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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 37 records · Page 2

The mineralogical, chemical, and chronological characteristics of the crystalline Apollo 16 impact melt rocks

A comparative review of mineralogical, chemical, and chronological data on crystalline Apollo 16 impact melt rocks is presented. The use of such data to identify distinct impact melt complex is discussed, and 22 distinct impact melt bodies are identified. The recently detected group of feldspathic microporphyritic (FM) melt rocks was tested for chemical and isotopic homogeneity; instrumental neutron activation analysis and new Rb-Sr isotopic whole rock data indicate that FMs were probably not derived from a single impact melt sheet, but might be representative of the Descartes basement. Stratigraphical and chronological concepts for the geological development of the landing site are discussed, and a model is presented for the formation of the Cayley Plains and the Descartes formation.

Reimold, W. U.↗

Chronologic Analysis of Terrestrial Sediments and Basin Evolution

The use of magnetic-polarity stratigraphy to provide detailed chronologies of numerous areas within a sedimentary basin is discussed. Sediments suitable for magnetostratigraphic studies are identified. Sets of figures intended to illustrate some of the applications of magnetic-polarity stratigraphy to various aspects of basin analysis are given. Most of the examples are drawn from the Himalayan molasse (Indo-Gangetic foredeep) in northern Pakistan and northwestern India. Each of the figures illustrates an example of how detailed chronologies can be utilized in enhancing and refining models of basin analysis and tectonic deformation.

Burbank, D.↗

Astronautics and aeronautics, 1977: A chronology

This publication is a chronology of events during the year 1977 in the fields of aeronautical and space research, development, activity, and policy. It includes appendixes, an index, and illustrations. Chronological entries list sources for further inquiry.

Ritchie, E. H.↗

Chronology of KSC and KSC-related events for 1985

A chronology of developments and events at the Kennedy Space Center (KSC) in 1985 documents the KSC role in NASA's progress. The chronology serves as a reference source for historians and other researchers. Arrangement is by day and month. Individual articles are attributed to published sources.

Nail, Ken, Jr.↗

Scheduling with chronology-directed search

The intelligent use of scheduling heuristics can enable the production of effective schedules in spite of the inherent intractability of scheduling in complex, real-world domains. In order to effectively use these heuristics, information is needed on the current state of the evolving schedule. One method to obtain this information is to use chronologies - limited histories of the scheduling process. Chronology-directed search is an important component of the heuristic approach to automated scheduling.

Biefeld, Eric W.↗

The formation and annealing of circumstellar dust, as gauged by IRAS low-resolution spectra and the microwave maser chronology

By comparing IRAS mean colors and LRS spectral differences in a large sample of Mira variables with the chronological sequence for development of microwave maser emission among such stars, it appears possible to describe a dust grain formation and annealing sequence. The early time spectra are dominated by aluminum oxides, which are then overrun by the emergence of silicates. Rather than the growth of silicate mantles on aluminate cores, this sequence is interpreted as a simple result of the higher electron affinity of aluminum for oxygen, resulting in an initial abundance of AlO bonds in the underoxidized grains. Once all the Al becomes fully oxidized, the relative abundances of Al and Si dictate that the AlO signature will be swamped by the growth of the SiO stretching fundamental. The correlations among the proposed dust chronology, the increasingly thick circumstellar envelopes, and the light curve asymmetries of Mira variables are instructive for understanding the evolutionary changes occurring in such stars.

Stencel, Robert E.↗

Marshall Space Flight Center 1990 annual chronology of events

A chronological listing is provided of the major events for the Marshall Space Flight Center for the calendar year 1990. The MSFC Historian, Management Operations Office, compiled the chronology from various sources and from supplemental information provided by the major MSFC organizations.

Wright, Michael↗

Chronology of KSC and KSC related events for 1992

This chronology is published to fulfill the requirements of KMI 2700.1 to describe and document KSC's role in NASA's progress. Materials for this chronology were selected from a number of published sources. The document records KSC events of interest to historians and other researchers. Arrangement is by date of occurrence, though the source cited may be dated one or more days after the event. An index is included.

Nail, Ken, Jr.↗

The chronology of the formation of the Galaxy

Recent advances in our understanding of horizontal-branch (HB) stars and in precision CCD photometry make it possible to establish a chronology of the formation of the Galaxy from the fossil record. The Lee et al. HB evolutionary models and the inferred age-metallicity relation of the Galactic globular-cluster system are now strengthened by many pieces of supporting evidence. This provides valuable information regarding the formation chronology of the halo and disk. Moreover, there is strong evidence from RR Lyrae stars that the radial variation in HB morphology observed in the halo continues to the very center of the Galaxy, which suggests that the formation of the bulge and halo was an inside-out process. These two crucial pieces of information are combined to extend the Searle and Zinn picture of halo formation to include the formation of the bulge and disk. The emerging picture is consistent with the idea that galaxies formed as clusters and mergers of many small gas-rich subsystems, rather than by the rapid collapse of single large protogalactic clouds.

Lee, Young-Wook↗

NASA historical report. First six years of NASA: A concise chronology

This chronology was compiled to satisfy numerous requests for highlights of historical information on the activities during the first six years that the National Aeronautics and Space Administration has existed as the Federal agency conducting the U.S. program for the scientific exploration of space and the exploitation of space science and technology for peaceful uses. The chronology shows the following: highlights of NASA's administrative, organizational, and policy; NASA milestones in space science and technology; items reflecting contributions of NASA offices, centers, and individuals; major policy statements by the President and NASA administrators; and a summary item reflecting evolution, growth, and accomplishments of NASA.

