ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
You have 0 saved results.
Mark results and click the "Add To Watchlist" link in order to add them to this list.
feed icon rss

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
Filter
  • Other Sources  (19)
  • 1985-1989  (19)
  • 1
    facet.materialart.
    Unknown
    In-situ detection of micron-sized dust particles in near-Earth space (1985)
    In:  CASI
    Details
    Publication Date: 2006-02-14
    Description: In situ detectors for micron sized dust particles based on the measurement of impact ionization have been flown on several space missions (Pioneer 8/9, HEOS-2 and Helios 1/2). Previous measurements of small dust particles in near-Earth space are reviewed. An instrument is proposed for the measurement of micron sized meteoroids and space debris such as solid rocket exhaust particles from on board an Earth orbiting satellite. The instrument will measure the mass, speed, flight direction and electrical charge of individually impacting debris and meteoritic particles. It is a multicoincidence detector of 1000 sq cm sensitive area and measures particle masses in the range from 10 to the -14th power g to 10 to the -8th power g at an impact speed of 10 km/s. The instrument is lightweight (5 kg), consumes little power (4 watts), and requires a data sampling rate of about 100 bits per second.
    Keywords: ASTRONAUTICS (GENERAL)
    Type: Orbital Debris; p 233-246
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 2
    facet.materialart.
    Unknown
    Hypervelocity impacts on Skylab 4/Apollo windows (1985)
    In:  CASI
    Details
    Publication Date: 2006-02-14
    Description: The three largest Skylab 4 Command Module windows that were exposed for 84 days to space were optically scanned for impact features as small as 30 microns in diameter. This scanning effort which was carried out at an opptical magnification of 35x, detected features approximately three times smaller than were found in the original 5x scanning effort over the entire window surface. Some 289 features were recorded from the 35x scan for later detailed analyses. Sixty of the largest and most promising features were cored from the windows for SEM and energy-dispersive X-ray spectrometer (EDS) analysis. Twenty-six of the cores contained craters with glassy pits, and of these, fourteen were found to contain strikingly obvious liners coating the interior of the glassy pit. The six largest features cored from the windows do not have a central glassy pit which leaves their previously reported hypervelocity origin in some doubt. The remaining twenty-eight features that were cored from the windows show no clear evidence for a hypervelocity origin and evidence available at this time is insufficient to identify an origin in Earth orbit or as ground damage. The EDS analysis of six of the seven liners that were examined show detectable aluminum in the liner or lip of the glassy pit. The source of aluminum is most probably an Earth orbiting population of aluminum oxide spherules, exhaust from solid rocket motors.
    Keywords: SPACECRAFT DESIGN, TESTING AND PERFORMANCE
    Type: Orbital Debris; p 177-189
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 3
    facet.materialart.
    Unknown
    A preliminary report on the study of the impact sites and particles of the solar maximum satellite thermal blanket (1985)
    In:  CASI
    Details
    Publication Date: 2006-02-14
    Description: A preliminary study of the work on examination of the impact pits in, or penetrations through, the thermal blankets of the Solar Maximum Satellite is presented. The three largest pieces of the thermal blanket were optically scanned with a total surface area of about one half square meter. Over 1500 impact sites of all sizes, including 432 impacts larger than 40 microns in diameter, have been documented. Craters larger in diameter than about 100 microns found on the 75 micron thick Kapton first sheet of the main electronics box blanket are actually holes and constitute perforations through the blanket. A summary of the impact pit population that were found is given. The chemical study of these craters is only in the initial stages, with only about 250 chemical spectra of particles observed in or around impact pits or in the debris pattern being recorded.
    Keywords: SPACECRAFT DESIGN, TESTING AND PERFORMANCE
    Type: NASA. Goddard Space Flight Center Proceedings of the SMRM Degradation Study Workshop; p 247-264
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 4
    facet.materialart.
    Unknown
    Analysis of micrometeorite material captured by the solar max satellite (1985)
    In:  CASI
    Details
    Publication Date: 2006-02-14
    Description: A Solar Maximum satellite was retrieved and repaired after being subjected for four years and 55 days to impacts by micrometeorites and Earth-orbiting space debris. The chemical variety and physical condition of particles associated with two particular impact structures in the insulation blanket of the main electronics box are studied. A scanning electron microscope equipped with an energy dispersive X ray analyzer was used to determine morphology and chemistry of impacted areas and associated particles. Some details are discussed.
    Keywords: SPACECRAFT DESIGN, TESTING AND PERFORMANCE
    Type: NASA. Goddard Space Flight Center Proceedings of the SMRM Degradation Study Workshop; p 243-244
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 5
    facet.materialart.
