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1.
KuaFu Mission     
The KuaFu mission-Space Storms, Aurora and Space Weather Explorer-is an "L1+Polar" triple satellite project composed of three spacecraft: KuaFu-A will be located at L1 and have instruments to observe solar EUV and FUV emissions, and white-light Coronal Mass Ejections (CMEs), and to measure radio waves, the local plasma and magnetic field,and high-energy particles. KuaFuB1 and KuaFu- B2 will bein polar orbits chosen to facilitate continuous 24 hours a day observation of the north polar Aurora Oval. The KuaFu mission is designed to observe the complete chain of disturbances from the solar atmosphere to geospace, including solar flares, CMEs, interplanetary clouds, shock waves, and their geo-effects, such as magnetospheric sub-storms and magnetic storms, and auroral activities. The mission may start at the next solar maximum (launch in about 2012), and with an initial mission lifetime of two to three years. KuaFu data will be used for the scientific study of space weather phenomena, and will be used for space weather monitoring and forecast purposes. The overall mission design, instrument complement, and incorporation of recent technologies will target new fundamental science, advance our understanding of the physical processes underlying space weather, and raise the standard of end-to-end monitoring of the Sun-Earth system.  相似文献   
2.
Radio synchrotron emission, its polarization and its Faraday rotation are powerful tools to study the strength and structure of magnetic fields in galaxies. Unpolarized emission traces turbulent fields which are strongest in spiral arms and bars (20–30?μG) and in central starburst regions (50–100?μG). Such fields are dynamically important, e.g. they can drive gas inflows in central regions. Polarized emission traces ordered fields which can be regular or anisotropic random, generated from isotropic random fields by compression or shear. The strongest ordered fields of 10–15?μG strength are generally found in interarm regions and follow the orientation of adjacent gas spiral arms. Ordered fields with spiral patterns exist in grand-design, barred and flocculent galaxies, and in central regions of starburst galaxies. Faraday rotation measures (RM) of the diffuse polarized radio emission from the disks of several spiral galaxies reveal large-scale patterns, which are signatures of regular fields generated by a mean-field dynamo. However, in most spiral galaxies observed so far the field structure is more complicated. Ordered fields in interacting galaxies have asymmetric distributions and are an excellent tracer of past interactions between galaxies or with the intergalactic medium. Ordered magnetic fields are also observed in radio halos around edge-on galaxies, out to large distances from the plane, with X-shaped patterns. Future observations of polarized emission at high frequencies, with the EVLA, the SKA and its precursors, will trace galactic magnetic fields in unprecedented detail. Low-frequency telescopes (e.g. LOFAR and MWA) are ideal to search for diffuse emission and small RMs from weak interstellar and intergalactic fields.  相似文献   
3.
The successful long-duration radiation measurements performed by the VIRTIS instrument aboard ESA’s Venus Express spacecraft have provided an excellent collection of atmospheric and surface data that stand out due to their high temporal and spatial coverage of the planet and due to a high diversity of measurement and environmental conditions.  相似文献   
4.
Howardite-eucrite-diogenite (HED) meteorites, thought to be derived from 4 Vesta, provide the best sampling available for any differentiated asteroid. However, deviations in oxygen isotopic composition from a common mass-fractionation line suggest that a few eucrite-like meteorites are from other bodies, or that Vesta was not completely homogenized during differentiation. The petrology and geochemistry of HEDs provide insights into igneous processes that produced a crust composed of basalts, gabbros, and ultramafic cumulate rocks. Although most HED magmas were fractionated, it is unresolved whether some eucrites may have been primary melts. The geochemistry of HEDs indicates that bulk Vesta is depleted in volatile elements and is relatively reduced, but has chondritic refractory element abundances. The compositions of HEDs may favor a magma ocean model, but inconsistencies remain. Geochronology indicates that Vesta accreted and differentiated within the first several million years of solar system history, that magmatism continued over a span of ??10 Myr, and that its thermal history extended for perhaps 100 Myr. The protracted cooling history is probably responsible for thermal metamorphism of most HEDs. Impact chronology indicates that Vesta experienced many significant collisions, including during the late heavy bombardment. The age of the huge south pole crater is controversial, but it probably ejected Vestoids and many HEDs. Continued impacts produced a regolith composed of eucrite and diogenite fragments containing only minor exotic materials. HED meteorites serve as ground truth for orbital spectroscopic and chemical analyses by the Dawn spacecraft, and their properties are critical for instrument calibration and interpretation of Vesta??s geologic history.  相似文献   
5.
This paper presents some approaches to the development of advanced detectors and to miniaturized instrument design which are pursued in the Institute of Space Sensor Technology of DLR (the German Aerospace Research Establishment). The instrument design approach is demonstrated for a low-weight (3 kg) dual camera system with narrow-angle in-track stereo and wide-angle multispectral features. Each camera has its own signal processor and 0,5 G Bit mass memory. The activities for advanced detector development are concentrated on two different kinds of detectors and instrumentations: infrared detector arrays and instruments at wavelengths out to about 240 μm, and superheterodyne receivers in the submillimeter and far-infrared spectral ranges.  相似文献   
6.
