The robot has fingers. It’s hard to say what the right number of fingers is for a robot, but it is safe to say that 16 fingers on each of four limbs seems an uncomfortable amount. However, at the end of each finger is a claw, built to latch onto a vertical rock face. The robotic hands click-click-click-click-click-click-click-click-click-click-click-click-click-click-click-click into place, then release, then click-click-click again.

Built by NASA, the LEMUR (Limbed Excursion Mechanical Utility Robot) is a machine built to address cliffs on distant worlds. It is also a fascinating lesson in the limitations and potential of a climbing robot.

NASA is in the business of designing sensor platforms for harsh and unusual environments. The kind of harsh that NASA platforms experience is different than most non-satellite military machines, to be sure. Fewer explosions and bullets, more extreme temperatures and unusual atmospheres ... that sort of thing. Despite that, military planners and designers can still learn a lot from NASA machines, especially since they can take the time to really tackle an environment.

Consider, then, the LEMUR.

Built to scale cliff faces, LEMUR is a four-legged machine with a total of 64 robotic fingers, each with fish-hook claws. Guided by AI, with each step up a cliff face LEMUR gets better at all subsequent steps up cliff faces. LEMUR, as a scientific instrument, is built to scan features of those cliff faces for new discoveries, like finding fossilized algae on a rock wall in Death Valley. That’s a slow and specialized mission, and one that the military would be unlikely to adapt outright for its sensor sets.

The ability to climb irregular vertical surfaces, however, could prove valuable.

While humans have scaled walls since shortly after humans invented walls, and climbed cliffs long before that, there are reasons the military might want to send robots in place first. The simplest use case is as a guide for humans, with the robot finding a useful path without risking life or limb. With tools to place climbing ropes and anchors into a wall, a many-fingered robotic scout could clear a path to an otherwise difficult location. This is especially true in scenarios where an adversary is expecting an attack to come from level ground or the air. An unexpected egress is a valuable egress.

Another lesson from LEMUR is that it is but one of many climbing robot designs explored by NASA. These include the perhaps even more unsettling “Ice Worms,” which adapts a single limb from LEMUR into a slowly crawling deliberate ice exploration machine, drilling and inching its way along a frozen surface. Using LEMUR-like claws, the Jet Propulsion Laboratory has already developed pocket-sized climbing robots for military customers.

Without the need to shelter a human inside, vehicles can take on far more interesting forms and missions. Turning impassable cliffs into manageable terrain with robots becomes a scalable problem.

Watch the delightfully cinematic video from NASA below: