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1.
In order to keep telecommunication infrastructure in the stricken area after a heavy earthquake, wireless ad-hoc mesh networks with satellite communication functions are studied as a survivability application. By using new control software for mesh network, the overall throughput of “KIZUNA” (WINDS) demonstration system was kept at around 25 Mbps.  相似文献   

2.
The National Space Biomedical Research Institute (NSBRI) is supporting the National Aeronautics and Space Administration's (NASA) education mission through a comprehensive Education and Public Outreach Program (EPOP) that communicates the excitement and significance of space biology to schools, families, and lay audiences. The EPOP is comprised of eight academic institutions: Baylor College of Medicine, Massachusetts Institute of Technology, Morehouse School of Medicine, Mount Sinai School of Medicine, Texas A&M University, University of Texas Medical Branch Galveston, Rice University, and the University of Washington. This paper describes the programs and products created by the EPOP to promote space life science education in schools and among the general public. To date, these activities have reached thousands of teachers and students around the US and have been rated very highly.  相似文献   

3.
A multidisciplinary group of students from the university and latter also from the high school was formed in 1988 with the objective to make them put in practice their knowledge in physics, chemistry and mathematics and engineering fields in experimental rocketry. The group was called “Grupo de Foguetes Experimentais”, GFE.Since that time more than 150 students passed throw the group and now many of them are in the space arena.The benefits for students in a space hands-on project are many:
1. More interest in their school subjects is gotten as they see an application for them;
2. Interrelation attitudes are learned as space projects is a team activity;
3. Responsibility is gained as each is responsible for a part of a critical mission project;
4. Multidisciplinary and international experience is gotten as these are space project characteristics;
5. Learn how to work in a high stress environment as use to be a project launch.
This paper will cover the educational experiences gotten during these years and how some structured groups work. It is explained the objectives and how the group was formed. The group structure and the different phases that at each year the new team passes are described. It is shown the different activities that the group uses to do from scientific seminars, scientific club and international meetings to technical tours and assistance to rocket activities in regional schools.It is also explained the group outreach activities as some launches were covered by the media in more then 6 articles in newspaper and 7 television news.In 1999 as formed an official group called NATA, Núcleo de Atividades Aerospaciais within the Universidade Estadual de Londrina, UEL, by some GFE members and teachers from university. It is explained the first group project results.  相似文献   

4.
While the Apex chert is one of the most well-studied Archean deposits on Earth, its formation history is still not fully understood. Here, we present Raman spectroscopic data collected on the carbonaceous material (CM) present within the matrix of the Apex chert. These data, collected within a paragenetic framework, reveal two different phases of CM deposited within separate phases of quartz matrix. These multiple generations of CM illustrate the difficulty of searching for signs of life in these rocks and, by extension, in other Archean sequences.  相似文献   

5.
城乡教育一体化的关键是我们要与时代同步,找到正确的道路,不断优化育人环境,提高城乡教育水平,把发展农村经济放在首位,努力缩小城乡教育设施差距、加快城乡师资力量的均衡发展。使教育资源科学分配与实现城乡教育一体化能够更好地契合在一起。  相似文献   

6.
高校青年教师思想道德建设刍议   总被引:1,自引:0,他引:1  
通过对当前高校青年教师思想道德现状的分析,在肯定青年教师积极、健康、向上主流的同时,指出了存在的三个方面的问题,进而从社会大环境、学校小环境和青年教师自身三个方面深入研究了青年教师思想道德“衰微”的成因。在此基础上,探讨了加强和改进高校青年教师思想道德建设的思路和对策。  相似文献   

7.
Preparations for the third UN Conference on the Exploration and Peaceful Uses of Outer Space (UNISPACE III) were intense. The conference itself was a success. But what forms will the follow-up take? Just reading the 150-page report is an effort in itself. Having played a central part in the preparations and organization, Europe fully appreciates the need to build on the spirit of cooperation which emerged from UNISPACE III. In November 1999, the European States gathered to analyze the results of the conference and to set a course for their future participation in the United Nations Programme on Space Applications (UNPSA), which is mainly done through ESA, and for their participation in the United Nations Committee on the Peaceful Uses of Outer Space (UNCOPUOS), which is done through coordination among ESA Member States. This article presents the authors’ personal accounts of the results of the European efforts around UNISPACE III and shows how ‘European foreign policy’ can work in international space policy. It also seeks to illustrate Europe's commitment to putting space technology to work for the benefit of development throughout the world.  相似文献   

