Survival of Deinococcus radiodurans against laboratory-simulated solar wind charged particles

In this experimental study, cells of the radiation-resistant bacterium Deinococcus radiodurans were exposed to several different sources of radiation chosen to replicate the charged particles found in the solar wind. Naked cells or cells mixed with dust grains (basalt or sandstone) differing in elemental composition were exposed to electrons, protons, and ions to determine the probability of cell survival after irradiation. Doses necessary to reduce the viability of cell population to 10% (LD(10)) were determined under different experimental conditions. The results of this study indicate that low-energy particle radiation (2-4?keV), typically present in the slow component of the solar wind, had no effect on dehydrated cells, even if exposed at fluences only reached in more than 1000 years at Sun-Earth distance (1 AU). Higher-energy ions (200?keV) found in solar flares would inactivate 90% of exposed cells after several events in less than 1 year at 1 AU. When mixed with dust grains, LD(10) increases about 10-fold. These results show that, compared to the highly deleterious effects of UV radiation, solar wind charged particles are relatively benign, and organisms protected under grains from UV radiation would also be protected from the charged particles considered in this study.     

Features of RadioAstron Mission Control

Support means of the Spektr-R spacecraft flight and features of the Mission Control Center operation and spacecraft control are considered. Software for scheduling and preparing sessions of controlling and simulating for the spacecraft operation are considered. The problems of ballistic navigation support of the spacecraft flight are presented. Ground spacecraft control segment and software for analyzing and imaging telemetric information are considered.     

Field-aligned current signature in the dusk magnetosphere by INTERBALL-AU and POLAR

The POLAR and INTERBALL-AU spacecrafts magnetic field experiments allow investigation of the time-spatial variation of field-aligned current structures at mid and high altitudes. The study includes two intervals over north high latitudes in the dusk magnetosphere: (1) 10 January 09 – 11 UT (consecutive transits) and (2) 11 January, 03 – UT (nearly conjugate situation at 04:30 UT). By using both spacecraft, the identification of current regions is more confident. On January 11 cycles of the polarization reversal of small-scale disturbances in the poleward portion of region R1 have been detected at high and mid altitudes.     

Barge traffic control in the lower Odra River using DGPS

The increase in the barge-carried cargo volumes in the lower Odra River area necessitates the tracking of barge traffic in order to ensure the safety of navigation. The Dziwnow DGPS reference station, designed for marine traffic, is located near the mouth of the Odra River. The paper presents the results of investigation into the availability of DGPS signal transmitted by the Dziwnow reference station in the lower Odra River area between Kostryd and Szczecin.     

Comets, Asteroids and Zodiacal Light as Seen by Iso

ISO performed a large variety of observing programmes on comets, asteroids and zodiacal light – covering about 1% of the archived observations – with a surprisingly rewarding scientific return. Outstanding results were related to the exceptionally bright comet Hale–Bopp and to ISO's capability to study in detail the water spectrum in a direct way. But many other results were broadly recognised: Discovery of new molecules in comets, the studies of crystalline silicates, the work on asteroid surface mineralogy, results from thermophysical studies of asteroids, a new determination of the asteroid number density in the main-belt and last but not least, the investigations on the spatial and spectral features of the zodiacal light.     

Plasma flow variations and energetic protons upstream of the earth’s bow shock: A statistical study

Foreshock is a special region located upstream of the Earth’s bow shock characterized by the presence of various plasma waves and fluctuations caused by the interaction of the solar wind plasma with particles reflected from the bow shock or escaping from the magnetosphere. On the other hand, foreshock fluctuations may modify the bow shock structure and, being carried through the magnetosheath, influence the magnetopause. During the years 1995–2000, the INTERBALL-1 satellite made over 10,000 hours of plasma and energetic particles measurements in the solar wind upstream of the Earth’s bow shock. We have sorted intervals according to the level of solar wind ion flux fluctuations and/or according to the flux of back-streaming energetic protons. An analysis of connection between a level of ion flux fluctuations and fluxes of high-energy protons and their relation to the IMF orientation is presented.     

An integrated Engineered Closed/Controlled EcoSystem for a lunar base.

Long-term human missions in space, such as the establishment of a human-tended lunar base, require autonomous life support systems. A Lunar Engineered Closed/Controlled EcoSystem (LECCES) can provide autonomy by integrating a human module with support plant and animal modules, and waste treatment subsystems. Integration of physical/chemical (P/C) and biological waste treatment subsystems can lead to viable and operational bioregenerative systems that minimize resupply requirements from Earth. A top-level diagram for LECCES is developed based on the human module requirements. The proposed diagram is presented and its components are discussed.     

Small scale solar wind ion flux and IMF quasi-harmonical structures in the earth''s foreshock: INTERBALL-1 and MAGION-4 observations

High time resolution data obtained by VDP and FM-31 instruments onboard INTERBALL-1 spacecraft were used to study the small-scale correlation between solar wind ion flux and magnetic field magnitude in the Earth's foreshock. Correlated quasi-harmonic structures were found simultaneously in ion flux and magnetic field data. Statistical analysis of these structures was done and a summary of obtained results is presented. Multipoint observations by INTERBALL-1 and MAGION-4 were used to estimate spatial correlation of small quasi-harmonic structures.     

Physics of Substorm Growth Phase,Onset, and Dipolarization

A new scenario of substorm growth phase, onset and dipolarization during expansion phase and the corresponding physical processes are presented. During the growth phase, as a result of enhanced plasma convection, the plasma pressure and its gradient continue to be enhanced over the quiet-time values in the plasma sheet. Toward the late growth phase, a strong cross-tail current sheet is formed in the near-Earth plasma sheet region, where a local magnetic well is formed. The equatorial plasma beta (β _eq ) can reach a local maximum with value larger than 50 and the cross-tail current density can be enhanced to over 10nA/m² as obtained from 3D quasi-static magnetospheric equilibrium solutions for the growth phase. The most unstable kinetic ballooning instabilities (KBI) are expected to be located in the tailward side of the strong cross-tail current sheet region. The field lines in the most unstable KBI region map to the transition region between the region-l and region-2 currents in the ionosphere, which is consistent with the observed initial brightening location of the breakup arc in the intense proton precipitation region. The KBI explains the AMPTE/CCE observations that a low frequency instability with a wave period of 50–75 seconds is excited about 2–3 min prior to substorm onset and grows exponentially to a large amplitude at the onset of current disruption (or current reduction). At the onset of current disruption higher frequency instabilities are excited so that the plasma and electromagnetic field fluctuations form a strong turbulent state. Plasma transport takes place due to the strong turbulence to relax the ambient plasma pressure profile so that the plasma pressure and current density are reduced and the ambient magnetic field intensity increases by more than a factor of 2–3 in the high-β _eq region and the field line geometry recovers from tail-like to dipole-like – dipolarization.