MIT engineers want to send thousands of tiny robots, or microbots, to Mars and other planets, according to a recent MIT news release. Each microbot would be a sphere about the size of a baseball. Powered by internal fuel cells, the balls would "hop, bounce, and roll". They'd roll across the sand, bouncing over rocks, and falling into holes and caves as they swarm across the planet. Each plastic robot would weigh about 100 grams. A small fuel cell would power Dielectric Elastomer Actuators (DEAs aka artificial muscles) that could make the robot hop along at up to 60 hops per hour, with each hop covering about 1.5 meters. The robots would carry cameras and environmental sensors. The swarm would be interconnected through a LAN which could relay information back to Earth. For more information as well as artist's renderings of micobots littering the surface of a planet, see the MIT Microbots website