8.
YES2 (launching 2007) aims to demonstrate a tether-assisted re-entry concept, whereby payload will be returned to Earth using momentum provided from a swinging tether. Deployment takes place in two phases: (1) deployment of 3.5 km of tether to the local vertical and hold, and (2) deployment to 30 km for a swinging cut. Optimal trajectories are determined for both phases after comparing the effect of different cost functions on the deployment dynamics. Closed-loop control is provided by linearizing the dynamics around the optimal trajectories and solving a receding horizon control problem for a set of linear feedback gains. The controllers are tested in a flexible tether model with large disturbances to the hardware model and environmental variables. Closed-loop simulations show that the system can be controlled quite well using only feedback of length and length rate.  相似文献   

9.
Space solar power shows great promise for future energy sources worldwide. Most central power stations operate with power capacity of 1000 MW or greater. Due to launch size limitations and specific power of current, rigid solar arrays, the largest solar arrays that have flown in space are around 50 kW. Thin-film arrays offer the promise of much higher specific power and deployment of array sizes up to several MW with current launch vehicles. An approach to early commercial applications for space solar power to distribute power to charge hand-held, mobile battery systems by wireless power transmission (WPT) from thin-film solar arrays in quasi-stationary orbits will be presented. Four key elements to this prototype will be discussed: (1) Space and near-space testing of prototype wireless power transmission by laser and microwave components including WPT space to space and WPT space to near-space HAA transmission demonstrations; (2) distributed power source for recharging hand-held batteries by wireless power transmission from MW space solar power systems; (3) use of quasi-geostationary satellites to generate electricity and distribute it to targeted areas; and (4) architecture and technology for ultra-lightweight thin-film solar arrays with specific energy exceeding 1 kW/kg. This approach would yield flight demonstration of space solar power and wireless power transmission of 1.2 MW. This prototype system will be described, and a roadmap will be presented that will lead to still higher power levels.  相似文献   

10.
This paper contemplates the efforts and developments in the field of sounding rockets carried out in Spain from the decade of the 1960s to the early 1990s when the use of such vehicles was abandoned worldwide.The initial sounding rocket planning within the National Space Research Programs around 1964 (when Spain joined ESRO) is presented.The status of the rocket technology in Spain in 1964 is analysed, reviewing the main technology gaps and the way they were filled to make the planned developments possible.Three Spanish sounding rockets are presented: the INTA-255 (150 km apogee with formative objectives, first launched in 1969), the INTA-300 (300 km apogee with high characteristics and commercial capabilities, first launched in 1974) and the INTA-100 (115 km apogee being finally a totally national product, first launched in 1980).Some guided rocket vehicle projects which were based, on some way, on the previous sounding rockets activities are also mentioned in this paper.  相似文献   

11.
This report describes recent progress in the UN Basic Space Science Initiative (UNBSSI), which aims to facilitate space science education and research, and attendant resources in developing countries. In addition to holding workshops across the developing world, the UN Committee on the Peaceful Uses of Outer Space (COPUOS) successfully implemented the International Heliophysical Year (IHY) as a catalyst for improving understanding of the Sun and of solar-terrestrial physics. Building on this it is now preparing for the International Space Weather Initiative (ISWI). Achievements of the former are discussed, as are the goals and anticipated activities of the latter.  相似文献   

12.
In the upcoming generation of satellite sensors, hyperspectral instruments will play a significant role. This payload type is considered world-wide within different future planning.Our team has now successfully finalized the Phase B study for the advanced hyperspectral mission EnMAP (Environmental Mapping and Analysis Programme), Germans next optical satellite being scheduled for launch in 2012. GFZ in Potsdam has the scientific lead on EnMAP, Kayser-Threde in Munich is the industrial prime.The EnMAP instrument provides over 240 continuous spectral bands in the wavelength range between 420 and 2450 nm with a ground resolution of 30 m×30 m. Thus, the broad science and application community can draw from an extensive and highly resolved pool of information supporting the modeling and optimization process on their results. The performance of the hyperspectral instrument allows for a detailed monitoring, characterization and parameter extraction of rock/soil targets, vegetation, and inland and coastal waters on a global scale supporting a wide variety of applications in agriculture, forestry, water management and geology. The operation of an airborne system (ARES) as an element in the HGF hyperspectral network and the ongoing evolution concerning data handling and extraction procedures, will support the later inclusion process of EnMAP into the growing scientist and user communities.  相似文献   

