Why is the military’s elite research arm so interested in robots with legs? It isn’t speed.

Boston Dynamics’ Cheetah robot, funded by DARPA, made headlines after it broke its own speed record yesterday and became the first robot to run on legs faster than the fastest human, track star Usain Bolt. Cheetah got up to 28.3 miles per hour . Sure, that was on a treadmill in a lab, with an external brace to keep Cheetah from falling over; but other, much slower Boston Dynamics robots like the “Big Dog” have already solved the balance problem and can walk on their own four feet over rough ground, even ice. So the obvious next step is to combine the two technologies to build a well-balanced, fast-running robot. But why? Keep reading →