Development and qualification of size No.4-No.10 mechanically locking, high vibration resistant fasteners for elimination of safety wire in missiles, satellites, space vehicles and robotic in-space assembly

Enduralock’s proposal is to develop the first mechanically locking, high vibration resistant fastener, that is reversible and reusable with a standard hexagonal socket in sizes of No.4 – No.10. A requirement of this research and development is that the fastener will remain mechanically locked even with loss of preload (clamping force), so that the fastened assembly will be unaffected by the extreme environmental temperatures (and the corresponding thermal expansion and contraction of the fastener components) experienced in space. The vibration resistance of the proposed fasteners will be comparable to a larger variant of the proposed technology, which was previously shown to survive 10 times the aerospace vibration requirement (NAS1312-7). The project will include design and finite element analysis to optimize the fasteners for performance and for manufacturability. This will be followed by qualification testing of the fasteners. Enduralock also proposes research and development of a novel fastener assembly automation process using a robotic arm and development of ultrasound preload measurement technology for reliable installation of fasteners in a space environment. The final deliverable of this project will be a fastener that could eventually replace fasteners that are currently safety-wired together in missiles, commercial satellites, space vehicles, space structures, and aircraft.