The nanorover would have been the smallest rover ever to fly on a space mission. It was designed especially for the very low gravity of a small asteroid. Although tiny, it was certainly not a toy. It was really hi-tech and complex!

The nanorover wheels were attached to struts—kind of like our toy nanorover, except that each wheel of the real nanorover operated independently, rather than in pairs. Why do you suppose it was designed this way?

Well, gravity can be a wonderful thing. We take it for granted here on Earth. But on asteroid 4660 Nereus, there is so little gravity that a rover would barely stick! The nanorover weighed one kilogram (a little over two pounds) here on Earth. But on Nereus it would weigh only 1/10th of a gram. A penny weighs 30 times more! A little bump would make the nanorover bounce way up in the sky and could easily flip it over. So it needed to be designed to operate even if that happened.

If the nanorover were to flip over, its struts could rotate to put the wheels back down on the ground! Solar energy cells on its belly would be able to provide enough power to get it turned back over.

There was another clever thing about this design. When the struts moved the wheels close together, the body of the rover could rotate so that its camera pointed straight up or straight down.

The nanorover didn't just roll on its wheels. It hopped! The strut design let it hop 20 centimeters (8 inches) per second. Rolling, it could go only 1 millimeter per second in the tiny gravity of Nereus. At this rate, it would take 18-1/2 days to go one mile! So, as you can see, The Space Place toy nanorover was a real hot rod!

Here is a computer animation of the nanorover hopping over a big crack. (900-Kb .mpg file).