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Giant Planet Observations in NASA's planetary data system

REMOTE SENSING 2022年第23期14卷 6112-6112页

作者： Chanover, Nancy J. Bauer, James M. Blalock, John J. Gordon, Mitchell K. Huber, Lyle F. Mace, Mia J. T. Neakrase, Lynn D. V. Tiscareno, Matthew S. Walker, Raymond J. New Mexico State Univ Astron Dept Las Cruces NM 88003 USA Univ Maryland Dept Astron College Pk MD 20742 USA US Geol Survey Astrogeol Sci Ctr Flagstaff AZ 86001 USA SETI Inst Carl Sagan Ctr 339 Bernardo Ave 200 Mountain View CA 94043 USA Univ Calif Los Angeles Dept Earth Planetary & Space Sci Los Angeles CA 90095 USA

While there have been far fewer missions to the outer Solar system than to the inner Solar system, spacecraft destined for the giant planets have conducted a wide range of fundamental investigations, returning data that continues to reshape our understanding of these complex systems, sometimes decades after the data were acquired. These data are preserved and accessible from national and international planetary science archives. For all NASA planetary missions and instruments the data are available from the science discipline nodes of the NASA planetary data system (PDS). Looking ahead, the PDS will be the primary repository for giant planets data from several upcoming missions and derived datasets, as well as supporting research conducted to aid in the interpretation of the remotely sensed giant planets data already archived in the PDS.

关键词： giant planets planetary atmospheres planetary interiors magnetospheres data archiving Jupiter Saturn Uranus Neptune planetary data system

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Aircraft Electric system Intermittent Arc Fault Detection and Location

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IEEE TRANSACTIONS ON AEROSPACE AND ELECTRONIC systemS 2015年第1期51卷 40-51页

作者： Yaramasu, Anil Cao, Yinni Liu, Guangjun Wu, Bin Ryerson Univ Aerosp Engn Toronto ON M5B 2K3 Canada

Intermittent arc faults appear in aircraft power systems in unpredictable ways when the degraded wires are wet, vibrating against metal structures, or under mechanical stresses. They could evolve into serious faults that may cause onboard fires, power interruptions, system damage and catastrophic incidents, and thus have raised concern. Recent trends in solid state power controllers (SSPCs) motivated the development of nondestructive diagnostic methods for health monitoring of aircraft wiring. In this paper, the ABCD matrix (or transmission matrix) modeling method is introduced to derive normal and faulty load circuit models with better accuracy and reduced complexity compared to the differential equation approach, and an intermittent arc fault detection method is proposed based on temporary deviations of load circuit model coefficients and wiring parameters. Furthermore, based on the faulty wiring model, a genetic algorithm is proposed to estimate the fault-related wiring parameters such as intermittent arc location and average intermittent arc resistance. The proposed method can be applied to both the alternating current power distribution system (PDS) and the direct current (DC) PDS. Experiments using a DC power source have been conducted, and the experimental results have demonstrated effectiveness of the proposed method.

关键词： WIRING planetary data system arcing fault arcs Mechanical stress pendrin aircraft power systems metal structure DC power supply ARC RESISTANCE transfer matrix Differential equations Load Circuit

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The MESSENGER science operations center

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SPACE SCIENCE REVIEWS 2007年第1-4期131卷 601-623页

作者： Winters, Helene L. Domingue, Deborah L. Choo, Teck H. Espiritu, Raymond Hash, Christopher Malaret, Erick Mick, Alan A. Skura, Joseph P. Steele, Joshua Johns Hopkins Univ Appl Phys Lab Laurel MD 20723 USA Appl Coherent Technol Herndon VA 22070 USA

The MESSENGER Science Operations Center (SOC) is an integrated set of subsystems and personnel whose purpose is to obtain, provide, and preserve the scientific measurements and analysis that fulfill the objectives of the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) mission. The SOC has two main functional areas. The first is to facilitate science instrument planning and operational activities, including related spacecraft guidance and control operations, and to work closely with the Mission Operations Center to implement those plans. The second functional area, data management and analysis, involves the receipt of science-related telemetry, reformatting and cataloging this telemetry and related ancillary information, retaining the science data for use by the MESSENGER Science Team, and preparing data archives for delivery to the planetary data system;and the provision of operational assistance to the instrument and science teams in executing their algorithms and generating higher-level data products.

关键词： MESSENGER Mercury science operations science planning data products data archiving planetary data system

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TRANSPORT AND OPTICAL-PROPERTIES OF A-GAP PREPARED AT DIFFERENT SUBSTRATE TEMPERATURES

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JOURNAL OF PHYSICS-CONDENSED MATTER 1994年第3期6卷 779-790页

作者： ELGUN, N DAVIS, EA UNIV LEICESTER DEPT PHYS & ASTRON LEICESTER LE1 7RH ENGLAND

The electronic properties of a series of nearly stoichiometric sputtered a-GaP films have been investigated as a function of increasing deposition and annealing temperatures up to 270 degrees C. The optical absorption coefficient (10 cm(-1) < cr ( 10(5) cm(-1)) as a function of photon energy, deduced both from transmission (T) and reflection (R) measurements and from photothermal deflection spectroscopy (PDS), shows a very large shift of the edge towards lower energies relative to that of c-GaP. The electrical conductivity data have an activation energy that varies continuously with temperature. The results are related to the atomic structure of films which was reported earlier by Elgun, Gurman and Davis and also to the microstructure which is shown to contain voids. In addition, a density-of-states picture based on theoretical calculations by O'Reilly and Robertson is used for interpretation of the results.

