NASA has built many adventurous robots that can fly in space, land on alien planets, roll across Martian and lunar terrain, and even fly helicopter-style across far-off worlds. But the next big challenge is climbing and clambering across rough or steep terrain, a common sight whether on rocky Mars or icy Enceladus.
To that end, NASA’s Jet Propulsion Laboratory in California has been developing what they call a Limbed Excursion Mechanical Utility Robot, or LEMUR. With four limbs, 16 fingers, and hundreds of tiny hooks, LEMUR and its descendants can climb steep walls, slippery surfaces, or otherwise uneven ground. Aided by an artificial intelligence system, these robots can maneuver their own way around obstacles to complete science goals like mapping new areas or searching for prized rock and soil samples. LEMUR itself isn’t going to be used for its original purpose, which was to crawl around the International Space Station and effect repairs. But its descendants might yet make their mark beyond Earth.
There Are Many Copies
LEMUR’s basic design is proving versatile. Built for climbing, gripping, and navigating, these same skills can be used in many environments.
One challenging world astronomers want to explore is Saturn’s icy moon Enceladus. RoboSimian has the same basic build as LEMUR, but instead of feet that grip, it has flexible wheels made from piano wire. It can walk, crawl, slide, or wiggle across untrustworthy and varying terrain. This is important, because standard rover wheels, while sturdy, have difficulty over ground that is too sharp, too soft, too slick or too steep. To venture into wilder worlds and territory, NASA needs new modes of transportation.
Another LEMUR offshoot built for icy worlds is Ice Worm, which crawls across the ground like an inch worm. It originated as one of LEMUR’s limbs, and shares its AI know-how for avoiding and navigating obstacles without a human driver. It can also climb sheer walls by drilling into their hard sides, one end at a time, and scientists have considered whether such drilling could also be used to collect samples. On Earth, it has so far explored glaciers and ice caves, prepping for its possible future on an icy moon.
Like Ice Worm, the Underwater Gripper is adapted from one of LEMUR’s parts, in this case a hand with 16 fingers. Also like Ice Worm, the Gripper has the ability to hang onto surfaces and drill into them. Drilling can be tricky even on normal surfaces, as the Mars InSight lander has discovered. But underwater or in places with low or no gravity, gripping is essential, or the force of a drill would simply push the robot away from its testbed.
LEMUR’s other descendant might come in handy on Mars or Titan, where flying robots have been approved for either testing or full mission use. While it has no name as yet, JPL is working on a flying robot that could land not just horizontally, but vertically, by gripping walls like a true dragonfly. Using LEMUR’s feet with many hooks would mean it won’t need to scout for flat surfaces before landing, but could do so on a variety of surfaces.
With these and other innovations, there may be no place in the solar system NASA can’t explore.