The Space Engineering and Technology magazine
¹ 3 (18), 2017
FLYING VEHICLES AERODYNAMICS AND HEAT EXCHANGE PROCESSES
Dyadkin A.A., Kostyuk V.K., Krylov A.N., Eremin V.V., Kazakov M.N., Mikhalin V.A., Stroilov A.V.
Numerical and experimental determination of aerodynamic behaviour of the abort stack of the launch escape system for the new-generation crew transportation spacecraft
In the development of crew transportation spacecraft one of the most important tasks is to assure the crew safety in case of a launch vehicle failure during ascent. In order to rescue the crew in offnominal situations, launch escape systems are developed, which are intended for separating and moving the spacecraft away from the failed launch vehicle to a safe distance at any point in time between the lift-off and completion of the orbital insertion.
To accomplish this task, an abort stack is formed within the launch vehicle which includes a rocket booster for emergency escape with a set of propulsion units, the crew transportation spacecraft and an adapter section between the escape rocket stage and the crew transportation spacecraft. This configuration was used in the abort stacks of escape systems for Soyuz, Apollo, Orion and other spacecraft.
The distinctive feature of the new rocket booster for escape system of the crew transportation spacecraft, in comparison with the existing hardware, is its two-stage configuration, which allows rescuing the crew during virtually any phase in the ascent.
An important stage in the development of the abort stack of an escape system and its sizing is the study of its aerodynamic behavior when thrusters are on and off during its free flight after separation from the failed launch vehicle.
In recent years, computer simulations have been finding an increasingly wider use for aerogas dynamics studies of vehicles under design, since they have a number of advantages over physical modeling, especially in the early stages of design. Industrial use of computer simulations for aerogas dynamics studies implies a certain process, which includes the stage of preliminary testing of the software to be used against experimental data from similar vehicles.
This paper discusses a sample application of such approach to the aerodynamics study of the abort stack of the escape system for the new-generation crew transportation spacecraft currently under development at RSC Energia. It presents results of computational studies with the use of two different software packages that were done at RSC Energia and TsNIImash, and their comparison against the results of model tests in wind tunnels of TsNIImash.
Key words: launch escape system, aerodynamic performance, computer simulation, new-generation crew transportation spacecraft.
Dyadkin A.A., Pavlov A.O., Simakova T.V.
Comparative analysis of computational and experimental studies of hydrodynamic loads on a model of a descent vehicle with inactive propulsion system during a splashdown
The reusable manned spacecraft Federatsiya that is being developed by RSC Energia is supposed to use a landing system based both on parachutes and rocket propulsion, which is expected to achieve an almost zero velocity of the spacecraft at touchdown. In nominal situations, the spacecraft lands on specially prepared unpaved ground. In of-nominal situations the spacecraft may have to land on all kinds of surfaces, including water. In that case, conducting design studies requires the knowledge of hydrodynamic loads on the spacecraft body and its dynamic behavior in water. In view of the existence of a great variety of splashdown modes, searching for the required parameters using the traditional experimental method that goes back to the development of the Apollo and Soyuz spacecraft is impractical, mostly because of the large scope of required tests and their limited informative value. Therefore, it stands to reason to run computer simulations of the splashdown in state-of-the-art software packages, having done their preliminary validation.
This paper discusses the results of testing the FlowVision software package developed by LLC TESIS using experimental data, obtained in tests on the models of Apollo Command Module. It presents data on pressure variations on the spacecraft surface in process of its immersion and its dynamic behavior in water. It demonstrates the advisability of using this package for studying the process of landing of the descent vehicle of the Federatsiya spacecraft.
Key words: splashdown, descent vehicle, veriication.
FLYING VEHICLES ENGINEERING, DESIGN AND MANUFACTURING
Anokhin M.V., Galkin V.I., Morozov O.V., Sazonov V.V.
Special aspects of radiation hardness assessment of space micro- and nano-electronics
The paper discusses an alternative to the conventional dosage-based approach to the evaluation of radiation hardness of electronic hardware for spacecraft, which is based on using energy release density spectra as the criterial parameter. The paper presents physical underpinnings of the feasibility of radiation tests for electronic equipment using compact isotopic sources. The new approach is not just a method of testing electronic equipment for radiation hardness, it also enables establishing an integral system for radiation hazard monitoring, studying radiation hardness of electronic components and optimizing the geometry of newly-designed electronic hardware, which draws upon lab-based and ield experiments and detailed Monte Carlo simulations. The use of such system will make it possible to signiicantly improve radiation hazard predictions through the use of more adequate physical models of radiation efects and data from real-time in situ radiation monitoring, while providing hardware designers and users with an opportunity to take part in the tests or even conduct them by themselves. The adoption of the proposed system will permit to signiicantly expand the list of electronic components allowed for use in space hardware.
