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Published on: February 12, 2013
From ball to rover: Transformable palm-sized rover SORA-Q for autonomous lunar exploration
D Hirano1,2, M Inazawa2, M Sutoh1
1Space Exploration Innovation Hub Center, Japan Aerospace Exploration Agency, Sagamihara 252-5210, Japan.
Science Robotics
|June 10, 2026
Summary
A miniature transforming rover, Lunar Excursion Vehicle 2 (LEV-2) or SORA-Q, successfully explored the Moon autonomously. This small robotic explorer navigated lunar terrain and transmitted images, demonstrating new capabilities for space missions.
Area of Science:
- Robotics and Space Exploration
- Planetary Science and Astrobiology
- Miniature Systems Engineering
Background:
- Miniature robots offer cost-effective solutions for space exploration with strict payload limits.
- Autonomous exploration with small robots faces challenges in computation, power, and locomotion.
- Previous lunar missions have not fully leveraged the capabilities of transforming, centimeter-scale rovers.
Purpose of the Study:
- To introduce the Lunar Excursion Vehicle 2 (LEV-2), also known as SORA-Q, a transforming centimeter-scale rover.
- To detail the system design and in situ lunar activities of LEV-2.
- To highlight the efficacy of technologies for autonomous exploration by small-scale space robots.
Main Methods:
- Development of a two-wheeled, centimeter-scale rover (LEV-2/SORA-Q) capable of transforming from a spherical to a wheeled configuration.
- Deployment of LEV-2 from the Smart Lander for Investigating Moon (SLIM) prior to its lunar landing.
- Autonomous navigation, image capture, and wireless data transmission on the lunar surface without ground control.
Main Results:
- LEV-2 successfully deployed and performed autonomous exploration around the SLIM lander on the lunar surface.
- The rover captured and transmitted images of the lander and its surroundings.
- The mission demonstrated the feasibility of autonomous operations for miniature lunar rovers.
Conclusions:
- The LEV-2 (SORA-Q) mission validates the effectiveness of transforming, centimeter-scale rovers for lunar exploration.
- The study highlights key technologies and operational strategies for future small-scale space robot missions.
- Lessons learned from encountered challenges, including data loss, will inform subsequent space exploration endeavors.
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