    Unknown
    Modeling (1985)
    In:  CASI
    Details
    Publication Date: 2006-02-14
    Description: A prediction of the future population of satellites, satellite fragments, and assorted spacecraft debris in Earth orbit can be reliably made only after three conditions are satisfied: (1) the size and spatial distributions of these Earth-orbiting objects are established at some present-day time; (2) the processes of orbital evolution, explosions, hypervelocity impact fragmentation, and atmospheric drag are understood; and (3) a reasonable traffic model for the future launch rate of Earth-orbiting objects is assumed. The theoretician will then take these three quantities as input data and will carry through the necessary mathematica and numerical analyses to project the present-day orbital population into the future.
    Keywords: ASTRONAUTICS (GENERAL)
    Type: Orbital Debris; p 421-423
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 6
    facet.materialart.
    Unknown
    Mass input into and output from the meteoritic complex (1985)
    In:  Other Sources
    Details
    Publication Date: 2011-08-19
    Description: The consequences which arise from the mutual collisions occurring between interplanetary meteoroids, the Poynting-Robertson (PR) effect and the radiation pressure ejection of small meteoroids are examined. The size distribution and flux of micrometeoroids at 1 AU are derived and the dependence of spatial density on distance from the sun is established. The following conclusions are made: (1) the lifetimes of meteoroids with masses approximately greater than 0.00001 g are dominated by catastrophic collisions; (2) after bering crushed by collisions, 70 to 85 percent of this mass will be in the form of zodiacal light particles (with masses in the range of 10 to the -10th g to 10 to the -5th g) which will in part be transported by the PR effect towards the sun where they will evaporate; (3) the 15 to 30 percent of the collisional fragments which have masses approximately less than 10 to the -10th g will, for the most part, be injected into hyperbolic orbits by radiation pressure.
    Keywords: ASTROPHYSICS
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 7
    facet.materialart.
    Unknown
    Optical detection of large meteoroids in space (1985)
    In:  Other Sources
    Details
    Publication Date: 2011-08-19
    Description: CCD sensors placed across the focal plane of large Schmidt telescopes have great potential for detecting and measuring the very low flux in space of meteoroids with diameters larger than 1 meter. With the Palomar 'Big Schmidt', a detection rate of 1.4 per hour is obtained for meteoroids between 0.6 and 200 meters in diameter. For the Baker-Nunn 'Satellite Tracking Camera', the corresponding rate is about 0.8 per hour. The key to obtaining such high detection rates derives from approximately setting the sensor integration time equal to the time it takes a meteoroid to cross a pixel field of view. This minimizes signal to noise problems and is accomplished, in practice, by multiple summing of short integration time data records to obtain data records of longer effective integration times.
    Keywords: ASTRONOMY
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 8
    facet.materialart.
    Unknown
    Selection effects against small comets (1985)
    In:  Other Sources
    Details
    Publication Date: 2011-08-19
    Description: Everhart's (1967) formulation is used to determine the correlation between the probability of discovering a comet and the size of its nuclear radius. The analysis is concentrated on comets that are not more than two or three hundred meters in diameter; hence, heliocentric variations in cometary brightness can be neglected. The effect of cometary physical decay is also considered, and a strong observational bias against the detection of small active comets is found. The following three factors are involved: (1) small comets must pass closer to the earth than large comets in order to be detected, (2) the resulting higher angular velocity for nearby comets leads to a decrease in the time available to discover a small comet, and (3) small comets physically decay and vanish faster than do large comets.
    Keywords: ASTROPHYSICS
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 9
    facet.materialart.
    Unknown
    The interplanetary micrometeoroid flux and lunar primary and secondary microcraters (1985)
    In:  Other Sources
    Details
    Publication Date: 2011-08-19
    Description: It is proposed that considerable care is required to properly interpret either spacecraft in situ data or lunar crater data as well as near-earth data; in the case of the former, complications may arise which may be attributed to secondary lunar ejecta impacts, in the latter, they may result from impacting earth-orbiting debris. Experimental evidence suggests that most impact pits on lunar rocks with pit diameters smaller than 7 micrometers have been generated by lunar secondary ejecta impacts and not by primary meteoroid impacts. It is also found that lunar crater production rates are more accurate when deduced from meteoroid space experiments and not from solar flare track ages. It is concluded that in so far as all of the above qualifications are taken into account, a self-consistent meteoroid flux versus mass distribution is obtained.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 10
    facet.materialart.
    Unknown
    Impact-driven supply of sodium and potassium to the atmosphere of Mercury (1988)
    In:  Other Sources
    Details
    Publication Date: 2011-08-19
    Description: The Mercury atmosphere is supplied with sodium atoms from both impacting meteoroids and the impacted regolith; the production of vaporized sodium due to such impact varies with the instantaneous distance of Mercury from the sun, in a way that differs from the distance-dependence of those source-and-sink processes driven by solar radiation. Such impact-driven vaporization will yield the Na/K ratio noted in the Mercury atmosphere only if both the meteoroids and the regolith of the planet are deficient in K relative to other solar system objects sampled, other than comets.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Icarus (ISSN 0019-1035); 75; 156-170
    Format: text
    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...