Large-aperture expandable truss microwave antenna

A space erectable truss antenna concept capable of deploying a rigid, lightweight (0.1 lb/ft²of aperture), parabolic reflector from 5 to 300 feet in diameter is discussed. A three-dimensional spring-loaded truss retracts into three optional packaging configurations, such that, a 100-foot diameter antenna can be packaged into a 10-foot payload envelope. Depth of the deployed antenna truss reduces thermal distortion enabling surface tolerance-to-diameter ratios less than2 times 10^{-4}to be achieved over the orbit. While the deployment is completely automatic, all functions can be supported by an astronaut. RF tests have been conducted on a 6-foot working model at 15 GHz with a peak gain frequency projected at 30 GHz.