To aid creative reuse of lunar resources, Greig and her colleagues propose a technology called ablative arc mining, which would slurp up water ice and the kinds of metals that could be used as building materials. “It’s like using controlled lightning bolts to mine the moon,” she said during her presentation. Her concept describes a van-sized moon crawler—named after the Jawa sandcrawlers of Star Wars—that picks a spot, and then places a ringed device that it carries on its front end parallel to the ground. Electric arcs zap across the ring, which can be made as large as a meter in diameter, ripping particles from the moon’s surface. Those particles, now charged, can then be moved and sorted by the machine’s electromagnetic fields. That way, rather than scoping just one resource, a single piece of equipment could fill one container with water, another with oxygen attached to other elements, and others with silicon, aluminum, or other metal particles.

An artistic representation of the ablative arc mining system deployed into a crater near the lunar south pole.

ILLUSTRATION: JANET HILL/CREATIVE STUDIOS/THE CENTER FOR FACULTY LEADERSHIP AND DEVELOPMENT/UTEP

But, like all early concepts, it faces practical challenges that would have to be overcome: In this case, the moon’s dusty environmentcould cause problems by getting stuck in the machinery, which would have to be made dust-proof. To hunt for water ice, the crawlers also will have to trundle into permanently shadowed craters, which contain water at about 6 percent by mass but are extremely cold and dark. The crawlers’ electronics would have to be designed to operate in those rugged conditions and with a non-solar power source. It also would be tough for any astronaut to oversee them, though they could monitor the mining from the crater’s rim. NASA estimates that permanent lunar settlements will need around 10,000 kilograms of water per year. That would require at least 20 of these kinds of crawlers roving about, gradually collecting those supplies, unless this technology was supplemented with something else. For now, Greig just hopes to test a smaller demonstration version of the crawler in a few years.

Space mining projects have also prompted ethical questions. For example, scientists and others have raised concerns about lunar mining permanently changing the look of the moon in the night sky. But Greig points out that ablative arc mining wouldn’t look like the environmentally harmful pit mines on Earth; the mining region could be spread out, making some craters only slightly deeper. And as for sustainability issues, she says, “there’s enough water to last human settlements hundreds of years.”

                    Stop-motion representation of the arc mining process on the lunar surface

As a potential launching point for moon-goers and expeditions to deep space, NASA has proposed a space station orbiting the moon called the Lunar Gateway. But Zachary Manchester, a roboticist at Carnegie Mellon University in Pittsburgh, argues that the limited size of rockets allows few options for launching large structures for a lunar station. “If you want something that’s bigger than a rocket fairing, which is at most a few meters, it has to get launched in multiple rockets and assembled in orbit, like the International Space Station. Or it has to somehow get scrunched up into that rocket and then somehow expand out,” Manchester says.

At a session Wednesday, he and Jeffrey Lipton, a mechanical engineer at the University of Washington, proposed a space station that would fit into that confined space. Then, once deployed, it would unfold autonomously, like origami, into a full-sized structure, some 150 times bigger than its folded size. Preliminary designs involve a many-jointed structure made of titanium, aluminum, or another metal.

Since future astronauts will likely be on-station for a while, it would need to rotate to generate artificial gravity to avoid the deleterious health effects of prolonged periods in zero-G. But humans are sensitive to spinning; no one wants to live on a merry-go-round. “If you try to build a rotating space habitat, the only way to do it without making people motion-sick is to spin at up to two revolutions per minute,” Manchester says. To produce Earth-like gravity, such a space station needs to be a kilometer across, he argues. Yet squishing such a massive structure into a tiny space until it’s deployed poses a significant engineering challenge. In addition, to make their idea a reality, Manchester and Lipton ultimately need to figure out how to make the unfolding process not get jammed, despite the structure’s thousands of links and joints.

Like packing for the biggest road trip ever, NASA will face similar challenges when fitting everything needed for moon or Mars structures onto rockets. To lighten the load, some scientists have suggested using Martian rocks as material for 3D-printing parts of structures. (A simulated lunar regolith is currently being test-printedaboard the International Space Station.) But Lynn Rothschild, an astrobiologist at NASA Ames Research Center in Mountain View, California, has a completely different idea: making structures out of mushrooms—or “mycotecture,” as she calls it. “The humble mushroom can provide an unbelievable building material. It’s completely natural, compostable, and the ultimate green building,” Rothschild says.

Although fungi could be used to grow the material for actual bricks and mortar that astronauts could use for construction, the best kind of space habitat would be assembled before they even arrive. Her team’s proposal involves launching a lander that would include plastic scaffolding and fungal mycelia, white filaments that make the root structure of fungi. (Like yeasts, mycelia can survive for a while without being fed.) The scaffolding would be a lattice of square hollow plastic cells, stitched into layers to make the shape of the final structure. On Mars, it would inflate to perhaps the size of a garage. Using water and oxygen—at least some of which would likely have been sourced or generated on Mars—the fungi would grow along those stitches and fill the cells, eventually turning a tent-like structure into a full-fledged building.

For strength and protection from space radiation, Rothschild thinks some kind of dark fungi could do the trick. “Black fungi—they make you say ‘Blecch,’ they look kind of disgusting. But the black pigment tends to protect from radiation, protecting the fungi and the people inside the habitat,” Rothschild says. She hopes to send a prototype to the International Space Station in the next few years.

Unlike the moon, Mars was once friendly to life. So Rothschild is designing the scaffolding to prevent any chance of renegade fungi escaping beyond the astronauts’ structures. (The last thing NASA wants is for a search for life on other worlds to turn up something that actually came from Earth.) In her team’s design, the fungi are essentially “double-bagged,” with an extra layer in the plastic lattice to ensure they all stay in.

To address those issues, space agencies have “planetary protection” experts like Moogega Cooper, supervisor of the Biotechnology and Planetary Protection Group at Jet Propulsion Laboratory in Pasadena, California, who spoke at the NIAC conference. “Anywhere you are possibly interacting with liquid water that is inherent to the place, your exploring would definitely catch our attention. Where you find water you may find life,” she says. The United States is one of the original signatories of the Outer Space Treaty, which requires that every space agency or company that wants to send a mission to an alien world make sure the spacecraft and all the equipment aboard are sterilized.

While the NIAC program has a budget of just $8.5 million per year, it supports many exploratory projects. A few of the ideas presented at this week’s conference could go on to the next level, or could get picked up by other agencies or private companies, as in the case of an earlier proposal to propel a smartphone-sized spacecraft to another stellar system with lasers, which inspired Breakthrough Starshot, a privately funded enterprise. Among a few of the topics on the menu for the rest of Wednesday and Thursday: multiple presentations about moon-based radio telescopes, as well as one about personal rovers for astronauts (since Artemis astronauts will be carrying 220-pound packs) and one about planting mushrooms in space regolith to make a more Earth-like growing soil.

“All of the concepts that are awarded are pushing the edge of our understanding, and they really allow us to take science fiction and make it science fact,” Cooper says.