Video: Mining moonbots
Home-built moonbots raked, scraped and dug their way across an artificial lunar landscape in Moffett Field, California, on Saturday and Sunday in pursuit of a half-million-dollar prize.
It was NASA’s third Regolith Excavation Challenge but the first in which any team’s machine performed well enough to claim the bounty. A robot built by students from Worcester Polytechnic Institute, Massachusetts, picked up and deposited more than 440 kilograms of material to win.
NASA’s motivation for the competition is simple: being able to dig on the moon is a prerequisite for establishing a permanent base there.
Lunar soil consists of rock dust particles on average a fifth the size of a grain of sand, but with sharp edges because the moon has no weathering process to grind them down. The Regolith Challenge takes place in a 4-metre-square arena filled half a metre deep with finely ground volcanic rock made as close to real moon dust as possible. Before each machine takes its turn, judges compact the material, rake the surface and randomly place football-sized rocks on top (see an image of the simulated lunar surface).
Each team got 30 minutes to harvest and deposit at least 150 kilograms of regolith into a container outside the arena. With the exception of one completely autonomous bot, teams controlled their excavators using laptops in the next room, with a 2-second delay added to simulate the time needed to relay signals between Earth and moon.
The first team to try its hand, hobbyists from Los Angeles, became the first ever to meet the minimum qualification for the prize. Their robot, Braundo, used a conveyor belt with cup-sized scoops to harvest and deposit over 260 kilograms of material (see an image of Braundo).
Most other teams failed to load any material into the hopper, as they struggled with last-minute malfunctions and network troubles that left them unable to direct their diggers.
None came close to Braundo’s score until Sunday, when the WPI team overloaded NASA’s scale with nearly 440 kilograms of regolith. After 30 minutes of deliberation about whether the team had violated a rule about digging too close to the starting position, the judges certified the result.
“We’re excited that the machine did what we designed it to do,” said team leader Paul Ventimiglia, an undergraduate at Worcester. The Worcester bot used a half-metre-wide digging belt and bright blue lights to navigate in the clouds of dust it kicked up, winning its inventors the $500,000 and recognition from NASA officials (see image, right).
“I’m very excited that we have a winner this year,” said Greg Schmidt, deputy director of NASA’s Lunar Science Institute in Moffett Field. “The fact that it’s taken three years shows what a difficult job it is.”
Lunar digging technology will be needed for many activities needed to establish a permanent moon base, from harvesting water to digging bunkers that would protect astronauts from solar flares and making bricks for construction, says Schmidt. Despite recent doubts over NASA’s budget and technology, he remains optimistic about making a return to the moon.
The Regolith Excavation Challenge is one of six “centennial challenges” developed by the agency to spur “citizen inventors” to develop new aerospace technologies while competing for cash prizes of up to $2 million. Other challenges offer prizes for fuel-efficient flight and beaming power via laser.
More on these topics: