| Abstract Scope |
Welding and joining are critical enabling processes for the rapidly growing in-space servicing, assembly, and manufacturing (ISAM) sector. Despite this, no metallurgical joining processes have yet been proven fit-for-service for applications in outer space, on the Moon, or on Mars. A fundamental lack of understanding of the effects of the space environment (e.g., gravity, vacuum, temperature) on the welding process—as well as on the metallurgy and performance of the resultant joint—remains a major impediment to long-term space exploration and habitation. Researchers at Ohio State’s Welding Engineering Program, in cooperation with NASA Marshall, AFRL, OFRN, and others, have developed equipment for space-simulative testing of laser beam welding. A large vacuum chamber, borrowed from NASA Langley, was re-instrumented with a 1070 nm, 1500W QCW fiber laser and an associated Cartesian motion system. The system is controlled via a custom LabVIEW and DAQ setup, enabling real-time measurement of attributes including weld plate temperature, gravity level, and pressure. Weld and thermal cameras have been integrated to monitor the weld pool through visible inspection. The initial parabolic flight, designed to simulate microgravity conditions, achieved a success rate exceeding 98%. Autogenous welds were completed on a combination of Aluminum 2219, Titanium 6Al-4V, and Stainless Steel 316L. Further experimentation was completed in a follow on parabolic flight in May 2025. While analysis of these welds is ongoing, preliminary results indicate differences in defect formation between microgravity and Earth gravity conditions. Further equipment enhancements, including the integration of a cryogenic cooling system and parabolic flight testing of true mechanical joints, are underway to better replicate space-like conditions. |