# Abstracts

## Space Engineering and Technology magazine

¹4 (11), 2015

### CONTENTS

#### FLYING VEHICLES AERODYNAMICS AND HEAT EXCHANGE PROCESSES

**Babakov A.V., Beloshitsky A.V., Gaydaenko V.I., Dyadkin A.A.**

*Numerical simulation and analysis of flow
patterns near a reentry space vehicle with firing rocket engines in the vicinity of the landing surface
*

The results of the numerical simulation of jets interaction of landing multi-nozzles engine with landing field are presented for recovery capsule of segment-conical form. The diffluent jets flow on landing surface and induced by jets flow near capsule are calculated. The investigations were carried out for several distances between landing surface and capsule. For each case the steady-state was achived. The time for realization steady-state flow and the values of the aerodynamic forces induced by ambient gas fluxes were defined. It was obtained that these values dependence from landing surface distance has monotonic character. In the configuration of engine nozzles under consideration the depression occur on all surfaces of the capsule. The force that deboost the engine thrust in vertical direction has place. In this case the gas flux that directed to capsule front part is formed. The calculations at deviations of the longitudinal capsule axis were realized. The flow structure and the effect on the aerodynamic characteristics were studied. The investigation of the engine thrust decreasing on parameters under consideration was actualized. In this case the engine thrust decreasing was modeling by jets pressure degression as well as the jets cross-section reduction. The visualization of spatial unsteady vortex structure is implemented. The numerical simulation is based on the unsteady finite-difference schemes of the flux method, approximating the conservation laws in integral form. The numerical simulation is carried out on parallel algorithms and realized on cluster multiprocessor systems.

** Key words: **aerodynamics, recovery capsule, landing engine jets, landing surface, numerical simulations, parallel algorithms, flow visualization.

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

**Katkov R.E., Lozino-Lozinskaya I.G., Mosolov S.V., Skoromnov V.I., Smolentsev A.A., Sokolov B.A.,
Strizhenko P.P., Tupitsyn N.N.**

*Experimental development of a multifunctional liquid rocket engine with oxygencooled
combustion chamber: results of 2009–2014
*

Results of the test program to provide confidence in liquid oxygen cooling without inner curtain cooling, performed in 2009–2014 on rocket engine test chambers of multifunctional oxygen-hydrocarbon liquid rocket engine 11D58MF, which is developing in RSC Energia, are presented. Design of thrust chamber cooling channels was based upon peculiarities of cryogenic oxygen in supercritical condition. Seven thrust chambers with different design were successfully tested 27 times. Fire tests were performed with various chamber pressure, propellant ratio and various ratio of oxygen feed in chamber and in cooling jacket. Basic design parameters of the thrust chambers – efficiency of propellants combustion, increase in specific impulse, coolant oxygen heating and pressure drop – are confirmed. Test results has approved efficiency of liquid oxygen cooling of oxygen-hydrocarbon fueled liquid rocket engine.

**Key words: **liquid rocket engine, combustion chamber, cooling, liquid oxygen, test results.

**Ganzburg M.F., Kropotin S.A., Murashko V.M., Popov A.N., Sevastyanov N.N., Smolentsev A.A.,
Sokolov A.V., Sokolov B.A., Sukhov Yu.I.**

*Results of ten years of operation of electric thrusters within
two telecommunication spacecrafts Yamal-200 in geostationary orbit
*

The paper presents results of operation of electric thrusters’ onboard two telecommunications spacecraft Yamal-200 over a period of ten years. It provides a description of propulsion systems and their major components: electric thruster modules, which bring the spacecraft to their stations in the geostationary orbit, provide stationkeeping and attitude control; power supply and control equipment, consisting of the power supply unit and thruster modules automatic control unit. It analyses propulsion system operational modes, peculiarities of operation of thruster modules and power supply and control equipment during steady-state operation, during transient processes – during startup (reaching the nominal power mode) and during surge anode currents that are characteristic of electric thrusters with ceramic discharge chamber. It demonstrates stable operation of propulsion systems over a period of more than ten years with thruster modules accumulating more than 1 100 running hours during ~2 500 firings. It provides the results of continuous analysis of thruster modules thrust using methods developed by RSC Energia. It demonstrates that the thrust remained unchanged over the ten years of operation.

**Key words: **electric thruster, thrust module, running hours, number of firings, anode current surges, thruster modules thrust.

**Gopanchuk V.V., Potapenko M.Yu.**

*Development of low-power plasma thrusters for small satellites
*

The paper presents the results of solutions to a number of practical problems, encountered during development of a new low-power plasma thruster and optimization of its configuration in order to improve its performance, as well as to reduce the energy cost of thrust generation. It provides a conceptual schematic of a plasma thruster with a hollow magnet anode. It presents the results of studies aimed at developing advanced low-power plasma thrusters within the range of 70 to 300 W, which provide improved output parameters while having lower mass and dimensions. The development effort resulted in low-power thrusters PlaS-34 and PlaS-40. It describes the results of studies into the effects of design parameters of magnetic and discharge systems on the performance of the thrusters. It describes operational features and behavior of specific parameters of the plasma thrusters of the new system at various operating points. It demonstrates the advantages of the PlaS thrusters in comparison with known analogs, as well as their competitive edge and the promising outlook for their application.

