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: The main task of the radiotransparent radome design is to develop a structure that reliably protects the aircraft components, sensitive instrumentation of the guidance system from incoming air flow and heating in all phases of operation, meeting all the requirements of minimum weight, allowable temperature under the radome, strength, centre of mass and radio characteristics. Development of the radome solves the complex task of coupling and optimization of the geometric aspects of design with physical-mechanical, radio and thermal properties of materials. The article dwells on the aspects of development of the radiotransparent radomes depending on the aircraft flight speed; basic requirements for the selection of outside perimeter configuration; structural materials, providing the required radio properties in combination with minimum mass and necessary strength, acceptable temperature inside the fairing. Yuzhnoye-developed radome for the up to 5 M aircraft was considered, consisting of ogive shell made of АФ-10ПО fiberglass, heat-resistant tip and structural ring made of aluminum alloy. Methods of thermal and strength analyses of the shell are considered, results of calculations confirming the fitness for work of the structure are presented. Options of configuration with ceramic shells and methods of their coupling with rings are presented for the aircraft that reaches up to 5 M speed. Basic principles of radiotransparent radomes development and aspects of ceramic shells coupling with structural rings are considered, as well as the results of strength analyses and thermal calculations that ensure the performance of the structure and equipment in the area under the radome.