The moon is a magnet, and it is pulling us back.
Half a century ago, the astronauts of Apollo 17 spent three days on that pockmarked orb, whose gravitational pull tugs not just on our oceans but our imaginations. For 75 hours, the astronauts moonwalked in their spacesuits and rode in a lunar rover, with humanity watching on television sets 240,000 miles away. The Apollo program was shuttered after they splashed back down to the Pacific Ocean in December 1972, and since then, the moon has hung, uncharted and empty, a siren in the sky.
NASA is now plotting a return. This time around, the stay will be long-term. To make it happen, NASA is going to build houses on the moon — ones that can be used not just by astronauts but ordinary civilians as well. It believes that by 2040, Americans will have their first subdivision in space. Living on Mars isn’t far behind. Some in the scientific community say NASA’s timeline is overly ambitious, particularly before a proven success with a new lunar landing. But seven NASA scientists interviewed for this article all said that a 2040 goal for lunar structures is attainable if the agency can continue to hit its benchmarks.
The U.S. space agency will blast a 3-D printer up to the moon and then build structures, layer by additive layer, out of a specialized lunar concrete created from the rock chips, mineral fragments and dust that sits on the top layer of the moon’s cratered surface and billows in poisonous clouds whenever disturbed — a moonshot of a plan made possible through new technology and partnerships with universities and private companies.
“We’re at a pivotal moment, and in some ways it feels like a dream sequence,” said Niki Werkheiser, NASA’s director of technology maturation. “In other ways, it feels like it was inevitable that we would get here.”
Ms. Werkheiser, whose family owned a small construction business when she was growing up in Franklin, Tenn., guides the creation of new programs, machinery and robotics for future space missions.
NASA is more open than ever before to partnering with academics and industry leaders, which has made the playing field much wider than it was in the days of the Apollo missions, Ms. Werkheiser said. “We’ve got all the right people together at the right time with a common goal, which is why I think we’ll get there,” she said. “Everyone is ready to take this step together, so if we get our core capabilities developed, there’s no reason it’s not possible.”
Turning a Problem Into a Solution
Among the many obstacles of taking up residence on the moon is the dust — fine powder so abrasive it can cut like glass. It swirls in noxious plumes and is toxic when inhaled.
But four years ago, Raymond Clinton Jr., senior technical adviser of the science and technology office at NASA’s Marshall Space Flight Center in Huntsville, Ala., pulled out a whiteboard to sketch the idea of houses, roads and landing pads. The dust is a problem, yes. But it could also be the solution.
If homes on Earth could be successfully 3-D printed from soil made from the minerals found here, he thought, homes on the moon could be printed from the soil up there, where temperatures can swing up to 600 degrees and a vicious combination of radiation and micrometeorites pose a risk to both buildings and bodies.
NASA is calling its return to the moon Artemis, named after the twin sister of Apollo. Last November, Artemis I, the first of five planned moon missions, blasted off from Kennedy Space Center with only robots on board, circled the moon and returned safely to Earth. Artemis II, which will carry four human crew members on a 10-day flight around the same path — including the first woman and the first Black person in history to make this trip — is scheduled for November 2024. That mission will be followed up one year later by Artemis III, when humans will land on the lunar surface. Two more crewed missions are planned before the end of the decade.
Dr. Clinton, 71, says he knows that average Americans may not be living on the moon during his lifetime, but for those just a few decades younger than him, it’s a real possibility.
“I wish I would be around to see it,” he said.
“When we talk about a sustainable human presence, to me that means that you have a lunar settlement and you have people living and working on the moon continuously,” Dr. Clinton said. “What that could be is only up to the imagination of entrepreneurs.”
‘No Home Depot Up There’
NASA has partnered with ICON, a construction technology company based in Austin, Texas, to reach its 2040 goal. ICON first received funding from NASA in 2020, and in 2022, it announced an additional $60 million for a space-based construction system that can be used beyond earth to print everything from rocket landing pads to habitats, all with concrete mixed on site. So far, the plans are little more than renderings, but they’ve enlisted the input of architects at both the Bjarke Ingels Group and SEArch+ (Space Exploration Architecture) to draw up concepts and designs.
Nearly any object can be printed in 3-D, and the process has been touted by ICON and other players in the field as a quick, cost-efficient solution to the nation’s housing crunch. 3-D printing builds objects layer by layer from a digital file; in its construction projects on Earth, ICON uses a proprietary building material called Lavacrete.
No stranger to ambitious projects, the company is the creator of the Vulcan robotic large-scale construction system, which has been used to build some of the first 3-D printed homes in North America. These include Austin’s Community First! Village, which is a collection of 400 houses for the homeless, and homes in a village of affordable, hurricane-resistant houses for Mexicans living in poverty in the remote town of Nacajuca.
“It’s a surprisingly natural progression if you are asking about the ways additive construction and 3-D printing can create a better future for humanity,” Jason Ballard, ICON’s chief executive, said in a news release.
But printing in deep space is another dimension.
“Chemistry is the same up there, but physics are different,” said Patrick Suermann, interim dean of the School of Architecture at Texas A&M University, which is working closely with NASA to develop a construction system that can be operated by robots in space.
Traveling light is critical, he said, because every additional kilogram of weight carried on a rocket to the moon costs about $1,000,000. Carrying materials from earth to build in space, Dr. Suermann said, is unsustainable. “And there’s no Home Depot up there. So you either have to know how to use what’s up there, or send everything you need.”
