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641.
Terai M  Nitta K 《Acta Astronautica》1991,25(4):239-243
A plan of the health care system for the crew on the lunar base is described in this study. The health care system consists of two subsystems. The first is the daily health care system. The system contains health care menus, similar to those on Earth, and some biochemical and ordinary medical examinations. The second system is a periodic medical inspection for the crew's bones and the determination of natural radioisotopes in the body. These care systems are automatically treated with the examination and data filing. Usually these examinations are carried out without the presence of a medical doctor. Examinations and files of the whole results are controlled by a computer. The daily results of examinations are compared with data in the file. If any abnormal values are found in the results, an appropriate message is sent advising whether he must receive an in-depth examination by a medical doctor, or be reexamined by the same submenu. The automatic health care system also records transactions with the life support monitoring system.  相似文献   
642.
This paper reports on the manufacturing and evaluation of a solar power sail membrane prototype for the OKEANOS project. The in-house prototype was built by the Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency. Mechanical and electrical evaluation tests were conducted. The membrane, thin-film solar cells, reflectivity control devices were good condition after the manufacturing and handling. The improvements in the manufacturing process and design were found. The manufacturing process and design were fundamentally established. After the prototype, improvement plans for the manufacturing process and design were tried. We have a prospect of manufacturing the flight model sail and continue to the development.  相似文献   
643.
OSIRIS-REx is the first NASA mission to return a sample of an asteroid to Earth. Navigation and flight dynamics for the mission to acquire and return a sample of asteroid 101955 Bennu establish many firsts for space exploration. These include relatively small orbital maneuvers that are precise to ~1 mm/s, close-up operations in a captured orbit about an asteroid that is small in size and mass, and planning and orbit phasing to revisit the same spot on Bennu in similar lighting conditions. After preliminary surveys and close approach flyovers of Bennu, the sample site will be scientifically characterized and selected. A robotic shock-absorbing arm with an attached sample collection head mounted on the main spacecraft bus acquires the sample, requiring navigation to Bennu’s surface. A touch-and-go sample acquisition maneuver will result in the retrieval of at least 60 grams of regolith, and up to several kilograms. The flight activity concludes with a return cruise to Earth and delivery of the sample return capsule (SRC) for landing and sample recovery at the Utah Test and Training Range (UTTR).  相似文献   
644.
A miniaturized in situ laser induced breakdown spectroscope-LIBS is one of the two lunar rover payloads to be flown in India’s next lunar mission Chandrayaan-2, with an objective to carry-out a precise qualitative and quantitative elemental analyses of lunar regolith at the proximity of the landing region. As per the imposed mission constraints and the executed design optimization studies, a compact and light-weight LIBS prototype model is developed at our premises. This paper mainly concerns with the estimation of theoretical aspects; especially on evaluation of elemental ablation parameters and signal-to-noise ratio (SNR) calculations for the designed instrument. Theoretical estimations and simulations yielded an incident laser power density of the order of 5 × 1010 W/cm2 on the target surface at a defined lens-to-surface distance (LTSD) of 200 mm and revealed an SNR > 100 for most of the elements under consideration. This paper also addresses the impact of LTSD variation on detection capability. The estimation of plasma-temperatures was carried out utilizing the emission spectra obtained under high vacuum environments employing the LIBS laboratory model. Experimental investigations and the performed theoretical estimations asserted the successful operation of the configured LIBS instrument for in situ elemental analyses on lunar surface.  相似文献   
645.
This paper is devoted to the study of propagation of disturbances caused by interplanetary shocks (IPS) through the Earth’s magnetosphere. Using simultaneous observations of various fast forward shocks by different satellites in the solar wind, magnetosheath and magnetosphere from 1995 till 2002, we traced the interplanetary shocks into the Earth’s magnetosphere, we calculated the velocity of their propagation into the Earth’s magnetosphere and analyzed fronts of the disturbances. From the onset of disturbances at different satellites in the magnetosphere we obtained speed values ranging from 500 to 1300 km/s in the direction along the IP shock normal, that is in a general agreement with results of previous numerical MHD simulations. The paper discusses in detail a sequence of two events on November 9th, 2002. For the two cases we estimated the propagation speed of the IP shock caused disturbance between the dayside and nightside magnetosphere to be 590 km/s and 714–741 km/s, respectively. We partially attributed this increase to higher Alfven speed in the outer magnetosphere due to the compression of the magnetosphere as a consequence of the first event, and partially to the faster and stronger driving interplanetary shock. High-time resolution GOES magnetic field data revealed a complex structure of the compressional wave fronts at the dayside geosynchronous orbit during these events, with initial very steep parts (10 s). We discuss a few possible mechanisms of such steep front formation in the paper.  相似文献   
646.
