An Experimental Study to Determine Mechanical and Thermophysical Characteristics of Thin-Walled Carbon Plastic Antenna Reflectors

High requirements are imposed on the mass and dimensional stability of reflectors of onboard mirror space antennas in promising communication satellites. To meet these requirements, new design and layout schemes for reflectors using composite materials are being developed. The use of flat reinforced carbon fabric composites in these designs is of particular interest. A technique is developed for the experimental determination of mechanical and thermophysical characteristics of the carbon fiber used in a thin-walled shell (0.6 mm) of the onboard space antenna reflector. Data are obtained on the elastic modulus of the carbon fiber based on Aspro-A80 carbon fabric and Huntsman Araldite LY8615 US/XB 5173 Hardener epoxy compound in two directions. The thermal conductivity of the material in the plane of reinforcement is determined.

Method of achievement the high accuracy of the shape of reflectors of mirror antennas of spacecraft

Analysis of conditions, which are required for mirror antennas of spacecrafts destined for transmission of high-frequent radio signals, is done in this paper. These conditions are regarded to resistance and rigidity of the construction features of the material of an antenna’s reflector and its surface’s quality. It is mentioned that the requirements to the accuracy of the reflector’s shape grow together with the frequency of a radio signal. Altogether, the existing constructions of antennas and the producing technologies are not capable to obtain those requirements. The innovative method of controlling the shape of a reflector of a mirror antenna is presented in the paper. Its application gives an opportunity to produce constructions with a highly accurate surface. This method deals with the fact that the required accuracy of a reflector can be achieved via elastic deformation of its shell. Design of the regulating units for different types of reflectors is developed. We propose an algorithm of choosing the number of the regulating units and their locations. This algorithm uses the results of finite-element modal analysis of a reflector’s shell. Innovative design of axisymmetric and offset reflectors which shell’s shape can arise from controlled deformation is developed. We also suggest the design of the reflector’s shell with a timber with regulating units on it. Such design provides an opportunity to significantly decrease the number of the regulating units. Project of the reflector with a timber and console rods possessing low mass and high stiffness is developed. Method of achievement the high accuracy of a reflector, presented in the paper, can be applied to design of new space antennas operating in high-frequency interval.

Design of the structural arrangement for a space reflector via parametric and topology optimization

Development of the optimal structural arrangement for a reflector with the aim to improve its mass and design is of importance due to the necessity to increase areal density and decrease rigidity of the modern space antennas vehicles. Currently, CAE-systems allow to design reflectors using both traditional methods, for example, parametric optimization, and methods which are innovative in this field, such as topology optimization. The paper compares two methods of the structural arrangement design for a thin dimensionally stable reflector operating as part of a geostationary spacecraft: parametric and topology optimization. The algorithms of the structural arrangement development which include the statement of the optimization problem, geometry design and a number of check analyses are presented. A number of structural of a space reflector design under the action of loads at the stage of launch, temperature gradients at the exploitation conditions and modal analysis is performed. The designed reflectors are compared. The studies performed allowed us to develop the optimal structural arrangement for a space reflector using the parametric and topology optimization. The optimal structural arrangement for a space reflector using the optimization could be produced surface figure error (estimated in RMS) with respect to the theoretical paraboloid.

Development of transformable reflectors of mirror space antennas

Currently, the task of designing large structures of space antennas is becoming increasingly important due to active research and development in the area of creating remote sensing and communication satellites. Designing such structures is a complicated task due to geometric features, a large number of joints, compactness requirements, as well as operating conditions of the outer space. These factors require special methods for assessing the workability of these structures. This paper presents the results of simulation and experimental studies aimed at creating transformable antenna reflectors. The results of choosing general structural layouts are considered. It is noted that the main reason for the reflector shape distortion is non-uniform heating by the solar radiation and radiation fluxes coming from the Earth. The paper presents the results of numerical modeling of temperature and stress-strain state of transformable antenna reflectors from metallic mesh sheet meeting the requirements for operating on the geostationary orbit.