ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

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
    Publication Date: 2019-07-12
    Description: In the last 100 years, the global population has more than quadrupled to over seven billion people. At the same time, the demand for food and standard of living has been increasing which has amplified the global water use by nearly eight times from approximately 500 to 4000 cu km per yr from 1900 to 2010. With the increasing concern to sustain the growing population on Earth it is necessary to seek other approaches to ensure that our planet will have resources for generations to come. In recent years, the advancement of space travel and technology has allowed the idea of mining asteroids with resources closer to becoming a reality. During the duration of the internship at NASA Kennedy Space Center, several geotechnical tests were conducted on BP-1 lunar simulant and asteroid simulant Orgueil. The tests that were conducted on BP-1 was to practice utilizing the equipment that will be used on the asteroid simulant and the data from those tests will be omitted from report. Understanding the soil mechanics of asteroid simulant Orgueil will help provide basis for future technological advances and prepare scientists for the conditions they may encounter when mining asteroids becomes reality in the distant future. Distinct tests were conducted to determine grain size distribution, unconsolidated density, and maximum density. Once the basic properties are known, the asteroid simulant will be altered to different levels of compaction using a vibrator table to see how compaction affects the density. After different intervals of vibration compaction, a miniature vane shear test will be conducted. Laboratory vane shear testing is a reliable tool to investigate strength anisotropy in the vertical and horizontal directions of a very soft to stiff saturated fine-grained clayey soil. This test will provide us with a rapid determination of the shear strength on the undisturbed compacted regolith. The results of these tests will shed light on how much torque is necessary to drill through the surface of an asteroid. Most of the known asteroids are believed to be left over material during the formation of the solar system that never accreted to form planets. Asteroids can be found in several groups such as Trojan Asteroids, Near Earth Asteroids (NEAs) and the main asteroid belt. The Trojan Asteroids orbit the 4th and 5th Lagrange points of major planets in the Solar System while the NEA's have orbits that are close to and sometimes intersect with Earths orbit and the Main Asteroid Belt which is found between the orbit of Mars and Jupiter. Gravitational perturbations can alter the orbit of asteroids in the Main Asteroid Belt causing them to move closer to earth causing them to become in the NEA class.
    Keywords: Lunar and Planetary Science and Exploration
    Type: KSC-E-DAA-TN42077
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Publication Date: 2020-01-04
    Description: The Origins, Spectral Interpretation, Resource Identification, and Security Regolith Explorer(OSIRISREx) mission observed the The Origins, Spectral Interpretation, Resource Identification, and SecurityRegolith Explorer (OSIRISREx) mission observed the Moon during the spacecraft's Earth gravity assist in 2017. From the spacecraft view, the lunar phase was 42, and the inview hemisphere was dominated by anorthositic highlands terrain. Lunar spectra obtained by the OSIRISREx Visible and InfraRed Spectrometer show evidence of several candidate absorption features. We observe the 2.8m hydration band, confirming the spectral results from other missions, but detected in fulldisk spectra. We also tentatively identify weak spectral features near 0.9 and 1.3 m, consistent with lunar regolith containing a mixture of plagioclase and orthopyroxene minerals, as expected for highlands terrain.
    Keywords: Lunar and Planetary Science and Exploration
    Type: GSFC-E-DAA-TN76610 , Geophysical Research Letters (ISSN 0094-8276) (e-ISSN 1944-8007); 46; 12; 6322-6326
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Publication Date: 2019-07-13
    Description: This paper presents the Orion Exploration Mission 1 Linear Covariance Analysis for the DRO mission using ground-based navigation. The Delta V statistics for each maneuver are presented. In particular, the statistics of the lunar encounters and the Entry Interface are presented.
    Keywords: Lunar and Planetary Science and Exploration
    Type: JSC-CN-35077 , AAS/AIAA Space Flight Mechanics Meeting; Feb 14, 2016 - Feb 18, 2016; Napa, CA; United States
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Publication Date: 2019-07-13
    Description: We report the design of a new application-specific integrated circuit (ASIC) for use in radio telescope correlators. It supports the construction of correlators for an arbitrarily large number of signals. The ASIC uses an intrinsically low-power architecture along with design techniques and a process that together result in unprecedentedly low power consumption. The design is flexible in that it can support telescopes with almost any number of antennas N. It is intended for use in an "FX" correlator, where a uniform filter bank breaks each signal into separate frequency channels prior to correlation.
    Keywords: Astronomy
    Type: United States National Committee of URSI National Radio Science Meeting (USNC-URSI NRSM); Jan 06, 2016 - Jan 09, 2016; Boulder, CO; United States
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    Publication Date: 2019-08-26
    Description: Radio telescopes that employ arrays of many antennas are in operation, and ever larger ones are being designed and proposed. Signals from the antennas are combined by cross-correlation. While the cost of most components of the telescope is proportional to the number of antennas N, the cost and power consumption of cross-correlationare proportional to N2 and dominate at sufficiently large N. Here we report the design of an integrated circuit (IC) that performs digital cross-correlations for arbitrarily many antennas in a power-efficient way. It uses an intrinsically low-power architecture in which the movement of data between devices is minimized. In a large system, each IC performs correlations for all pairs of antennas but for a portion of the telescope's bandwidth (the so-called "FX" structure). In our design, the correlations are performed in an array of 4096 complex multiply-accumulate (CMAC) units. This is sufficient to perform all correlations in parallel for 64 signals (N=32 antennas with 2 opposite-polarization signals per antenna). When N is larger, the input data are buffered in an on-chipmemory and the CMACs are re-used as many times as needed to compute all correlations. The design has been synthesized and simulated so as to obtain accurate estimates of the IC's size and power consumption. It isintended for fabrication in a 32 nm silicon-on-insulator process, where it will require less than 12mm2 of silicon area and achieve an energy efficiency of 1.76 to 3.3 pJ per CMAC operation, depending on the number of antennas. Operation has been analyzed in detail up to N = 4096. The system-level energy efficiency, including board-levelI/O, power supplies, and controls, is expected to be 5 to 7 pJ per CMAC operation. Existing correlators for the JVLA (N = 32) and ALMA (N = 64) telescopes achieve about 5000 pJ and 1000 pJ respectively usingapplication-specific ICs in older technologies. To our knowledge, the largest-N existing correlator is LEDA atN = 256; it uses GPUs built in 28 nm technology and achieves about 1000 pJ. Correlators being designed for the SKA telescopes (N = 128 and N = 512) using FPGAs in 16nm technology are predicted to achieve about 100 pJ.
    Keywords: Astronomy
    Type: Journal of Astronomical Instrumentation; 5; 2; 1650002
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...