Holme, Molly↗

Marshall Space Flight Center 1989 annual chronology of events

A chronological listing of the major events for the Marshall Space Flight Center for the calendar year 1989 is provided. The MSFC Historian, Management Operations Office, compiled the chronology from various sources and from supplemental information provided by the major MSFC organizations.

Wright, Michael↗

Early Mars: A regional assessment of denudation chronology

Within the oldest highland units on Mars, the record of crater degradation indicates that fluvial resurfacing was responsible for modifying the Noachian through middle-Hesperian crater population. Based on crater frequency in the Noachian cratered terrain, age/elevation relations suggest that the highest exposures of Noachian dissected and plateau units became stabilized first, followed by successively lower units. In addition, studies of drainage networks indicate that the frequency of Noachian channels is greatest at high elevations. Together, these observations provide strong evidence of atmospheric involvement in volatile recycling. The long time period of crater modification also suggests that dendritic highland drainage was not simply the result of sapping by release of juvenile water, because the varied geologic units as well as the elevation dependence of stability ages makes it unlikely that subsurface recycling could provide a continuous supply of water for channel formation by sapping. While such geomorphic constraints on volatile history have been established by crater counts and stratigraphic relations using the 1:2M photomosaic series, photogeologic age relationships at the detailed level are needed to establish a specific chronology of erosion and sedimentation. Age relations for discrete erosional slopes and depositional basins will help refine ages of fluvial degradation, assess effectiveness of aeolian processes, and provide a regional chronology of fluvial events.

Maxwell, T. A.↗

Wilbur and Orville Wright: A Reissue of a Chronology Commemorating the Hundredth Anniversary of the Birth of Orville Wright, August 19, 1871

During the year 2003, hundreds of events will mark the one-hundredth anniversary of the Wright brothers historic first flights at Kitty Hawk, North Carolina. The centennial year will witness exhibitions, lectures, television documentaries, films, air shows, flight recreations of Wright aircraft, the issuing of postage stamps and medals, the publication of dozens of new books and articles, and numerous other commemorative activities. One of these events, although not likely to make the evening news, is among the most important of all in terms of a lasting contribution to the observance of this ultimate aviation milestone: the reprinting of Arthur G. Renstrom WIlbur & Orville Wrght: A Chronology Commemorating the Hundredth Anniversary of the Birth of Orville Wright, August 19, 1871. Since its appearance in 1975, Wilbur end Orville Wright: A Chronology has become indispensable to students and authors concerned with the life and work of the famous brothers. No doubt every book on the subject published in the last quarter century, including three of my own, was written with this treasure close at hand. This volume is far more than a simple compilation of dates and facts. Renstrom was a master reference librarian and bibliographer with a passion for aviation and the Wright brothers. He brought his considerable research skills to bear on the topic, and the result is a richly detailed, ever-informative, often entertaining walk through the lives and achievements of these two extraordinary individuals. Renstrom was not content to offer a date with a one-line tidbit. His entries are brimming with information. This is a highly readable reference work that, believe it or not, can be enjoyably read from cover to cover. The project was clearly a labor of love by a talented professional. During most of the last twenty years, I have been privileged to be the curator of the 1903 Wright Flyer at the Smithsonian Institution s National Air and Space Museum. The position brings a steady stream of inquiries about the Wright airplane and the endlessly fascinating brothers who created it. I do not know how I would have done this job without Renstrom s superb volume on my bookshelf. It is the first place I go to check anything on the Wright brothers, and I typically find what I am looking for in its pages. Arthur Renstrom also published two other classic reference works on the Wright brothers: Wilbur & Orville Wright: A Bibliography Commemorating the Hundredth Anniversary of the Birth of Wilbur Wright, April 16, 1867, in 1968 (an updated revision was published by the National Aeronautics and Space Administration in 2002) and Wilbur & Orville Wright, Pictorial Materials: A Documentary Guide in 1982, completing a series of research tools for which there are few peers on any subject. He was also part of the team that produced the landmark two-volume compilation of the Wrights letters, notebooks, and diaries in 1953, The Papers of Wilbur and Orville Wright, edited by Marvin W. McFarland. Renstrom s contribution to the documentation and preservation of the Wright story is a lasting legacy that will serve researchers, students, and general enthusiasts for generations to come. In this busy, high-profile anniversary year, the reprinting of a nearly thirty-year-old reference book may seem a mundane and quiet contribution to the celebration surrounding the Wright brothers world-changing achievement, but it is perhaps one of the most important. The U.S. Centennial of Flight Commission and NASA are to be commended for their foresight.

Renstrom, Arthur George↗

Lunar and Planetary Science XXXV: Early Solar System Chronology

The following topics were presented in this report: Iron Isotopic Fractionation During Vacuum Evaporation of Molten W?stite and Solar Compositions; Mg Isotope Ratio Zonation in CAIs - New Constraints on CAI Evolution; Sm-Nd Systematics of Chondrites; AMS Measurement of Mg-24(He-3,p)Al-26 Cross Section, Implications for the Al-26 Production in the Early Solar System; On Early Solar System Chronology: Implications of an Initially Heterogeneous Distribution of Short-lived Radionuclides; Revisiting Extraterrestrial U Isotope Ratios; Helium-Shell Nucleosynthesis and Extinct Radioactivities; High Spatial Resolution Ion Microprobe Measurements Refine Chronology of Orgueil Carbonate Formation; and Calibration of the Galactic Cosmic Ray Flux.

Source record↗

Chronology of KSC and KSC Related Events for 2012

This 2012 Chronology is published to describe and document KSC's role in NASA's progress. Materials for this Chronology were selected from a number of published sources. The document records KSC events of interest to historians and other researchers. Arrangement is by date of occurrence, though the source cited may be dated one or more days after the event. Materials were researched and compiled for publication by Archivist Elaine Liston.

Liston, Elaine E.↗