It's just another day of work for NASA's Desert RATS, a group of more than 100 scientists and engineers participating in field tests in Arizona's high desert. Robots, rovers and space suited subjects test the latest interplanetary gear trekking over some of the state's harshest topography. In this photo, a half-humanoid robot known as Centaur, far left, is joined by the K-10 robot with its 3-D vision and a futuristic lunar vehicle known as SCOUT. (NASA Media Archives). Buy this as a superb wall poster, a canvas print or a framed print.