A Waterloo Engineering student design team has taken another step toward repairing electronics in space by designing, building and testing an automated soldering device aboard a microgravity flight. As missions travel farther from Earth, the ability to fix equipment in-space is becoming increasingly important.
The Waterloo Space Soldering Team, made up of 17 students and recent alumni, was one of four teams across Canada selected by Students for the Exploration and Development of Space Canada for this year's Canadian Reduced Gravity Experiment Design Challenge, held August 31 to September 4. Over two flights aboard a reduced-gravity research aircraft in Ottawa, the team operated its experiment through 16 parabolas — steep climbs and dives that each create about 20 seconds of weightlessness — and collected 35 solder samples for analysis.
The challenge is Canada's first microgravity research competition for students and runs in collaboration with the National Research Council of Canada and the Canadian Space Agency. This was the team's second time taking part, after winning the competition’s Overall Excellence Award in 2024.
Team members pose in front of Falcon 20 aircraft at the National Research Council's (NRC) Research Laboratory in Ottawa. From left to right: Megan Chang, Shamanthi Rajagopal, Nitish Thumkunta Reddy, Ziren Ji, Asmi Gujral and Devshi Perera.
Putting a spin on soldering
Repairing electronics usually means soldering: melting metal to join components to a circuit board. On Earth, gas bubbles in the melted solder rise and escape before it hardens. In microgravity, they stay trapped, leaving joints riddled with tiny holes that don't hold up as well.
In 2023, the team proposed a fix: solder inside a spinning centrifuge. The spin creates a force that mimics gravity, giving the bubbles a way out. If it works, crews could make repairs on board rather than relying on costly resupply from Earth.
At the 2024 challenge, the team put this idea to the test. Analysis of the samples afterward revealed a flaw in the method. To fit the soldering into each brief window of weightlessness, the team had shortened the heating process. That rushed heating turned out to be a major cause of the holes.
"What we initially thought was a failed attempt back in 2024 ultimately became a source of both motivation and expertise," says Megan Chang, a recent Mechatronics Engineering graduate and founding member of the team. "We had the same mission as before for this year's competition, but a new and improved method, and much more experience."
This year, the team set out to fix that flaw. Its new device solders working electronic components instead of melted samples, and it works like an automated handheld soldering iron. Two miniature irons inside the centrifuge heat the component and circuit board directly, forming a joint in one to three seconds, well within each window of weightlessness. The device can solder at simulated gravity levels from zero to five times Earth's gravity. According to the team, no previous microgravity experiment has demonstrated automated, repeatable soldering of components under controlled centrifuge conditions.
Turning the new design into flight-ready hardware drew on a full range of engineering skills. Mechanical, electrical and software subteams each built their own part of the system: the centrifuge and soldering system, a custom heating board and power system, and the code controlling each moving part. The hardest part, team members say, was making everything work together as one system precise enough for the research. After repeated testing and design reviews with experts from the Canadian Space Agency and the National Research Council of Canada, the device was approved to fly.
Four team members then flew as mission specialists, operating the experiment on board and experiencing microgravity for the first time.
"Being weightless and floating through the aircraft was the most memorable moment of my engineering degree yet," says Shamanthi Rajagopal, a third-year Electrical Engineering student and the team's electrical lead. "Imagine being at the peak of a rollercoaster, right before the drop — that's what it felt like, but continuously for 20 seconds each parabola."
What comes next
Now the team will analyze its samples using CT scanning and microscope imaging. It will compare joints soldered in microgravity, with and without the centrifuge, against joints soldered on Earth. The results will show whether spinning the solder produces joints with measurably fewer holes, the question at the heart of the team's research.
Looking further ahead, the team hopes to improve the system's precision, test a wider range of components and eventually demonstrate the technology in a more realistic spacecraft or space station environment. Its long-term vision is a compact system that astronauts or robotic systems could use to repair or manufacture electronics in space.
The team sees its device as one small step toward spacecraft that can maintain and repair themselves, bringing repair work that is now done almost entirely on Earth into space.
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The Waterloo Space Soldering Team is part of a student space research design team in the Sedra Student Design Centre, which provides undergraduate students with hands-on opportunities to design, build and test real research projects. Its members come from seven programs, ranging from Mechatronics Engineering to Physics and Global Business and Digital Arts.
Shamanthi Rajagopal, Asmi Gujral, Jerry Chen, Ziren Ji and NitishThumkunta Reddy led the development of this year's device. Other members include Adelina Nguyen, Krish Patel, Emma Pileggi, Caleb Bellsmith, Catherine Hsu, Mysha Hamid, Faraaz Hamid, Rishi Patni, Katherine Godden, Chrisandra Vaz, Megan Chang, and Devshi Perera.
Dr. Michael Mayer and Dr. Michael Benoit, professors in the Department of Mechanical and Mechatronics Engineering, advised on materials science and experimental design.
This article was originally published on the University of Waterloo Faculty of Engineering website.
For more on the team's earlier work, read Waterloo students win microgravity research competition in Québec and Students share microgravity soldering research on global stage.