The team at Michigan Tech's HIROLab devised a way to safely capture rogue drones with its "robotic falcon," or drone catcher. Watch their prototype capture another drone during its test flight. (Human-Interactive Robotics Lab/Michigan Technological University)

Rogue drones are getting into risky encounters more and more frequently, it seems. There was one that sparked a geopolitically-charged brawl when it flew over a soccer match. Then there was the crash that interrupted a match at the U.S. Open. And the recent close-call where a drone nearly fell on a skier.

Watching the World Cup last year, Mo Rastgaar had a terrifying thought of what could happen if a rogue drone wasn’t just shooting aerial photography.

“What if a drone coming has something it shouldn’t have attached to them?” he said to the Washington Post.

There are safeguards in place to control crowds if something goes wrong, he said, but what about a drone?

“You can’t shoot a drone that has explosives. And also, force landing, that is also not a good idea,” Rastgaar said. “So, probably a drone catching another drone.”

And so the idea for the drone-catching “robotic falcon” was born.

Rastgaar is an associate professor in the Department of Mechanical Engineering at Michigan Tech and the founding director of the school’s Human-Interactive Robotics Lab. He took his idea to his 9-person team, which usually focuses on robotic prosthesis, in the fall of 2014.

“This drone catcher thing is actually a pet project,” he said with a chuckle. “It was a good excuse so all of us could get out of the lab.”

By early 2015, Rastgaar, his colleague Evandro Ficanha and his students Guilherme Ribeiro, Ruiyu Kang and Dean Keithly had an operable system. And in November of 2015, they applied for a patent.

Their “drone catcher” is a drone itself, outfitted with a deployable net. It can fire the net from up to 40 ft. away to ensnare an intruding drone. Once caught, the net swings below the drone catcher. It can then bring its snared cargo to a safe area.

Rastgaar is intent on making the system available to law enforcement only, however.

“These small drones, they are aircrafts. No one has the authority to do any seizing or damaging other drones, even if the drone is in your yard. You can’t touch it,” he said.

[You may be powerless to stop a drone from hovering over your own yard]

Rastgaar can see it being used to protect sensitive or restricted areas from spying or malicious intrusions. But it wouldn’t be able to patrol 24/7, he cautioned, because of battery life limitations.

The drone in the video is a prototype, so it hasn’t been completely developed yet. Rastgaar’s team plans to continue working on the drone catcher so authorities like the Federal Aviation Administration and security officials can use it, hopefully to prevent drone disruptions like these.

The increase of cheap, easy-to-fly, remotely piloted aircraft buzzing around America's skies is becoming a nuisance. Drones have crashed into buildings, impeded efforts to fight wildfires and even landed on the grounds of the White House. Here are a few instances of rogue drones. (Jason Aldag/The Washington Post)