关键词： photoabsorption picture Electronic properties PHOTOTHERMAL DEFLECTION SPECTROSCOPY annealing Voids planetary data system Activation energy pendrin stoichiometric atomic structure Films edges Function interpretation

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Lessons learned from planetary science archiving

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ADVANCES IN SPACE RESEARCH 2006年第9期38卷 2013-2022页

作者： Zender, J. Grayzeck, E. ESTEC European Space Agcy NL-2201 AZ Noordwijk Netherlands NASA Goddard Space Flight Ctr Solar Syst Explorat Data Serv Off Greenbelt MD 20771 USA

The need for scientific archiving of past, current, and future planetary scientific missions, laboratory data, and modeling efforts is indisputable. To quote from a message by G. Santayama carved over the entrance of the US Archive in Washington DC - "Those who can not remember the past are doomed to repeat it." The design, implementation, maintenance, and validation of planetary science archives are however disputed by the involved parties. The inclusion of the archives into the scientific heritage is problematic. For example, there is the imbalance between space agency requirements and institutional and national interests. The disparity of long-term archive requirements and immediate data analysis requests are significant. The discrepancy between the space missions archive budget and the effort required to design and build the data archive is large. An imbalance exists between new instrument development and existing, well-proven archive standards. The authors present their view on the problems and risk areas in the archiving concepts based on their experience acquired within NASA's planetary data system (PDS) and ESA's planetary Science Archive (PSA). Individual risks and potential problem areas are discussed based on a model derived from a system analysis done upfront. The major risk for a planetary mission science archive is seen in the combination of minimal involvement by Mission Scientists and inadequate funding. The authors outline how the risks can be reduced. The paper ends with the authors view on future planetary archive implementations including the archive interoperability aspect. (c) 2005 COSPAR. Published by Elsevier Ltd. All rights reserved.

关键词： planetary data system planetary science archive archiving long-term data preservation

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Artificial Equilibrium Points near Irregular-Shaped Asteroids with Continuous Thrust

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JOURNAL OF GUIDANCE CONTROL AND DYNAMICS 2018年第6期41卷 1308-1319页

作者： Yang, Hongwei Bai, Xiaoli Li, Shuang Nanjing Univ Aeronaut & Astronaut Coll Astronaut Nanjing 210016 Jiangsu Peoples R China Rutgers State Univ Dept Mech & Aerosp Engn Piscataway NJ 08854 USA

Artificial equilibrium points near irregular-shaped asteroids are generated by using continuous thrust to enlarge the feasible regions of body-fixed hovering missions. The dynamics of artificial equilibrium points and feasible sets with constraints of the control magnitude and direction are investigated. The linearized motion near artificial equilibrium points is derived with the generalized effective potential for analysis of topological classification, bifurcations, and stability. Collision and annihilation of equilibrium points and Hopf bifurcation are found during numerical continuation. A parametric study is conducted to investigate the influence of the control magnitude on the sets of artificial equilibrium points. The linearly stable regions are obtained by a grid searching. Moreover, a method based on the polyhedral model of asteroids is proposed to solve the feasible artificial equilibrium points with constraints of the control direction and observation. The observable area at feasible artificial equilibrium points is also obtained by the proposed method. In numerical simulations, 433 Eros is selected as a representative irregular-shaped asteroid to validate the effectiveness of the methods.

关键词： 951 Gaspra Thrust Numerical Simulation Low Thrust Propulsion Closed Loop Control Near Earth Asteroid Rendezvous planetary data system Newton's Method Earth Propulsion system

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data Processing at KAGUYA Operation and Analysis Center

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SPACE SCIENCE REVIEWS 2010年第1-4期154卷 317-342页

作者： Hoshino, Hirokazu Yamamoto, Yukio Sobue, Shin-ichi Yonekura, Katsuhide Ogawa, Mina Iwana, Yasunori Matsui, Kai Okumura, Hayato Kato, Manabu Japan Aerosp Explorat Agcy JAXA Chuo Ku Kanagawa 2525210 Japan

The functions of KAGUYA(SELENE) Operation and Analysis Center (SOAC) are to operate three satellites: the main orbiter KAGUYA and two small satellites, Relay satellite OKINA and VRAD (VLBI (Very Long Baseline Interferometry) RADio source) satellite OUNA;and to process, archive and provide mission data. SOAC has two main functional areas, "Tracking and Control system" and "Mission Operation and data Analysis system." The former is for operational planning of bus and mission instruments including satellite navigation, and for the implementation of those plans and for the evaluation of satellite conditions. The latter is the system that processes, archives and provides mission data, and which principal investigators use to generate higher-level data products. data up to the end of the operation in June 2009 have been processed and the total amount of Level-2 data products reaches about 50 TB. The data products have been released to the public since November 2009.

