High Stiffness Latch Technology for Deployed Structures

A significant technical challenge presented by future space-based precision deployable structures (NGST, SBL and others) is the requirement that the structure be rigid after deployment. This requirement is warranted, as a very stiff, dimensionally stablestructure simplifies system control complexity and improves system reliability. To create a rigid structure, the components must be fixed in the deployed configuration with ultra-stiff latches (stiffness>1X106 lbf/inch). The proposed innovation willvalidate self-rigidizing, ultra-high stiffness capture latch (HSL) technology for deployable structures. Ultra-high stiffness is obtained through solidification of low melting point metal alloy within the latch joint. This unique, innovative approach isfundamentally different from other latching concepts. It has the potential to provide extremely high stiffness from a compact, lightweight package, enabling the development of highly stiff deployable structures.The proposed innovation can also be applied to deployable or separable space structures requiring zero dead band and high strength. Generally, in large structures with articulated joints, current joining methods (elements pre-loaded together by springs,motor torque or cam lock devices) require high pre-load, resulting in mass-prohibitive and high release shock systems. Such system-level issues are easily resolved using the proposed innovation. Enabling applications include:,h Self-rigidizing hinge joints - A small spring or motor powered hinge joint combined with HSL will give high deployed strength, high stiffness and zero dead band at low mass.,h Smart space structures - A hybrid application of HSL with Starsys¿¿ PPM (¿Part Per Million¿