Trapped proton fluxes measured on board LEO satellites in comparison with models

The proton fluxes from the low-Earth orbital satellites databases (NPOES-17 and CORONAS-F) were analyzed for the quiet geomagnetic period in April 2005. The satisfactory consent was found between the experimental and the AP8 model fluxes of the trapped protons with energy more than ∼10 MeV. At the same time, trapped proton fluxes with energy less than 10 MeV measured by LEO satellites were higher than the ones predicted by the AP8 model in the region of the SAA (drift shell L < 1.5).     

The concept of selecting the main parameters of a lightweight airplane with regard to the requirements of the contemporary Russian market

The basic principles of selecting some design parameters of a lightweight airplane for the contemporary Russian market are presented. Recommendations for selecting these parameters with the service requirements specified are given based on the study performed.     

Biologically weighted measurement of UV radiation in space and on Earth with the biofilm technique.

Biological dosimetry has provided experimental proof of the high sensitivity of the biologically effective UVB doses to changes in atmospheric ozone and has thereby confirmed the predictions from model calculations. The biological UV dosimeter 'biofilm' whose sensitivity is based on dried spores of B. subtilis as UV target weights the incident UV radiation according to its DNA damaging potential. Biofilm dosimetry was applicated in space experiments as well as in use in remote areas on Earth. Examples are long-term UV measurements in Antarctica, measurements of diurnal UV profiles parallel in time at different locations in Europe, continuous UV measurements in the frame of the German UV measurement network and personal UV dosimetry. In space biofilms were used to determine the biological efficiency of the extraterrestrial solar UV, to simulate the effects of decreasing ozone concentrations and to determine the interaction of UVB and vitamin D production of cosmonauts in the MIR station.     

Determination of parameters of rotational motion of the <Emphasis Type="Italic">Monitor-E</Emphasis> spacecraft from the telemetry data on solar batteries’ current

The Monitor-E spacecraft executed uncontrolled flight due to emergency situation, no telemetry information on parameters of the spacecraft’s attitude motion being available. So, the problem arose to determine the spacecraft’s rotational motion from the accessible indirect information—the electric current provided by solar batteries. In this paper the integrated statistical technique is described, that allows one to solve this problem. The values of current, obtained over the time interval some tens of minutes long, have been processed simultaneously by the least squares method using the integration of the equations of spacecraft’s rotational motion. As a result of processing, the initial conditions of motion were estimated, and the spacecraft’s moments of inertia were updated, as well as the angles, specifying solar batteries position in the spacecraft-fixed coordinate system. The results of processing of 12 data sets are presented, which allowed us to reconstruct the actual rotational motion of the spacecraft.     

The human cardiovascular system during space flight

Purpose of the work is to analyze and to summarize the data of investigations into human hemodynamics performed over 20 years aboard orbital stations Salyut-7 and Mir with participation of 26 cosmonauts on space flights (SF) from 8 to 438 days in duration. The ultrasonic techniques and occlusive plethysmography demonstrated dynamics of changes in the cardiovascular system during SF of various durations. The parameters of general hemodynamics, the pumping function of the heart and arterial circulation in the brain remained stable in all the space flights; however, there were alterations in peripheral circulation associated with blood redistribution and hypovolemie in microgravity. The anti-gravity distribution of the vascular tone decayed gradually as unneeded. The most considerable changes were observed in leg vessels, equally in arteries (decrease in resistance) and veins (increase in maximum capacity). The lower body negative pressure test (LBNP) revealed deterioration of the gravity-dependent reactions that changed for the worse as SF duration extended. The cardiovascular deconditioning showed itself as loss of descent acceleration tolerance and orthostatic instability in the postflight period.     

Effect of Dimensions on the Efficiency of Radiant Energy Cells

This paper deals with the enhancement of the quantum efficiency and photovoltaic energy conversion efficiency of a p-n semiconducting cell by optimizing the dimensions of the cell. Based on the Shockley-Read statistics a general expression for the quantum efficiency of monochromatic incident radiant energy photons has been derived in terms of the absorption coefficient of the incident photons, the minority carrier diffusion length, the built-in electrostatic field appearing in diffused cells, and the surface recombination velocity in the exposed layer of the cell. Although the expressions derived may be used for all semiconducting p-n cells, special efforts have been made in the analysis and computations of the germanium p-n cell. The germanium cells show a great potential for photovoltaic energy conversion from radiant sources other than the sun. The results for germanium indicate that the quantum efficiency strongly depends upon the thicknesses of the exposed and base layers. The built-in electrostatic field and the surface recombination velocity in the exposed layer influence the quantum efficiency greatly. Optimization studies for the thicknesses of the exposed and base layers of an n-p type germanium for different values of minority carrier diffusion length, built-in electrostatic field, and surface recombination velocity have been worked out.     

Prototype design and testing of a Venus long duration,high altitude balloon

This paper describes the design, fabrication and testing of a full scale prototype balloon intended for long duration flight in the upper atmosphere of Venus. The balloon is 5.5 m in diameter and is designed to carry a 45 kg payload at an altitude of 55 km. The balloon material is a 180 g/m² multi-component laminate comprised of the following layers bonded together from outside to inside: aluminized Teflon film, aluminized Mylar film, Vectran fabric and a polyurethane coating. This construction provides the required balloon functional characteristics of low gas permeability, sulfuric acid resistance and high strength for superpressure operation. The design burst superpressure is 39,200 Pa which is predicted to be 3.3 times the worst case value expected during flight at the highest solar irradiance in the mission profile. The prototype is constructed from 16 gores with bi-taped seams employing a sulfuric acid resistant adhesive on the outside. Material coupon tests were performed to evaluate the optical and mechanical characteristics of the laminate. These were followed by full prototype tests for inflation, leakage and sulfuric acid tolerance. The results confirmed the suitability of this balloon design for use at Venus in a long duration mission. The various data are presented and the implications for mission design and operation are discussed.