# Abstracts

## The Space Engineering and Technology magazine

¹ 1 (20), 2018

### Contents

#### INNOVATIVE TECHNOLOGIES IN AEROSPACE ACTIVITIES

**Shevchenko V.V.**

*Utilization of the asteroid subject on the Moon — a more economic way to obtain cosmic resources of high value
*

In recent years, in analytical reviews, experts are increasingly paying attention to the growing scarcity of rare and rare-earth elements necessary for the development of advanced technologies in modern industry. To solve this problem, in the future, projects were proposed for the utilization of a substance of asteroids approaching the Earth. Despite the difficulties of seizing, transporting and further developing such an object in space, this way of solving the problem seemed technologically feasible and cost-effective justified. A 10-m iron-nickel asteroid could contain up to 75 tons of rare and rare-earth metals, primarily platinum-group metals, which is equivalent to a commercial price of about $2.8 billion in 2016 prices. In this paper it is shown that the utilization of an asteroid substance entering the lunar surface can be technologically more simple and economically more cost-effective. Until now, it was believed that the lunar impact craters do not contain the rocks of the asteroids that formed them, since at high velocities the impactors evaporate during a collision with the lunar surface. According to the latest research, it turned out that at a fall rate of less than 12 km /s the drummer can partially survive in a mechanically fractured state. Consequently, the number of possible resources present on the lunar surface can be attributed to nickel, cobalt, platinum and rare metals of asteroid origin. The calculations show that the total mass, for example, of platinum and platinoids on the lunar surface as a result of the fall of asteroids may amount to 14.1 million tons.

**Key words: ** The moon, lunar resources, asteroids, the chemical composition of asteroids, rare metals, rare earth metals, impact processes on the Moon, space technology for the development of asteroids, the processes of bringing an asteroid substance to the moon.

**Belyaev M.Yu., Karasev D.V., Matveeva T.V., Rulev D.N.**

*Progress cargo vehicles in orbital-station programs
(dedicated to the 40th anniversary of the world’s irst cargo vehicle space light to an orbital station)
*

Missions of the first-generation orbital stations demonstrated that in order to support their long-term efficient operation in orbit it was necessary to have regular deliveries of propellant for the propulsion system, consumables and food for the crew, spares for onboard systems, new hardware for station utilization, etc.. To address these concerns, in 1973 RSC Energia began to develop a new cargo transportation spacecraft based on the already proven design of the manned Soyuz spacecraft, and by the end of 1977 the first flight model was ready. The launch of Progress-1 took place forty years ago on January 20, 1978, and on January 22, 1978 the logistics spacecraft docked with the orbital station Salyut-6, which marked the beginning of many years of successful operation of the world's first logistics spacecraft. By now, all those Progress spacecraft that were successfully put into orbit, have docked with orbital stations and completed the cargo delivery program. Instrumental in successful operation of Progress spacecraft were mission control methods that were developed for them and enabled reliable performance of transportation operations even in contingency situations. From 1978 onwards, the mission plans of many logistics spacecraft that flew to stations Salyut, Mir, and the International Space Station included space experiments and studies. New methods and technologies were developed for conducting experiments wit the use of logistics spacecraft. They permitted to launch satellites into higher orbits, to study Earth and its atmosphere and carry out many other research tasks. The proposed methods also provided the level of microaccelerations in the Progress logistics spacecraft that was required for conducting experiments in microgravity.

**Key words:** logistics spacecraft Progress, orbital station, mission plan, control methods, technologies for conducting experiments.

#### FLYING VEHICLES ENGINEERING, DESIGN AND MANUFACTURING

**Avershyev A.S., Bobylev S.S., Falin K.A. **

*The updated veriication procedure of detailed inite element structural models of rocket-space technology for analysis of dynamic loading in light by the example of the Progress MS cargo transport vehicle
*

The verification procedure of detailed finite element structural models of rocket-space technology products (spacecraft, launch vehicles, etc.) described in this article extends the capabilities of their verification based on the results of modal tests as it includes additional phases to update the model parameters including the results of actual measurements in operation of these structures. The stiffness properties of structural elements models and dynamic characteristics of structures are updated during the verification procedure. Such a verification procedure makes it possible to obtain qualitatively better models considering the actual operating conditions for structures. The models verified in this way can be used to analyze dynamic loading of structures with a high level of accuracy and also to restore the actual dynamic behavior in operation.

