Regolith: A Quick Note. Don't get excited about “Rover” tests in dry sand, since this is completely unlike the Moon's surface. The photos of Apollo Astronaut footprints show (and experts confirm) that the “Angle or Repose” for Lunar Regolith is essentially unlimited. (There are vertical edges at the side of footprints with limited crumbling and no “slip”.) This characteristic is like normal “damp” casting sand, which holds the shape of a “pattern”. The Lunar material has a cohesiveness which has nothing to do with liquid surface tension but does include electrostatic effects. Many of its particles are not smoothed (like water eroded sand) but very rough. Thus they have little tendency to roll over one another, or slide on one another. Vacuum welding can also occur easily on the unoxidized surfaces.

The regolith can certainly be shoveled and pushed around, but acts very differently than dry sand.