13.
More than 60 years after the late Nobel laureate Hannes Alfvén had published a letter stating that oscillating magnetic fields can accelerate ionised matter via magneto–hydrodynamic interactions in a wave like fashion, the technical implementation of Alfvén waves for propulsive purposes has been proposed, patented and examined for the first time by a group of inventors.Consequently improved since then, the name of the latest concept, relying on magneto-acoustic waves to accelerate electric conductive matter, is MOA2—Magnetic field Oscillating Amplified Accelerator. Based on computer simulations, which were undertaken to get a first estimate on the performance of the system, MOA2 is a corrosion free and highly flexible propulsion system, whose performance parameters might easily be adapted in operation, by changing the mass flow and/or the power level. As such the system is capable of delivering a maximum specific impulse of 13116 s (12.87 mN) at a power level of 11.16 kW, using Xe as propellant, but can also be attuned to provide a thrust of 236.5 mN (2411 s) at 6.15 kW of power. First tests—that are further described in this paper—have been conducted successfully with a 400 W prototype system at an ambient pressure of 0.20 Pa, delivered 9.24 mN of thrust at 1472 s ISP, thereby underlining the feasibility of the concept.Based on these results, space propulsion is expected to be a prime application for MOA2—a claim that is supported by numerous applications such as Solar and/or Nuclear Electric Propulsion or even as an ‘afterburner system’ for Nuclear Thermal Propulsion. However, MOA2 has so far seen most of its R&D impetus from terrestrial applications, like coating, semiconductor implantation and manufacturing as well as steel cutting. Based on this observation, MOA2 resembles an R&D paradigm buster, as it is the first space propulsion system, whose R&D is driven primarily by its terrestrial applications. Different terrestrial applications exist, but the most successful scenarios so far revolve around MOA2's unique features with respect to high throughput/low target temperature coatings on sensitive materials. In combination with its intrinsic high flexibility, MOA2 is highly suited for a common space-terrestrial application research and utilisation strategy.This paper presents the recent developments of the MOA2 R&D activities at Q2 Technologie(s), the company in Vienna, Austria, which has been set up to further develop and test the magneto-acoustic wave technology and its applications.  相似文献   

14.
Implementation of an ESA delta-DOR capability   总被引:2,自引:0,他引:2  
This paper describes the implementation of delta-DOR (delta-differential one-way ranging) receivers within the ESA Deep Space ground station network. Delta-DOR provides very accurate plane-of-sky measurements of spacecraft position which complement existing line-of-sight ranging and Doppler measurements. We discuss how this technique has been adapted and implemented at the two ESA deep-space ground stations using existing equipment and infrastructure. These new capabilities were added by writing new software modules for the standard ESA digital receiver (the intermediate frequency modem system—IFMS). With these upgrades the receiver has the ability to record accurately timetagged signals from up to eight IF sub-channels. These sub-channels can have bandwidths of 50 kHz–2 MHz with a sample quantization of 1–16 bits per component. The IF samples are stored locally for subsequent retrieval over a WAN by the correlator facility at ESOC.  相似文献   

15.
Petr Lla 《Acta Astronautica》1996,39(9-12):647-655
The Committee on the Peaceful Uses of Outer Space (COPUOS) was established in 1959 by the United Nations General Assembly in order to review and foster international cooperation in the peaceful uses of outer space and to consider legal issues arising from the exploration of outer space. Since its establishment, the Committee has addressed such issues as benefits from space activities, the definition and delimitation of outer space and the use of the geostationary orbit, implications of remote sensing, space sciences, space-based communications, navigation and meteorological systems, as well as use of nuclear power sources in outer space, space debris and spin-off benefits of space technology. At its session in 1996, a symposium on the ‘Utilization of micro- and small satellites for the expansion of low-cost space activities, taking into particular account the needs of developing countries’ was organized by COSPAR and IAF to complement discussions on this theme. It was noted at the symposium that the increasing number of small satellites, in particular the proposed introduction of multi-satellite ‘constellations’ at low orbits, would result in concentrations of satellite mass at certain regions of space around the Earth. Special provisions would be needed to minimize the probability of satellite breakups and collisions which might create more space debris and compromise the future of spaceflight.  相似文献   