Dr. Suermann was a civil engineering professor at the Air Force Academy and has built projects in some of the most remote spots on earth, from Afghanistan’s Helmand Province to the Arctic Circle. Building in space, he said, reminds him of the lesson he learned then — the greatest threats to life come not from other humans, but from the environment itself.
“We built a base out of next to nothing in Afghanistan. It’s all the same, just with more radiation and lower gravity,” he said. “And Mother Nature and the solar system are going to win every time.”
‘First Thing’ and Furniture
Any equipment that goes to the moon needs to be tested on earth to ensure it can withstand the environment, so Marshall also has over a dozen testing chambers that subject items to the same radiation and thermal vacuum conditions that they would endure off earth. In February 2024, ICON’s printer will be lowered into the largest chamber for its first test.
“If you can survive our chambers, then you’re very likely to survive space,” said Victor Pritchett, director of experimental fluids and environmental test branch for Marshall.
And before NASA and company can build homes, NASA needs to build landing pads, so that when the rockets carrying the 3-D printers land on the moon, the dust spread that kicks up can be mitigated.
NASA scientists are currently working to perfect a simulated lunar concrete that can stand in for the moon-made material while they run tests on earth. At Marshall, in a nondescript laboratory deep in the bowels of one of their low-slung buildings, scientists are running tests on spheres of simulated moon dust that has been poured and cast into a small cylinder. They don’t look like much — just a rounded hunk of concrete small enough to fit into your palm — but when held up to a plasma torch, they can withstand temperatures of 3,400 degrees Fahrenheit. This gives scientists hope that when they build out of the real thing, it will perform well under the conditions of an actual rocket landing, where temperatures reach hellfire-level hot.
“The first thing that needs to happen is a proof of concept. Can we actually manipulate the soil on the lunar surface into a construction material?” said Jennifer Edmunson, the lead geologist at Marshall Space Flight Center for the project. “We need to start this development now if we’re going to realize habitats on the moon by the 2040 time frame.”
Of course, a house is made of more than walls — even in space, humans need a door to enter and exit from, and once inside, they need objects on which to sit and sleep, and all the other accoutrements of life.
NASA is working with a handful of universities and private companies to create prototypes for space furniture and interior design, Dr. Edmunson said. NASA’s Ames Research Center, working with researchers at Stanford University, have even separated some of the minerals in synthetic lunar soil to make tiles of different colors, like green, gray and white, that could potentially even be used for kitchens and bathrooms.
Prime Real Estate Is Really on Mars
ICON and NASA’s shared vision is for a space-based lunar construction system called Olympus, controlled on earth by human technicians skilled in the emerging field of space construction. For those technicians, classes are already in session.
“In 10 years construction technology might be very different, the type of robots we use might be very different, and the A.I. that we use will be different. But what we can do right now is come up with the training strategies that make construction workers ready for the future to come,” said Amirhosein Jafari, an assistant professor of construction technology at Louisiana State University, who is helping develop simulation-based trainings for construction teams that would coordinate with robots in space.
His colleague Ali Kazemian is working with NASA on the printing material itself, focusing on a waterless concrete fashioned from simulated versions of the rock material that exists on the moon. Dr. Kazemian sees in the rich lunar minerals an even deeper potential than just concrete for 3-D printing: He sees resources that can be used extensively by those who stay behind on earth.
“People talk about humans living on the moon,” he said. “But there’s another likely scenario, too. At some point on earth we are going to run out of resources. So establishing mines and fully automated factories on the moon is a possibility too.”
Scientists at NASA say that it is too early to consider the market value of homes on the moon, or even how an ownership structure for lunar habitats could look. But they acknowledge that the moon presents a potentially significant cache of untapped resources, and that other nations will undoubtedly be interested in a stake.
India last month landed a spacecraft on the moon, earning the distinction of the first nation to ever land near the southern polar region, where the most precious of resources — water — is believed to be lying in wait. The achievement came just two days after a Russian craft crashed ahead of a landing attempt, after it failed to adjust to its orbit. American astronauts famously planted their flag on the moon’s surface in 1969, but two years earlier, the 1967 Outer Space Treaty, a multilateral treaty that sits at the heart of international space law, declared that no one, in fact, can own the moon.
The Artemis Accords, launched by the United States together with seven other founding nations in 2020, gave a refresh to the principles of peaceful, cooperative exploration of the moon, and are now signed by 29 countries, including the United Kingdom, Japan, Italy, Canada, and Brazil. But notably, neither China nor Russia has signed.
Defense, ownership and international claims on the moon and Mars are not the purview of NASA, Ms. Werkheiser said. But for now, she said, in this newest iteration of space race, she believes the global community feels aligned.
The moon is not the final frontier. Wrapped into NASA’s push to build on the moon is a longer and even more far-flung goal: getting to Mars.
The moon is a practical spot for a layover, as NASA believes that the water on the lunar surface could be converted to rocket fuel. A spacecraft traveling from Earth to Mars may make a pit stop on the moon, where astronauts can stretch their legs, grab a bite to eat inside a 3-D printed structure and then gas up before hitting the proverbial road.
In Houston in June, with much fanfare, four volunteers standing in as NASA astronauts waved to a gathered crowd and then walked inside the Mars Dune Alpha, a 1,700-square-foot structure that was 3-D printed by ICON with Lavacrete tinted in the same burnt rust color as Mars itself. They then locked the doors, and will spend the next year living in simulated conditions to practice for one day living on Mars in reality.
Audio produced by Kate Winslett.