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341.
H. U. Auster I. Apathy G. Berghofer A. Remizov R. Roll K. H. Fornacon K. H. Glassmeier G. Haerendel I. Hejja E. Kührt W. Magnes D. Moehlmann U. Motschmann I. Richter H. Rosenbauer C. T. Russell J. Rustenbach K. Sauer K. Schwingenschuh I. Szemerey R. Waesch 《Space Science Reviews》2007,128(1-4):221-240
The scientific objectives, design and capabilities of the Rosetta Lander’s ROMAP instrument are presented. ROMAP’s main scientific
goals are longterm magnetic field and plasma measurements of the surface of Comet 67P/Churyumov-Gerasimenko in order to study
cometary activity as a function of heliocentric distance, and measurements during the Lander’s descent to investigate the
structure of the comet’s remanent magnetisation. The ROMAP fluxgate magnetometer, electrostatic analyser and Faraday cup measure
the magnetic field from 0 to 32 Hz, ions of up to 8000 keV and electrons of up to 4200 keV. Additional two types of pressure
sensors – Penning and Minipirani – cover a pressure range from 10−8 to 101 mbar. ROMAP’s sensors and electronics are highly integrated, as required by a combined field/plasma instrument with less
than 1 W power consumption and 1 kg mass. 相似文献
342.
Karl-Heinz Glassmeier Hermann Boehnhardt Detlef Koschny Ekkehard Kührt Ingo Richter 《Space Science Reviews》2007,128(1-4):1-21
The ROSETTA Mission, the Planetary Cornerstone Mission in the European Space Agency’s long-term programme Horizon 2000, will
rendezvous in 2014 with comet 67P/Churyumov-Gerasimenko close to its aphelion and will study the physical and chemical properties
of the nucleus, the evolution of the coma during the comet’s approach to the Sun, and the development of the interaction region
of the solar wind and the comet, for more than one year until it reaches perihelion. In addition to the investigations performed
by the scientific instruments on board the orbiter, the ROSETTA lander PHILAE will be deployed onto the surface of the nucleus.
On its way to comet 67P/Churyumov-Gerasimenko, ROSETTA will fly by and study the two asteroids 2867 Steins and 21 Lutetia. 相似文献
343.
344.
THE ELECTRIC FIELD AND WAVE EXPERIMENT FOR THE CLUSTER MISSION 总被引:1,自引:0,他引:1
G. Gustafsson R. BostrÖM B. Holback G. Holmgren A. Lundgren K. Stasiewicz L. ÅHLÉN F. S. Mozer D. Pankow P. Harvey P. Berg R. Ulrich A. Pedersen R. Schmidt A. Butler A. W. C. Fransen D. Klinge M. Thomsen C.-G. FÄLTHAMMAR P.-A. Lindqvist S. Christenson J. Holtet B. Lybekk T. A. Sten P. Tanskanen K. Lappalainen J. Wygant 《Space Science Reviews》1997,79(1-2):137-156
The electric-field and wave experiment (EFW) on Cluster is designed to measure the electric-field and density fluctuations with sampling rates up to 36000 samples s-1. Langmuir probe sweeps can also be made to determine the electron density and temperature. The instrument has several important capabilities. These include (1) measurements of quasi-static electric fields of amplitudes up to 700 mV m-1 with high amplitude and time resolution, (2) measurements over short periods of time of up to five simualtaneous waveforms (two electric signals and three magnetic signals from the seach coil magnetometer sensors) of a bandwidth of 4 kHz with high time resolution, (3) measurements of density fluctuations in four points with high time resolution. Among the more interesting scientific objectives of the experiment are studies of nonlinear wave phenomena that result in acceleration of plasma as well as large- and small-scale interferometric measurements. By using four spacecraft for large-scale differential measurements and several Langmuir probes on one spacecraft for small-scale interferometry, it will be possible to study motion and shape of plasma structures on a wide range of spatial and temporal scales. This paper describes the primary scientific objectives of the EFW experiment and the technical capabilities of the instrument. 相似文献
345.
