Annotation: The pyrobolts, or explosive bolts, belong to the pyrotechnical devices with monolithic case consisting o f the cap, as a rule with hexagonal surface, and of cylindrical part with thread. The pyrobolts are separated into parts using the pyrotechnical charge placed inside the case. Owing to the simple design, reliability and short action time, the pyrobolts have found wide application in aerospace engineering for separation of assemblies and bays, in particular, stages, head modules, launching boosters, etc. So, for example, about 400 pyrobolts are used in the Proton launch vehicle. The designs of pyrobolts are markedly different. By method of explosive substance action on case structural elements, the pyrobolts are divided into two types: the pyrobolts using the shock wave formed at detonation of brisant explosive substance for case wall destruction and the pyrobolts using the pressure of gases arising at pyrotechnical charge blasting. By method of separation into parts, they are divided into fragmenting pyrobolts with ridge-cut, with piston, and shear pyrobolts. The paper deals with the design of various types of pyrobolts, their disadvantages are considered. The Yuzhnoye SDO-developed pyrobolt of shear type with segments is presented that uses radial shear forces of segments located in the hole of cylindrical part to separate the case parts. The above segments a re actuated using a rod with sealing rings and a piston connected to the rod through a rubber gasket; the piston moves under pressure of gases formed during pyro cartridge action. The following calculations are presen ted: strength analyses with determination of case load-carrying capacity; power analyses with justification of pyro cartridge selection for pyrobolt actuation. In the developed pyrobolt of shear type with segments, the case parts are separated without considerable shock loads and without high-temperature gases and fragments release into environment, ensuring reliable separation of bays and assemblies without damaging sensitive equipment.

Annotation: The article analyzes the energy potential of alternative sources of Ukraine. The projects using hydrogen technologies aimed at attracting solar energy to the infrastructure of energy technological complexes, in particular water desalination systems and for refueling automobile vehicles located in areas with high solar radiation potential, are considered. During the operation of water desalination plants using a solar power station as an energy source, contingencies are very likely to arise due to either a power outage (due to cloudy weather) or an emergency failure of individual elements of the system. In this case, it is required to ensure its removal from service without loss of technological capabilities (operability). For this purpose, it is necessary to provide for the inclusion in the technological scheme of the energy technological complex of an additional element that ensures operation of the unit for a given time, determined by the regulations for its operation. As such an element, a buffer system based on a hydrogen energy storage device is proposed. The current level of hydrogen technologies that are implemented in electrochemical plants developed at the Institute of Mechanical Engineering named after A. N. Podgorny of the National Academy of Sciences of Ukraine allows producing and accumulating the hydrogen under high pressure, which eliminates the use of compressor technology.

Annotation: Launch vehicle lift-off is one of the most critical phases of the whole mission requiring special technical solutions to ensure trouble-free and reliable launch. A source of increased risk is the intense thermal and pressure impact of rocket propulsion jet on launch complex elements and on rocket itself. The most accurate parameters of this impact can be obtained during bench tests, which are necessary to confirm the operability of the structure, as well as to clarify the parameters and configuration of the equipment and systems of complex. However, full-scale testing is expensive and significantly increases the development time of the complex. Therefore, a numerical simulation of processes is quite helpful in the design of launch complexes. The presented work contains simulation of liquid rocket engine combustion products jet flowing into the gas duct at the rocket lift-off, taking into account the following input data: the parameters of propulsion system, geometric parameters of launch complex elements, propulsion systems nozzles and gas duct. A three-dimensional geometric model of the launch complex, including rocket and gasduct, was constructed. The thermodynamic parameters of gas in the engine nozzle were verified using NASA CEA code and ANSYS Fluent. When simulating a multicomponent jet, the equations of conservation of mass, energy, and motion were solved taking into account chemical kinetics. The three-dimensional problem was solved in ANSYS Fluent in steady-state approach, using Pressure-based solver and RANS k-omega SST turbulence model. The calculation results are the gas-dynamic and thermodynamic parameters of jets, as well as distribution of gas-dynamic parameters at nozzle exit, in flow and in boundary layer at gas duct surface. The methodology applied in this work makes it possible to qualitatively evaluate the gas-dynamic effect of combustion products jets on gas duct for subsequent optimization of its design.

