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11.
Anton Afanasev Mikhail Shavin Anton Ivanov Dmitry Pritykin 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2021,67(10):3294-3307
This note presents a study of a four-satellite tetrahedral formation to collect, process, and exchange multipoint measurements of geomagnetic field in a near-polar orbit. The study is conducted as a series of numerical experiments based on simulated spacecraft orbits and corresponding geomagnetic field models output. The four satellites are assumed to move in near-circular orbits specifically chosen to maintain the tetrahedron quality. The satellites exchange their simulated magnetometers readings and the collected multipoint measurements are processed on board of any of them thus creating an instantaneous interpolated map of the geomagnetic field in the interior of the tetrahedron. Interpolation is carried out with the use of Kriging algorithms, known in geostatistics for capturing spatial correlation of the data and taking into account statistical properties of the interpolated variables. We propose a concept of a servicing formation, and analyze interpolation accuracy for different formation sizes. It is then discussed how the processed multipoint measurements can be provided as a service to other nearby satellites. Finally, we show that using the existing COTS magnetometers it is possible to obtain real-time interpolation data, which are more precise at a given point and time than a conventional onboard magnetic field model, thus ensuring better attitude determination routines performance in the serviced spacecraft. 相似文献
12.
I. G. Mitrofanov M. L. Litvak A. B. Varenikov Y. N. Barmakov A. Behar Y. I. Bobrovnitsky E. P. Bogolubov W. V. Boynton K. Harshman E. Kan A. S. Kozyrev R. O. Kuzmin A. V. Malakhov M. I. Mokrousov S. N. Ponomareva V. I. Ryzhkov A. B. Sanin G. A. Smirnov V. N. Shvetsov G. N. Timoshenko T. M. Tomilina V. I. Tret’yakov A. A. Vostrukhin 《Space Science Reviews》2012,170(1-4):559-582
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U Micke M Sch?fer A Anton G Horneck H Bücker 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1992,12(2-3):59-63
DNA damage induced by heavy ions in bacterial cells and bacteriophages such as Bacillus subtilis, E. coli and Bacteriophage T1 were investigated by analyzing the double strand breaks in the chromosomal DNA. This kind of lesion is considered as one of the main reasons for lethal events. To analyze double strand breaks in long molecules of DNA--up to some Mbp in length--the technique of pulse field agarose gel electrophoresis has been used. This allows the detection of one double strand break per genome. Cell lysis and DNA isolation were performed in small agarose blocks directly. This procedure secured minimum DNA destruction by shearing forces. After running a gel, the DNA was stained with ethidium bromide. The light intensity of ethidium bromide fluorescence for both the outcoming (running) DNA and the remaining intact DNA were measured by scanning. The mean number of double strand breaks was calculated by determining the quotient of these intensities. Strand break induction after heavy ion and X-ray irradiation was compared. 相似文献
15.
M. L. Litvak I. G. Mitrofanov I. O. Nuzhdin A. V. Vostrukhin D. V. Golovin A. S. Kozyrev A. V. Malakhov M. I. Mokrousov A. B. Sanin V. I. Tretyakov F. S. Fedosov 《Cosmic Research》2017,55(2):110-123
Results of measurements of neutron-flux spectral density in the vicinity of the International Space Station (ISS) based on BTN-Neutron space experimental data acquired in 2007–2014 have been presented in this paper. It has been shown that, during the flight of the ISS over different regions of the Earth’s surface, neutron flux in the energy range of 0.4 eV–15 MeV varies from 0.1 n/sm2/s in equatorial regions to 50 n/sm2/s in the South Atlantic anomaly region. The measurements were used to estimate the contribution of the neutron component to the overall exposure dose rate. The total contribution of fast neutrons is about 0.1–0.4 μ Zv/h above the equator area and more than 50 μ Zv/h above the South Atlantic anomaly region. A data analysis of BTN-Neutron data also showed that the time profile of neutron flux has long-periodic variations. It was found that, under the influence of Galactic cosmic rays (GCRs), modulation during 24th solar cycle neutron flux changed almost twofold (above high latitude regions). Maximum values of neutron flux were observed in January 2010 and minimum values were observed in January 2014. 相似文献
16.
