It would be irrational to use rubber on the Moon because of the extreme temperatures and intense ultraviolet radiation, which quickly degrade such chemical compounds. Therefore, both wheels are completely metal.
The first model is designed for light rovers and has fewer spokes. The second one is characterised by a more complex structure. It is designed for medium-sized rovers that can operate on difficult surfaces.
The new products complemented Bridgestone's previous concept wheels for moon rovers. So, in 2024, the Japanese company showed a model with a flexible internal structure and a tread made of "steel wool". But the first generation most resembled conventional land vehicle tyres with a fully enclosed coil spring structure.
Bridgestone will demonstrate its new "space tyres" at the "40th Space Symposium" as part of the Japan Space Industry Exposition. The scientific conference will be held from 7 to 10 April in Colorado Springs, USA.
Source: Bridgestone