Tiny bulldozer rovers may some day dish up the dirt and pack it in on Mars. The scoop-and-dump design of a prototype bulldozer rover being developed by NASA engineers mimics that of a bulldozer and dump truck.

Unlike a life-size bulldozer and dump truck, which can weigh several thousand pounds, these rovers are lightweight, intelligent and can work without an operator at the wheel. Yet they have the same capabilities, relative to their size, as their heavy-duty counterparts.

Researchers are conducting basic research on a new breed of rovers. These "bulldozer" rovers have a tiny scoop to dig up and dump soil into an overhead bucket. Photo: NASA/JPL

Robotics engineers think the basic research on these bulldozing rovers may support future missions to look for life or those to sustain a human presence.

"If water sources, such as hot springs, layers of ice or groundwater reservoirs are discovered on Mars, a network of these rovers could conduct scientific investigation and excavate the site piece-by-piece, just as humans would on an archeological dig," said Brian Wilcox, supervisor of the Robotic Vehicles Group at NASA's Jet Propulsion Laboratory, Pasadena, Calif. "Rovers like these may also play a role in establishing a space outpost for eventual human occupancy. They may be used to create buried habitats or utility trenches and to excavate resources to support life.

"We think a greater amount of terrain can be excavated if the workload is shared among several smaller vehicles. Smaller solar powered vehicles have a higher power-to-weight ratio than bigger vehicles, yet together can perform the same tasks as a large vehicle," said Wilcox.

Weighing approximately 3.6 kilograms (8 pounds), the bulldozer rovers have arms with a tiny scoop to dig up and dump the soil into an overhead bucket. They use their arms to right themselves if they fall over. Working in groups, they will create a virtual communications network with a central control tower, equipped with stereo cameras that will provide a 360-degree view of the terrain. A reflector will unfurl from the tower and divert the sun's energy to bulldozer rovers that are down a hole or ditch.

The bulldozer rovers share the same processor and software as the nanorover originally designed to fly on a Japanese asteroid mission. Four prototypes are working at this time. Engineers are working to determine the optimum size of the rovers for excavation tasks. They expect to have several more working prototypes by the end of the year.

"When people hear about the work we do, they sometimes think we are just talking science fiction," said Wayne Schober, manager for advanced robotics surface systems at JPL. "We worked on some of the most advanced robotic vehicle designs of the mid-1980s, such as those that enabled the two-armed coordinated robots for the International Space Station, the Mars Pathfinder Rover and the rovers about to explore Mars. We are not all fun and games. We mean business."

These researchers are working on the next generation of air, surface and subsurface vehicles for exploration of the planets, including Mars and Venus, Jupiter's moon Europa and Saturn's largest moon Titan. The vehicles include a tumbleweed ball, which can blow with the wind; blimps; and all-terrain rovers, which can traverse down steep hills and gullies.

NASA's Cross Enterprise Technology Development Program provided funding for this work. The California Institute of Technology in Pasadena manages JPL for NASA. JPL is the lead American center for robotic exploration of the solar system.