Spiny-Footed Ice Dart Drone Grips Steep Icebergs for Long-Term Monitoring

IEEE Spectrum reports that engineers at the Université de Sherbrooke in Quebec have built a drone called Ice Dart that can touch down on steep, slippery ice and hold its position using tiny spikes. The aircraft, which weighs 2.65 kilograms and has a carbon-fiber frame, is designed to perch on icebergs and glaciers—surfaces that are normally impossible for conventional drones to land on.

In tests detailed in IEEE Transactions on Field Robotics, the researchers deployed Ice Dart at the Fjallsjökull glacier in southeast Iceland, where it landed successfully on ice slopes as steep as 58 degrees and at approach speeds up to three meters per second. The team reports a 100 percent success rate even in winds of 30 kilometers per hour, with temperatures between 0 and 10 degrees Celsius.

The goal is to expand where drones can operate, since safe landing sites are a major constraint on drone missions, according to the study's authors. Alexis Lussier Desbiens, a coauthor and engineering professor at Université de Sherbrooke, told IEEE Spectrum that landing instead of hovering sharply cuts energy use, enabling much longer observation periods with a small aircraft. Once on the ground, he said, the drone becomes silent and can reduce or eliminate its thermal and radio-frequency signature by shutting down major onboard systems.

The drone's four legs, arranged in an X shape and connected to the body by a pivot joint, were adapted from earlier landing gear the group developed for drones that land on moving trucks, trailers, boats, and steep roofs. Each leg absorbs impact through a stack of 38 friction disks that generate torque as the leg moves, lowering the center of mass and spreading out landing energy. The feet each carry two retractable spines—one larger spine for downhill grip under higher load, and a smaller, thinner spine for uphill grip under low load. The spines only penetrate the ice as the suspension compresses, protecting them from high-impact forces.

Lead author Isaac Tunney, a postdoctoral researcher at Université de Sherbrooke, said the retractable spine design was inspired by how a cat's claws deploy only when needed. He wanted the feet to engage passively in the ice at the right moment regardless of drone orientation, surface shape, or ice conditions.

William D. Harcourt, a researcher at the University of Aberdeen who was not involved in the study, told IEEE Spectrum that the technology could be used near the front of tidewater glaciers to measure stress and strain and improve understanding of calving processes. He noted that drones could act as mobile GPS receivers on ice, but that tilting issues would need to be solved because precise 3D measurements usually require a horizontal antenna. If those problems are addressed, the system could track iceberg movements.

The Sherbrooke team plans to add autonomous landing-site selection and an emergency takeoff capability in case an iceberg rolls or breaks apart. According to IEEE Spectrum, the drone is scheduled to be deployed during a Canadian Arctic mission in August to land on icebergs, collect data, and help validate ship-based iceberg-detection systems.