The harrowing Fukushima Daiichi nuclear meltdown, the catastrophic Deepwater Horizon oil spill, the Chilean Copiapó mine collapse: extraordinarily dangerous circumstances that called for not just human but superhuman solutions.

Enter the DARPA Robotics Challenge (DRC), a gauntlet-dropping cool-as-it-sounds competition sponsored by the U.S. Department of Defense in which advanced robotics researchers work to create robots capable of executing "complex tasks in dangerous, degraded, human-engineered environments." To the winner, the spoils — to the tune of $2 million.

The DRC launched back in April 2012, entering its second phase last October, which was when I noticed Boston Dynamics' Pet-Proto, a bipedal robot capable of sussing its surroundings and navigating complex obstacle courses, including climbing and leaping with uncanny agility from platforms.

During DARPA's two-year competition, teams must work to design, tweak and test either humanoid or non-humanoid robots: agile and durable mechanical servants capable of treading where most humans wouldn't dare, like exploring collapsed mines or caves, defusing explosive devices and working in deadly radiation-saturated areas.

We're starting to see some of the challenge's contenders take shape: Carnegie Mellon just announced that it's building an ape-like robot, but with tank treads undergirding all four limbs. The 10-person research team with CM's National Robotics Engineering Center calls it a CMU Highly Intelligent Mobile Platform, or CHIMP for short, and it's part of a project dubbed "Tartan Rescue."

According to Carnegie Mellon News:

"Though the appearance of ... CHIMP, is vaguely simian, its normal mode of locomotion will be much like that of a tank, with the tracks of all four limbs on the ground. This configuration would offer a particular advantage when moving over debris and rough terrain. But CHIMP also can move on the treads of just two limbs when needed, such as when it must use one or more limbs to open a valve, or to operate power tools."

Not only that, but look closely at CHIMP's "foot" treads and yep — that's a second pair of hands jutting from its robotic heels, sporting two fingers and an opposable thumb. Creepy and cool! CHIMP's drive joints allow it to grasp objects like a human, and the team says this extends their application to "mobile manipulation and manufacturing."