**Key words:** spacecraft, launch vehicle, dynamic loading analysis, detailed finite element model, verification, modal tests, dynamic characteristics, stiffness properties.

**Akkuratov I.L., Alyamovskiy A.I., Vinogradov A.S., Gerasimova T.I., Zemtsova E.V., Kirillov S.V.,
Kopyl N.I., Magzhanov R.M., Senkovskiy A.N., Sokolova S.P., Shcherbakov E.V.**

*Results of studies into the properties of carbon iber-reinforced plastics based on various polymer binders, viewed as candidates for manufacturing structures for space hardware
*

Selected for manufacturing structures of space hardware that have to bear high loads (primary structure of the front heat shield, aerodynamic shell, propulsion section body and pressurized habitable compartment) are composite materials – carbon fiber-reinforced plastics that have high specific strength and stiffness as compared with traditional structural materials. This article provides results of experimental studies on carbon plastics based on various carbon filler and polymer binders: PSB250/A, PSB250/B, PSB250/V, 22500/NIKAM-RS, KMKU-4m.175, KMU-4E, KMKU3.150.E01. The studies resulted in determining the following properties: mechanical, thermal, optical, electrical, off-gassing level in vacuum, material samples leakage using helium/air mixture, safe use parameters, including toxicology and fire safety and microbiological resistance. These properties are required for the design analysis of the above structures.

**Key words: ** carbon fiber-reinforced plastic, binders, carbon fiber-reinforced plastics, pressurized habitable compartment, composite materials.

#### FLYING VEHICLES STRENGTH AND THERMAL ENVIRONMENTS

**Stavitskiy I.B., Ryabtseva A.V., Kaminskaya V.S.**

*Optimization of electrical discharge machining process for titanium alloy BT14 based on the solution of the heat task of moving the boundary of the phase conversion of material
*

The results of theoretical studies of titanium alloy machinability by electrical discharge machining based on the solution of the heat problem of moving the boundary of the phase conversion of material are presented in this article. The description of the computer program developed for solving the above-mentioned heat problem is given. The procedure of defining rational modes of electrical discharge machining of titanium alloy ÂÒ14 is proposed and recommendations are given for the purpose intended. The minimum heat flux density and the duration required to implement the process of electrical discharge machining of titanium alloy BT14 are determined. The dependence of the minimum pulse duration of the heat flux on the heat flux density is established at which the electrical discharge machining of titanium alloy BT14 is possible. The following is determined: the maximum pulse duration of the acting heat flux which results in the greatest removal of alloy BT14 per pulse; the effective duration of the heat flux providing the maximum efficiency of the process of electrical discharge machining of titanium alloy.

**Key words: ** electrical discharge machining, heat task, heat flux density, electrical pulse duration, titanium alloy BT14, modes of electrical discharge machining, machinability of titanium alloy BT14.

#### FLYING VEHICLES THERMAL, ELECTRIC PROPULSION ENGINES AND POWER GENERATING SYSTEMS

**Kirenkov V.V., Mikitenko V.G., Sirosh A.N.**

*Determining the actual values of specific impulse for the main
engines of the Block DM upper stages as a routine inverse problem
*

One of the most important parameters for space launcher vehicles (including Block DM upper stages) to be determined from flight test results is Ð_{sp}, which is the actual value of the main engine specific impulse. The importance of this parameter lies in the fact that, on the one hand, it is what meeting the upmass performance requirements depends on, and on the other hand, it is one of the main diagnostic parameters of propulsion systems. Traditionally, the most common method for solving such a problem under conditions where direct measurements of this parameter are impossible is the use of the classical Tsiolkovsky formula with inputs from mass-weight analysis. However, experience has shown that this method, due to the low accuracy of such inputs does not provide the required accuracy of the Ð_{sp} estimates, and in some cases is not applicable at all. This paper shows how the use of some peculiar aspects of the variable-mass mechanics permits to solve such a problem. This is achieved through stating a classical inverse problem where mass properties are treated not as inputs, but rather as perturbing factors with respect to design values.
The discussed methodology of stating and solving inverse problems can also be recommended for other similar problems in evaluating test results when direct measurements of monitored parameters are impossible. It was used for evaluating Ð_{sp} for upper stages similar to Block DM, as well as parameters with other physical meaning, for which the available measurements made it possible to state an inverse problem.

