Annotation: The article dwells on the problem of enhancement of durability for the mechanical rubber articles, which is directly related to the enhance of rubber resistance to various types of heat aging. Heat resistance during compression is most important for rubbers used for seals of various types: rings, collars, armored collars, gaskets for aviation and rocket technology hardware. Stress relaxation and the accumulation of relative residual deformation of rubbers, caused by the kinetic rearrangement of chemical bonds, are extremely sensitive to the influence of high temperatures. The main cause of the defects is the loss of elastic properties of the seals because of the accelerated heat aging of the nitrile group under conditions of long-term exposure to elevated temperatures in conditions of hot climate. The results of accelerated climatic testing of specimens of mechanical rubber articles, as well as the results of climatic endurance testing of the units for the period simulating 20-year service life are specified, and the main types of defects which result in the loss of performance properties of the mechanical rubber articles are as follows: great (up to 100%) residual deformation of intersections, cracking, loss of elasticity. The warranty life of fuel system units, made of ИРП-1078 nitrile rubber, does not exceed 12 years. Replacing the existing rubbers with rubbers created on the basis of more heat-bearing rubbers is the most promising way to improve the performance properties of the mechanical rubber articles under the high temperatures. The new D2301 rubber is based on fluorosiloxane rubber. It provides high thermal stability and, especially, the ability to maintain high performance properties for a long time under the simultaneous impact of hostile environment and high temperatures. The results of climatic endurance testing of fuel system units, equipped with rubber articles made of D2301 rubber, fully justify the increase of the specified service life of the specified units from 12 to 16 years. It is recommended to introduce D2301 rubber into the effective normative documentation and continue studies in order to extend the nomenclature of mechanical rubber articles made of D2301 rubber to provide the reliable sealing of units during the service life of 16 years or longer.

Annotation: The remote control method of launch vehicle hydrosystem detachable joints airtightness by mass spectrometer at the Launch Complex in conditions of limited access to hydrosystem elements is under consideration. The additional design development of hydrosystems prior to article roll-out to the launch side is provided for control.

Annotation: One of the main types of arming of modern tactical and short-range missiles are cassette warheads based on nonguided blast-fragmentation submunitions that are widely used to kill group targets. The fullscale testing (flight tests) is an integral part of their creation. In the process of flight tests of tactical and shortrange missiles with cassette warheads, the safety issues are topical. Based on the capabilities of existing test ranges, it is planned to conduct such tests for the tactical and short-range missiles, being under development in Ukraine, in the Black sea water area where the cassette warheads with nonguided blastfragmentation submunitions (or their equivalents) will pose major hazard for ships. In the paper, two mathematical models are proposed to assess probability of killing (risk) a ship that may be present in the impact area of submunitions (submunitions equivalents) of cassette warhead. The first model was constructed in the assumption that the coverage area of cassette warhead and group dispersion of submunitions are known. Such model may be used to determine safety in the initial phases of cassette warheads development. The second model assumes that the configuration of cassette warhead and the scheme of submunitions firing were finalized, and accordingly, the nominal impact points of submunitions and their group and ind ividual dispersion are considered to be known. Practical application of both models requires the use of numerical procedures.

Annotation: The possibility is considered of using rocket propellant thermal neutralization units for decontamination of dangerous industrial wastes. The advantages of thermal neutralization units are considered, their operating principle is described, by the example of high-temperature toxic rocket propellants, the chemical reactions that take place in combustion chamber are formulated. The combustion chamber is a component of the neu tralization unit, it is in the combustion chamber, in the environment of created high temperatures, that the process of elimination of dangerous substances takes place. Taking into consideration the high cost of neutralization units, which will be a factor hindering the wide-scale introduction of neutralization units to decrease technogenic load on environment of Ukraine, the option is proposed of reducing the costs during the use of thermal neutralization units by way of combining the function of oxidizer neutralization unit and fuel neutralization unit in a single universal neutralization unit. The article substantiates the topicality and necessity of works to create the universal thermal neutralization unit from the viewpoint of economic and ecological aspects. The article presents a generalized description of technology and methodology of research tests of pilot samples of assemblies for high-temperature rocket propellants vapor and industrial wastewater supply into the neutralization unit. The assemblies for high-temperature rocket propellants vapor and industrial wastewater supply are considered as most critical components of the universal neutralization unit from the viewpoint of neutralized substance changing. The experiments were conducted on water solutions of rocket propellants that in this case simulated the contact of internal cavities of supply assemblies with aggressive toxic media. The conditions were created at which the probability existed of interaction of rocket propellants residues in stagnation zones at the moment of changing the supplied propellant component. In the frameworks of research tests of pilot samples, the obtained results were considered and analyzed. The findings are presented that confirm practical feasibility of using integrated supply assemblies.

