The First Metal-Cutting in Space: Findings from a Demonstration of Friction Milling as an Essential Manufacturing Process in Space

The OMD-1 mission was a demonstration of metal cutting in space using friction milling. Friction milling induces heat in the subject material to induce pliability and minimize the creation of fragments from the cutting process. This is an important feature for space operations, as uncontrolled fragments introduce significant operational risk. The OMD-1 mission was a successful execution of the cutting demonstration, and the outcomes of the mission provide new knowledge that is useful for other in-space cutting operations and technologies. These learnings include physical considerations about friction milling in space, but also more general considerations. Friction milling is an appropriate process for cutting in space, but the cutting tool must be selected based upon a clear understanding of the thermal environment. Additionally, the spin rate of the cutting tool must be controlled to avoid shard creation at the first, cold contact between the two. Finally, uncertainty in the demonstration of a novel technology must be contained to that of the technology itself. The context of space contributes a significant risk, but the supporting functions, such as data handling and communications, can and should be mitigated to avoid a degradation of the demonstration.