When we think of planetary rovers, images of wheeled or legged machines crawling across the rocky surfaces of the Moon or Mars usually come to mind. But at Texas A&M University, a team led by Robert Ambrose is exploring a far more unconventional design: a spherical robot that rolls across terrain like a giant ball.
Dubbed RoboBall, the project was originally conceived in 2003 as a NASA project. Ambrose revived the idea after joining Texas A&M’s Robotics and Automation Design Lab (RAD Lab), with support from graduate students Rishi Jangale and Derek Pravecek and funding from the Chancellor’s Research Initiative and Governor’s University Research Initiative.
The result: two working prototypes, RoboBall II and RoboBall III, designed to test the potential of spherical robots for lunar crater exploration and beyond.
RoboBall II, the smaller lab prototype, measures about 2 feet (61 cm) in diameter and features a soft outer shell. Inside, a pendulum-driven propulsion system shifts momentum to roll the sphere in different directions. Despite its compact size, it has reached speeds of up to 20 mph (32 km/h) in tests on grass, sand, gravel, and even water.
RoboBall III, the larger version, is 6 feet (183 cm) across and built for practical missions. It can carry payloads of sensors, cameras, and sampling equipment, making it suitable for planetary exploration. Unlike traditional rovers, it can inflate or deflate its outer shell to adapt traction for different terrains and to minimize wear. With no fixed “up” or “down,” it never risks tipping over a major advantage in unpredictable environments.
The research team’s next step is to conduct field trials on the beaches of Galveston, where RoboBall’s ability to transition seamlessly from water to land will be tested. Alongside space exploration, the team sees vast potential for Earth-based missions, particularly in disaster response.
As graduate student Rishi Jangale explained: “Imagine a swarm of these balls deployed after a hurricane. They could map flooded areas, find survivors and bring back essential data—all without risking human lives.”