16.
K.F. Long  R.K. Obousy  A. Hein 《Acta Astronautica》2011,68(11-12):1820-1829
The Daedalus spacecraft design was a two-stage configuration carrying 50,000 tonnes of DHe3 propellant. Daedalus was powered by electron driven Inertial Confinement Fusion (ICF) to implode the pellets at a frequency of 250 Hz. The mission was to Barnard's star 5.9 light years away in a duration of around 50 years. This paper is related to the successor Project Icarus, a theoretical engineering design study that began on 30 September 2009 and is a joint initiative between the Tau Zero Foundation and The British Interplanetary Society. In the first part of this paper, we explore ‘flyby’ variations on the Daedalus propellant utilisation for two different mission targets: Barnard's star and Epsilon Eridani, 10.7 light years away. With a fixed propellant mass a number of staged configurations (1–4) are derived for an optimal configuration but then moving to an off-optimal configuration due to the requirement for a high final science payload mass. Some comments are then made on the ICF pellet configuration compared to the typical pellets fielded at the National Ignition Facility (NIF) and those proposed for the Vista and Longshot fusion based propulsion designs. This is a working progress report, which aims to study perturbations of the Daedalus baseline design as part of a trade study. This is a submission of the Project Icarus Study Group.  相似文献   

17.
With the rapid advancement in remote sensing technology and corresponding applications, the Earth Observation Ground Segment has undergone a significant change at NRSA. From dedicated data acquisition and processing systems, we have realized multi-mission data acquisition quick look and browse systems and also multi-mission integrated information management systems. Front end of data reception station has been upgraded to handle wider bandwidth and data rates up to 320 Mbps for near future missions such as the Radar Imaging Satellite (RISAT). Antenna, feed, down converters and RF chain have been upgraded. To cater to multi-mission scenario mission independent, fully configurable demodulator/bit synchs have been deployed. For handling data acquisition in multi-satellite scenario where in data from 5 to 6 remote sensing satellites are to be received almost simultaneously, automation of operations has been incorporated towards station configuration to avoid manual errors. From media-based data handling, there has been a shift towards net centric data handling among the various work centers such as user order processing, data processing systems, special processing systems, data quality evaluation, and product quality control work centers. The turn around time for dissemination of user desired data products has been improved from two weeks to one day. Presently a state of the art integrated environment has been envisaged which will bring down the turn around time for the supply of data products significantly. Automation has been incorporated at both data acquisition and data processing to improve the product throughput. Presently NRSA is catering to a demand of about 30,000 data products per annum and in the next two years it is aimed to reach a level of 50,000 products per annum by realizing the integrated multi-mission ground system for earth observation (IMGEOS). This will significantly modify the entire data production and dissemination chain so that data can be made available to user within 1 h from data acquisition at Shadnagar in some cases. Some of these novel developments planned in the near future will be discussed in this paper.  相似文献   

18.
Perek  Luboš 《Space Debris》2000,2(2):123-136
Rules for activities in outer space are agreed upon in the Committee on the Peaceful Uses of Outer Space of the United Nations. Several international treaties have been adopted in the 1970s, that is, at a time before space debris became a concern for the international community. In the years 1979–1988 numerous documents were prepared by the UN Secretariat on space debris, but no official discussions of the problem were initiated by states members of the COPUOS. First proposals for introducing the matter to the UN appeared around 1988, after important studies on the subject were published by states and leading intergovernmental organizations. Also the International Telecommunication Union became concerned about the proliferation of space debris in the geostationary orbit and adopted in 1993 a recommendation to restrict the generation of debris and to re-orbit satellites approaching the end of their active lives into disposal orbits beyond the belt populated by active satellites. In 1994, the UN started discussing scientific and technical aspects of space debris. In the following years, with the assistance of experts from prominent space agencies, it elaborated a Technical Report on space debris. Legal aspects of the problem have not yet begun being discussed because the necessary consensus among states members of the COPUOS has not yet been achieved. Very recently, the UN received first information on a wider subject, space traffic management.  相似文献   

19.
A mission to the surface of Venus would have high scientific value, but most electronic devices and sensors cannot operate at the 450 °C ambient surface temperature of Venus. Power and cooling systems were analyzed for Venus surface operation. A radioisotope power and cooling system was designed to provide electrical power for a probe operating on the surface of Venus. For a mission duration of substantial length, the use of thermal mass to maintain an operable temperature range is likely impractical, and active refrigeration may be required to keep components at a temperature below ambient. Due to the high thermal convection of the high-density atmosphere, the heat rejection temperature was assumed to be at a 500 °C radiator temperature, 50 °C above ambient. The radioisotope Stirling power converter designed produces a thermodynamic power output capacity of 478.1 W, with a cooling power of 100 W. The overall efficiency is calculated to be 23.36%. The mass of the power converter is estimated at approximately 21.6 kg.  相似文献   

20.
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