Analysis and testing of ultrathin shell 2 m diameter reflector demonstrator

Abstract

Ultra-thin shell foldable and self-deploying composite reflectors are being developed for space antennas to meet low cost, low mass and high surface accuracy. For Ku-band missions, a full-scale offset parabolic reflector antenna is designed by considering different concepts of monolithic and nonmonolithic structures, different stiffening schemes, manufacturing ease, and lower cost. The resulting reflector is based on stiffened spring back reflector concept but it provides much simpler design, significantly lower mass and lower cost. It is a simple monolithic structure and consists of a reflector surface and a flat skirt. The skirt is an integral part of the reflector and is used to stiffen the reflector. The full-size version is an offset parabolic reflector with a diameter of 6 m, a focal length of 4.8 m, and an offset of 0.3 m. In order to demonstrate the concept, 1/3-scaled version is designed, manufactured, and tested. Experiments of the demonstrator are conducted for quasi-static folding, dynamic deployment behavior, stiffness measurements, modal analysis, and surface accuracy in deployed configuration; the experimental results are compared with the results of finite elements solutions where applicable.