NASA seems to be continuously developing rovers to explore and possibly colonize the moon and Mars, but none is as downright bizarre as the Athlete, an imposing, spidery robot that H.G. Wells might love. Initially built in 2005, the latest-generation Athlete (or, All-Terrain Hex-Limbed Extra-Terrestrial Explorer) is actually two three-limbed robots that join together to form a platform for transporting payloads weighing up to 990 pounds in Earth gravity. At full height when standing, the prototype is about 13 feet tall, but that's only half the size of what a launch version of Athlete might be. The six articulated limbs can either roll or walk depending on the terrain, with a top speed of about 2 mph. Each limb can also serve as a manipulator.