where at least one of the galaxies is gas rich.

Smith, Beverly J.↗
NASA NTRS1994

Computer Program Helps Enhance Images

Pixel Pusher is Macintosh application program for viewing and performing minor enhancements on imagery. Works with color images digitized to 8 bits. Reads image files in JPL's two primary image formats VICAR and PDS as well as in Macintosh PICT format. VICAR (NPO-18076) handles array of image-processing capabilities used for variety of applications, including processing of biomedical images, cartography, imaging of Earth resources, and geological exploration. Pixel Pusher also imports color lookup tables in VICAR format for viewing images in pseudocolor (256 colors). Written in Symantec's Think C.

Stanfill, Daniel F., IV↗
NASA NTRS1993

A reference model for scientific information interchange

This paper presents an overview of an Information Interchange Reference Model (IIRM) currently being developed by individuals participating in the Consultative Committee for Space Data Systems (CCSDS) Panel 2, the Planetary Data Systems (PDS), and the Committee on Earth Observing Satellites (CEOS). This is an ongoing research activity and is not an official position by these bodies. This reference model provides a framework for describing and assessing current and proposed methodologies for information interchange within and among the space agencies. It is hoped that this model will improve interoperability between the various methodologies. As such, this model attempts to address key information interchange issues as seen by the producers and users of space-related data and to put them into a coherent framework. Information is understood as the knowledge (e.g., the scientific content) represented by data. Therefore, concern is not primarily on mechanisms for transferring data from user to user (e.g., compact disk read-only memory (CD-ROM), wide-area networks, optical tape, and so forth) but on how information is encoded as data and how the information content is maintained with minimal loss or distortion during transmittal. The model assumes open systems, which means that the protocols or methods used should be fully described and the descriptions publicly available. Ideally these protocols are promoted by recognized standards organizations using processes that permit involvement by those most likely to be affected, thereby enhancing the protocol's stability and the likelihood of wide support.

Reich, Lou↗
NASA NTRS1995

DITDOS: A set of design specifications for distributed data inventories

The analysis of space science data often requires researchers to work with many different types of data. For instance, correlative analysis can require data from multiple instruments on a single spacecraft, multiple spacecraft, and ground-based data. Typically, data from each source are available in a different format and have been written on a different type of computer, and so much effort must be spent to read the data and convert it to the computer and format that the researchers use in their analysis. The large and ever-growing amount of data and the large investment by the scientific community in software that require a specific data format make using standard data formats impractical. A format-independent approach to accessing and analyzing disparate data is key to being able to deliver data to a diverse community in a timely fashion. The system in use at the Planetary Plasma Interactions (PPI) node of the NASA Planetary Data System (PDS) is based on the object-oriented Distributed Inventory Tracking and Data Ordering Specification (DITDOS), which describes data inventories in a storage independent way. The specifications have been designed to make it possible to build DITDOS compliant inventories that can exist on portable media such as CD-ROM's. The portable media can be moved within a system, or from system to system, and still be used without modification. Several applications have been developed to work with DITDOS compliant data holdings. One is a windows-based client/server application, which helps guide the user in the selection of data. A user can select a data base, then a data set, then a specific data file, and then either order the data and receive it immediately if it is online or request that it be brought online if it is not. A user can also view data by any of the supported methods. DITDOS makes it possible to use already existing applications for data-specific actions, and this is done whenever possible. Another application is a stand-alone tool to assist in the extraction of data from portable media, such as CD-ROM's. In addition to the applications, there is a set of libraries that can facilitate building new DITDOS compliant applications.

King, T. A.↗
NASA NTRS1997

Planetary Data System Spaceborne Thermal Data Sub-Node of the Geosciences Node

The objectives of this proposal were: (1) to assemble the existing spacecraft thermal-infrared data and to place these data into a uniform format as specified by the PDS; (2) to develop a standardized software package, user interface, and catalog database to support the access and analysis of existing and planned thermal infrared datasets in order to provide wide community access to these data; (3) to support the distribution of Thermal SubNode data to users as requested; (4) to incorporate future spacecraft thermal observations into the Thermal SubNode; and (5) to sponsor workshops on the applications of Thermal SubNode data.

