SANTA MARIA, CA (AFRL) – The Air Force Research Laboratory, or AFRL, recently participated in a parabolic flight experiment led by a team of scientists and engineers from The Ohio State University. The NASA-funded endeavor was conducted at the Central Coast Jet Center in Santa Maria, California, Aug. 21–22, 2024, to explore the potential of autonomous laser welding in space. A parabolic flight test allows engineers to test the performance of equipment that will be used in space, by simulating the microgravity environment of a low earth orbit.
Because of increased reliance on space-based applications, from remote sensing and navigation to satellite communications, there has been a recent push by the U.S. government to develop In-Space Servicing Assembly and Manufacturing, or ISAM.
Dr. Arlene Smith, an engineer with AFRL’s Composite, Ceramic, Metallic, and Materials Performance division, said that AFRL was introduced to OSU’s project through the AFRL Midwest Regional Network. AFRL is offering the OSU team consulting support via subject matter experts and leveraging that role with an eye toward workforce development.
OSU has the only welding engineering program in the country, with 11 faculty devoted to the area of welding and joining processes, metallurgy, modeling, and performance.
"By fostering meaningful research collaborations, we not only enhance our knowledge at AFRL but also create lasting connections that inspire students to remain engaged and contribute their talents long after the collaboration ends,” said Smith. “These students have already established experience in formulating, conducting, and leading space research and have the potential to integrate their skills seamlessly into Department of the Air Force initiatives."
Smith said the need to develop and leverage manufacturing technology (such as laser welding) in space has become increasingly vital to assist in the movement and support of military equipment and personnel. However, while scientists understand how laser welding functions on Earth, little is known about how it performs in the extreme conditions of space.
During the test, the autonomous laser welding system was not only put through its paces in a microgravity environment but also simulated the vacuum of space by being placed in a vacuum chamber. The team was excited by the results, as 69 out of the 70 welds attempted on the flights were successful.
“These recent parabolic flight experiments take what we know about welding on Earth and allow us to gather and analyze data in a simulated space environment,” said Smith. “The goal is to provide proof of concept and eventually conduct testing in space.”
Dr. Antonio Ramirez, a professor of welding engineering at The Ohio State University, said it had been 51 years since the U.S. performed its first and only welding in space experiment onboard the Skylab orbital space station in 1973.
Ramirez said the successful development of manufacturing capabilities in space will provide point-of-need service, providing parts, repairs and even new systems that, because of their size, could be more efficiently built in space.
“These large structures might (potentially) include solar panels, housing for astronauts, or large mirrors or antennae that can collect energy and irradiate back to earth,” said Ramirez. “It would also allow us to make quicker and more effective repairs. Right now, if you have a vessel out in space and a micro meteor makes a hole in it, you can’t just pull up to a repair station.”
Additionally, he said that manufacturing in space technology could potentially provide cost savings by allowing the Department of the Air Force to repurpose some of the expensive systems and materials already in space.
Ramirez said that prior welding in space research involved electron beam, gas tungsten arc, plasma arc and gas metal arc welding. Laser welding has yet to be tested in space and, until now, has only been tested separately under microgravity or in a vacuum environment.
Eugene Choi, a welding engineering Ph.D. student at OSU who participated in the flight test, began working with the program as a senior capstone student. He said his mission on the project was simple: to “make it work,” citing in part the myriad challenges he faced in updating software and equipment to get the vacuum chamber, provided by NASA Langley, ready for this unique experiment.
In the end, Choi said that data they gathered made it worth the effort.
“It was very exciting to achieve this,” said Choi. “Now it’s time to analyze the results, look into what went right and what went wrong, make changes, and do it all over again.”
He said that some of the analyses of the data will be done on equipment at AFRL.
Graduate students like Choi are being trained to become the future of manufacturing in space. In addition to OSU, students from Central State University’s Manufacturing Engineering program were also able to gain valuable experience by machining the test samples for the welding experiments.
“Opportunities like this allow students to integrate theoretical knowledge with practical experience and provide targeted learning opportunities,” said Dr. Saleh Almestiri, an associate professor with Central State University’s Manufacturing Engineering Department.
Ramirez predicts that welding in space will become viable within the next 10 years. A second parabolic flight set of tests will be scheduled for February 2025, with hopes to perform low Earth orbit testing within two to three years, he added.
About AFRL
The Air Force Research Laboratory, or AFRL, is the primary scientific research and development center for the Department of the Air Force. AFRL plays an integral role in leading the discovery, development, and integration of affordable warfighting technologies for our air, space and cyberspace force. With a workforce of more than 12,500 across nine technology areas and 40 other operations across the globe, AFRL provides a diverse portfolio of science and technology ranging from fundamental to advanced research and technology development. For more information, visit www.afresearchlab.com.