Aeroelastic deformation of a solid-propellant rocket engine during supercharging

A problem of aeroelastic interaction between gas and a cylindrical structure in the course of supercharging is considered. To analyze the processes progressing in the system gas-deformable solid body, the unified difference method is implemented. The stress-strain state and gas-dynamic processes are analyzed with the use of the space-time mesh that is common for the gas and structure.     

Energy spectrum of proton flux near geomagnetic equator at low altitudes

The results of proton energy (tens keV – several MeV) spectrum measurements near geomagnetic equator (L < 1.15) at low altitudes (<1000 km) are presented. We used data of experiments onboard ACTIVE, SAMPEX, NOAA TIROS-N satellites and SPRUT-VI (MIR station) and cover a time range of about 30 years (including previous measurements). It was found that the kappa-distribution function fits the experimental spectrum with the best correlation coefficient. A comparison of energy spectra of near-equatorial protons and ring-current protons was made. Using the estimation of the life time of near-equatorial protons we explain the difference in spectral indices of radiation belt and near-equatorial proton formation. We conclude that the ring current is the main source of the near-equatorial protons.     

Absorbed doses in October–November 2003 onboard the Russian segment of the International Space Station according to the data of radiation control system

The results of radiation control onboard the Service Module of the International Space Station are considered for the period of increased radiation background from 28 to 30 October, 2003. The values of additional irradiation dose caused by strong solar proton events on October 28 and 29, 2003 are obtained. A comparison is made with similar data obtained in the periods of disturbed radiation conditions of fall 2001. The results of estimating the dependence of the absorbed dose on the shield thickness, based on the onboard measurements, are presented. It is established that the daily-averaged dose power onboard the International Space Station increased after the solar proton events of October 2003.     

Investigation of dose and flux dynamics in the Liulin-5 dosimeter of the tissue-equivalent phantom onboard the Russian segment of the International Space Station.

Described is the Liulin-5 active dosimetric telescope designed for measurement of the space radiation dose depth-distribution in a human phantom on the Russian Segment of the International Space Station (ISS). The Liulin-5 experiment is a part of the international project MATROSHKA-R on ISS. The MATROSHKA-R project is aimed to study the depth-dose distribution at the sites of critical organs of the human body, using models of human body-anthropomorphic and spherical tissue-equivalent phantoms. The aim of Liulin-5 experiment is a long term (4-5 years) investigation of the radiation environment dynamics inside the spherical tissue-equivalent phantom, mounted in different compartments. Energy deposition spectra, linear energy transfer spectra, and flux and dose rates for charged particles will be measured simultaneously with near real time resolution at different depths of the phantom by means of three silicon detectors. Data obtained together with data from other active and passive dosimeters will be used to estimate the radiation risk to the crewmembers, which verify the models of radiation environment in low Earth orbit. Presented are the test results of the prototype unit. Liulin-5 will be flown on the ISS in the year 2003.     

Multi-dimensional asymptotically stable adaptive systems for coordinate-parametric control of nonstationary spacecraft

The paper is concerned with control of multidimensional nonstationary processes regarded as adaptive systems of coordinate-parametric control     

Informational approaches to angular motion control of spacecraft

Any information concepts may be used for motion control with respect to the center of masses of a reusable transport spacecraft (RTS). Using comparative analysis of the two concepts (the first one, based upon information about attitude parameters with respect to the inertial reference system and the second one, based upon parameters of angular motion with respect to wind-body coordinate system) for specific features of RTS dynamics and control at the stages of orbital flight, atmospheric flight under gas dynamic and aerodynamic control, and landing, paper demonstrates that information on angles of attack, slip and speed roll should be used for angular motion control at this stage of flight.     

Radiation: risk and protection in manned space flight.

Space radiation is the primary source of hazard for orbital and interplanetary space flight. Radiation levels for different space mission durations, have been established in order to determine the level of hazard. The risk of exceeding the established levels should not be more than 1%. Radiation environment models have been developed to estimate these values. It is possible to build spacecraft shielding based on the calculation of doses and the risk of exceeding these. By reviewing various calculated estimates of the risk, the radiation hazard and the efficiency of protective measures can be established for specific flights.     

Quality factor and dose equivalent investigations aboard the Soviet space station MIR.

Since Dec 1988, date of the French-Soviet joint space mission "ARAGATZ", the CIRCE device (Compteur Intégrateur de Rayonnement Complexe dans l'Espace) had recorded dose equivalent and quality factor inside the MIR station (380-410 km, 51.5 degrees). After the initial gas filling two years ago, the low pressure tissue equivalent proportional counter is still in good working conditions. Some results of three periods, viz Dec 1988, Mar-Apr 1989 and Jan-Feb 1990 are presented. The average dose equivalent rates measured are respectively 0.6, 0.8 and 0.6 mSv/day with a quality factor equal to 1.9. Some detailed measurements show the increasing of the dose equivalent rates through the SAA and near polar horns. The real time determination of the quality factors allows to point out high LET (Linear Energy Transfer) events with quality factors in the range 10-20.     

Radiation measurements inside a human phantom aboard the International Space Station using Liulin-5 charged particle telescope

Liulin-5 is a particle telescope developed for the investigation of the radiation environment within the Russian spherical tissue-equivalent phantom on the International Space Station (ISS). Liulin-5 experiment is conducted aboard the Russian segment of ISS since 28 June 2007 as an adherent part of the international project MATROSHKA-R. The main objective of Liulin-5 experiment is to study the depth-dose distribution of the different components of the orbital radiation field in a human phantom. Additional objectives are mapping of the radiation environment in the phantom and its variations with time and orbital parameters (such as solar cycle, solar flare events, inclination and altitude). Liulin-5 is an active instrument, capable to provide real-time radiation data for the particle flux and dose rates, energy deposition and LET spectra. Data are recorded automatically on memory cards, periodically transported to ground by returning vehicles. In this report we present some first results from data analysis including energy deposition spectra, absorbed dose, dose rate and flux distribution measured simultaneously at 3 different depths of phantom’s radial channel and linear energy transfer (LET) spectrum. Data discussed are for the period July 2007–April 2008.