Christensen, Philip R.↗
NASA NTRS1996

Grant Proposal for the Continuation of the Voyager Interstellar Mission: LECP Investigation

This proposal documents the plans of the Low Energy Charged Particle (LECP) investigation team for participation in NASA's Voyager Interstellar Mission (VIM) as the Voyager 1 and 2 spacecraft explore the outer reaches of the heliosphere and search for the termination shock and the heliopause. The proposal covers the four year period from 1 January 1997 to 31 December 2000. The LECP instruments on Voyager 1 and 2 measure in situ intensities of charged particles with energies from about 30 keV to 100 MeV for ions, and about 20 keV to greater than 10 MeV for electrons. The instruments provide detailed spectral, angular, and compositional information about the particles. Composition is available for greater than 200 keV/nuc using multi-parameter measurements. Angular information is obtained by a mechanically scanned platform that rotates at various commanded rates. Measurements of low energy ion and electron intensities versus time and spatial location within the heliosphere contain an abundance of information regarding various transport and acceleration processes on both local (approx. 1 hr, approx. 0.01 AU) and global (approx. 11 yrs, approx. 100 AU) scales. The LECP instruments provide unique observations of such dynamical processes, and we anticipate that it will return critical information regarding the boundaries of the heliosphere. Several recent and exciting discoveries based on LECP measurements emphasize the important role that low energy charged particle distributions play in physical processes in the interplanetary medium. Yet, at the same time, these discoveries also underscore the fact that our understanding of processes in the outer heliosphere is, in most cases, incomplete, and in others, only rudimentary at best. Among the discoveries referred to above are the following: (1) Shocks: Examination of greater than 30 keV ion intensities have revealed: (a) a total absence of acceleration beyond only -100-200 keV at a strong transient shock in May 1991 at 35 AU, despite an enhanced level of seed particles; (b) a large transient shock in September 1991 of global scale, with intensities of shock-accelerated ions greater than or equal to 30 keV to approx. 30 MeV showing complex, highly energy-dependent spatial evolution, and small-scale (approx. few gyroradii), often anisotropic, micro-structures; (c) recurrent intensity increases in greater than or equal to 30 keV to -few MeV ions, with structures that, in some cases, show no correlation with the associated corotating shock. (2) Superthermal ion pressure: A global merged interaction region with a leading shock, downstream of which the superthermal ion (greater than or equal to 30 keV to approx. 4 MeV) pressure is comparable to that of the thermal plasma, and the total particle pressure yields a plasma beta of order unity. (3) Pickup ions: Measurements of the C/O ratio within transient structures at 35-45 AU showing the first clear evidence that transient shocks can pre-accelerate interstellar pickup ions from approx. 1 keV/nuc to at least 1 MeV/nuc. (4) Seed particles: Injection of ions for acceleration to high energies at the termination shock is unlikely to be a problem, since interplanetary transient and recurrent shocks are continually accelerating ions, of solar wind or interstellar origin, to highly superthermal energies. (5) Precursor electrons: Ambient solar electrons (greater than or equal to few tens of keV) that exist in the outer heliosphere ca form a broad precursor, several days wide, that is upstream of the termination shock and potentially observable a few months prior to the shock crossing. (6) Solar wind velocity at Voyager 1: We can use LECP ion data to obtain the solar wind velocity at Voyager 1, enabling us to provide critical measurement of the plasma flow as we approach and encounter the termination shock and other regions (necessary due to the partial failure of the Voyager 1 PLS experiment). The work of the LECP investigator team during the VIM will include: (1) Continuing operations with regard to the receipt, processing, verification, cataloging, display, and distribution of the data from the LECP instruments on Voyager 1 and 2, (2) Monitoring the health and performance of the LECP instruments, and evaluating and characterizing the response of the LECP instruments to various energetic particle and plasma environments, (3) Participating in, and supporting Voyager Project planning exercises and other coordinated activities relevant to exploration of the outer heliosphere, (4) Developing analysis techniques and operational procedures suitable for searching for and characterizing the boundaries and unique regions of the outher heliosphere, (5) Continuing the preparation of data sets appropriate for submission to the National Space Sciences Data Center (NSSDC) and, where appropriate, the Planetary Data System (PDS), (6) Maintaining direct Web access to online LECP data through the JHU/APL Voyager LECP home page, (7) Performing scientific evaluations of the Voyager 1 and 2 LECP data sets in conjunction with other data sets and other investigators, with particular focus on the outer regions of the heliosphere, and (8) Publishing the results of these evaluations in the scientific literature and presenting the results in scientific conferences.