Mokrousov M. I. Mitrofanov I. G. Anikin A. A. Golovin D. V. Karpushkina N. E. Kozyrev A. S. Litvak M. L. Malakhov A. V. Pekov A. N. Sanin A. B. Tretyakov V. I. 《Cosmic Research》2022,60(5):387-396
Cosmic Research - As recent studies onboard various spacecraft have shown, one unresolved technical problem of manned interplanetary flights at the moment is the high radiation background of... 相似文献
17.
Peter Plötner Markus Czupalla Anton Zhukov 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2013
The Virtual Habitat (V-HAB), is a Life Support System (LSS) simulation, created to perform dynamic simulation of LSS’s for future human spaceflight missions. It allows the testing of LSS robustness by means of computer simulations, e.g. of worst case scenarios. 相似文献
18.
E.N. Grigoryan H.J. Anton V.A. Poplinskaya K.S. Aleinikova E.I. Domaratskaya Y.P. Novikova E. Almeida 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2012
The effects of real and simulated microgravity on the eye tissue regeneration of newts were investigated. For the first time changes in Müller glial cells in the retina of eyes regenerating after retinal detachment were detected in newts exposed to clinorotation. The cells divided, were hypertrophied, and their processes were thickened. Such changes suggested reactive gliosis and were more significant in animals exposed to rotation when compared with desk-top controls. Later experiments onboard the Russian biosatellite Bion-11 showed similar changes in the retinas that were regenerating in a two-week spaceflight. In the Bion-11 animals, GFAP, the major structural protein of retinal macroglial cells, was found to be upregulated. In a more recent experiment onboard Foton-M3 (2007), GFAP expression in retinas of space-flown, ground control (kept at 1 g), and basal control (sacrificed on launch day) newts was quantified, using microscopy, immunohistochemistry, and digital image analysis. A low level of immunoreactivity was observed in basal controls. In contrast, retinas of space-flown animals showed greater GFAP immunoreactivity associated with both an increased cell number and a higher thickness of intermediate filaments. This, in turn, was accompanied by up-regulation of stress protein (HSP90) and growth factor (FGF2) expressions. It can be postulated that such a response of Müller cells was to mitigate the retinal stress in newts exposed to microgravity. Taken together, the data suggest that the retinal population of macroglial cells could be sensitive to gravity changes and that in space it can react by enhancing its neuroprotective function. 相似文献
19.
Anton de Ruiter 《Acta Astronautica》2011,68(1-2):160-171
This paper presents a spin-stabilization algorithm for the Japan Canada Joint Collaboration Satellite-Formation Flying (JC2Sat-FF) mission using magnetic actuation only. It is shown that under a reasonable assumption on the Earth’s magnetic field, the resulting control law is asymptotically stabilizing for an axisymmetric spacecraft, even under the failure of up to two magnetic torque rods and magnetic torque rod saturation. It is also stabilizing under quantization. The satellite motion remains stable under control outages, meaning that the error can be reduced by implementing the control intermittently. The effectiveness of the control law is demonstrated using a high fidelity attitude control system simulator for the JC2Sat-FF satellite. 相似文献
20.
V. I. Tret’yakov I. G. Mitrofanov Yu. I. Bobronitskii A. V. Vostrukhin N. A. Gunko A. S. Kozyrev A. V. Krylov M. L. Litvak M. Lopez-Alegria V. I. Lyagushin A. A. Konovalov M. P. Korotkov P. V. Mazurov M. I. Mokrousov A. V. Malakhov I. O. Nuzhdin S. N. Ponomareva M. A. Pronin A. B. Sanin G. N. Timoshenko T. M. Tomilina M. V. Tyurin A. I. Tsygan V. N. Shvetsov 《Cosmic Research》2010,48(4):285-299