Shielding Lunar Rovers

Wesley Ian Bruce

While heavy iron plating may be the best local vehicle building material on the moon it should be noted that on the moon a heavy looking ceramic object will seem very much lighter and could even be used for moon rover construction. The Apollo moon buggy suffered from a traction and braking problem; it was too light to get a good grip on the ground. A stone shelled vehicle might sound strange but such an option is available. As stone and ceramics have good strength in compression but not in tension, for high tensile strength we will need to make fiberglass on the moon, possibly from imported materials. Fiberglass or fiber reinforced ceramic sheets are very strong in tension. Wrapping stone or ceramics with fiberglass will allow those two strengths to be combined.

An eight-inch stone-hulled rover with a shielded volume of 378 cubic feet has an approximate shell volume of 15.5 cubic feet. At 135 pounds per cubic foot on Earth and the moon that's a mass of 2092 lb, 1.05 tons but on the moon its weight is only 349 lb or 0.175 tons. The high mass adds a large load to the rover but the relatively high weight also adds 349lb of weight for traction.

The resulting mass will be higher than metals but a vehicle's acceleration is dependent on its traction and its inertial mass. If its inertial mass is very low and its traction is low then a normal sized power plant will propel it at very high speeds but with no control at all. With a higher mass the acceleration is much lower but the traction and handling are both better. Enclosed moon rovers will need to be shielded from radiation, and that shielding will add weight to the vehicle. With fiberglass reenforced stone or ceramics as structural materials we achieve both strength and high radiation shielding with a material that is 80 to 90 percent lunar material by mass.

These vehicles will still look nifty because they will have a thin mirror shell to keep them cool in the sun and a metal or plastic lining inside to keep the air in.