Medium energy neutral atom (MENA) imager for the IMAGE mission 总被引:1,自引:0,他引:1
Pollock C.J. Asamura K. Baldonado J. Balkey M.M. Barker P. Burch J.L. Korpela E.J. Cravens J. Dirks G. Fok M.-C. Funsten H.O. Grande M. Gruntman M. Hanley J. Jahn J.-M. Jenkins M. Lampton M. Marckwordt M. McComas D.J. Mukai T. Penegor G. Pope S. Ritzau S. Schattenburg M.L. Scime E. Skoug R. Spurgeon W. Stecklein T. Storms S. Urdiales C. Valek P. van Beek J.T.M. Weidner S.E. Wüest M. Young M.K. Zinsmeyer C. 《Space Science Reviews》2000,91(1-2):113-154
The Medium Energy Neutral Atom (MENA) imager was developed in response to the Imaging from the Magnetopause to the Aurora for Global Exploration (IMAGE) requirement to produce images of energetic neutral atoms (ENAs) in the energy range from 1 to 30 keV. These images will be used to infer characteristics of magnetospheric ion distributions. The MENA imager is a slit camera that images incident ENAs in the polar angle (based on a conventional spherical coordinate system defined by the spacecraft spin axis) and utilizes the spacecraft spin to image in azimuth. The speed of incident ENAs is determined by measuring the time-of-flight (TOF) from the entrance aperture to the detector. A carbon foil in the entrance aperture yields secondary electrons, which are imaged using a position-sensitive Start detector segment. This provides both the one-dimensional (1D) position at which the ENA passed through the aperture and a Start time for the TOF system. Impact of the incident ENA on the 1D position-sensitive Stop detector segment provides both a Stop-timing signal and the location that the ENA impacts the detector. The ENA incident polar angle is derived from the measured Stop and Start positions. Species identification (H vs. O) is based on variation in secondary electron yield with mass for a fixed ENA speed. The MENA imager is designed to produce images with 8°×4° angular resolution over a field of view 140°×360°, over an energy range from 1 keV to 30 keV. Thus, the MENA imager is well suited to conduct measurements relevant to the Earth's ring current, plasma sheet, and (at times) magnetosheath and cusp. 相似文献
346.
This report is divided into three parts: Section 1 gives a short introduction and a summary of the topics discussed. Section 2 is a position statement by J. Kuhn on the interpretation of the irradiance measurements, while Section 3 gives a position statement by M. Schüssler discussing observations of stars that could be useful for understanding solar variability. 相似文献
347.
Sharon Kedar Jose Andrade Bruce Banerdt Pierre Delage Matt Golombek Matthias Grott Troy Hudson Aaron Kiely Martin Knapmeyer Brigitte Knapmeyer-Endrun Christian Krause Taichi Kawamura Philippe Lognonne Tom Pike Youyi Ruan Tilman Spohn Nick Teanby Jeroen Tromp James Wookey 《Space Science Reviews》2017,211(1-4):315-337
InSight’s Seismic Experiment for Interior Structure (SEIS) provides a unique and unprecedented opportunity to conduct the first geotechnical survey of the Martian soil by taking advantage of the repeated seismic signals that will be generated by the mole of the Heat Flow and Physical Properties Package (HP3). Knowledge of the elastic properties of the Martian regolith have implications to material strength and can constrain models of water content, and provide context to geological processes and history that have acted on the landing site in western Elysium Planitia. Moreover, it will help to reduce travel-time errors introduced into the analysis of seismic data due to poor knowledge of the shallow subsurface. The challenge faced by the InSight team is to overcome the limited temporal resolution of the sharp hammer signals, which have significantly higher frequency content than the SEIS 100 Hz sampling rate. Fortunately, since the mole propagates at a rate of \(\sim1~\mbox{mm}\) per stroke down to 5 m depth, we anticipate thousands of seismic signals, which will vary very gradually as the mole travels.Using a combination of field measurements and modeling we simulate a seismic data set that mimics the InSight HP3-SEIS scenario, and the resolution of the InSight seismometer data. We demonstrate that the direct signal, and more importantly an anticipated reflected signal from the interface between the bottom of the regolith layer and an underlying lava flow, are likely to be observed both by Insight’s Very Broad Band (VBB) seismometer and Short Period (SP) seismometer. We have outlined several strategies to increase the signal temporal resolution using the multitude of hammer stroke and internal timing information to stack and interpolate multiple signals, and demonstrated that in spite of the low resolution, the key parameters—seismic velocities and regolith depth—can be retrieved with a high degree of confidence. 相似文献
348.
