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141.
Matthew A. Siegler Suzanne E. Smrekar Matthias Grott Sylvain Piqueux Nils Mueller Jean-Pierre Williams Ana-Catalina Plesa Tilman Spohn 《Space Science Reviews》2017,211(1-4):259-275
The 2018 InSight (Interior Exploration using Seismic Investigations, Geodesy and Heat Transport) Mission has the mission goal of providing insitu data for the first measurement of the geothermal heat flow of Mars. The Heat Flow and Physical Properties Package (HP3) will take thermal conductivity and thermal gradient measurements to approximately 5 m depth. By necessity, this measurement will be made within a few meters of the lander. This means that thermal perturbations from the lander will modify local surface and subsurface temperature measurements. For HP3’s sensitive thermal gradient measurements, this spacecraft influence will be important to model and parameterize. Here we present a basic 3D model of thermal effects of the lander on its surroundings. Though lander perturbations significantly alter subsurface temperatures, a successful thermal gradient measurement will be possible in all thermal conditions by proper (\(>3~\mbox{m}\) depth) placement of the heat flow probe. 相似文献
142.
The Juno Radiation Monitoring (RM) Investigation 总被引:1,自引:0,他引:1
H. N. Becker J. W. Alexander A. Adriani A. Mura A. Cicchetti R. Noschese J. L. Jørgensen T. Denver J. Sushkova A. Jørgensen M. Benn J. E. P. Connerney S. J. Bolton The Selex Galileo Juno SRU Team J. Allison S. Watts V. Adumitroaie E. A. Manor-Chapman I. J. Daubar C. Lee S. Kang W. J. McAlpine T. Di Iorio C. Pasqui A. Barbis P. Lawton L. Spalsbury S. Loftin J. Sun 《Space Science Reviews》2017,213(1-4):507-545
The Radiation Monitoring Investigation of the Juno Mission will actively retrieve and analyze the noise signatures from penetrating radiation in the images of Juno’s star cameras and science instruments at Jupiter. The investigation’s objective is to profile Jupiter’s \(>10\mbox{-MeV}\) electron environment in regions of the Jovian magnetosphere which today are still largely unexplored. This paper discusses the primary instruments on Juno which contribute to the investigation’s data suite, the measurements of camera noise from penetrating particles, spectral sensitivities and measurement ranges of the instruments, calibrations performed prior to Juno’s first science orbit, and how the measurements may be used to infer the external relativistic electron environment. 相似文献
143.
M. A. Janssen J. E. Oswald S. T. Brown S. Gulkis S. M. Levin S. J. Bolton M. D. Allison S. K. Atreya D. Gautier A. P. Ingersoll J. I. Lunine G. S. Orton T. C. Owen P. G. Steffes V. Adumitroaie A. Bellotti L. A. Jewell C. Li L. Li S. Misra F. A. Oyafuso D. Santos-Costa E. Sarkissian R. Williamson J. K. Arballo A. Kitiyakara A. Ulloa-Severino J. C. Chen F. W. Maiwald A. S. Sahakian P. J. Pingree K. A. Lee A. S. Mazer R. Redick R. E. Hodges R. C. Hughes G. Bedrosian D. E. Dawson W. A. Hatch D. S. Russell N. F. Chamberlain M. S. Zawadski B. Khayatian B. R. Franklin H. A. Conley J. G. Kempenaar M. S. Loo E. T. Sunada V. Vorperion C. C. Wang 《Space Science Reviews》2017,213(1-4):139-185
144.
G. Randall Gladstone Steven C. Persyn John S. Eterno Brandon C. Walther David C. Slater Michael W. Davis Maarten H. Versteeg Kristian B. Persson Michael K. Young Gregory J. Dirks Anthony O. Sawka Jessica Tumlinson Henry Sykes John Beshears Cherie L. Rhoad James P. Cravens Gregory S. Winters Robert A. Klar Walter Lockhart Benjamin M. Piepgrass Thomas K. Greathouse Bradley J. Trantham Philip M. Wilcox Matthew W. Jackson Oswald H. W. Siegmund John V. Vallerga Rick Raffanti Adrian Martin J.-C. Gérard Denis C. Grodent Bertrand Bonfond Benoit Marquet François Denis 《Space Science Reviews》2017,213(1-4):447-473
The ultraviolet spectrograph instrument on the Juno mission (Juno-UVS) is a long-slit imaging spectrograph designed to observe and characterize Jupiter’s far-ultraviolet (FUV) auroral emissions. These observations will be coordinated and correlated with those from Juno’s other remote sensing instruments and used to place in situ measurements made by Juno’s particles and fields instruments into a global context, relating the local data with events occurring in more distant regions of Jupiter’s magnetosphere. Juno-UVS is based on a series of imaging FUV spectrographs currently in flight—the two Alice instruments on the Rosetta and New Horizons missions, and the Lyman Alpha Mapping Project on the Lunar Reconnaissance Orbiter mission. However, Juno-UVS has several important modifications, including (1) a scan mirror (for targeting specific auroral features), (2) extensive shielding (for mitigation of electronics and data quality degradation by energetic particles), and (3) a cross delay line microchannel plate detector (for both faster photon counting and improved spatial resolution). This paper describes the science objectives, design, and initial performance of the Juno-UVS. 相似文献
145.
John H. McElroy 《Space Policy》1987,3(4):313-325
Earth observations is a controversial subject because of the diversity of interests involved, but one that should not be ignored, as is currently the case, by the US government. This article describes the changing character of Earth observations and the opportunities it provides for economic benefit and national and international economies of scale. Such opportunities can best be met by the formation of an international Earth observations body, in which the USA, represented by an expanded EOSAT, should play a leading role. 相似文献
146.