Krimigis, Stamatios M.↗
NASA NTRS1997

Operation of the Planetary Plasma Interactions Node of the Planetary Data System

Five years ago NASA selected the Planetary Plasma Interactions (PPI) Node at UCLA to help the scientific community locate, access and preserve particles and fields data from planetary missions. We propose to continue to serve for 5 more years. During the first five years we have served the scientific community by providing them with high quality data products. We worked with missions and individual scientists to secure the highest quality data possible and to thoroughly document it. We validated the data, placed it on long lasting media and made sure it was properly archived for future use. So far we have prepared and archived over 10(exp 11) bytes of data from 26 instruments on 4 spacecraft. We have produced 106 CD-ROMs with peer reviewed data. In so doing, we have developed an efficient system to prepare and archive the data and thereby have been able to steadily increase the rate at which the data are produced. Although we produced a substantial archive during the initial five years, we have an even larger amount of work in progress. This includes preparing CD-ROM data sets with all of the Voyager, Pioneer and Ulysses data at Jupiter and Saturn. We will have the Jupiter data ready for the Galileo encounter in December, 1995. We are also completing the Pioneer Venus data restoration. The Galileo Venus archive and radio science data from Magellan will be prepared early in the next period. We are assisting the Small Bodies Node of PDS in the preparation of comet data and will be archiving the asteroid data from Galileo. We will be moving in several new directions as well. We will archive the PPI Node's first Earth based data with data from the International Jupiter Watch and Hubble data taken in support of Ulysses particles and field observations. We will work with the Cassini mission in archive planning efforts. For the inner planets we will begin an archive of Mars data starting with Phobos data and will support the US and Russian Mars missions in the late 1990's. We will restore the Mercury data from Mariner 10 and prepare the lunar data from Clementine in time for the lunar data analysis program in 1995. We will work with the Discovery mission teams to plan their archive and have already started with one, NEAR. Finally we will begin archiving our first heliospheric data from Voyager, Galileo, and Mars observers. We will continue to serve the science community by providing access to the data products. During the past 19 months we have filled nearly 6000 requests for on-line and CD-ROM data. The data delivered directly by the PPI Node has been - 5 x 10(exp 11) bytes. In addition to providing the data, we have provided users with software tools to manage and read the data which are computer, operating system and format independent. We have developed scalable systems so that the same software we use to manage and access the data for the entire PPI Node can be used by individual investigators to manage the data on a single CD-ROM, thereby greatly reducing the software development effort for both the PPI Node and users. We deliver this software with the disks. Recent technical advances have made it possible for us to serve a broader community than before. In the next five year period we plan to extend our outreach to the general public and in particular to increase our support for education. Since planetary plasma data are varied and require expertise in many areas the PPI Node will continue to be distributed. In addition to the primary node at UCLA, the PPI Node has three subnodes with an Outer Planets Subnode at the University of Iowa, an Inner Planets Subnode at UCLA, and a Radio Science Subnode at Stanford University. During the first two years of the renewal period there will be a Radio Astronomy Data Node at GSFC. These organizations will provide scientific expertise on the data, participate in node data selection activities and help with data restoration and mission activities.

Walker, Raymond J.↗
NASA NTRS1998

Application of the Probabilistic Dynamic Synthesis Method to the Analysis of a Realistic Structure

The Probabilistic Dynamic Synthesis method is a new technique for obtaining the statistics of a desired response engineering quantity for a structure with non-deterministic parameters. The method uses measured data from modal testing of the structure as the input random variables, rather than more "primitive" quantities like geometry or material variation. This modal information is much more comprehensive and easily measured than the "primitive" information. The probabilistic analysis is carried out using either response surface reliability methods or Monte Carlo simulation. A previous work verified the feasibility of the PDS method on a simple seven degree-of-freedom spring-mass system. In this paper, extensive issues involved with applying the method to a realistic three-substructure system are examined, and free and forced response analyses are performed. The results from using the method are promising, especially when the lack of alternatives for obtaining quantitative output for probabilistic structures is considered.

