KAIST, UEL Develop Origami-Inspired Airless Wheel for Lunar Rovers

A joint research team from the Korea Advanced Institute of Science and Technology (KAIST) and the Unmanned Exploration Laboratory (UEL) has developed a deployable airless wheel designed to navigate some of the Moon’s most extreme terrains, including steep lunar pits and subsurface lava tubes.

The research introduces an origami-inspired variable-diameter wheel capable of significantly expanding its size to overcome obstacles that would immobilize conventional rover designs. The work was published in the December issue of Science Robotics.

Lunar lava tubes and pits are widely regarded as promising candidates for future human habitats owing to their natural shielding from cosmic radiation and extreme temperature fluctuations. However, accessing these subsurface environments presents significant technical challenges. One proposed approach is to deploy swarms of small, independent rovers rather than a single large platform. This strategy enhances mission resilience through redundancy, enabling continued exploration even if individual units fail.

Small rovers, however, face inherent mobility constraints. Their compact wheel size limits their ability to traverse steep, rugged terrain, such as pit entrances and collapsed lava-tube regions. While variable-diameter wheels could theoretically address this limitation by increasing traversability on demand, designing such systems for the lunar environment has proven difficult. Lightweight, transformable wheels must operate reliably in vacuum conditions and withstand abrasive lunar dust, which can cause conventional metal components to seize due to cold welding.

To address these challenges, the research team—led by Professor Dae-Young Lee from KAIST’s Department of Aerospace Engineering—developed a compliant wheel design that eliminates traditional mechanical joints. Drawing on the structural principles of the “Da Vinci bridge” and origami-based engineering, the wheel relies on material flexibility rather than hinges or complex linkages to achieve transformation.

The wheel can expand from a compact diameter of 230 mm to 500 mm, allowing small rovers to maintain a low profile during transport while enabling enhanced obstacle traversal once deployed. The use of a specialized elastic metal frame and fabric tensioning elements helps ensure reliable operation under lunar conditions, reducing the risk of fine dust contamination and cold welding.

Performance testing was conducted using artificial lunar soil simulants, with additional driving evaluations performed under extreme temperatures and across muddy and rocky terrain to assess robustness under varied surface conditions. During testing, the wheel demonstrated improved traction on loose slopes and maintained structural integrity during impact tests equivalent to a 100-meter fall under lunar gravity.

The project involved collaboration among multiple Korean space research institutions to validate the technology’s readiness. Prof. Lee described the wheel as a practical and reliable solution for accessing the Moon’s most challenging terrain, expressing optimism that the approach could support future lunar missions despite ongoing challenges in communication and power systems.

From a scientific standpoint, Dr. Chae Kyung Sim, Head of the Planetary Science Group at the Korea Astronomy and Space Science Institute (KASI), emphasized the importance of lunar pits as “natural geological heritages,” stating that the new wheel technology significantly lowers the technical barriers to accessing these environments and brings realistic exploration missions closer to realization. Dr. Jongtae Jang, Principal Researcher at the Korea Aerospace Research Institute (KARI), highlighted the engineering rigor behind the design, explaining that the wheel was optimized and validated using mathematical thermal models to withstand lunar temperature variations of up to 300 degrees.

About KAIST

KAIST is Korea’s first science and technology university, with a long-standing focus on advanced research, innovation, and entrepreneurship. Its graduates have played a central role in Korea’s technological development across multiple industries.

About Unmanned Exploration Laboratory, Inc. (UEL)

UEL, Inc. specializes in planetary mobility robotics technologies in the Republic of Korea. The company develops unmanned exploration systems, including rover mobility platforms designed for missions on Earth, the Moon, and beyond.

[Journal Reference: Science Robotics DOI: 10.1126/scirobotics.adx2549]

Source/Photo Credit: KAIST

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