Novel Structural Connector System for In-space Assembly of Truss Structures

As access to space becomes increasingly available to both the private and commercial sector, technology for in-space operations must be advanced in order to take full advantage of the domain. Establishing the capability for space system assembly on orbit has the potential to increase spacecraft and mission capabilities, while significantly reducing cost. In 2016, the NASA Langley Research Center published the results of a study aimed at assessing areas of necessary development for Space Assembly of Large Structural System Architectures (SALSSA). The study included a list of technical capabilities necessary to achieve a robust assembly system, providing a roadmap for future development. The purpose of this research was to design a structural connector system that succeeded in demonstrating two of these specific technical capabilities: modularity and autonomous operation. The proposed design consists of a worm gear lead screw mechanism housed inside a casing with a mating interface. The mechanism drives a quarter-inch bolt linearly along the axial direction of a truss element. The mating interface is non-binary, and meant to connect with an identical copy of itself. The interface is geometrically designed to allow for initial connector misalignment. The connection is secured by driving each quarter-inch bolt into the opposing interface after initial mating is complete. The connector system was structurally analyzed using classical hand calculations to determine maximum allowable loads, both during truss construction and in operation in a truss member. A complimentary robotic end-effector was also designed for autonomous assembly testing purposes.