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391.
Fedorov  A.  Budnik  E. 《Cosmic Research》2000,38(6):540-546
Localization of the reconnection region at the dayside magnetopause is among the unsolved problems of magnetospheric physics. There are two alternative models, one of which predicts the reconnection at the equatorial magnetopause, and the other predicts the reconnection in the region where the magnetic field of the solar wind flowing around the magnetosphere is antiparallel to the geomagnetic field. The statistical analysis carried out for 53 INTERBALL-1crossings of the high-latitude magnetopause in a special coordinate frame invariant with respect to the interplanetary conditions shows that the model of a reconnection in antiparallel fields agrees well with the experimental data.  相似文献   
392.
Bariteau  M.  Mandeville  J.-C. 《Space Debris》2000,2(2):97-107
When a micro-debris or a micrometeoroid impacts a spacecraft surface, a large number of secondary particles, called ejecta, are produced. These particles can contribute to a modification of the debris environment: either locally by the occurrence of secondary impacts on the components of complex and large space structures, or at great distance by the formation of a population of small orbital debris. This paper describes firstly, the ejecta overall production, and secondly, the lifetime and the orbital evolution of the particles. Finally the repartition of ejecta in LEO is computed. Some results describing the population as a function of size and altitude are presented.  相似文献   
393.
Banka  D.  Leushacke  L.  Mehrholz  D. 《Space Debris》2000,2(2):83-96
A monostatic 24-h debris observation campaign (BPE-1/2000) has been prepared and conducted using FGAN's TIRA L-Band system. Based on experiences from previous Beam-park experiments a similar largely automated data processing is applied on an extended range window of 300–2000km. More than 1500 detections are encountered, 471 of them are verified as being real objects in Low-Earth-Orbit (LEO). PROOF's observation forecasting of catalogued objects is evaluated against the observed objects, and the difficulties obtaining radar cross-sections (RCSs) and object sizes from Beam-park experiments are discussed. Sidelobe detections are identified by using background information like two-line element (TLE) sets and/or catalogued RCSs.In comparison with previous experiments, the statistics show similarities confirming the concept of Beam-park experiments for space debris observations, despite the snapshot character of 24-h experiments. The comparison with MASTER/PROOF'99 and ORDEM2000 leads to a reasonable agreement between models and observations.  相似文献   
394.
The strain–stress state of the solid propellant rocket engines (SPREs) is simulated under impact. The effect of orientation of elastic and strength properties of orthotropic organoplastic shell material on the strain–stress state of the solid propellant is investigated. Normal and oblique impact of single steel cylinder projectiles, both simultaneous and at different times of multiple, converging steel spheric particles with SPRE are investigated in this study. The investigation is conducted numerically. The numerical modeling was carried out in a three-dimensional formulation by the method of finite elements for the continuous approach of the mechanics of a deformable solid. The destruction of the anisotropic material is described by the tensor-polynomial criterion of the fourth degree, which takes into account the influence of hydrostatic pressure.  相似文献   
395.
The RELEС scientific payload of the Vernov satellite launched on July 8, 2014 includes the DRGE spectrometer of gamma-rays and electrons. This instrument comprises a set of scintillator phoswich-detectors, including four identical X-ray and gamma-ray detector with an energy range of 10 kev to 3 MeV with a total area of ~500 cm2 directed to the atmosphere, as well as an electron spectrometer containing three mutually orthogonal detector units with a geometric factor of ~2 cm2 sr. The aim of a space experiment with the DRGE instrument is the study of fast phenomena, in particular Terrestrial gamma-ray flashes (TGF) and magnetospheric electron precipitation. In this regard, the instrument provides the transmission of both monitoring data with a time resolution of 1 s, and data in the event-by-event mode, with a recording of the time of detection of each gamma quantum or electron to an accuracy of ~15 μs. This makes it possible to not only conduct a detailed analysis of the variability in the gamma-ray range, but also compare the time profiles with the results of measurements with other RELEC instruments (the detector of optical and ultraviolet flares, radio-frequency and low-frequency analyzers of electromagnetic field parameters), as well as with the data of ground-based facility for thunderstorm activity. This paper presents the first catalog of Terrestrial gamma-ray flashes. The criterion for selecting flashes required in order to detect no less than 5 hard quanta in 1 ms by at least two independent detectors. The TGFs included in the catalog have a typical duration of ~400 μs, during which 10–40 gamma-ray quanta were detected. The time profiles, spectral parameters, and geographic position, as well as a result of a comparison with the output data of other Vernov instruments, are presented for each of candidates. The candidate for Terrestrial gamma-ray flashes detected in the near-polar region over Antarctica is discussed.  相似文献   
396.
The results of updating the parameters of motion of the Spektr-R spacecraft at the end of 2016 have shown that, in January 2018, with a probability close to unity, the condition that a spacecraft stay in the Earth’s shadow is violated; however, in May of the same year, the ballistic life of the spacecraft will be terminated. Thus, in 2017, the question arose of how to design the correction of flight of this spacecraft using its onboard propulsion system. The correction was designed with allowance for the fact that, for the first time since it was launched, the spacecraft in the course of several years, beginning with 2017, repeatedly approaches the Moon, deeply immersing into its sphere of influence. This paper presents the technologically and organizationally convenient, allowable versions of upcoming correction of the Spektr-R spacecraft trajectory and justifies the particular scheme of its implementation.  相似文献   
397.
398.
This paper discusses and evaluates two innovative SETI education programs conducted at the University of Western Sydney, viz: the SETI Pathways Program and the Life in the Universe Curriculum Project.  相似文献   
399.
Over the past several hundred years, many ideas have been expressed as to how human beings might communicate with extraterrestrials. These ideas have been put forth by experts from a diverse range of fields including physical scientists, mathematicians, behavioral scientists, philosophers and creative writers who have widely differing views on how to express ourselves coherently with civilizations from other worlds.This paper will look at some of these differing viewpoints and stress the need for an inter-disciplinary approach to the challenges of sending and, perhaps most important, receiving messages. Could we decipher a message if we got one? Who is doing the listening and what advantages could an inter-disciplinary approach bring to these efforts? What are some inter-disciplinary approaches to sending messages to extraterrestrials?  相似文献   
400.
Despite its straightened circumstances and doubts about how much political support it receives, Russia's space programme continues — and continues to plan for new activities and applications. This edited version of the National Paper of the Russian Federation, presented at Unispace III in July 1999, details some of the country's major achievements in space in recent years and sets out the main areas it intends to pursue for the early twentieth-first century. While emphasis is placed on communications, remote sensing, navigation and space science, the commitment to manned flight remains.  相似文献   
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