Generations of Graduates: A Full-Circle Celebration

Several University of Maryland (UMD) A. James Clark School of Engineering MATRIX Lab researchers are closing chapters of their education journeys after graduating years apart.

Years after earning his Ph.D. in the middle of the pandemic, Dr. Donald "Bucket" Costello finally crossed the graduation stage at UMD’s Spring 2026 Clark School commencement ceremony on May 21.

But Costello, now an assistant professor in the Department of Aerospace Engineering and the MATRIX Lab Director for Test and Evaluation of Autonomous Systems, wasn’t celebrating alone.

As Costello was hooded alongside his former advisor, UMD associate professor Dr. Mumu Xu, two of his own graduate students - Ryan Lowe (M.Eng. ’26, Robotics) and Jacob Safeer (M.S. ’26, Aerospace Engineering) - received their master’s degrees at the same ceremony, marking a milestone moment for three MATRIX Lab researchers at different stages of their academic journeys.

"It was a full-circle day for me," said Dr. Costello. "My advisor Dr. Xu, who is now my fellow Aerospace Faculty colleague here at UMD, was able to present me with my hood. My family was there to share the experience with me, and I was able to see my first graduate students get their degrees."

"Bucket was my very first PhD student, so this ceremony was a special way to mark the end of a chapter. I could not be prouder of his accomplishments and look forward to celebrating many more," said Dr. Xu.

"I am proud of the incredible research we were able to accomplish this past year towards autonomous aerial refueling. I am also extremely thankful for Dr. Costello, my fellow graduate students, and the entire MATRIX Lab team for the unparalleled support and family-like environment that made all of this possible. I look forward to leveraging what I've learned about autonomous systems here at the MATRIX Lab during my service in the Navy," said Lowe.

"It was incredibly special to graduate alongside Ryan and to see Dr. Costello finally be hooded at the same ceremony. My time at the MATRIX Lab has given me the opportunity to work on meaningful autonomous systems research, and I’m very grateful for the mentorship, collaboration, and support that helped make this accomplishment possible," said Safeer.

Costello successfully defended his University of Maryland Mechanical Engineering Ph.D. thesis in 2021, but pandemic restrictions prevented him from attending an in-person graduation ceremony at the time. This fall, he will take over leadership of Aerospace Engineering’s Design Build Fly program, mentoring the next generation of student engineers.

Lowe is heading to flight school to train as a Naval Aviator, while Safeer recently accepted a position with the Johns Hopkins Applied Physics Laboratory, where he will work in autonomous systems development, testing, and artificial intelligence.

For the three researchers, the ceremony was more than a graduation - it was a shared milestone marking the transition from one chapter of engineering research and education to the next.

Published May 28, 2026