Small robots the size of riding mowers could prepare a safe landing site for NASAs Moon outpost, according to a NASA-sponsored study prepared by Astrobotic Technology Inc. Researchers showed how small robots could comb the lunar soil for rocks, gathering them to pave a durable grit-free landing pad, said John Kohut, Astrobotics chief executive officer. This might reduce the need to build protective berms. To discern the best approach, early robotic scouting missions need to gather on-site information about the soils cohesion levels and whether rocks and gravel of the right size can be found at the site.