A general formulation of the deployment dynamics of tether connected two-body systems taking into account the three dimensional librational motion, longitudinal and transverse vibrations of the continuous tether, eccentricity of the orbit and aerodynamic drag in a rotating, oblate atmosphere, is presented. Three simple deployment procedures (uniform, exponential and their combination) are considered. In the beginning analytical solutions are obtained for the degenerate case of negligible vibrations in a circular orbit, which help in establishing trends for the more general situation. This is followed by the general dynamics of the system investigated through integration of the linearized autonomous equations of motion numerically. Typical plots are presented which describe the effects of various system parameters on the tether dynamics during deployment of a subsatellite from the Space Shuttle.  相似文献   
647.
The Total Electron Content (TEC) from four locations in the Indian sector namely, Trivandrum (8.47°N, 76.91°E, Geomag.0.63°S, 0.3° dip), Waltair (17.7° N, 83.3°E, Geomag. 6.4°N, 20° dip), Bhopal (23.28°N, 77.34°E, Geomag.14.26°N, 33.2° dip), and Delhi (28.58°N, 77.21°E, Geomag.19.2°N, 43.4° dip) during a low sunspot year of 2004 are used to study the variabilities of the TEC. The day time TEC values are higher over Waltair and Bhopal compared to those at Trivandrum and Delhi. Considerable day-to-day variations in the diurnal values of TEC are observed at the anomaly crest locations. The observed GPS-TEC has been compared with the IRI-2007 model derived TEC considering three different options (IRI-2001, IRI-2001 corrected and Ne-Quick) available in the model for the topside electron density. The TEC derived with Ne-Quick and IRI-01 corrected options show better agreement with GPS-TEC while the TEC from IRI-01 method shows larger deviations. From the correlation analysis carried out between TEC value at 1300 h LT and solar indices parameters namely sunspot number (SSN), F10.7 and EUV, it is observed that the correlation is more during equinoctial months and less during summer months. The correlation coefficients observed over the anomaly locations, Bhopal and Delhi are lower compared to those at Trivandrum and Waltair.  相似文献   
648.
Based on the spectrophotometric data, by decomposition of the observed continuum, the power - law continuum characteristics of the central source are obtained. The behaviour of both electron temperature Te and density ne in the Narrow - Line Region (NLR) of NGC 7469 is discussed on the thermal and ionization equilibria calculations. Te in NLR of the Sy1 galaxies are higher than the Sy2 ones, and the possible explanation is the lack of the dense (ne 1010 cm−3) zone close to the central source in the Sy2 galaxies.  相似文献   
649.
A High-Resolution Radar Detection Strategy   总被引:5,自引:0,他引:5  
A comparison of single range cell detection and integrated contiguous range cell detection for a high range resolution radar is presented. A simulation was used to generate probability of detection curves for the two detection strategies using 10 target models with different target scattering characteristics. The integrated range cell detection strategy was found to be superior in all cases except when the target is composed of a single strong flare point.  相似文献   
650.
Low fluxes of protons with energies 0.3–10 MeV were studied during 21–23 solar cycles as a function of the MgII index using the data of the instruments CPME, EIS (IMP8), and EPHIN (SOHO). It has been shown that a) during quiet time of solar activity the fluxes of protons (background protons) have a positive correlation with the MgII index value throughout the solar cycle, b) specific features of variations of the MgII index during the solar minima of 1986–1987 and 1996–1997 can be considered, as well as variations of background fluxes of low energy charged particles, to be manifestations of the 22-year magnetic cycle of the Sun, and c) periods of the lowest value of the MgII index are also characterized by the smaller values of the ratio of intensities of protons and helium nuclei than in other quiet periods. A hypothesis is put forward that acceleration in a multitude of weak solar flares is one of the sources of background fluxes of low energy particles in the interplanetary space.  相似文献   
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