Stanford professor Marco Pavone showed us an early simulation of a robot that, in about ten years, will look like a titanium soccer ball covered in spikes. Pavone calls it a hedgehog. It could one day explore Mars' biggest moon called Phobos. It's a moon that's about the size of San Francisco Bay and has almost no gravity.
"Gravity levels that are thousands of times less than the gravity we have on earth," Pavone said.
Though NASA's Mars rovers have wheels, wheels might not work on Phobos.
"If you were to try to do a wheeled system in low gravity, you could flip it over, you could just completely lose control of it," said Stanford aeronautics doctoral student Ross Allen.
So instead of rolling, Pavone and his students are making hedgehogs tumble and hop, using spinning motors sealed inside. They've started with a two-dimensional model of how it'll work in micro-gravity.
"You see if I just let it go, it very slowly drifts back down, and that's as if this were the ground," Allen said.
But the next prototype will be in three dimensions. Researchers will use what's essentially a small model of the giant shipping cranes at the Port of Oakland to simulate microgravity on a miniature model of the rover.
"Applying very little force, I can move this entire system," Allen said.
Already, their partners at NASA are working on a full-scale model.
"To study tumbling and hopping on different types of surfaces so we looked at doing that on sandy surfaces, concrete surfaces, rocky surfaces," NASA robotics group supervisor Issa Nesnas said.
Hedgehogs could carry cameras and microscopes and send findings back to an orbiting satellite to help scientists learn where Phobos came from, and whether humans could land there.
"For example, water," NASA research scientist Julie Castillo said. "Looking for water is a very important objective of that type of project."
Phobos could even be key to proving or disproving theories on how the universe began.
"Enable us to better understand where we're coming from and where we're heading to," Pavone said.