Annotation: The shell structures widely used in space rocket hardware feature, along with decided advantage in the form of optimal combination of mass and strength, inhomogeneities of different nature: structural (different thicknesses, availability of reinforcements, cuts-holes et al.) and technological (presence of defects arising in manufacturing process or during storage, transportation and unforseen thermomechanical effects). The above factors are concentrators of stress and strain state and can lead to early destruction of structural elements. Their different parts are deformed according to their program and are characterized by different levels of stress and strain state. Taking into consideration plasticity and creeping of material, to determine stress and strain state, the approach is effective where the calculation is divided into phases; in each phase the parameters are entered that characterize the deformations of plasticity and creeping: additional loads in the equations of equilibrium or in boundary conditions, additional deformations or variable parameters of elasticity (elasticity modulus and Poisson ratio). Then the schemes of successive approximations are constructed: in each phase, the problem of elasticity theory is solved with entering of the above parameters. The problems of determining the lifetime of space launch vehicles and launching facilities should be noted separately, as it is connected with damages that arise at alternating-sign thermomechanical loads of high intensity. The main approach in lifetime determination is one that is based on the theory of low-cycle and high-cycle fatigue. Plasticity and creeping of material are the fundamental factors in lifetime substantiation. The article deals with various aspects of solving the problem of strength and stability of space rocket objects with consideration for the impact of plasticity and creeping deformations.

Annotation: The article describes the problems of manufacturing large-size nozzle blocks by classical for Ukrainian space industry method of high-temperature brazing. The Yuzhnoye SDO-selected way of solving this problem and the first strides on the way to organization of new production using innovative technologies of laser welding and surfacing are presented. The step-by-step sequence and procedure of research work to develop and test a new technology of cooled nozzle block manufacturing are described. Four phases are identified, out of which the first two phases have already been successfully performed. The laser welding and surfacing technology will allow avoiding the use of costly and unique equipment and will allow reducing and optimizing the technological manufacturing cycle rejecting the long –term and energy-consuming technological operations. The scientific-and-technological works performed showed the principle feasibility of making connection between the external jacket and internal wall of a nozzle block using laser welding. The test samples manufactured confirmed the high strength characteristics, which had been preliminary obtained by the theoretical calculation methods. The sections obtained by surfacing demonstrate good metallurgical connection between the layers. On the test samples, the technique was tried-out allowing repairing defect areas in a welded seam obtained by laser welding method. This is especially important from the technological and economic viewpoints, as the technology of high-temperature brazing applied currently does not allow making guaranteed repair of brazed joints.

Annotation: The article presents the experience of creating LRE turbopump units by the Rocket Engines Design Office (DO-4) at Yuzhnoye SDO. The best known turbopump units designs developed by DO are described. Both earlier developments of DO and the turbopump unit being now in final testing phase are considered. The design evolution of both separate assemblies and of entire unit is shown. The design evolution allowed increasing the unit’s lifetime dozens times. For example, the lifetime of the first turbopump units developed by DO did not exceed 150 s. Currently, the DO has in stock the engines with lifetime of ~19000 s. The information is presented on the problems that the designers faced in testing the turbopumop unit and the ways to solve them. The unique achievement are presented. At present, there are no analogs of some units in the world. The article presents the information on the latest achievements of DO, such as the face seal on pump vane discs whose use fully excludes unwanted leaks. Having analyzed the data presented, one may conclude that the Rocket Engines Design Office and Yuzhnoye SDO as a whole accumulated sufficient experience and knowledge allowing solving any problems that may arise when developing a new LRE turbopump unit, and successfully operating LRE with turbopump units, including those in the engines with generator gas afterburning created in recent years testify to a great value of accumulated experience.

