Researchers at NASA’s Marshall Space Flight Center have developed new modular fixtures for holding metal in place during the assembly and welding of cylindrical and conical sections of rocket bodies. Previous methods required time-consuming design, fabrication, and assembly of expensive, project-specific fixtures, which often required up to six months of lead time and cost millions of dollars to complete. NASA’s modular fixtures are designed to be adjustable and to easily form different fixture body configurations for rocket sections with various diameters and heights. This improved setup efficiency allows for a more rapid shift from one project to the next, reducing the time a newly designed fixture body takes to complete, allowing welding to begin in a matter of weeks rather than months. NASA is currently seeking licensees that may benefit from modular fixtures in large-scale manufacturing.
The tooling was developed to fabricate unique, monolithic fixture bodies for different segments of the Space Launch System (SLS). Before NASA staff can configure and weld rocket sections, they must assemble modular tooling atop a large turntable with radial grooves. Supporting braces (tombstones) that form the base of the modular structure slide into radial grooves. Other extending, clamping, and joining fixtures can be variously connected to the base structure to provide circumferential support for producing conical and cylindrical structures.
NASA has used the tooling to produce structures with diameters of up to 27 feet. Depending on the desired application, the base can be scaled to produce larger or smaller diameters, and the grooves can be arranged with a longitudinal arrangement for production of parts with bilateral symmetry.
The development of these modular fixtures required an initial investment similar to that of a single project’s tool design and fabrication costs. Once produced, only a fraction of that time/cost is required to begin all subsequent projects. NASA has used this new, adaptable tooling in the construction of several different rocket stages, proving its cost-saving capabilities.