**Key words: ** upper stage, mass properties, specific impulse, inverse problem.

#### FLYING VEHICLES DYNAMICS, TRAJECTORY AND MOTION CONTROL

**Salmin V.V., Starinova O.L., Chetverikov A.S., Bryukhanov N.A., Khamits I.I., Filippov I.M., Lobykin A.A., Burylov L.S.**

*Trajectory design analysis of transport operations of an electrically propelled
space tug during transfers to geostationary orbit, orbit around the Moon and to libration points in the Earth–Moon system
*

A trajectory design analysis has been conducted for transfers of an electrically propelled space tug with a solar power system from low-Earth orbit to geostationary orbit, low lunar orbits, and to libration points with return to the parking orbit. The analyses were done for a range of the tug design parameters, which were selected by varying exhaust velocities (specific impulse) of the propellant. Taken into account was the fact that the thrust efficiency of actual engines varies according to the operational mode and usually increases with an increase in the exhaust velocity. Two options for the solar power generating system were considered: one based on existing photovoltaic converters having a 28% efficiency; and the other based on advanced photovoltaic converters having an up to 40% efficiency. The analysis has demonstrated the feasibility in principle of efficient use for transportation operations in the Earth-Moon system of an electrically–propelled tug with an about 400 kW solar power-generating system.

**Key words: ** trajectory design analysis, transport operation, trajectory plan, design parameters, space tug, electrically-propelled space tug, electric propulsion, geostationary orbit, lunar orbit, libration points.

**Mezhin V.S., Obukhov V.V.**

*The development and experimental veriication of solar array in folded
coniguration dynamic inite element model with taking into account an air environment
*

During launcher’s take-off, spacecraft and its equipment units are subjected to intensive vibration and acoustic loads. The structure analysis of equipment that is characterized by small mass and big surface square of some structure elements (in particular, solar arrays in folded configuration) to such type loads is very actual and carried out by many aerospace companies. The aim of this study is development and experimental verification of spacecraft solar array in folded configuration dynamic finite element model with taking into account an air environment action. Realization of the mentioned aim has been made based on the one of spacecraft’s solar array that has been developed by RSC Energia. Short description of solar array mathematic (dynamic) model is presented. The modelling is realized with taking into account environmental air action. Dynamic model verification was implemented based on frequency response functions determined under solar array (in folded configuration) vibration strength tests which was a part of general qualification testing program. The model developed is dedicated for making loads calculations for low frequency range up to 100 Hz. Using the calculation results and experimental data comparison, the analysis has been implemented and corresponding conclusions about air environment influence on solar array structure's dynamic parameters has been made.

**Key words: ** air environment, spacecraft, solar array, folded configuration, finite-element dynamic model, dynamic model verification, frequency response function, structure's dynamic parameters.

#### ROBOTS, MECHATRONICS AND ROBOTIC SYSTEMS

**Rasskazov Ya.V., Yaskevich A.V. **

*Using cylindrical inite elements in the spiral spring tape angular
deformation model of docking mechanism damper
*

Specified damping features of advanced spacecraft docking mechanisms can be realized using attenuation elements based on spiral tape springs with nonlinear stiffness behavior. The existing approximate engineering methods allow to calculate certain parameters of constant-width spiral springs operating only in a clockwork mode, when resistance torque is close to constant on the whole range of angular movement. The required nonlinear stiffness behavior can be realized only by using a width-variable tape spring. New cylindrical finite elements are proposed in this paper for describing a shape of such tape spring. The calculating algorithm for spring deformation under torque is considered. A variation of the torque value makes it possible to determine the spring stiffness behavior. The described model and deformation calculating algorithm for the spiral tape-spring form the basis for analysis and synthesis of spring attenuation elements for future docking mechanisms.

**Key words:** spacecraft docking mechanism, spiral tape spring, cylindrical finite element, numerical method of deformation calculation.

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**¹ 1 (20) january-march 2018**