DARPA calls it the SideArm system. It's part of the larger Tern program that seeks ways to integrate drones into Navy ships and operations without having to drastically renovate the vessels in accommodation. As such, this system is built to fit in a standard shipping container and can be set up and operated by just 2 - 4 people. DARPA tested the system with a 400-pound Lockheed Martin Fury UAS, but it's reportedly sturdy enough to catch drones weighing up to 1,100 pounds.

The SideArm works much like existing arresting wire system that aircraft carriers employ, just upside down. As you can see in the video above, the drone is launched along a horizontal rail. Upon its return, the drone flies back under that rail, hopefully snagging its tailhook on an arresting line suspended below it. When the tailhook catches, the drone is slowed and gently swung up into a net where the aircraft's nose barbs hold it in place. Now that testing is complete, DARPA is looking for transition partners and investigating whether the system could be employed with other drone systems.