MIT in conjunction with Draper Laboratory is developing a robot known as Talaris or Terrestrial Artificial Lunar and Reduced Gravity Simulator. This robot will be used on the Moon or other planet to hop over the rough terrain, instead of using wheels or treads.
The three foot wide robot will weigh about 110 pounds and currently has two propulsion systems. It has four fans used to help simulate the correct gravity for wherever it will be going and a nitrogen gas system to actually do the thrusting and maneuvering. The robot will be able to make hops of hundreds of kilometers, depending on it’s final size.
MIT and Draper Laboratory are part of a team called Next Giant Leap and are aiming for the Lunar X Prize. They have until the end of 2014 to get Talaris to the moon to try and claim the Lunar X Prize.
Last we heard, Boston Dynamics was also working on a hopping robot, but in their case it is for DARPA.