Scientists at ETH Zurich have been working since July 2012 on aerial construction, which is basically exactly what it sounds like. As you can see in the video embedded below, a trio of drones were equipped with rope spools before setting off on their tasks of constructing a rope bridge.

“Flying machines offer a number of advantages compared to traditional construction machines”, the Institute for Dynamic Systems and Control noted in its related statement, “Flying machines offer a number of advantages compared to traditional construction machines”. The researchers started making waves in this area in 2011, when they had drones use mathematical algorithms to translate digital design data into flight paths, neatly arranging 1,500 polystyrene bricks into a 6-meter (20-ft) tall tower.

Are unmanned aerial vehicles the future of flimsy rope bridges spun out over deep and terrifying chasms? This kind of structure could be built at any height, and could be useful for emergency situations or at construction sites, where drones are already making their way into everyday use for surveying purposes. The customised drones are simply following a pre-programmed route, calculated by knowing the distance between the two towers and where the rope anchor points are. Motorized spools were attached to the bottom of the drones, allowing them to control for tension when wrapping and weaving the structure. A system on board each drone estimates the external forces and torque exerted on it; this is taken into account to adjust how the drone flies and behaves in the air. The drones were able to scan the gap, work out the structure, and do their weird robo-rope-dance all without any human intervention. The researchers say this is the first time quadcopters have proven themselves capable of autonomously building load-bearing structures that can support a person.