Key words: radiation hardness, energy release spectrum density, Monte Carlo simulation.
FLYING VEHICLES STRENGTH AND THERMAL ENVIRONMENTS
Romanenkov V.A., Kolesnichenko A.F., Martynov M.V., Tarasov V.A., Komkov M.A., Boyarskaya R.V.
Improving physical and mechanical properties of thermal insulation using autoclave molding in inert medium
The structure of the descent vehicle of the manned spacecraft Soyuz TMA uses composite materials based on glass fiber and phenol-formaldehyde binder. The binder contains a large amount of chemically active, including highly lammable, components. Such materials are molded and cured using vacuum and autoclave method under high temperature and pressure of the working medium. When the working medium that is used is air there is a likelihood that reactions involving oxygen may occur, which have a negative effect on physical and mechanical properties of the material and create a threat of runaway oxidizing reactions up to thermal oxidative breakdown of the material.
The newly developed technology of molding in an inert medium rules out the material oxidization, breakdown and depressurization of the evacuated rubber covers used in the molding, improves safety and stability of the manufacturing process, the quality and reliability of the products.
Particular emphasis was given to creating an environment which provides minimal temperature gradients on the products during heating, thermostatting and cooling, as well as to assuring uniform distribution the binder within the material during molding.
The work has resulted in improving the level of physical and mechanical properties of thermal insulation materials, weight, accuracy of the geometric parameters of the products and reduction in mass.
The most important factor which enabled the achievement of the above results was the development of a new technology for manufacturing thermal insulation coatings in the inert medium and the highly automated autoclave system, which also provides a technological foundation for manufacturing new advanced products made of composite materials.
Key words: descent vehicle, thermal insulation, autoclave molding, inert medium.
FLYING VEHICLES THERMAL, ELECTRIC PROPULSION ENGINES
AND POWER GENERATING SYSTEMS
Gribkov A.S., Popov A.N., Sinyavskiy V.V.
Dual-mode space nuclear power system based on a thermionic conversion reactor and thermoelectrochemical generator
Within the context of development of a transportation and power module for electricallypropelled delivery and subsequent long-term power supply of power-hungry functional equipment of a spacecraft, the paper provides the results of conceptual design studies into the feasibility of using a combined dual-mode nuclear power system with a thermionic conversion reactor and thermoelectrochemical generator. The feasibility of using a ThermoElectroChemical Converter (TECC) to generate electric power hinges upon the fact that TECC hot zone temperature lies within the range of temperatures of the lithium cooling system for the high-temperature lithiumniobium nuclear power system designed for the Hercules orbital transfer vehicle. The paper demonstrates the practicability of using a part of the heat radiating surface of the cooling system for the power system to place on it TECC elements. Within the thermionic reactor there is a zone of booster heat-producing elements that are cooled by a lithium coolant. Installed on the heat pipes of the heat-rejection system are TECC elements with the upper temperature of the thermodynamic cycle of about 1200 K and the lower temperature of about 500–550 K. Used as TECC working medium is sodium, the main structural material is niobium alloy NbZrC, the solid electrolyte is â-Al2O3. The above materials have a mix of properties that makes it possible to construct a highly efficient TECC operating within the specified range of temperatures. The paper provides performance data for the element and the entire generator with 30 kW electrical output.
Key words: transportation and power module, dual-mode nuclear power system, thermionic conversion reactor, lithium-niobium technology, niobium alloy NbZrC, sodium, â-Al2O3.
GROUND FACILITIES, LAUNCHING EQUIPMENT, OPERATION OF FLYING VEHICLES
Among major problems posed by the threat of predicted changes in the global climate in the 21st century is the problem of replacing hydrocarbon power with renewables. The use of space technology for solar insolation of the Earth surface can make a positive contribution to solving this problem, while at the same time contributing to preservation of the vulnerable environment of Polar regions.
This paper discusses the safety of systems for illuminating from orbit subpolar towns in Russia and abroad. Based on the chosen safety criterion for a generic lighting system, its actual value was calculated and compared with established standards, and parameter association was provided for safe lighting system, that have orbital architecture and lighting patterns on the ground that are similar to those of the reviewed generic system.
