The short takeoff and landing distances aircraft carriers give manned aircraft provide numerous tactical advantages. Now DARPA is looking to bring similar advantages to smaller ships, fixed bases and even trucks through its SideArm research project. As part of the project, Aurora Flight Sciences has successfully tested a demonstration system that scales down an aircraft carrier's launch and capture technology and turns it on its head to horizontally launch unmanned aerial systems and pluck them from the air.
The goal of the SideArm project is to develop a self-contained, portable system that can horizontally launch and retrieve unmanned aerial systems (UASs) weighing up to 900 lb (408 kg) without long runways or massive structures. The full-scale technology demonstration system successfully tested in December 2016 exceeds these objectives, with its ability to retrieve aircraft of up to 1,100 lb (499 kg). However, during testing the system repeatedly captured a 400-lb (181-kg) Lockheed Martin Fury UAS that had been launched from an external catapult.
The system fits in a standard 20-ft (6-m) shipping container, making it easy to transport by truck, ship, rail, C-130 transport plane or CH-147 heavy-lift helicopter, while its small footprint also means it can be operated essentially anywhere, from dedicated facilities to truck- or ship-mounted mobile stations – which can be set up by a team of two to four people.
Rather than simply relying on a big net like "traditional" drone-catching systems, which can bring the aircraft to an abrupt and potentially damaging halt, the SideArm uses a hook to snag the back of the incoming drone, which is then slowed as it slides along a rail. According to its creators, this slider decelerates the drone in a more controlled way, which lessens the chances of damage. Once it's been slowed by the slider, the drone is brought to a complete stop by a small net, coupled with a set of barbs mounted on the nose of the aircraft to make sure it doesn't slip loose.
"SideArm aims to replicate carriers' capability to quickly and safely accelerate and decelerate planes through a portable, low-cost kit that is mission-flexible, independent from local infrastructure, and compatible with existing and future tactical unmanned aircraft," says Graham Drozeski, DARPA program manager. "We've demonstrated a reliable capture mechanism that can go anywhere a 20-foot container can go – the DARPA-worthy challenge we had to overcome to make SideArm's envisioned capabilities possible. We are pleased with the progress we've made enabling a wide variety of sea- and land-based platforms with persistent intelligence, surveillance, and reconnaissance (ISR) and strike capabilities."
SideArm is a part of the Tactically Exploited Reconnaissance Node (Tern) program, which seeks to develop flexible ship-based aircraft systems that don't require expensive modifications to existing equipment. If successful, the system should be able to operate on a wide range of ships working in essentially any "sea state." Now the SideArm system has been successfully tested, DARPA is looking for potential partners to build it, and looking at how it can be used with other types of drones.