** Key words:**small satellite, electric propulsion, stationary plasma thruster, thrust efficiency, plasma thruster with a hollow magnet anode.

#### CHECKING AND TESTING FLYING VEHICLES AND THEIR SYSTEMS

**Kirenkov V.V., Mikitenko V.G.**

*Solving inverse problems in evaluation of tests of rocket and space hardware using the methods of the optimal control theory
*

There are many known examples in the history of applied sciences where methods and approaches developed for one field of studies turn out to be quite effective for other fields, which at first glance seem to be absolutely unrelated. This observation is fully applicable to problems in processing and interpretation of experimental data from the results of tests on some dynamic systems, in particular, onboard systems of rocket and space equipment. This paper discusses from that standpoint some of the typical inverse problems encountered when evaluating the state of such systems. It shows how, in a number of cases that often occur in practice, methodological difficulties of solving such problems can be overcome by using methods developed in another known area of applied math, optimal control theory.

** Key words: **inverse problem, dynamic systems, inverse problems, applied math, optimal control theory.

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

**Mikrin E.A., Orlovskiy I.V., Bragazin A.F., Uskov A.V.**

*
New capabilities of the autonomous control system of upgraded Soyuz and Progress spacecraft for implementing a «quick» rendezvous with the ISS
*

The paper discusses algorithms for navigation, guidance and trajectory control implemented in the course of upgrading the control system of Russian spacecraft of Soyuz and Progress series. The control system is based on an adjustable strapdown inertial navigation system, using a realistic model of spacecraft motion. The upgrade of control algorithms was prompted by the new navigation capabilities provided by the installation of satellite navigation hardware onboard spacecraft and the International Space Station, which allow starting automatic rendezvous from the initial position. It provides a description of the guidance algorithm for calculating onboard the spacecraft all the maneuvers of the rendezvous plan, which takes into account the requirement of safe approach and constraints on the spacecraft velocity with respect to the orbital station during rendezvous. It discusses the feasibility of implementing the rendezvous operation using the so-called “quick” docking profiles. It provides an estimate of the relationship between the boundaries of the optimal range of phases and the duration of the rendezvous operation for «quick» profiles. It describes a strategy for expanding the range of phases for the currently used 4-orbit rendezvous profile with navigation support from radio monitoring of the orbit. It provides the results of the rendezvous with the ISS performed by Soyuz TMA-15M spacecraft, and the results of a simulation of a rendezvous using satellite navigation equipment.

**Key words: **spacecraft, space station, «quick» rendezvous, maneuver, satellite navigation, guidance, control.

**Kovtun V.S., Kochergina M.N.**

*
Use of phased antenna lattice as magnetic actuator of orientation system
*

At the moment, space based flat phased antenna lattices (PAL) have found broad application for the problem solving of provision of personal satellite communications. Normally, PALs have large square working surfaces. Modern spacecrafts under design with PAL use powered gyroscopes for orientation maintenance. This article looks into possibility of PAL use (existing designs) as magnetic actuator for unloading of kinematic momentum. In the process of interaction between intrinsic magnetic moments of the current loops of the array power supply and the Earth magnetic field, a control moment is generated which is directed oppositely to kinetic moment accumulated in the system of control moment gyros. The values of the intrinsic magnetic moments depend on the intended functionality of the PAL and the implemented design solutions related to current flows in the primary and secondary power supply circuits. The advantage of using PAL as final control devices consists in the fact that they do not require any additional increases in the mass of the spacecraft in order to conduct dynamic operations.

**Key words: **the phased antenna lattice, powered gyroscopes, kinetic moment, magnetic moment, control moment, module, emitter.

#### SYSTEMS ANALYSIS, CONTROL AND DATA PROCESSING

**Ulybyshev Yu.P.**

*Short survey of international conferences SPACE 2014
*

A short survey of reports on astronautics conferences held by American Institute of Aeronautics and Astronautics (AIAA) in August 2014 (San-Diego, USA) is presented. About a quarter of the reports (86) of AIAA Space Conferenñe and AIAA/AAS Astrodynamics Specialist Conference are mentioned in the review. Subjects of the reports are wide range. Projects of manned spaceflights without circumterrestrial space — cislunar flights, mission at lunar libration points, asteroids and the Mars. A number of messages are included complex associative analysis of such missions. Much reports are related with different matter for circumterrestrial spaceflights — orbital rendezvous and inspection, Earth’s remote sensing and space coverage, satellite constellations. New astrodynamics methods are traditionally presented.

**Key words: **space missions, flights to Moon, interplanetary flights, space flight dynamics, astrodynamics, conferences, survey.

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**¹ 4 (11) october— december 2015**