The Axel rover. Credit: NASA
The rover, being developed by NASA's Jet Propulsion Laboratory and researchers at the California Institute of Technology, uses only three actuators: one to control each of its two wheels and a third to control the lever. This allows it to operate upside down and right side up, turn in place, and follow difficult paths. The lever has a scoop for gathering scientific data and can adjust its two stereo cameras by as much as 360 degrees.
You can see the video demonstration here .