ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    facet.materialart.
    Unknown
    The drift of Saturn's north polar spot observed by the Hubble Space Telescope (1993)
    In:  Other Sources
    Details
    Publication Date: 2011-08-24
    Description: Polar projections of 50 images of Saturn at 889 nanometers and 25 images at 718 nanometers taken by the HST in November 1990, as well as three images at each wavelength taken in June 1991, have been examined. Among them, 31 show the north polar spot, which is associated with Saturn's polar hexagon, in locations suitable for measurement. The movement of the spot with respect to Saturn's system III rotation rate was studied. During the period of observation, the polar spot had first a short-term westward movement and then a long-term eastward drift. The rate of the long-term drift was -0.060 +/- 0.008 deg/day with respect to system III, approximately 50 percent greater than previously determined from Voyager. The original 1980 and 1981 Voyager data were combined with the new Hubble images to form an 11-yr baseline. The eastward drift over the longer period was -0.0569 degrees per day. The long-term drift could be due to uncertainty in the standard value of the internal rotation period. The short-term movement in November 1990 has a rate that is greater in magnitude but opposite in sign and probably represents a real, transient motion of the spot relative to the internal rotation system.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Science (ISSN 0036-8075); 260; 5106; p. 326-329.
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 2
    facet.materialart.
    Unknown
    HL-20 operations and support requirements for the Personnel Launch System mission (1993)
    In:  Other Sources
    Details
    Publication Date: 2011-08-24
    Description: The processing, mission planning, and support requirements were defined for the HL-20 lifting-body configuration that can serve as a Personnel Launch System. These requirements were based on the assumption of an operating environment that incorporates aircraft and airline support methods and techniques that are applicable to operations. The study covered the complete turnaround process for the HL-20, including landing through launch, and mission operations, but did not address the support requirements of the launch vehicle except for the integrated activities. Support is defined in terms of manpower, staffing levels, facilities, ground support equipment, maintenance/sparing requirements, and turnaround processing time. Support results were drawn from two contracted studies, plus an in-house analysis used to define the maintenance manpower. The results of the contracted studies were used as the basis for a stochastic simulation of the support environment to determine the sufficiency of support and the effect of variance on vehicle processing. Results indicate the levels of support defined for the HL-20 through this process to be sufficient to achieve the desired flight rate of eight flights per year.
    Keywords: SPACE TRANSPORTATION
    Type: Journal of Spacecraft and Rockets (ISSN 0022-4650); 30; 5; p. 597-605.
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 3
    facet.materialart.
    Unknown
    Theoretical predictions (1990)
    In:  CASI
    Details
    Publication Date: 2006-06-13
    Description: In order to understand the impact of man made chemicals on the atmospheric ozone layer, it is essential to develop models that can perform long term predictions of future ozone changes. An advantage of using two dimensional models is that they can be used to predict latitudinal and seasonal changes in ozone. The formulation and recent improvements are described in 2-D models, which are used herein, along with the three dimensional models that are currently being developed to better simulate transport of chemically active trace gases, especially in polar regions. The range in 2-D model calculations is described. Selected fields calculated by these models are compared with observations. A number of scenarios have been defined, which encompass possible emission rates of different halocarbons. Because of the large uncertainties in the rates for heterogeneous processes, the calculated responses of the models include only the effects of homogeneous chemistry. One important distinction among the models is their ability to account for temperature feedbacks on the calculated ozone changes.
    Keywords: ENVIRONMENT POLLUTION
    Type: NASA, Scientific Assessment of Stratospheric Ozone: 1989, Volume 1; p 283-399
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 4
    facet.materialart.
    Unknown
    The 2-micron polar haze of Jupiter (1991)
    In:  Other Sources
    Details
    Publication Date: 2011-08-19
    Description: Model spectra have been constructed for the CH4 lines of the polar regions of Jupiter in such as way as to encompass the hydrogen pressure-induced opacity and haze layers revealed by high-resolution spectroscopy. Comparisons between observation and model spectra indicate that, for optically thin haze models, the polar haze is primarily located between the 70 and 5 mbar pressure levels; for opaque haze models, the top of the haze layers lies in the vicinity of the 15-mbar level. It is concluded that the polar haze is widely distributed over both polar regions and exhibits no strong correlation with auroral activities.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Icarus (ISSN 0019-1035); 91; 145-153
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 5
    facet.materialart.
    Unknown
    International Jupiter Watch - A program to study the time variability of the Jovian system (1990)
    In:  Other Sources
    Details
    Publication Date: 2011-08-19
    Description: The International Jupiter Watch is a program for the encouragement and coordination of the study of temporal variations in the Jovian system. It consists of six discipline working groups concerned with: the Io torus under N. Schneider; the Jovian atmosphere under R. West; the magnetosphere and radio emissions under I. de Peter and M. Klein; aurora under J. Caldwell; the Galilean satellites under W. Sinton and J. Goguen; and laboratory measurement and theory under B. Lutz. To date the IJW has held two workshops and selected several Jupiter Watch periods for coordinated observations. The next Jupiter Watch workshop is tentatively scheduled for 1990 in association with the next COSPAR meeting.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Advances in Space Research (ISSN 0273-1177); 10; 1, 19
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 6
    facet.materialart.