Brown, Andrew M.↗
NASA NTRS1998

Application of the Probabilistic Dynamic Synthesis Method to Realistic Structures

The Probabilistic Dynamic Synthesis method is a technique for obtaining the statistics of a desired response engineering quantity for a structure with non-deterministic parameters. The method uses measured data from modal testing of the structure as the input random variables, rather than more "primitive" quantities like geometry or material variation. This modal information is much more comprehensive and easily measured than the "primitive" information. The probabilistic analysis is carried out using either response surface reliability methods or Monte Carlo simulation. In previous work, the feasibility of the PDS method applied to a simple seven degree-of-freedom spring-mass system was verified. In this paper, extensive issues involved with applying the method to a realistic three-substructure system are examined, and free and forced response analyses are performed. The results from using the method are promising, especially when the lack of alternatives for obtaining quantitative output for probabilistic structures is considered.

Brown, Andrew M.↗
NASA NTRS1999

Product Structure, the Heart of Product Definition

This paper describes the LMMSS Product Definition System (PDS) philosophy and approach were the use of each item parts document or software can be traced to a specific end item (EI) serial/tail number of the product. It explains why a part-oriented approach to data organization and configuration management is required. The definition of part-oriented is that all appropriate product definition data products will be collected. Referenced and managed by their linkage/relationship to parts/items, The paper will touch upon how LMMSS store/controls product definition information under each project's top product designator in a two tiered approach. One tier for each product end item and another tier which contain/controls listings of drawings, documents. Specifications and standards that are required for hardware item definition.

DeHoog, C., Jr.↗
NASA NTRS1998

Studies of Planetary Ring Systems

We propose to extend our current cooperative agreement for another three years to continue this highly productive collaboration. The extension will provide ongoing full-time support for Stanford Research Associate Mark R. Showalter (henceforth MRS). His activities are divided into three separate but closely related activities. First, he will continue to pursue a variety of scientific problems related to the ring systems of Jupiter, Saturn, Uranus and Neptune. Second, he will continue to manage the activities of the Planetary Data System (PDS) Rings Node located at NASA Ames. Third, for at least one more year he will oversee a project to develop a software package for planetary image processing and analysis.

Showalter, Mark R.↗
NASA NTRS1998

Analysis of Stellar Occultation and Imaging Data for the Rings of Saturn and Uranus

The principal goals of this research were as follows: 1. To carry out photometric modelling of Saturn's B Ring; 2. To re-examine dynamical perturbations of the Uranian c ring, 'While delivering relevant occultation data to the PDS Rings Node; and 3. Prepare data from the Saturn ring-plane crossing observations for delivery to the Rings Node.

Nicholson, Philip D.↗
NASA NTRS2001

Status of Mars Global Surveyor Science Data Archives

The Mars Global Surveyor has been in orbit around Mars since September 1997, completing its primary mission on January 31, 2001. As of that date the spacecraft had completed more than 8000 mapping orbits. Data from its science instruments, radio science experiment, and SPICE files have been released regularly to the NASA Planetary Data System (PDS) as described in the MGS Archive Plan and Addendum and are available online. Additional information is contained in the original extended abstract.

Slavney, S.↗
NASA NTRS2001

Experimental Structural Dynamic Response of Plate Specimens Due to Sonic Loads in a Progressive Wave Tube

The objective of the current study was to assess the repeatability of experiments at NASA Langley's Thermal Acoustic Fatigue Apparatus (TAFA) facility and to use these experiments to validate numerical models. Experiments show that power spectral density (PSD) curves were repeatable except at the resonant frequencies, which tended to vary between 5 Hz to 15 Hz. Results show that the thinner specimen had more variability in the resonant frequency location than the thicker sample, especially for modes higher than the first mode in the frequency range. Root Mean Square (RMS) tended to be more repeatable. The RMS behaved linearly through the SPL range of 135 to 153 dB. Standard Deviations (STDs) of the results tended to be relatively low constant up to about 147 dB. The RMS results were more repeatable than the PDS results. The STD results were less than 10% of the RMS results for both the 0.125 in (0.318 cm) and 0.062 in (0.1588 cm) thick plate. The STD of the PSD results were around 20% to 100% of the mean PSD results for non-resonant and resonant frequencies, respectively, for the 0.125 in (0.318 cm) thicker plate and between 25% to 125% of the mean PSD results, for nonresonant and resonant frequencies, respectively, for the thinner plate.

