Designing a Snap-Fit Connection Appropriate for In-Space Servicing, Assembly, and Manufacturing

This paper describes a novel, uncomplicated positive latch mechanism design that utilizes additive manufacturing (AM) fabrication techniques to connect modular spacecraft structures. The simple design allows for multi-dimensional rigid mechanical and electrical connections, exhibits intuitive user-friendly affordance, and does not require unnecessary additional components such as fasteners and 3D-printed support material. Orbital AM is a critical component to fabricate modular and scalable spacecraft structures to further in-space servicing, assembly, and manufacturing (ISAM) efforts. Current convention to design spacecraft to have a stowed configuration to fit within a launch vehicle fairing that deploys after separation increases the risks of mission failure, in addition to placing limitations on the mass, volume, and mission objectives. Orbital AM changes the infrastructure and process to enable integration and assembly of spacecraft in an environment in which they are to operate in. This eliminates the constraints to optimize the mass and volume of structures to fit and survive the environments within a launch vehicle and, instead, optimizes the delta-v budgets and lifetime of hardware to extend mission capabilities and timelines. This new proof-of-concept design satisfies requirements for fabrication using current AM technology and is intended to be fabricated in a microgravity environment. Terrestrial prototype testing of the snap-fit positive latch mechanism verified rigidity within six degrees of freedom of the mated-structure and demonstrated ease of repeated assembly and disassembly to enable quick integration of modular spacecraft by astronauts and autonomous robots to build ever-larger modular spacecraft structures.