Curiosity’s Mars Hand Lens Imager (MAHLI) Investigation 总被引:1,自引:0,他引:1
Kenneth S. Edgett R. Aileen Yingst Michael A. Ravine Michael A. Caplinger Justin N. Maki F. Tony Ghaemi Jacob A. Schaffner James F. Bell III Laurence J. Edwards Kenneth E. Herkenhoff Ezat Heydari Linda C. Kah Mark T. Lemmon Michelle E. Minitti Timothy S. Olson Timothy J. Parker Scott K. Rowland Juergen Schieber Robert J. Sullivan Dawn Y. Sumner Peter C. Thomas Elsa H. Jensen John J. Simmonds Aaron J. Sengstacken Reg G. Willson Walter Goetz 《Space Science Reviews》2012,170(1-4):259-317
The Mars Science Laboratory (MSL) Mars Hand Lens Imager (MAHLI) investigation will use a 2-megapixel color camera with a focusable macro lens aboard the rover, Curiosity, to investigate the stratigraphy and grain-scale texture, structure, mineralogy, and morphology of geologic materials in northwestern Gale crater. Of particular interest is the stratigraphic record of a ~5?km thick layered rock sequence exposed on the slopes of Aeolis Mons (also known as Mount Sharp). The instrument consists of three parts, a?camera head mounted on the turret at the end of a robotic arm, an electronics and data storage assembly located inside the rover body, and a calibration target mounted on the robotic arm shoulder azimuth actuator housing. MAHLI can acquire in-focus images at working distances from ~2.1?cm to infinity. At the minimum working distance, image pixel scale is ~14?μm per pixel and very coarse silt grains can be resolved. At the working distance of the Mars Exploration Rover Microscopic Imager cameras aboard Spirit and Opportunity, MAHLI’s resolution is comparable at ~30?μm per pixel. Onboard capabilities include autofocus, auto-exposure, sub-framing, video imaging, Bayer pattern color interpolation, lossy and lossless compression, focus merging of up to 8 focus stack images, white light and longwave ultraviolet (365 nm) illumination of nearby subjects, and 8 gigabytes of non-volatile memory data storage. 相似文献
147.
The Search Coil Magnetometer for THEMIS 总被引:2,自引:0,他引:2
A. Roux O. Le Contel C. Coillot A. Bouabdellah B. de la Porte D. Alison S. Ruocco M. C. Vassal 《Space Science Reviews》2008,141(1-4):265-275
THEMIS instruments incorporate a tri-axial Search Coil Magnetometer (SCM) designed to measure the magnetic components of waves associated with substorm breakup and expansion. The three search coil antennas cover the same frequency bandwidth, from 0.1 Hz to 4 kHz, in the ULF/ELF frequency range. They extend, with appropriate Noise Equivalent Magnetic Induction (NEMI) and sufficient overlap, the measurements of the fluxgate magnetometers. The NEMI of the searchcoil antennas and associated pre-amplifiers is smaller than 0.76 pT $/\sqrt{\mathrm{Hz}}$ at 10 Hz. The analog signals produced by the searchcoils and associated preamplifiers are digitized and processed inside the Digital Field Box (DFB) and the Instrument Data Processing Unit (IDPU), together with data from the Electric Field Instrument (EFI). Searchcoil telemetry includes waveform transmission, FFT processed data, and data from a filter bank. The frequency range covered depends on the available telemetry. The searchcoils and their three axis structures have been precisely calibrated in a calibration facility, and the calibration of the transfer function is checked on board, usually once per orbit. The tri-axial searchcoils implemented on the five THEMIS spacecraft are working nominally. 相似文献
148.
After recalling the motivations for expecting supersymmetry to appear at energies 1 TeV, the reasons why the lightest supersymmetric particle is an ideal candidate for cold dark matter are reviewed. Recent calculations of the relic density including coannihilations and rapid annihilations through direct-channel Higgs boson poles are presented. The experimental constraints from LEP and elsewhere on supersymmetric dark matter are reviewed. The potential implications of a Higgs boson weighing about 115 GeV and the recent measurement of the anomalous magnetic moment of the muon are summarized. 相似文献
149.
Direct and indirect dark matter detection relies on the scattering of the dark matter candidate on nucleons or nuclei. Here, attention is focused on dark matter candidates (neutralinos) predicted in the minimal supersymmetric standard model and its constrained version with universal input soft supersymmetry-breaking masses. Current expectations for elastic scattering cross sections for neutralinos on protons are discussed with particular attention to satisfying all current accelerator constraints as well as insuring a sufficient cosmological relic density to account for the dark matter in the universe. 相似文献
150.
John M. Logsdon 《Space Policy》2011,27(1):1-2
2010 saw both the unveiling of a new US National Space Policy and the announcement of a fundamentally different strategy for US human spaceflight that would move from the NASA-government-led Apollo-style approach to a greater reliance on the private sector and international cooperation. This viewpoint puts forward arguments on why change in the US approach to human spaceflight is needed, while acknowledging that achieving it in the face of vested interests and threats to jobs and livelihoods is extremely difficult. It suggests that greater US recognition of the need to ensure the sustainability of space activity (by addressing debris, radio-frequency interference and potential deliberate disruption of spacecraft), and an apparent willingness to countenance international norms to govern space activities, could be the new policy’s most lasting heritage. 相似文献