A tiny robot developed by Japan's space agency operated autonomously on the moon for more than 100 minutes and sent a series of images back to Earth.
Image Credit
LEV-2 moon robot closed (left) and open (right). AXA/TOMY/Sony Group Corporation/Doshisha University
Share
Exploring the moon’s surface lays crucial groundwork for future crewed settlements, and swarms of tiny robots could be the key. Now researchers have given the first demonstration of the idea after a palm-sized rover autonomously navigated the moon and transmitted images back to Earth.
The moon is a tough environment for robots. Its surface is strewn with craters and abrasive moon dust, and communication delays make remotely piloting vehicles a painstaking and risky process. The cost of launching and landing hardware and the real prospect of losing expensive equipment justifies an extremely cautious approach that can significantly slow down exploration.
One way around these challenges is to replace traditional rovers with many small, cheap, and hardy robot explorers, which could increase coverage and introduce redundancy. And now Japan’s space agency JAXA has given us the first compelling demonstration of the approach.
In a paper published in Science Robotics, JAXA researchers provide a technical report detailing the successful deployment of the agency’s LEV-2 robot during the its SLIM mission, which touched down near the Shioli crater in January 2024. LEV-2 is a three-inch-wide sphere that converts into a wheeled robot after landing. The robot operated autonomously for more than 100 minutes, covering an estimated 24 meters and relaying a series of images back to Earth.
"Although the capabilities of an individual small rover are inherently limited, the results highlight the potential of such platforms as independent explorers, capable of accessing environments beyond the reach of a primary large spacecraft," the authors write.
Nicknamed SORA-Q—derived from the Japanese words for space and sphere—the robot weighs just eight ounces. Upon arrival, the shiny metal sphere splits open and expands horizontally, allowing its two hemispheres to become wheels that spin around a central shaft. This central area also features a front-facing camera and a tail to help stabilize the robot.
JAXA developed the device in partnership with Sony and toymaker TOMY. The design borrows directly from technology used in transformer toys that convert from vehicles into robots. But the team had to make considerable modifications to account for the harsh lunar environment.
One of the biggest challenges for any lunar robot is maneuvering in the dust, or regolith, that coats the moon’s surface. The fine, powdery material can be hard for smaller wheeled robots to navigate as they lack the traction of their larger counterparts.
To solve this problem, the team designed the wheels to rotate around a point slightly offset from their center, causing a lopsided spinning motion that lifts the rover up slightly on every rotation. This helps the wheels to dig into the surface and generate enough traction to keep moving in the loose regolith.
Communication delays also present a significant barrier to smooth operation, so the team engineered the robot to handle most operations autonomously. An onboard image-processing system allowed the rover to detect the SLIM lander in its camera feed and use this as a navigational reference point, estimating its own position relative to the spacecraft in real time.
Be Part of the Future
Sign up to receive top stories about groundbreaking technologies and visionary thinkers from SingularityHub.
Because of its diminutive size, it was impractical to give SORA-Q the equipment needed to communicate directly with Earth, so the team paired it with a hopping robot called LEV-1 that can transmit data. Power constraints and narrow communication windows still cap the amount of data the robot can send to Earth, so SORA-Q has an onboard image-processing algorithm that picks out the best photos to share.
Due to power and mass constraints, the team fitted the robot with a low-power chip designed for small devices rather than complex tasks like image processing. The algorithm relies on a very simple approach—it detects the SLIM lander’s distinctive gold insulating material and then picks the photos where this is featured prominently in the frame.
Around seven minutes after activation, the rover had moved roughly five meters from the lander, selected the two best images from 12 it had captured, and transmitted them to LEV-1. One of those images actually proved unexpectedly useful as it showed the lander had landed at an odd angle with its solar panels facing the wrong direction. This gave ground teams critical information that helped them diagnose the spacecraft's operational status.
Image SLIM lander taken by LEV-2. Image Credit: JAXA/TOMY/Sony Group Corporation/Doshisha University
But the system wasn’t flawless. It lost some data in transmission, partly because LEV-1's hopping maneuvers appeared to disrupt the wireless link and partly due to changing antenna orientations as the rover moved. The team also lost telemetry data before the mission ended, making it impossible to determine exactly how far the rover ultimately traveled or when it stopped working.
Still, the mission was strong evidence that small, cheap vehicles like SORA-Q could greatly expand the scope of robotic exploration. That could prove invaluable as we attempt to scope out promising locations for future scientific missions or even permanent bases on the moon.
Related Articles
Orbital Airbag Could Shield Earth From Devastating Solar Storms
AI Can Now Design and Run Thousands of Experiments Without Human Hands. We Aren’t Ready for the Risk to Biosecurity.