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 exploratory and experimental investigations were conducted into design of propellant tank made of composite polymer materials for work in cryogenic environment at operating pressure of 7.5 kgf/cm2 . When determining the configuration of a liner-free composite propellant tank, the main requirement was ensuring its leak-tightness at internal excess pressure and cryogenic temperature effect. The world experience of creating similar designs was analyzed and the requirements were defined imposed on configuration of propellant tank load-bearing shells. Before defining the final configuration, the types of materials, reinforcing patterns, and possible ways to ensure leak-tightness were analyzed, and preliminary tests were conducted of physical and mechanical characteristics of thin-wall samples of composite materials and tubular structures with different reinforcing patterns. The tests of carbon plastic samples were conducted at different curing modes to determine the most effective one from the viewpoint of strength characteristics and the tests for permeability by method of mouthpiece were conducted. The tests of pilot propellant tank showed that the calculated values of deformations and displacements differ from the experimental values by no more than 10 %. Using the parameters measurement results from the tests on liquid nitrogen, the empirical formulas were obtained to calculate linear thermal expansion coefficient of the package of materials of load -bearing shell. The empirical dependences were constructed of relative ring deformations at load-bearing shell middle section on pressure and temperature. The tests confirmed correctness of adopted solutions to ensure strength and leak-tightness of propellant tank load-bearing shell at combined effect on internal excess pressure and cryogenic temperature, particularly at cyclic loading. The materials used and propellant tank manufacturing technologies ensure leak-tightness of load-bearing shell at liquid nitrogen operating pressure of 7.5 kgf/cm2 and strength at excess pressure of 15 kgf/cm2 and allow conducting approbation of prospective stage of the integrated launch vehicle.

Annotation: One of the tasks of the development tests conducted on a launch pad is verification of its strength properties. The tests are carried out after the launch pad was manufactured and assembled on-site as well as during the whole operating period (if necessary). Load mode was chosen in consideration of cost and possibility of providing the required loading conditions. Two modes of creating the required test load were examined: usage of weights with corresponding mass (load simulators) or special devises (which have smaller mass as compared with load simulators). The descriptions, basic characteristics, advantages and disadvantages of composite and bulk weights and pad loading device are given. This article studies the pad loading device under development. This device enables to conduct static nondestructive tests on the launch pad in order to check its strength after manufacturing and during the whole operating period. The device consists of the load-bearing frame, hydraulic system, locks, control system and measurement system. Advantages of the pad loading device include low materials consumption, low cost in comparison with composite weights (with large load values), provision of the required modes for applying and removing the test load, controlled separate loading of each support of the launch pad, high mobility, short duration of testing, possibility of using launch pads of other rocket complexes with lower or equal test load values for testing. Therefore, the pad loading device enables to achieve the required test load values while having considerably smaller dimensions and mass as compared with composite weights and bigger functional possibilities as compared with bulk weights. Small overall dimensions and operability reduce the number of needed personnel and equipment.

Annotation: The measurement errors upon conducting flight tests for launch vehicles are evaluated by considering the interferences and uncertainties in the measurement system procedure. Formal use of this approach can lead to unpredictable consequences. More reliable evaluation of errors upon conducted measurements can be achieved if the measurement process is regarded as a procedure of successive activities for designing, manufacturing, and testing the measurement system and the rocket including measurements and their processing during the after-flight analysis of the received data. The sampling rates of the main controlled parameters are three to ten times higher than the frequency range of their changing. Therefore, it is possible to determine the characteristics of the random error components directly on the basis of registered data. The unrevealed systematic components create the basic uncertainty in the evaluation of the examined parameter’s total measurement error. To evaluate the precision and measurement accuracy of a particular launch, the article suggests specifying the preliminary data on measurement error components determined during prelaunch processing and launch. Basic structures of algorithms for evaluation of precision and measurement accuracy for certain mathematical models that form the measured parameters were considered along with the practical case when static correlation existed among the measured parameters.

Annotation: The problem is defined of designing the space rocket low-pressure air thermostating systems joints. The basic requirements imposed to the joints from the side of space rocket and ground complex are determined and stated. For this purpose, the analysis of operating conditions and possible situations during rocket launches is made. Besides, the methodological principles based on problematic, systematic, and structuralfunctional approach were applied using the theoretical and empirical capabilities, attraction of general scientific and special investigation methods, as well as historical and logical methods. The list of topical issues is reflected for implementation in joint’s design. The ways are proposed to create the joints meeting the requirements imposed. As a result, it was ascertained that the joints can be made of simpler and at the same time failure-free design in the form of combined triune rubber hose fitted with a metal fixation/release unit installed on a sealing flange in a special groove. Of special note is the versatility of the proposed technical solution for use in any of the space launch systems known in the world’s practice. The article is concluded with following: the basic requirements have been formulated for ground complexes thermostating systems joints to ensure space rockets prelaunch processing and launch, in doing so, the topical problems were defined; the scientific principles were proposed to design the thermostating systems joints for comprehensive solution of the topical problems , including potential critical situations; the thermostating systems joints have been developed, manufactured and have successfully passed the ground development tests with simulation of the conditions maximally close to operating ones at static operating air pressures and in off-nominal situations.