Key words: lighting systems, safety criterion, orbital architecture, lighting pattern.
FLYING VEHICLES DYNAMICS, TRAJECTORY AND MOTION CONTROL
Arkhangelskiy N.I., Akimov V.N., Eliseev I.O., Kuvshinova E.Yu.
On the advantages of employing elliptical staging orbits to improve the efficiency of using reusable nuclear space tugs
A trajectory design analysis has been conducted to demonstrate the effect of parameters of auxiliary orbital transfer stages and of elliptical staging orbits that they establish for a reusable space tug based on a nuclear power system and a megawatt-class electrical propulsion system on the eiciency of its application to the task of delivering payloads into the geostationary orbit. It has been demonstrated that, as compared with the option of a circular nuclear safe orbit with the altitude of Hêð= 800 km, the use of elliptical staging orbits in combination with auxiliary orbital transfer stages based on oxygen-hydrogen liquid rocket engines makes it possible to improve energy and mass performance of the reusable space tug, as well as to make greater cost savings through its application in comparison with the most efficient conventional vehicles for orbital transfer — the expendable oxygen-hydrogen upper stages.
Key words: reusable orbiter transfer vehicle, nuclear power system, electric propulsion system, staging orbit.
Zykov À.V., Subbotin À.V.
Mathematical modeling of releasing the tether system from a rotating central body
The article studies a problem of releasing a heavy tether representing a part of a circular solar sail cloth in a folded coniguration subject to centrifugal inertia forces. The slope angle of a quasistationary shape of the tether being released with a constant speed is analytically calculated. Consideration is given to various methods of tether release: at a constant speed, a uniformly decreasing speed and a speed ensuring a permanent deviation of the tether end from the radial direction. The advantages and disadvantages of each release method are considered. Most of the focus is on minimizing the disturbing efect of the tether on the central rotating body, from which the folded sail cloth is released. The results obtained can be used in designing systems of the initial phase of deploying solar sails on space platforms with large rotating solar sails.
Key words: solar sail, quasistationary shape, methods of releasing from the folded configuration, mathematical modeling.
MACHINERY AND EQUIPMENT, PROCESSES OF REFRIGERATION AND CRYOGENIC TECHNOLOGY, AIR CONDITIONING AND LIFE SUPPORT SYSTEMS
Romanov S.Yu., Guzenberg A.S., Ryabkin A.M.
Crew life support system concept for interplanetary missions
The paper defines the configuration of the systems which provide water and oxygen recycling from the crew waste products within the physically and chemically closed-looped life support system for interplanetary space missions. This is a system with upgraded subsystems for reclaiming water from all possible sources, dehydrated food rations, a subsystem for recovering oxygen from carbon dioxide through electrolysis of carbon dioxide producing oxygen and carbon monoxide, which is subsequently hydrogenated down to water and methane, and includes biological elements.
Such a system can be built as a standard life support system based on upgraded life support systems of space stations Mir and ISS for both lunar and interplanetary missions, and missions in low-Earth orbit. It also signiicantly reduces the traic to the manned space station carrying subsystems consumables and food for the crew. The paper discusses the concepts and parameters of the proposed major regenerative subsystems and of the standard system as a whole, as well as the mass and power budget of the system.
Key words: crew, spaceflight, habitat, a system of physical and chemical life support subsystems, water and oxygen recycling from waste products, variable mass of systems, biological life support systems.
SYSTEMS ANALYSIS, CONTROL AND DATA PROCESSING
Bogachev A.V., Vorobyeva E.A., Zybov N.E.
Attitude control and momentum management for the spacecraft with inertial actuators on high-elliptical orbit
The article deals with the dynamics of the angular motion of the spacecraft on the high-elliptical orbit. The attitude control and momentum management algorithm is designed for the spacecraft with inertial actuators on the high-elliptical orbit using gravity gradient torque. Accurate pole placement method is used to develop attitude control and momentum management control laws. A numerical solution is derived for attitude control low and momentum management of the spacecraft on the high-elliptical orbit on all three control channels in the vicinity of the perigee of the orbit. Also, the stability analysis is performed for the linearized diferential equations describing the dynamics of the spacecraft on the high-elliptical orbit.
Key words: attitude control, momentum management, inertial actuator, high-elliptic orbit, spacecraft, gravity gradient forces, accurate pole placement method.
¹ 3(18) july-september 2017