Annotation: The Ukrainian companies Yuzhnoye SDO and SE PA YMZ supply VG143 main engine assembly for Vega LV AVUM upper stage, which is a one-chamber LRE of 250 kg thrust with five ignitions in flight. By the present, 11 successful launches of Vega LV have been made. In the process of flight operation, there were no critical comments on engines operation. This LRE has a combination of attractive characteristics, such as high specific pulse, low mass, multiple ignitions in flight, high reliability confirmed by good results of flight test of the prototype engines. The reserve of this engine from the viewpoint of further modernization is far from being exhausted. Enhancing the capabilities of payload injection by launch vehicles into various orbits of artificial Earth satellites is the main task for the developers of ILV as a whole and for the developers of separate assemblies and systems, such as LRE being part of ILV. With consideration for the experience of prototype engines testing, we should note the following ways of main engine assembly modernization: – increasing the specific pulse due to the increase of nozzle expansion ratio; – decreasing the volume of internal manifolds and mass of chamber; – increasing the operation time; – increasing the ignitions number; – increasing the duration of pauses between ignitions and orbital functioning time. Increasing the thrust and specific pulse of Vega LV VG143 main engine assembly and AVUM stage takes place due to the use of pneumopump propellant feeding system instead of standard pressure feeding. Besides, the information is presented on RD859, RD864, RD866 and RD869 prototype engines, the data on their basic characteristics, testing and operation. The below information is of interest to LRE and LV developers.

Annotation: One of the important directions in the development of Yuzhnoye SDO liquid rocket engines is creation of the engines for launch vehicle upper stages, boosters, space tugs and takeoff-and-landing vehicles. The article presents an overview of Yuzhnoye SDO – developed liquid rocket engines, their basic characteristics, distinctive features and the current status of development and operation. The article presents the information on the following engines: RD858 and RD859 operating on storable propellants, for lunar takeoff-and-landing Block E module; RD809M and RD809K operating on liquid oxygen + kerosene created on the basis of RD8 serial control engine of Zenit launch vehicle second stage. In this case, RD809M engine is RD8 version with tight integration and RD809K engine is its one-chamber version; RD805 engine operating on liquid oxygen + kerosene created on the basis of combustion chamber of RD8 serial control engine of Zenit launch vehicle second stage.; RD835 engine operating on liquid oxygen + kerosene created for the second stages of launch vehicles of Mayak type; the engines and propulsion systems operating on storable propellants, such as RD861K (main engine of Cyclone-4 third stage and Cyclone-4M launch vehicle second stage), DU802 (liquid propulsion system of Krechet autonomous space tug of conversion Dnepr launch vehicle), RD840 (apogee liquid rocket engine of liquid propulsion system of geostationary communication satellite bus), VG143 (main engine assembly of the fourth stage of European Vega launch vehicle), RD864 and RD869 (main engines of Dnepr launch vehicle upper stages). The information presented in the article is of interest to liquid rocket engines and launch vehicles developers.

Annotation: During 60 years of existence of specialized Liquid Rocket Engines Design Office – DO-4 as a part of Yuzhnoye Design Office, extensive experience was accumulated in development of liquid rocket engines of various purpose on storable and cryogenic propellant components. The required test benches and production base were created. When developing the engines, the DO-4 specialists widely use the experience accumulated during manufacturing and testing of the engines developed by the other design offices for Yuzhnoye SDO LVs that were manufactured by SE PA Yuzhny Machine-Building Plant and tested at Yuzhnoye SDO’s and Plant’s test benches. Along with the conventional ones, new original engine designs were developed to achieve high energy-mass characteristics, reliability and quality. Among them we should mention the RD858 and RD859 engines for the soviet lunar take-off-and –landing module of Block E, the unique RD857 and RD862 engines with afterburning of reducing generator gas and gas dynamic method of thrust vector control, the RD866 multifunctional engine of space tug ensuring multiple ignition in flight, and many others. At present, Yuzhnoye SDO jointly with SE PA Yuzhny Machine-Building Plant deliver the engine for the European Vega LV forth stage propulsion system under the contract with Avio company (Italy). Based on Yuzhnoye SDO–created engines, propulsions systems for ballistic missiles and space rockets that are unique by their characteristics and scope of functions, the engines, propulsions systems for spacecraft, LV upper stages and transfer orbit stages can be developed in short terms and at minimal costs.

Annotation: Several measures to ensure long service life of electrochemical batteries are proposed: electrochemical battery performance evaluation, study of theoretical basis for improvement and building of experimental bench equipment.