The combatants entered the field of competition sporting a rainbow of colors — shiny silvers, brilliant blues, bold reds. They wielded tools such as propellers, flapping wings, grappling hooks and tentacles. And they employed graceful, almost ethereal movements, which made sense since they were lighter-than-air (LTA) vehicles, also called blimps.

These air warriors made their presence known at the Office of Naval Research (ONR)-sponsored Defend the Republic competition, most recently held at George Mason University in Virginia. The latest iteration of Defend the Republic featured student teams from 10 universities — eight of the teams received ONR support — competing in matches where blimps attempted to move balls through hoops suspended from the ceiling, while other blimps tried to thwart them.

Held multiple times a year at varying locations, Defend the Republic showcases numerous university teams led by ONR-sponsored professors who mentor their student participants. Support comes from STEM (science, technology, engineering, mathematics) funding from ONR’s Warfighter Performance Department. Teams create their blimps with a focus on their mentors’ respective research areas.

The challenge of the game is designing, building and controlling autonomous swarms of LTA vehicles that can adapt quickly to shifting situations while staying aloft. This capability is valuable for diverse scenarios of naval interest, including disaster recovery, reconnaissance and surveillance, and delivering supplies and humanitarian aid.

“Defend the Republic is not just a competition but also a valuable proving ground and program review,” said Dr. Michael LaFiandra, a division director in ONR’s Warfighter Performance Department. “You see what solutions and approaches work best, what works well in the lab and what needs further improvements in the field, so to speak.

“Lessons learned during Defend the Republic could benefit ONR and the Navy by being applied to systems currently being explored,” he continued. “Examples include autonomous vehicle design, multiagent control, and swarm behaviors and communication.”

Each match between two teams was divided into two 30-minute halves. The teams, composed of both undergraduate and graduate engineering students, launched multiple LTA vehicles into play, and the goal was to score by placing ball-shaped balloons into a set of three goals of varying shapes.

Before game time, students programmed the blimps, which then had to battle their adversaries autonomously through most of the match. Blimps were constructed of lightweight materials such as balsa wood and mylar (often used for model airplanes); used lighter-than-air gasses such as helium; and were equipped with intricate motors, sensors, cameras and microprocessors.

Teams adopted diverse game plans, particularly on defense, said Dr. Scott Koziol, an associate professor at Baylor University. Some teams bobbed up and down to distract attacking blimps; others pinned opponents against walls and the ceiling or pulled them away from goals as they were about to score.

Koziol’s squad, the Baylor University Blimps, proved adept at both autonomous control and blocking opponents from scoring, which enabled them to win the latest Defend the Republic competition by defeating Indiana University’s Hoosier High Flyers in the final round.

“Participating in this competition has benefited my undergraduate students by allowing them to get their hands dirty and perform challenging engineering under stressful circumstances,” said Koziol. “My graduate students also improved their leadership, mentoring and collaboration skills.”

Dr. Or Dantsker, an assistant professor at Indiana University Bloomington, who mentored the second-place Hoosier High Flyers, said, “Defend the Republic is great to showcase the work of ONR-funded teams, as it provides a venue to demonstrate technical prowess and research innovation in a peer-to-peer competition.

“The competition also drives my students to become better engineers,” he continued. “Some had previously only worked with software and others only with hardware, and to succeed at the competition, they must apply both as part of a team. Our Indiana University students really came together to software and hardware co-design the autonomous blimps, and built most onsite at the competition, under a tent and with minimal tools.”

ONR’s LaFiandra agreed: “Sometimes, too much specialization in research can hinder the ability to collaborate and fuel innovation. Through Defend the Republic, we get the next generation of scientists and engineers to work together, perform first-class basic research and support broader STEM efforts.”

Warren Duffie Jr. is a contractor for ONR Corporate Strategic Communications.