The Space Engineering and Technology magazine
¹1 (12), 2016
FLYING VEHICLES AERODYNAMICS AND HEAT EXCHANGE PROCESSES
Antipova M.S., Dyadkin A.A., Zapryagaev V.I., Krylov A.N.
Computational simulation of cold supersonic jet exit from conical nozzle using FLOEFD software package
To assure a soft landing, the descent vehicle of the manned transportation vehicle that is being designed at RSC Energia will use a parachute and rocket landing system. The solid-rocket landing propulsion system is to be operated in the immediate vicinity of the Earth surface, at the altitude of about 5–10 meters. The jets of the propulsion system have an impact on the aerodynamic properties of the descent vehicle during that mission phase and also affect the landing surface. The nozzles of the solid-rocket landing system have an unconventional shape – a rectangular throat with variable area, intricately shaped entry, and obliquely truncated exit section. Flows through such nozzles are poorly known and require special research. To determine the effects of the landing solid rocket jets on the aerodynamic properties of the descent vehicle and their impact on the landing surface within the framework of computer simulations, there are plans to use the FloEFD software package. In accordance with the computer simulation practice established at RSC Energia, industrial computations are preceded by test computations to validate the application of a software package to solving a particular problem. Selected for the purpose of testing the FloEFD package for its fitness to be used in the analysis of flow in the nozzles of the landing solid rocket was the problem of analyzing the exit of a cold supersonic air jet from an axially symmetric conical nozzle. The paper provides computation results and their comparison with experimental data.
Key words: computer simulation, supersonic nozzle, stream flow, experiment.
FLYING VEHICLES STRENGTH AND THERMAL ENVIRONMENTS
The paper discusses the principles of the Russian system for assuring the vibration strength of rocket and space hardware, which guarantees reliable resistance of the structures to vibration loads. It covers the role of dynamic simulations within the domain of vibration strength testing problems. Based on the experience of completed projects, it provides practical recommendations for solving these problems. Taking into account the experience of other countries, it outlines the prospects for further development of the system. There has been put together, and is set forward in the paper, a package of problem-solving measures, which need to be implemented to reform the system.
Key words: structure, vibration strength, simulation, computations, experimental development.
A study of shear strength of adhesive bonds using heat-resistant glues for bonding a thermal protection coating based on a syntactic composite material at temperatures of 20, 150, 200 °C
Based on the engineering specifications, high-temperature adhesives from various producers (designers) were selected for shear strength studies. High-temperature adhesives were considered: epoxy adhesives K-300-61 and VK-58, hot curing film adhesive VK-36, foaming adhesive UTC-9, structural adhesive CMK-22-1, epoxy metal-filled adhesives-compounds Anàterm-201, Anàterm-203, Anàterm-204, Anàterm-216, polyurethane adhesives ADV-11-1 and ADV-11-2. The paper discusses the major steps in the manufacturing process of adhesive joints based on syntactic composite material, carbon fiber, aluminum alloy D16. It provides curing modes for high-temperature adhesives. It provides a description of the surface preparation for bonding. Results of experimental studies are also provided. A comparative analysis was performed on results obtained for the ultimate shearing strength and fracture patterns of adhesive joints at temperatures 20, 150, 200 °C.
Key words: high-temperature adhesives, shear strength, syntactic composite material, carbon-fiber reinforced plastic, aluminum alloy Ä16.
FLYING VEHICLES THERMAL, ELECTRIC PROPULSION ENGINES
AND POWER GENERATING SYSTEMS
Zernov A.S., Nikolaev V.D.
Experience of operating solar arrays on the service module of the International Space Station
The paper provides performance characteristics of solar arrays on the Service Module of the International Space Station obtained in on-orbit tests; a comparison between separate and joint operation of solar array panels, as well as the amount of current generated when the solar arrays are oriented so that their edge or their backside is facing towards the Sun; an estimate of an increase in the generated current produced by the light reflected from the underlying Earth surface; a description of off-nominal situations; temperature variations on the solar array panels; changes in the efficiency of the solar arrays over the 15 years of their life in orbit; a prediction of further nominal changes in the efficiency of solar arrays on the Service Module till 2020 based on the results of studies of the solar array panels retrieved from the Mir space station.
Key words: International Space Station, Service Module, solar arrays, generated current, operation analysis.
Zakharenkov L.E., Semenkin A.V., Solodukhin A.E.