关键词： KAGUYA(SELENE) JAXA Moon Ground systems Mission operations data processing data products data archiving planetary data system

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Modeling Heat-Shield Erosion due to Dust Particle Impacts for Martian Entries

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JOURNAL OF SPACECRAFT AND ROCKETS 2020年第5期57卷 857-875页

作者： Palmer, Grant Ching, Eric Ihme, Matthias Allofs, Dirk Guelhan, Ali AMA Inc Aerothermodynam Branch Moffett Field CA 94035 USA Stanford Univ Dept Mech Engn Stanford CA 94305 USA Stanford Univ Inst Computat & Math Engn Stanford CA 94305 USA German Aerosp Ctr DLR Dept Superson & Hyperson Technol D-51147 Cologne Germany

Heat-shield design for spacecraft entering the atmosphere of Mars may be affected by the presence of atmospheric dust. Particle impacts with sufficient kinetic energy can cause spallation damage to the heat shield that must be estimated. The dust environment in terms of particle size distribution and number density can be inferred from ground-based or atmospheric observations at Mars. Using a Lagrangian approach, the particle trajectories through the shock layer can be computed using a set of coupled ordinary differential equations. The dust particles are small enough that noncontinuum effects must be accounted for when computing the drag coefficient and heat transfer to the particle surface. Surface damage correlations for impact crater diameter and penetration depth are presented for fused silica, AVCOAT, shuttle tiles, cork, and Norcoat (R) Liege. The cork and Norcoat Liege correlations are new and were developed in this study. The modeling equations presented in this paper are applied to compute the heat-shield erosion due to dust particle impacts on the ExoMars Schiaparelli entry capsule during dust storm conditions.

关键词： Thermal Protection system Freestream Conditions Shock Layers Heat Transfer Coefficients planetary data system Kinetic Energy Mars Science Laboratory Computing Thermodynamic Equilibrium Conservation of Mass

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Overcoming turbulence-induced space-variant blur by using phase-diverse speckle

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JOURNAL OF THE OPTICAL SOCIETY OF AMERICA A-OPTICS IMAGE SCIENCE AND VISION 2009年第1期26卷 206-218页

作者： Thelen, Brian J. Paxman, Richard G. Carrara, David A. Seldin, John H. Gen Dynam Adv Informat Syst Ypsilanti MI 48197 USA Michigan Tech Res Inst Ann Arbor MI 48105 USA Essen Instruments Ann Arbor MI 48108 USA

Space-variant blur occurs when imaging through volume turbulence over sufficiently large fields of view. Space-variant effects are particularly severe in horizontal-path imaging, slant-path (air-to-ground or ground-to-air) geometries, and ground-based imaging of low-elevation satellites or astronomical objects. In these geometries, the isoplanatic angle can be comparable to or even smaller than the diffraction-limited resolution angle. We report on a postdetection correction method that seeks to correct for the effects of space-variant aberrations, with the goal of reconstructing near-diffraction-limited imagery. Our approach has been to generalize the method of phase-diverse speckle (PDS) by using a physically motivated distributed-phase-screen model. Simulation results are presented that demonstrate the reconstruction of near-diffraction-limited imagery under both matched and mismatched model assumptions. In addition, we present evidence that PDS could be used as a beaconless wavefront sensor in a multiconjugate adaptive optics system when imaging extended scenes. (C) 2008 Optical Society of America

关键词： planetary data system Imaging pendrin phase method adaptive optics system postdetection Speckle Astronomical Objects Comparable SURFACE AIR images Visual system Imagery (Psychotherapy)

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Martian surface wind speeds described by the Weibull distribution

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JOURNAL OF SPACECRAFT AND ROCKETS 1996年第5期33卷 754-756页

作者： Lorenz, RD University of Arizona Tucson Arizona 85721-0092

The Viking landers recorded meteorological data at two locations on Mars, enabling the identification of general conditions on the surface, atmospheric tides, seasonal effects, and dust storms. Analysis to date has focused on hodographs and identifying the diurnal variations in wind speed and direction. These analyses, however, are not convenient for engineering and geophysical applications, where a probability of wind speed exceeding a given value often is required. Concise two-parameter descriptions of windspeed probability distributions, based on analysis of the hourly averaged windspeeds recorded by the Viking landers, are presented, which are much more useful than the simple mean speed that is usually reported.

关键词： Viking Lander Wind Energy planetary data system Hot Film Anemometers Earth Probability Distribution Atmospheric Tides Orbital Transfer Renewable Energy Mars Atmosphere

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