During the past ten years the French laboratories working in the field of fluids and material sciences had access to regular, long-lasting manned missions onboard the Russian MIR Space Station. Beyond the French scientific program that was performed with the ALICE apparatus, a cooperative research program was developed with DLR, NASA and RSA. This cooperation was based on bartered agreements that included the joint utilization of the instruments onboard the MIR station (ALICE, TITUS furnace from DLR, vibration device from RKK Energia) and the funding of dedicated cartridges (DLR) or thermostats (DLR and NASA), as well as launch services (NASA) by the Cooperating Agencies. We present a review of this program with a particular emphasis on its scientific results and on the progress that has been achieved in science and applications. They covered a large field of condensed matter physics, from material sciences to near-critical and off-critical phase separation kinetics and near critical fluid hydrodynamics (thermoacoustic heat transport and vibrational convection). The high microgravity relevance of all these investigations naturally led to outstanding results that was published in the world's best scientific journals. The analysis of the latest experiments performed during the PEGASUS mission shows they will not be an exception to that evaluation. Off-critical phase separation with NASA, pressure-driven piston effect and equiaxed solidification with DLR, heat transport under calibrated vibrations with RKK Energia, all will be presented. The conclusion will stress the international character of this microgravity research program, the conditions of its success and what can be gained from it in the perspective of the space station utilization.  相似文献   
7.
An advanced, multiple projection, dual energy x-ray absorptiometry (AMPDXA) scanner system is under development. The AMPDXA is designed to make precision bone and muscle loss measurements necessary to determine the deleterious effects of microgravity on astronauts as well as develop countermeasures to stem their bone and muscle loss. To date, a full size test system has been developed to verify principles and the results of computer simulations. Results indicate that accurate predictions of bone mechanical properties can be determined from as few as three projections, while more projections are needed for a complete, three-dimensional reconstruction.  相似文献   
8.
Interplanetary scintillation (IPS) observations may be used to study large-scale propagation properties of transient interplanetary disturbances in a three-dimensional manner, although current IPS observations have several limitations, e.g., poor time resolution and line-of-sight integration. Comparative studies with spacecraft solar wind and white-light coronal mass ejection (CME) observations are quite helpful in interpretation of IPS observations. An interplanetary disturbance apparently in association with a disappearing solar filament, which took place near the central meridian of the Sun on late 22 April, 1979, is discussed to examine previous deductions from IPS observations. Three-station IPS observations of the flow speed and spacecraft observations suggest that a quasi-spherical interplanetary disturbance was formed around the Sun-Earth line, whereas the center of the disturbance derived from the distribution of enhanced IPS across the sky (g-maps) is located to the east of the Sun-Earth line.Permanently at Research Institute of Atmospherics, Nagoya University, Toyokawa 442, Japan.  相似文献   
9.
The earth's magnetosphere absorbs only a minor fraction (≈ 10?3) of the incident solar wind energy. Variations of the solar wind can often cause lively reactions in the earth's close environment. However, the physical mechanisms involved are not yet understood. It appears now that the combined action of the solar wind momentum flux, the direction of the interplanetary magnetic field as well as its fluctuations might play the dominant role. The behaviour of these parameters is governed in some characteristic way by the solar wind stream structure which reflects the condition of the solar corona and its magnetic field topology. Transients in the sun's atmosphere associated with solar activity cause reactions in the interplanetary medium which also show some typical, though very different, signatures. Taking into account the interdependence of the solar wind parameters in context with the underlying solar phenomena, we may be able to pinpoint the mechanism which controls the action of the solar wind on the magnetosphere.  相似文献   
10.
Treatment strategies for Space Motion Sickness (SMS) were compared using the results of postflight oral debriefings. Standardized questionnaires were administered to all crewmembers immediately following Space Shuttle flights by NASA flight surgeons. Cases of SMS were graded as mild, moderate, or severe based on published criteria, and medication effectiveness was judged based on subjective reports of symptom relief. Since October 1989, medication effectiveness is reported inflight through Private Medical Conferences with the crew. A symptom matrix was analyzed for 19 crewmembers treated with oral combination of scopolamine and dextroamphetamine (scopdex) and 15 crewmembers treated with promethazine delivered by intramuscular i.m. or suppository routes. Scopdex has been given preflight as prophylaxis for SMS, but analysis showed delayed symptom presentation in 9 crewmembers or failed to prevent symptoms in 7. Only 3 crewmembers who took scopdex had no symptoms inflight. Fourteen out of 15 crewmembers treated with i.m. promethazine and 6 of 8 treated with promethazine suppositories after symptom development had immediate (within 1-2 h) symptom relief and required no additional medication. There were no cases of delayed symptom presentation in the crewmembers treated with promethazine. This response is in contrast to untreated crewmembers who typically have slow symptom resolution over 72-96 h. We conclude that promethazine is an effective treatment of SMS symptoms inflight. NASA policy currently recommends treating crewmembers with SMS after symptom development, and no longer recommends prophylaxis with scopdex due to delayed symptom development and apparent variable absorption of oral medications during early flight days.  相似文献   
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