Experimental study of multi-thruster system based on several simultaneously operating electric propulsion thrusters with anode layer
The paper presents the results of an experimental study of thrust performance of a test-bench model of a multi-thruster system based on three electric propulsion thrusters with anode layer and of properties of a plasma plume formed during their simultaneous operation. The paper discusses various implementation schemes of the power supply system for several simultaneously operating electric thrusters. It presents the results of studies into propagation of electromagnetic oscillations over the circuits of a multi-thruster system when various power supply schemes are used. The paper discusses the possibility of operating the test-bench model with a neutralizing cathode moved outside the bulk of the model. The paper provides the results of studies into the stability of the test-bench model operation in case of deviation of parameters in one of its thrusters. The paper describes procedures for measuring local and integral parameters of jets from thrusters with azimuthal electron drift. It presents the results of comparison between the properties of plasma jets from a multi-thruster system and a single thruster within the system. It presents the results of studies into the effect of the conditions during ground testing of this type of electric thrusters on the measured parameters of the plasma jets.
Key words: thruster with azimuthal drift of electrons, thruster with anode layer, cathode neutralizer, plasma jet, test-bench model of a multi-thruster system, thrust performance, electric thruster, measurement procedure for jet parameters.
Pustovalov A.A., Pankin M.I., Prilepo Yu.P., Rybkin N.N., Sinyavskiy V.V.
Americium-241-powered space radioisotope thermoelectric generator
Since there is a shortage of the plutonium-238 radionuclide, which had been used in radioisotope thermoelectric generators (RTG) as a source of electric power for deep-space spacecraft, the paper discusses and demonstrates the feasibility of developing and RTG, which will use as its primary source of power the americium-241 radionuclide with half-life period of 432 years. The paper provides general information about americium-241 and current status of work on the application of americium-241 to RTG. The paper describes americium-241–based RTG designs for 1...5 and 5...50 W electrical power and prototypes of micro-modular low-temperature and two-stage medium-temperature thermoelectric battery. A comparison of parameters of RTGs based on americium-241 and plutonium-238 in the 1…30 W electrical power range showed that RTGs with electrical power above 10 W, both based on americium-241 and plutonium-238, have similar levels of efficiency estimated at about 7%. The paper discusses the existing options and obstacles that need to be overcome in order to develop americium-241 RTGs for space applications using existing and future thermoelectric materials.
Key words: americium-241, plutonium-238, radioisotope thermoelectric generator, RTG design, thermoelectric battery, spacecraft, deep space.
CHECKING AND TESTING FLYING VEHICLES AND THEIR SYSTEMS
Zyablov V.A., Romanov S.Yu., Troynikov V.I., Shcherbakov E.V.
Development, developmental testing and practical application of high-sensitivity tests for total leak rate of pressurized compartments and fluidic subsystems of large scale space vehicles without the use of vacuum chambers
The paper discusses the results of many years of development, developmental testing and practical application of highly-sensitive tests for total leakage without the use of vacuum chambers on pressurized compartments and fluidic subsystems of large scale space vehicles, taking as an example the Russian Docking Compartment DC (1995) and Mini Research Module MRM-1 (2010), Russian systems and the pressurized compartment of the five European Automatic Transfer Vehicle ATV (2005–2014) during ground pre-flight processing at launch sites. The tests are conducted in accordance with an improved accumulation method at atmospheric pressure using Helium as the tracer gas. The minimal detectable leak rate of 100% helium can be as low as 3,27·10–2 mTorr·L/s at air absolute atmospheric pressure in the 100 m3 accumulation volume and one hour of exposure time. The use of helium leak detectors with turbomolecular pumps and procedures improved on the base of test results makes it possible to develop test processes that in certain cases can replace the conventional process of testing of assembled space vehicles and modules in large vacuum chambers if the ones are not available at the launch sites.
Key words: leak tests, spacecraft, space station modules, pre-launch processing at the launch site, helium mass spectrometer leak detector, vacuum chamber, method of tracer gas accumulation at atmospheric pressure.
Krivolapova O.Yu., Laletina E.A., Tverdokhlebova E.M.
