LEV-2 tiny – A two-wheeled “transformer” rover from JAXA, called LEV-2, tested on the Moon alongside SLIM in January 2024. New research published in Science Robotics says the baseball-sized robot could point to a lighter, more flexible class of lunar explorers—while also e
For an hour and a half on the Moon. LEV-2 did exactly what it was designed to do: it rolled. shimmied. and wheeled its way around the surface near Japan’s Smart Lander for Investigating Moon (SLIM). The rover even turned its transformation trick into something engineers could study in motion. making its way in the vicinity of the lander—and then. when it mattered most for the team. it stopped being reachable.
The new study. published on Wednesday in the journal Science Robotics. puts that strange mix of capability and failure into sharper focus. It’s the kind of report space teams can’t afford to romanticize. because every connection. command. and image has to survive the harsh reality of distance. And in LEV-2’s case. the reality included multiple communication dropouts—followed by a complete loss of contact after an hour and a half on the lunar surface.
LEV-2 landed in January 2024 as part of JAXA’s mission set, riding to the Moon alongside SLIM. Once there. the rover succeeded at moving around near the lander. and it captured images of the lander as well as images of the Moon itself. Those pictures were transmitted back to Earth via LEV-1, a sister rover SLIM also carried to space.
What makes LEV-2 stand out isn’t just what it managed to do—it’s how small it was. and how it was built for motion. The robot is about the size of a baseball. with a diameter of three inches (eight centimeters) and a weight of eight ounces (less than 230 grams)—roughly the mass of two sticks of butter. JAXA described it as a rover that could easily morph between appearances: it can look like a high-tech hamster ball and then become a two-wheeled rover capable of autonomously exploring the lunar surface.
JAXA says the design work included collaboration with Japanese toy company TOMY. and that LEV-2’s transformation abilities come largely from a rotating shaft inside the rover. That internal shaft unlocks the wheels, borrowing a core idea from children’s toys. In the paper. the authors credit that toy-derived mechanism—along with specific design changes aimed at keeping the system from getting stuck. In their words. “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.”.
Still, the mission’s problems mattered just as much as its successes. LEV-2 lost connection with LEV-1 multiple times during its visit to the Moon. After an hour and a half on the lunar surface, it lost communication entirely with LEV-1—and with Earth.
The authors connect those operational lessons to what comes next. “The lessons learned from this mission provide practical guidance for the design and operation of next-generation distributed space robotic systems,” they write.
That guidance lands in a broader reality for robotic exploration: 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, as the study’s themes reflect, often end up heavy or clumsy. LEV-2’s small. lightweight approach is positioned as a possible workaround—if the communication and system reliability issues can be addressed.
The thread between what LEV-2 achieved and what it couldn’t sustain is straightforward: it proved that a tiny. transforming rover can move and gather images on the Moon and send them back through another rover. It also showed that distributed systems—where one robot depends on another and the chain ultimately depends on Earth—need robust links that can survive the mission. not just start it.
Two years after JAXA put LEV-2 to the test on the Moon’s surface, the findings arrive with a clear message for future lunar missions: smaller robots like this one may help broaden what can be explored, but the path to that future runs through the hard engineering of connectivity.
LEV-2 JAXA SLIM moon rover lunar robotics Science Robotics autonomous exploration distributed space robotic systems TOMY toy-derived transformation mechanism
So it lasted 1.5 hours and then just vanished? That sounds like a prototype fail, not an achievement.
Baseball sized rover… that’s cool but why is it “transforming” like a toy?? Also the article says communication dropouts which means it kinda couldn’t be controlled.
I think the whole point is it stopped being reachable after an hour and a half, so maybe it crashed into the SLIM lander or got stuck on a rock. But then they still took images, so maybe it was fine until it ran out of battery? Not sure.
This sounds like that “tiny robots on the moon” thing that keeps getting hyped, but it lost contact anyway. If they can’t keep a signal from the moon, what are we even doing up there? I’m guessing the Japanese lander was the problem? Like interference or something.