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91.
Kugusheva A. D. Kalegaev V. V. Vlasova N. A. Petrov K. A. Bazilevskaya G. A. Makhmutov V. S. 《Cosmic Research》2021,59(6):446-455
Cosmic Research - The results of an analysis of the space–time characteristics and dynamics of precipitations of magnetospheric electrons with energies in the range from 0.1 to 0.7 MeV are... 相似文献
92.
The mass loss of spacecraft polyimide films under the action of atomic oxygen and vacuum ultraviolet radiation 总被引:1,自引:0,他引:1
The threshold values of the annual fluence of atomic oxygen (F AO ≈ 1020 cm?2), as well as the ratios of the energy-flux density of vacuum ultraviolet radiation of the solar spectrum to the flux density of atomic oxygen (Φ ν /Φ AO ≈ 8 × 10?15 mJ) were determined, which are characterized the influence of the synergistic effect on the mass loss of Kapton-H, PM-A, and PM-1E polyimide films, which are spacecraft materials. 相似文献
93.
94.
S. Mühlbachler D. Langmayr A.T.Y. Lui N.V. Erkaev I.V. Alexeev P.W. Daly H.K. Biernat 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2009
This study presents several observations of the Cluster spacecraft on September 24, 2003 around 15:10 UT, which show necessary prerequisites and consequences for the formation of the so-called modified-two-stream instability (MTSI). Theoretical studies suggest that the plasma is MTSI unstable if (1) a relative drift of electrons and ions is present, which exceeds the Alfvèn speed, and (2) this relative drift or current is in the cross-field direction. As consequences of the formation of a MTSI one expects to observe (1) a field-aligned electron beam, (2) heating of the plasma, and (3) an enhancement in the B-wave spectrum at frequencies in the range of the lower-hybrid-frequency (LHF). In this study we use prime parameter data of the CIS and PEACE instruments onboard the Cluster spacecraft to verify the drift velocities of ions and electrons, FGM data to calculate the expected LHF and Alfvèn velocity, and the direction of the current. The B-wave spectrum is recorded by the STAFF instrument of Cluster. Finally, a field aligned beam of electrons is observed by 3D measurements of the IES instrument of the RAPID unit. Observations are verified using a theoretical model showing the build-up of a MTSI under the given circumstances. 相似文献
95.
Yuming Fu Hui Liu Lingzhi Shao Minjuan Wang Yu A. Berkovich A.N. Erokhin Hong Liu 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2013
Vegetable cultivation plays a crucial role in dietary supplements and psychosocial benefits of the crew during manned space flight. Here we developed a ground-based prototype of horn-type sequential vegetable production facility, named Horn-type Producer (HTP), which was capable of simulating the microgravity effect and the continuous cultivation of leaf–vegetables on root modules. The growth chamber of the facility had a volume of 0.12 m3, characterized by a three-stage space expansion with plant growth. The planting surface of 0.154 m2 was comprised of six ring-shaped root modules with a fibrous ion-exchange resin substrate. Root modules were fastened to a central porous tube supplying water, and moved forward with plant growth. The total illuminated crop area of 0.567 m2 was provided by a combination of red and white light emitting diodes on the internal surfaces. In tests with a 24-h photoperiod, the productivity of the HTP at 0.3 kW for lettuce achieved 254.3 g eatable biomass per week. Long-term operation of the HTP did not alter vegetable nutrition composition to any great extent. Furthermore, the efficiency of the HTP, based on the Q-criterion, was 7 × 10−4 g2 m−3 J−1. These results show that the HTP exhibited high productivity, stable quality, and good efficiency in the process of planting lettuce, indicative of an interesting design for space vegetable production. 相似文献
96.
W.D. Apel J.C. Arteaga-Velázquez K. Bekk M. Bertaina J. Blümer H. Bozdog I.M. Brancus E. Cantoni A. Chiavassa F. Cossavella K. Daumiller V. de Souza F. Di Pierro P. Doll R. Engel J. Engler M. Finger B. Fuchs D. Fuhrmann H.J. Gils R. Glasstetter C. Grupen A. Haungs D. Heck J.R. Hörandel D. Huber T. Huege K.-H. Kampert D. Kang H.O. Klages K. Link P. Łuczak M. Ludwig H.J. Mathes H.J. Mayer M. Melissas J. Milke B. Mitrica C. Morello J. Oehlschläger S. Ostapchenko N. Palmieri M. Petcu T. Pierog H. Rebel M. Roth H. Schieler S. Schoo F.G. Schröder O. Sima 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2014
97.
H. Kunow N. U. Crooker J. A. Linker R. Schwenn R. von Steiger 《Space Science Reviews》2006,123(1-3):1-2
98.
A. G. Yahnin I. V. Despirak A. A. Lubchich B. V. Kozelov N. P. Dmitrieva M. A. Shukhtina H. K Biernat 《Space Science Reviews》2006,122(1-4):97-106
Although the auroral substorm has been long regarded as a manifestation of the magnetospheric substorm, a direct relation
of active auroras to certain magnetospheric processes is still debatable. To investigate the relationship, we combine the
data of the UV imager onboard the Polar satellite with plasma and magnetic field measurements by the Geotail spacecraft. The
poleward edge of the auroral bulge, as determined from the images obtained at the LHBL passband, is found to be conjugated
with the region where the oppositely directed fast plasma flows observed in the near-Earth plasma sheet during substorms are
generated. We conclude that the auroras forming the bulge are due to the near-Earth reconnection process. This implies that
the magnetic flux through the auroral bulge is equal to the flux dissipated in the magnetotail during the substorm. Comparison
of the magnetic flux through the auroral bulge with the magnetic flux accumulated in the tail lobe during the growth phase
shows that these parameters have the comparable values. This is a clear evidence of the loading–unloading scheme of substorm
development. It is shown that the area of the auroral bulge developing during substorm is proportional to the total (magnetic
plus plasma) pressure decrease in the magnetotail. These findings stress the importance of auroral bulge observations for
monitoring of substorm intensity in terms of the magnetic flux and energy dissipation. 相似文献
99.