Mihail P. Petkov Steven M. Jones Gerald E. Voecks Kenneth J. Hurst Olivier Grosjean Delphine Faye Guillaume Rioland Cecily M. Sunday Emma M. Bradford William N. Warner Jerami M. Mennella Ned W. Ferraro Manuel Gallegos David M. Soules Philippe Lognonné W. Bruce Banerdt Jeffrey W. Umland 《Space Science Reviews》2018,214(8):112
We report on the development of a passive sorption pump, capable of maintaining high-vacuum conditions in the InSight seismometer throughout the duration of any extended mission. The adsorber material is a novel zeolite-loaded aerogel (ZLA) composite, which consists of fine zeolite particles homogeneously dispersed throughout a porous silica network. The outgassing species within the SEIS evacuated container were analyzed and the outgassing rate was estimated by different methods. The results were used to optimize the ZLA composition to adsorb the outgassing constituents, dominated by water, while minimizing the SEIS bakeout constraints. The InSight ZLA composite additionally facilitated substantial CO2 adsorption capabilities for risk mitigation against external leaks in Mars atmosphere. To comply with the stringent particle requirements, the ZLA getters were packaged in sealed containers, open to the SEIS interior through \(1~\upmu\mbox{m}\)-size pore filters. Results from experimental validation and verification tests of the packaged getters are presented. The pressure forecast based on these data, corroborated by rudimentary in situ pressure measurements, infer SEIS operational pressures not exceeding \(10^{-5}~\mbox{mbar}\) throughout the mission. 相似文献
349.
In this paper, we discuss the main ways of improving the aircraft aerodynamics. The results of a physical experiment are presented that is aimed to verify the theoretical results obtained earlier on the possible improvement in a seaplane wing model lift-to-drag ratio, by using a deflectable triangular extension along the wing leading edge near the wingtip. We confirm the slight effectiveness of using the wingtip leading edge triangular extensions on the nature of flow around the wing. 相似文献
350.
Alberto Adriani Gianrico Filacchione Tatiana Di Iorio Diego Turrini Raffaella Noschese Andrea Cicchetti Davide Grassi Alessandro Mura Giuseppe Sindoni Massimo Zambelli Giuseppe Piccioni Maria T. Capria Federico Tosi Roberto Orosei Bianca M. Dinelli Maria L. Moriconi Elio Roncon Jonathan I. Lunine Heidi N. Becker Alessadro Bini Alessandra Barbis Luciano Calamai Claudio Pasqui Stefano Nencioni Maurizio Rossi Marco Lastri Roberto Formaro Angelo Olivieri 《Space Science Reviews》2017,213(1-4):393-446
JIRAM is an imager/spectrometer on board the Juno spacecraft bound for a polar orbit around Jupiter. JIRAM is composed of IR imager and spectrometer channels. Its scientific goals are to explore the Jovian aurorae and the planet’s atmospheric structure, dynamics and composition. This paper explains the characteristics and functionalities of the instrument and reports on the results of ground calibrations. It discusses the main subsystems to the extent needed to understand how the instrument is sequenced and used, the purpose of the calibrations necessary to determine instrument performance, the process for generating the commanding sequences, the main elements of the observational strategy, and the format of the scientific data that JIRAM will produce. 相似文献