The idea of using soil on the moon to make solar cells that could power a permanent human settlement may seem bizarre, but two companies say they’ve made big strides on that front: Each say they’ve already made solar cells using fake moon dirt.
Jeff Bezos’ company Blue Origin says it has been making solar cells this way since 2021, but just made that information public in a blog post on Friday. Separately told Lunar Resources, which aims to develop technologies for the “large-scale industrialization of space.” The verge in a call today that it has been doing the same for the past few years.
The hope is that the technology could one day power human life on the moon
Every company has yet to take a giant leap: from making solar cells out of fake dirt in Earth-bound labs to achieving the same thing on the rough surface of the moon. But this is a dream decades in the making. And if their technologies succeed, they could help build outposts on the moon.
The idea of tapping the moon’s resources to support human settlements, technically called in-situ resource utilization (ISRU), has only recently passed from the realm of science fiction. Now, with its Artemis program, NASA is trying to establish “the first long-term presence on the moon.”
“They laughed [at ISRU] 10 years ago, they stopped laughing five years ago, and now they’re really saying, ‘Hey, this is important. We have to do it,” said Alex Ignatiev, chief technology officer at Lunar Resources and professor emeritus of physics at the University of Houston.
Ignatiev says he proposed the idea of making solar cells using materials found on the moon to NASA 15 years ago. The project eventually lost its funding, he says. (NASA did not immediately respond to a request for comment.) Since then, Ignatiev has had better luck pushing the idea in the private sector. Lunar Resources got off the ground four years ago with funding from NASA, the Department of Defense and the National Science Foundation.
But he says the concept grew out of NASA’s research into extracting oxygen from lunar debris, or lunar regolith. The by-products of that process are metals and other valuable materials that Ignatiev thought you could use to make solar cells.
“The waste materials were the metals from which you extracted the oxygen. And to me, that wasn’t waste material. That was something I can use,” Ignatiev tells me The edge.
The layer of “dirt” covering the moon is nothing like Earth’s soil. The moon has no atmosphere, so its surface is constantly infested with micrometeorites. The result of that pounding is lunar regolith, dirt-like debris that just happens to be rich in metals and — crucially for solar cells — silicon.
The way to turn that debris into a treasure, Ignatiev explains, is through a process called molten regolith electrolysis. Lunar regolith is melted at extremely high temperatures and then shot through with an electric current to extract iron, silicon and aluminum. (This also separates the oxygen.) This provides the basic ingredients for making solar cells. Stitch those cells together and you have a solar panel, and you can hypothetically scale up from there.
“Our approach, Blue Alchemist, can be scaled up indefinitely, eliminating power anywhere on the moon as a constraint,” Blue Origin says in its Feb. 10 announcement of the technology. Blue Origin did not immediately respond to a press request from The edge.
But that’s a lot of talk coming from a company that has seemingly yet to test its technology with real moon dirt. There just isn’t enough of the stuff on Earth to hand it out to every commercial space company trying to run experiments on regolith. Instead, an entire cottage industry for regolith simulants has sprung up to fuel those experiments. You can even buy the fake moon dirt online. Blue Origin says it made its own regolith simulants to be “chemically and mineralogically equivalent” to the real thing, but again, the composition of lunar regolith varies from region to region on the moon.
Another challenge in the real world (or real moon) will be finding a way to generate the high temperatures needed to melt the regolith. Both Blue Origin and Lunar Resources rely on reactors to reach temperatures above 1500 degrees Celsius. “You have to send the tools to the moon, right?” Ignatiev says. “Our reactor is not small.” It weighs a ton, about 1,000 kilograms (2,204.62 pounds).
And getting people back to the moon in the first place is still years away. NASA’s Artemis III lunar landing mission has been delayed for several years, probably as late as 2026 at the earliest.