    Unknown
    Particle astrophysics (1991)
    In:  CASI
    Details
    Publication Date: 2013-08-31
    Description: The following scientific areas are reviewed: (1) cosmology and particle physics (particle physics and the early universe, dark matter, and other relics); (2) stellar physics and particles (solar neutrinos, supernovae, and unconventional particle physics); (3) high energy gamma ray and neutrino astronomy; (4) cosmic rays (space and ground observations). Highest scientific priorities for the next decade include implementation of the current program, new initiatives, and longer-term programs. Essential technological developments, such as cryogenic detectors of particles, new solar neutrino techniques, and new extensive air shower detectors, are discussed. Also a certain number of institutional issues (the funding of particle astrophysics, recommended funding mechanisms, recommended facilities, international collaborations, and education and technology) which will become critical in the coming decade are presented.
    Keywords: ASTROPHYSICS
    Type: National Academy of Sciences(National Research Council, Working Papers: Astronomy and Astrophysics Panel Reports; 23 p
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 7
    facet.materialart.
    Unknown
    A HOL theory for voting (1990)
    In:  CASI
    Details
    Publication Date: 2013-08-31
    Description: Central to fault-tolerant computing is redundancy management, and common to proofs of fault-tolerance is a maximum fault assumption. Typically a maximum fault assumption is rather restrictive. Usually, this is necessary to avoid assumptions about the behavior of faulty channels. A maximum fault assumption is useful because it allows reasoning about fault tolerance in the presence of arbitrarily malicious fault behavior. However, analysis of the architecture may establish certain scenarios in which the assumption may be weakened. Proofs comparing majority and plurality and proofs of simple reconfiguration strategies are presented in viewgraph form.
    Keywords: COMPUTER PROGRAMMING AND SOFTWARE
    Type: NASA Formal Methods Workshop, 1990; 15 p
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 8
    facet.materialart.
    Unknown
    High level design proof of a reliable computing platform (1990)
    In:  CASI
    Details
    Publication Date: 2013-08-31
    Description: The main objectives are: to establish hardware/software platform for ultra-reliable computing; to use fault tolerant computer architecture; to use formal methods to prevent design and implementation errors; and to construct reliability model to quantify reliability estimate. The results show that: ultra-reliable control systems are hard to achieve; simple fault tolerant design is postulated; formal specification of design is constructed; and preliminary correctness proofs are obtained.
    Keywords: COMPUTER OPERATIONS AND HARDWARE
    Type: NASA Formal Methods Workshop, 1990; 28 p
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 9
    facet.materialart.
    Unknown
    Modeling aerosol emissions from the combustion of composite materials (1994)
    In:  CASI
    Details
    Publication Date: 2013-08-31
    Description: The use of advanced composite materials (ACM) in the B-2 bomber, composite armored vehicle, and F-22 advanced tactical fighter has rekindled interest concerning the health risk of burned or burning ACM. The objective of this work was to determine smoke production from burning ACM and its toxicity. A commercial version of the UPITT II combustion toxicity method developed at the University of Pittsburgh, and subsequently refined through a US Army-funded basic research project, was used to established controlled combustion conditions which were selected to evaluate real-world exposure scenarios. Production and yield of toxic species varied with the combustion conditions. Previous work with this method showed that the combustion conditions directly influenced the toxicity of the decomposition products from a variety of materials.
    Keywords: COMPOSITE MATERIALS
    Type: NASA. Goddard Space Flight Center, Environmental, Safety, and Health Considerations: Composite Materials in the Aerospace Industry; p 219-230
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 10
    facet.materialart.
    Unknown
    Measurements of the methane relaxation times for application to the infrared emission models of the upper atmospheres of outer planets and Titan (1990)
    In:  CASI
    Details
    Publication Date: 2016-06-07
    Description: The 7.8 micrometer emission from the nu(sub 4) band of methane (CH4) is a regularly observed feature in the stratosphere of all the giant planets and Titan. On Jupiter, enhancements in this emission are associated with the infrared hot spots in the auroral zone. Attempts to model this phenomenon in particular, and to understand the role of methane in general, have been hampered in part by a lack of adequate laboratory measurements of the collisional relaxation times for the nu(sub 3) and nu(sub 4) levels over the appropriate temperature range. To provide this needed data, a series of laboratory experiments were initiated. In the experimental arrangement the nu(sub3) band of methane is pumped at 3.3 micrometers using a pulsed infrared source (Nd:YAG/dye laser system equipped with a wave-length extender). The radiative lifetime of the nu(sub 3) level (approximately 37 ms) is much shorter than the nu(sub 4) lifetime (approximately 390 ms); however, a rapid V-V energy transfer rate ensures that the nu(sub 4) level is substantially populated. The photoacoustic technique is used to acquire relaxation rate information. The experiments are performed using a low-temperature, low-pressure cell. Experimental apparatus and technique are described. In addition some of the experimental difficulties associated with making these measurements are discussed and some preliminary results are presented.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: First International Conference on Laboratory Research for Planetary Atmospheres; p 157-163
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...