New Algae Robots Swarm Like Locusts at the Flick of a Switch
What we’re reading
Facts Only
Japan’s space agency, JAXA, deployed the LEV-2 robot during its SLIM mission in January 2024.
LEV-2, nicknamed SORA-Q, is a three-inch-wide spherical robot that transforms into a wheeled rover upon landing.
The robot operated autonomously on the moon for over 100 minutes near the Shioli crater.
LEV-2 covered an estimated 24 meters and transmitted images back to Earth.
The robot was developed in partnership with Sony and toymaker TOMY.
Its design was inspired by transformer toys but modified for lunar conditions.
LEV-2’s wheels rotate around an offset point to improve traction in moon dust (regolith).
The robot used onboard image processing to detect the SLIM lander and navigate relative to it.
Communication with Earth was facilitated by a companion hopping robot, LEV-1.
The mission revealed that the SLIM lander had landed at an odd angle, affecting its solar panels.
Some data was lost due to disruptions in the wireless link between LEV-2 and LEV-1.
Telemetry data was lost before the mission ended, making the final distance traveled uncertain.
Executive Summary
Japan’s space agency, JAXA, successfully demonstrated the potential of small, autonomous robots for lunar exploration through its SLIM mission in January 2024. The mission deployed LEV-2, a palm-sized, spherical robot nicknamed SORA-Q, which transformed into a wheeled rover upon landing near the Shioli crater. Operating autonomously for over 100 minutes, LEV-2 covered approximately 24 meters and transmitted images back to Earth, including critical data about the SLIM lander’s orientation. Developed in collaboration with Sony and toymaker TOMY, the robot’s design drew inspiration from transformer toys but was adapted to handle the moon’s harsh conditions, including its abrasive regolith. Challenges included communication delays and data loss, but the mission proved that swarms of small, cost-effective robots could expand exploration capabilities, reducing risks associated with larger, more expensive hardware. The success suggests a viable path for future lunar missions, including scouting for potential settlement sites.
While the mission highlighted the advantages of redundancy and autonomous operation, limitations such as power constraints and communication issues were evident. The robot’s image-processing algorithm, though simple, effectively prioritized useful data, but some telemetry was lost due to disruptions in the wireless link with its companion hopping robot, LEV-1. Despite these hurdles, the demonstration underscores the feasibility of deploying multiple small robots to enhance coverage and resilience in lunar exploration, particularly as humanity prepares for sustained lunar presence.
Full Take
This demonstration of Japan’s LEV-2 robot on the moon is a compelling case study in how innovation can overcome the inherent challenges of space exploration. The mission’s success lies in its pragmatic approach: leveraging small, expendable robots to mitigate the risks and costs associated with larger, more complex hardware. The design—borrowing from transformer toys—shows how cross-disciplinary collaboration (space engineering and consumer electronics) can yield creative solutions. However, the limitations—data loss, communication disruptions, and power constraints—highlight the trade-offs of miniaturization. The mission’s reliance on autonomous navigation and simple image-processing algorithms also raises questions about the balance between complexity and reliability in extreme environments.
The broader implication is a shift in lunar exploration strategy. Swarms of small robots could democratize access to the moon’s surface, enabling more frequent and diverse missions. Yet, this approach also introduces new vulnerabilities, such as the potential for coordinated failures or the challenges of managing multiple autonomous systems. The mission’s unintended discovery—revealing the SLIM lander’s awkward orientation—underscores the value of redundancy and serendipity in exploration.
**Patterns detected: none**
Root cause: The narrative reflects a broader trend in space exploration toward modular, cost-effective solutions, driven by the high stakes of traditional missions. The assumption that smaller, cheaper robots can achieve comparable results to larger systems is being tested here, with promising but not flawless results.
Implications: If this model scales, it could accelerate lunar exploration by reducing barriers to entry for both scientific and commercial missions. However, the reliance on autonomous systems also means ceding some control, which could complicate mission planning and data interpretation.
Bridge questions: How might the lessons from LEV-2’s traction system apply to other planetary surfaces with challenging terrain? What safeguards are needed to ensure that swarms of small robots don’t create new risks, such as interference or collision? Could this approach be adapted for other high-risk environments on Earth, such as disaster zones or deep-sea exploration?
Counterstrike scan: A coordinated influence campaign might exaggerate the mission’s success to push a narrative of rapid technological progress, downplaying the limitations. However, the article presents both achievements and challenges transparently, aligning with a balanced assessment rather than a manipulative playbook.
Sentinel — Human
This article exhibits the characteristics of professional science journalism, featuring specific technical details and clear attribution that strongly suggest human authorship based on primary source material.