A team of researchers from Stanford University, along with scientists from NASA's Jet Propulsion Laboratory and the Massachusetts Institute of Technology, have proposed a new class of robots that could someday roll and hop across the surface of the Martian moon, Phobos. Called 'hedgehogs,' they would be launched from a mothership and then autonomously explore the surface.

The spherical robots would measure about half a meter in width (1.6 feet) and be equipped with spikes to help it along as it rolls around low gravity environments (Phobos has gravity that's 1,000 times weaker than Mars). As the hedgehogs performs its work, it would transmit the details of its findings back to the mothership, the Phobos Surveyor, which is waiting in orbit. And in return, the ship will jointly determine its location and orientation, along with mapping its trajectory.

In order to allow for the movement, the hedgehogs will have three rotating orthogonal flywheels inside it, each aimed in a different direction. The spinning disks have intertial forces that will allow the sphere to move with precision in an environment where traditional rovers would bounce or float with reckless abandon.

After a quick acceleration, each hedgehog will be able to hop for long-range ground coverage (as much as 10 meters high (32 feet) in some circumstances). Further accelerations will allow them to tumble in a way that will allow for fine movements.

Should the proposal be approved, the entire mission could last up to three years.