Design of a Deployable Antenna Truss Structure with Variable-Length Members

We describe how to build three-dimensional deployable truss structures from the viewpoint of deployment reliability. We propose a method for designing a closed-loop deployable truss structure for a future large space antenna by using a kinematic degree-of-freedom analysis of the mechanical system. Using this method, it is possible to attain a truss structure with the appropriate constraints. We have designed and fabricated a prototype of the proposed antenna truss structure, and have achieved successful deployment under the microgravity environment yielded by the parabolic flight trajectory of an aircraft. Thus we have demonstrated the effectiveness of the deployable truss structure design using the kinematic degree-of-freedom analysis.