Robots out on the factory floor pretty much know what's coming. Constrained as they are by programming and geometry, their world is just an assembly line. But for robots operating outdoors, away from civilization, both mission and geography are unpredictable. Here, robots with the ability to change their shape could be of great value, since they could adapt to constantly varying tasks and environments. Modular reconfigurable robots—experimental systems made by interconnecting multiple, simple, similar units--can perform such shape shifting.