If humans ever want to establish a base on the Moon, Mars, or in deep space, they may need to mine local rocks to support themselves. Now a team of scientists is taking a first step toward finding out whether rock-chowing bacteria can lend a hand.

On Tuesday, astronauts on the International Space Station fired up a series of miniaturized reactors that'll allow them to grow specialized bacteria capable of extracting resources from rocks here on Earth. The experiment, called Biorock, seeks to learn whether the microbes' abilities are altered in low gravity conditions—and ultimately, whether these tiny miners can help support a future off-Earth base.

On Earth, microbes are already used in so-called "biomining" applications; helping humans to extract metals like copper, iron, and gold from rocks or mining waste.