Yuri N. Kulikov Helmut Lammer Herbert I. M. Lichtenegger Thomas Penz Doris Breuer Tilman Spohn Rickard Lundin Helfried K. Biernat 《Space Science Reviews》2007,129(1-3):207-243
Because the solar radiation and particle environment plays a major role in all atmospheric processes such as ionization, dissociation,
heating of the upper atmospheres, and thermal and non-thermal atmospheric loss processes, the long-time evolution of planetary
atmospheres and their water inventories can only be understood within the context of the evolving Sun. We compare the effect
of solar induced X-ray and EUV (XUV) heating on the upper atmospheres of Earth, Venus and Mars since the time when the Sun
arrived at the Zero-Age-Main-Sequence (ZAMS) about 4.6 Gyr ago. We apply a diffusive-gravitational equilibrium and thermal
balance model for studying heating of the early thermospheres by photodissociation and ionization processes, due to exothermic
chemical reactions and cooling by IR-radiating molecules like CO2, NO, OH, etc. Our model simulations result in extended thermospheres for early Earth, Venus and Mars. The exospheric temperatures
obtained for all the three planets during this time period lead to diffusion-limited hydrodynamic escape of atomic hydrogen
and high Jeans’ escape rates for heavier species like H2, He, C, N, O, etc. The duration of this blow-off phase for atomic hydrogen depends essentially on the mixing ratios of CO2, N2 and H2O in the atmospheres and could last from ∼100 to several hundred million years. Furthermore, we study the efficiency of various
non-thermal atmospheric loss processes on Venus and Mars and investigate the possible protecting effect of the early martian
magnetosphere against solar wind induced ion pick up erosion. We find that the early martian magnetic field could decrease
the ion-related non-thermal escape rates by a great amount. It is possible that non-magnetized early Mars could have lost
its whole atmosphere due to the combined effect of its extended upper atmosphere and a dense solar wind plasma flow of the
young Sun during about 200 Myr after the Sun arrived at the ZAMS. Depending on the solar wind parameters, our model simulations
for early Venus show that ion pick up by strong solar wind from a non-magnetized planet could erode up to an equivalent amount
of ∼250 bar of O+ ions during the first several hundred million years. This accumulated loss corresponds to an equivalent mass of ∼1 terrestrial
ocean (TO (1 TO ∼1.39×1024 g or expressed as partial pressure, about 265 bar, which corresponds to ∼2900 m average depth)). Finally, we discuss and
compare our findings with the results of preceding studies. 相似文献
100.
MESSENGER: Exploring Mercury’s Magnetosphere 总被引:1,自引:0,他引:1
James A. Slavin Stamatios M. Krimigis Mario H. Acuña Brian J. Anderson Daniel N. Baker Patrick L. Koehn Haje Korth Stefano Livi Barry H. Mauk Sean C. Solomon Thomas H. Zurbuchen 《Space Science Reviews》2007,131(1-4):133-160
The MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) mission to Mercury offers our first opportunity
to explore this planet’s miniature magnetosphere since the brief flybys of Mariner 10. Mercury’s magnetosphere is unique in
many respects. The magnetosphere of Mercury is among the smallest in the solar system; its magnetic field typically stands
off the solar wind only ∼1000 to 2000 km above the surface. For this reason there are no closed drift paths for energetic
particles and, hence, no radiation belts. Magnetic reconnection at the dayside magnetopause may erode the subsolar magnetosphere,
allowing solar wind ions to impact directly the regolith. Inductive currents in Mercury’s interior may act to modify the solar
wind interaction by resisting changes due to solar wind pressure variations. Indeed, observations of these induction effects
may be an important source of information on the state of Mercury’s interior. In addition, Mercury’s magnetosphere is the
only one with its defining magnetic flux tubes rooted beneath the solid surface as opposed to an atmosphere with a conductive
ionospheric layer. This lack of an ionosphere is probably the underlying reason for the brevity of the very intense, but short-lived,
∼1–2 min, substorm-like energetic particle events observed by Mariner 10 during its first traversal of Mercury’s magnetic
tail. Because of Mercury’s proximity to the sun, 0.3–0.5 AU, this magnetosphere experiences the most extreme driving forces
in the solar system. All of these factors are expected to produce complicated interactions involving the exchange and recycling
of neutrals and ions among the solar wind, magnetosphere, and regolith. The electrodynamics of Mercury’s magnetosphere are
expected to be equally complex, with strong forcing by the solar wind, magnetic reconnection, and pick-up of planetary ions
all playing roles in the generation of field-aligned electric currents. However, these field-aligned currents do not close
in an ionosphere, but in some other manner. In addition to the insights into magnetospheric physics offered by study of the
solar wind–Mercury system, quantitative specification of the “external” magnetic field generated by magnetospheric currents
is necessary for accurate determination of the strength and multi-polar decomposition of Mercury’s intrinsic magnetic field.
MESSENGER’s highly capable instrumentation and broad orbital coverage will greatly advance our understanding of both the origin
of Mercury’s magnetic field and the acceleration of charged particles in small magnetospheres. In this article, we review
what is known about Mercury’s magnetosphere and describe the MESSENGER science team’s strategy for obtaining answers to the
outstanding science questions surrounding the interaction of the solar wind with Mercury and its small, but dynamic, magnetosphere. 相似文献