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101.
The National Space Research Institute (INPE) is developing the first Brazilian Scientific Microsatellite (SACI-1) based on the vanguard technology and on the experience acquired through projects developed by Brazilian Space Program. The SACI-1 is a 750km polar orbit satellite. The spacecraft will combine spin stabilization with geomagnetic control and has a total mass of 60 kg. The overall dimensions are 640×470×470 mm. The SACI-1 satellite shall be launched together with CBERS (China-Brazil Earth Resource Satellite). Its platform is being designed for multiple mission applications. The Brazilian Academy of Sciences has selected four scientific payloads that characterize the mission. The scientific experiments are: ORCAS (Solar and Anomalous Cosmic Rays Observation in the Magnetosphere), PLASMEX (Study of Plasma Bubbles), FOTSAT (Airglow Photometer), and MAGNEX (Geomagnetic Experiment).  相似文献   
102.
When discussing problems related to medical service in space flight, particular attention should be given to the specific living conditions and changes associated with space flight. In disease and injury, surgery can be provided only after conservative therapy has failed. In this context gnotobiological chambers allowing surgery in aseptic conditions seem promising. A portable set of interchangeable surgical tools should be made of light-weight alloys that can be readily sterilized. Electroanalgesia in combination with auriculoacupuncture as well as peridureal anesthesia may be used as they allow normal operations in autonomous space flight conditions. Changes in the sympatho-adrenal and kallikrein-kinin systems, as well as water-electrolyte balance, should be taken into account in developing methods and means of medical service in critical situations. Special attention should be given to the prevention and treatment of brain edema in view of weightlessness-induced cephalad fluid shifts.  相似文献   
103.
In the 25 years since the launch of the first weather satellite, meteorological observations from space have become an essential part of weather forecasting and global environmental monitoring. Beginning in the 1970s, constrained national budgets and the need for a coordinated approach to global satellite observing have caused satellite operators to pursue international cooperation to assure the continuity and compatibility of these systems. This article reviews current bilateral and multilateral cooperation and technical coordination in environmental satellite activities. It also explores the potential for alternative institutional arrangements for maintaining the continuity of environmental satellite data in the decades to come.  相似文献   
104.
The Space Shuttle Orbiter employs a fly-by-wire control system of 200 major avionic hardware devices interfacing with five flight computers through a complex data bus system. Responses to man-in-the-loop commands are dependent on the flight software. Early program development testing of the computer and avionic hardware has been accomplished at Rockwell International's Shuttle Avionics Development Laboratory (ADL). Hardware development has led to complete multi-string system testing and flight software evaluations. This paper provides an overview of the ADL. Its role and test capabilities in support of Shuttle development are defined. The nature of computer driven test programs for the Orbiter displays, the Digital Autopilot, and flight software development describe the test bed provided by the ADL.  相似文献   
105.
The creation of artificial plasma density irregularities (AI) with prescribed spectra in the ionospheric heating experiments is discussed. We show that periodic successions of powerful pulses, pumped into the F-region of the ionosphere lead to obtaining AI with the controlled stationary spatial spectrum and allow us to change power low spectral index 2β at least from 2β = 2.2 to 2β = 3.4 by changing of the powerful pulse time schedule.  相似文献   
106.
Of all the other planets in the solar system, Mars remains the most promising for further elucidating concepts about chemical evolution and the origin of life. Strategies were developed to pursue three exobiological objectives for Mars exploration: determining the abundance and distribution of the biogenic elements and organic compounds, detecting evidence of an ancient biota on Mars, and determining whether indigenous organisms exist anywhere on the planet. The three strategies are quite similar and, in fact, share the same sequence of phases. In the first phase, each requires global reconnaissance and remote sensing by orbiters to select sites of interest for detailed in situ analyses. In the second phase, lander missions are conducted to characterize the chemical and physical properties of the selected sites. The third phase involves conducting "critical" experiments at sites whose properties make them particularly attractive for exobiology. These critical experiments would include, for example, identification of organics, detection of fossils, and detection of extant life. The fourth phase is the detailed analysis of samples returned from these sites in Earth-based laboratories to confirm and extend previous discoveries. Finally, in the fifth phase, human exploration is needed to establish the geological settings for the earlier findings or to discover and explore sites that are not accessible to robotic spacecraft.  相似文献   
107.
It is well known that the solar wind can significantly affect high-latitude ionospheric dynamics. However, the effects of the solar wind on the middle- and low-latitude ionosphere are much less studied. In this paper, we report observations that large perturbations in the middle- and low-latitude ionosphere are well correlated with solar wind variations. In one event, a significant (20–30%) decrease of the midlatitude ionospheric electron density over a large latitudinal range was related to a sudden drop in the solar wind pressure and a northward turning of the interplanetary magnetic field, and the density decrease became larger at lower latitudes. In another event, periodic perturbations in the dayside equatorial ionospheric E × B drift and electrojet were closely associated with variations in the interplanetary electric field. Since the solar wind is always changing with time, it can be a very important and common source of ionospheric perturbations at middle- and low-latitudes. The relationship between solar wind variations and significant ionospheric perturbations has important applications in space weather.  相似文献   
108.
Engineering concepts for inflatable Mars surface greenhouses.   总被引:1,自引:0,他引:1  
A major challenge of designing a bioregenerative life support system for Mars is the reduction of the mass, volume, power, thermal and crew-time requirements. Structural mass of the greenhouse could be saved by operating the greenhouse at low atmospheric pressure. This paper investigates the feasibility of this concept. The method of equivalent system mass is used to compare greenhouses operated at high atmospheric pressure to greenhouses operated at low pressure for three different lighting methods: natural, artificial and hybrid lighting.  相似文献   
109.
In this work we have tracked coronal mass ejections observed with the ground based Mirror Coronagraph for Argentina (MICA) and the Large Angle and Spectroscopic Coronagraph (LASCO) C2 and C3 on board of the Solar and Heliospheric Observatory (SOHO). The MICA telescope is located at El Leoncito (31.8 S, 69.3 W), San Juan (Argentina), since 1997 as part of a bilateral scientific project between Germany and Argentina. SOHO is a project of international cooperation between ESA and NASA. Together these instruments are able to observe the solar corona ranging from 1.05 to 32 solar radii. MICA images the Fe XIV emission line corona and LASCO coronagraphs observe the Thomson scattered white light corona. We have selected events for which there are observations from the three coronagraphs. Using the composite data we were able to obtain height-time diagrams for the corresponding dynamical coronal features traveling outwards in order to determine some of their kinematical properties, i.e., plane of sky velocity and acceleration.  相似文献   
110.
A properly weighted measure of histogram distortion is proposed to evaluate data with different time scales for any index in any field. This approach is applied to produce a long-term data base of disturbance measure of the geomagnetic indices and ionospheric VI sounding characteristics. It is shown that the ionosphere disturbances detected by the proposed technique include all the storm periods defined by the statistical procedure used earlier at IRPL, NBS, Washington, D.C.  相似文献   
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