Betts, Juan F.↗
NASA NTRS2001

Probing AGN with Masers and X-Rays-SAX Proposals

We have made BeppoSAX observations of the Seyfert 2/1.9 galaxy ESO103-G35, which contains a nuclear maser source and is known to be heavily absorbed in the X-rays. Analysis of the X-ray spectra observed by SAX in October 1996 and 1997 yields an energy index = 0.74 +/- 0.07, typical of Seyfert galaxies and consistent with earlier observations of this source. The strong, soft X-ray absorption has a column density, N_H of (1.79 +/- 0.09)E23 cmE-02, again consistent with earlier results. The best fitting spectrum is that of a power law with a high energy cutoff at 29 +/- 10 keV, a cold (E=6.3 +/- 0.1 keV, rest frame), marginally resolved (sigma = 0.35 +/- 0.14 keV, FWHM approximately (31 +/- 12)E03 km/s) FeKalpha line with EW 290 +100 -80 eV (1996) and a mildly ionized Fe K-edge at 7.37 +0.15 -0.21 keV, tau 0.24 +0.06 -0.09. The Fe Kalpha line and cold absorption are consistent with origin in a accretion disk/torus through which our line-of-sight passes at a radial distance of approximately 0.01 pc. The Fe K-edge is mildly ionized suggesting the presence of ionized gas probably in the inner accretion disk, close to the central source or in a separate warm absorber. The data quality is too low to distinguish between these possibilities but the edge-on geometry implied by the water maser emission favors the former. Comparison with earlier observations of ESO103-G35 shows little/no change in spectral parameters while the flux changes by factors of a few on timescales of a few months. The 2-10 keV flux decreased by a factor of approximately 2.7 between Oct 1996 and Oct 1997 with no detectable change in the count rate greater than 20 keV (i.e. the PDS data). Spectral fits to the combined datasets indicate either a significant hardening of the spectrum (energy index approximately 0.5) or an approximate constant or delayed response reflection component. The high energy cutoff (29 +/- 10 keV) is lower than the typical approximately 300 keV values seen in Seyfert galaxies. A significant subset of similar sources would affect current models of the AGN contribution to the cosmic X-ray background (CXRB) which generally assume a high energy cutoff of approximately 300 keV.

Wilkes, Belinda J.↗
NASA NTRS2001

International Space Station Payload Analytical Integration Overview

This paper contains a general description of the NASA Space Station Payloads Office (SSPO) integration process for International Space Station (ISS) payloads. The end-to-end processes described herein cover the Increment and execute preparation, real-time operations and post-flight phases of payload integration. The paper describes the necessary agreements, plans, documents and reviews required to integrate and operate payloads into standard payload locations. It also summarizes the Program boards, panels and points of contact that a Payload Developer (PI)) will participate in or interface with during the course of the process. The purpose is to provide potential PDs with an outline of the SSPO processes to deliver payloads to orbit, conduct research on orbit and return them to Earth.

Scheib, J.↗
NASA NTRS2002

Mars Radar Observations with the Goldstone Solar System Radar

The Goldstone Solar System Radar (GSSR) has successfully collected radar echo data from Mars over the past 30 years. As such, the GSSR has played a role as a specific mission element within Mars exploration. The older data provided local elevation information for Mars, along with radar scattering information with global resolution. Since the upgrade to the 70-m Deep Space Network (DSN) antenna at Goldstone completed in 1986, Mars data has been collected during all but the 1997 Mars opposition. Radar data, and non-imaging delay-Doppler data in particular, requires significant data processing to extract elevation, reflectivity and roughness of the reflecting surface. The spatial resolution of these experiments is typically some 20 km in longitude by some 150 km in latitude. The interpretation of these parameters while limited by the complexities of electromagnetic scattering, do provide information directly relevant to geophysical and geomorphic analyses of Mars. The usefulness of radar data for Mars exploration has been demonstrated in the past. Radar data were critical in assessing the Viking Lander 1 site as well as, more recently, the Pathfinder landing site. In general, radar data have not been available to the Mars exploration community at large. A project funded initially by the Mars Exploration Directorate Science Office at the Jet Propulsion Laboratory (JPL), and later funded by NASA's Mars Data Analysis Program has reprocessed to a common format a decade's worth of raw GSSR Mars delay-Doppler data in aid of landing site characterization for the Mars Program. These data will soon be submitted to the Planetary Data System (PDS). The radar data used were obtained between 1988 and 1995 by the GSSR, and comprise some 63 delay-Doppler radar tracks. Of these, 15 have yet to be recovered from old 9-track tapes, and some of the data may be permanently lost.

Haldemann, A. F. C.↗