Miniature Japanese Robot Reveals Why SLIM Lander Touched Down Upside Down on the Moon

A palm-sized robot explorer known as the Palm-Sized Lunar Excursion Vehicle 2 (LEV-2) has helped scientists understand the difficulties experienced by Japan’s SLIM lander when it touched down on the lunar surface in January 2024. Developed by the Japan Aerospace Exploration Agency (JAXA), LEV-2 was deployed from the SLIM spacecraft shortly after landing. The robot, which resembles the BB-8 droid from Star Wars, can transform from a miniature ball no larger than a human palm into a small wheeled vehicle. Its unique design allowed it to roll across the lunar surface and photograph its surroundings, providing the flexibility to navigate obstacles and complex terrain without human intervention. Research published in the journal Science Robotics explains that one of the images captured successfully revealed the cause of SLIM’s problems: the lander had ended up in an upside-down position. ‘The results highlight the potential of such platforms as independent explorers capable of accessing environments beyond the reach of larger primary spacecraft,’ wrote the research team led by Daichi Hirano of JAXA. During approximately 100 minutes of operation on the lunar surface, LEV-2 transmitted information via its companion robot, LEV-1, before contact was lost. In that time, the robot autonomously explored the area around SLIM, documented its surroundings, and sent selected visuals back to Earth through wireless communication. The mission’s success demonstrates that small, independent robots can complement larger spacecraft, enabling scientists to gather detailed data with reduced risk. The project’s achievement signals a shift in space exploration, where future missions may deploy swarms of intelligent small robots to perform specialised tasks rather than relying solely on large rovers. ‘In the long term, this approach could enable more flexible, resilient, and cost-effective planetary exploration missions,’ the researchers stated.