Lunar Excursion Vehicle 2 (LEV-2), a lunar robot from the Japan Aerospace Exploration Agency (JAXA), could have been plucked from a science-fiction movie. It’s small—about the size of a baseball—it’s cute and it can transform, easily morphing from what looks like a high-tech hamster ball into a two-wheeled rover capable of autonomously exploring the moon’s surface.
Now, two years after JAXA put LEV-2 to the test on the moon’s surface, the results are in: according to a new study, this cute little silver transformer could be a powerful new kind of robot for future moon missions.
LEV-2 landed on the moon alongside JAXA’s Smart Lander for Investigating Moon (SLIM) in January 2024. LEV-2 successfully rolled, shimmied and wheeled its way around the moon’s surface near the lander. The little bot also captured images of the lander and of the moon and successfully transmitted those pictures back to Earth via LEV-1, a sister rover SLIM also carried to space.
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LEV-2
D. Hirano
Autonomous space robots are critical to space exploration because they can navigate and map harsh or dangerous environments without putting humans at risk. But roving robots are often clunky and heavy: LEV-2, on the other hand, was designed to be small and lightweight, measuring a dainty three inches (eight centimeters) in diameter and weighing eight ounces (less than 230 grams)—about the same as two sticks of butter.
Part of why LEV-2 looks uncannily cute may be by design: JAXA worked with Japanese toy company TOMY to develop LEV-2, according to the space agency. Its transformation abilities are largely the result of a rotating shaft inside the rover that unlocks the robot’s wheels—a feature LEV-2 borrowed from children’s toys.
“This transformation mechanism incorporated technology from commercial toys that transform vehicles into robots, with specific design improvements implemented to prevent jamming during the transformation sequence,” the authors write.
The 2024 mission didn’t come without challenges, however. LEV-2 lost connection with LEV-1 multiple times throughout its visit to the moon. In fact, after an hour and a half on the moon, LEV-2 lost communication entirely with LEV-1—and Earth.
“The lessons learned from this mission provide practical guidance for the design and operation of next-generation distributed space robotic systems,” the authors write.
The study was published on Wednesday in the journal Science Robotics.