The image that flickered onto Moscow TV screens last week showed an awkward, eight-wheeled contraption that looked somewhat like the top half of a huge samovar. But what the outlandish vehicle lacked in styling, it more than made up for in performance. Three hours after reaching the moon aboard the latest unmanned Russian moon probe, Luna 17, Lunokhod I (literally "moonwalker") lumbered down one of two ramps extended by the mother ship and moved forward under the direct control of TV monitors on earth—thus taking the first giant step for robotkind on another celestial body.
The Soviets were understandably exultant. "The flight...