Procedure for using onboard systems and scientific equipment during space experiment Plasma-ISS to study electrical and physical parameters of the environment in the vicinity of the ISS
The paper describes the features of the environment in the vicinity of the International Space Station (ISS), associated with the currents between oppositely charged structural elements of the space station. It presents objectives and tasks of a space experiment to study plasma environment on the outer surface of the ISS, conducted within the program of applied scientific research on the Russian Segment. Determined in the course of the experiment were relationships between the range of intensities of currents in the station plasma environment and its configuration and orbital position, firing of the attitude control thrusters and other systems that release gasses, seasonal variation in the external space environment. The paper discusses various options for setting up measuring sessions and procedures for using onboard science and systems equipment during these sessions. The procedures are based on the use of equipment available onboard the station without the need to build additional scientific equipment, which makes it possible to obtain new scientific results with minimal expenditure of funds and time.
Key words: environment in the vicinity of the vehicle, plasma environment, International Space Station, space experiment, scientific equipment.
FLYING VEHICLES DYNAMICS, TRAJECTORY AND MOTION CONTROL
Andreyko A.N., Kravets V.G., Kucherov M.A., Luchinsky V.P.
Portable telemetry information receiving complex for transmission to the Mission Control Center data on the manned transport spacecraft descent
In the article the following is given: prerequisites for the development and the main characteristics of a portable ground telemetry information receiving complex intended to receive and transmit to the Mission Control Center (MCC) data on the Soyuz TMA spacecraft descent from Earth satellite orbit (ESO) in real time including the separation process of the spacecraft compartments when flying the trajectory which passes beyond the areas of communication with the tracking stations in the territory of the Russian Federation. This portable ground complex is developed on a modern system-technical base with controlled mathematical software, easy to operate. In this case Internet Network was used for the first time as the main channel to transmit a full flow of telemetry information to MCC. At a period of 2011…2015 the portable ground complex reliably provided telemetry reception during all the descents of the Soyuz TMA spacecraft from the ESO in the mode of data transmission to MCC in real time.
Key words: portable ground telemetry information receiving complex, tracking stations, Mission Control Center, landing areas of the transport spacecraft descent module.
MACHINERY AND EQUIPMENT, PROCESSES OF REFRIGERATION AND CRYOGENIC TECHNOLOGY, AIR CONDITIONING AND LIFE SUPPORT SYSTEMS
Glebov I.V., Zheleznyakov A.G., Romanov S.Yu., Ryabkin A.M.
Advanced garment washing system onboard the manned space module
The paper considers the issues of using equipment for sanitary and hygiene processing (washing) of astronauts’ personal hygiene items and garment as part of the crew life support systems complex of the manned space module. An advanced technology to develop a sanitary and hygiene processing system for astronauts’ personal hygiene items and garment is proposed, options of its design concepts to be implemented in the manned space module are addressed, advantages and disadvantages of each proposed concept are identified. The proposed technology of sanitary and hygiene processing of astronauts’ personal hygiene items and garment onboard the manned space module will make it possible to significantly reduce the mass and volume of delivered cargo. The use of equipment for sanitary and hygiene processing (washing) of astronauts’ personal hygiene items and garment within the life support systems complex will increase the degree of the complex enclosure.
Key words: manned space module, life support systems complex, personal hygiene items, degree of the complex enclosure.
Ozerov D.S., Nosovsky A.M., Mukhamedieva L.N., Tsarkov D.S., Pakhomova A.A., Guzenberg À.S., Yurgin À.V.
Statistical patterns of contaminants distribution in the atmosphere of manned space stations
The paper provides a statistical analysis of contaminants concentrations measured in the atmosphere of the International Space Station (ISS) over the period 2001...2014. Air samples were taken and delivered to Earth in solid sorbent samplers AK-1M, jointly developed by IBMP and RSC Energia. The samples were analyzed at IBMP using the methods of gas chromatography and combined gas chromatography mass-spectrometry. A statistical analysis of the identified chemical substances established the following features of their distribution in the ISS air: positive asymmetry, peaked density distribution, approaching lognormal distribution pattern, correspondence of the arithmetic mean value of the distribution to 70th percentile. It is demonstrated that the distribution of substances in the ISS air is valid for contaminants belonging to various classes of chemical compounds and for various averaging times. The distribution of contaminants in the ISS atmosphere is consistent with patterns established for chemical substances in the air of the working area and atmospheric air. The correspondence of the arithmetic mean value of the distribution to 70th percentile will allow to use general hygienical methodology for accelerated setting of environmental standards for contaminants content in the atmosphere of manned spacecraft, for validating a math model of accelerated setting of environmental standards for contaminants content in the atmospheres of air-tight rooms and manned spacecraft.
Key words: chemical substances in the ISS air, lognormal substance distribution pattern, accelerated setting of environmental standards.
¹ 1 (12) january — march 2016