Lightweight deployable space radar arrays

Abstract

As a part of a NASA's effort to develop enabling technologies for the next generation of space synthetic aperture radars (SAR's), a design concept for deployable antenna arrays, called the fold-up array design is being developed at the Jet Propulsion Laboratory (JPL). To achieve the mass goal, a carpenter-tape hinge and latch mechanism design that allows for excellent reliability, repeatability, high stiffness and low mass was implemented. These devices provide near-zero free-play and possess highly reliable deployment characteristics at a very low cost. The hinge mechanism is utilized to deploy and latch the array panels in the fully open position. The basic structure of every panel is a rectangular frame approximately 3 m by 0.5 m wide, formed by six lightweight, high-stiffness beams made of advanced composite materials. The full array is composed of two wings, each approximately 3 m by 5 m long, after deployment, which are supported by a spacecraft bus. The proposed system can be used for single, dual or even triple frequency operation. A modal analysis of the entire system shows that a natural frequency well above 0.5 Hz is achievable for the deployed configuration which is important for the operation of the SAR. Additionally, hinge configurations are discussed.