In 2010, during a speech at the Kennedy Space Center in Florida, President Barack Obama directed NASA away from its primary target, the moon, to focus its human exploration missions beyond the lunar surface toward an asteroid and Mars.
“I have to be pretty blunt here: we’ve been there before,” he said. “There’s a lot more room to explore, and a lot more to learn when we do.”
The United States has since changed course, with the moon once again the centerpiece of NASA’s exploration goals. Under its Artemis program — born during President Donald Trump’s tenure and embraced by the Biden administration — NASA has real momentum and bipartisan political support for one of the most ambitious human spaceflight efforts in decades. It began with the launch of its massive SLS lunar rocket and Orion spacecraft on Nov. 16, a mission with no humans on board. The Artemis I mission will be followed by subsequent astronaut flights – first into lunar orbit and finally landing on the surface.
But despite the progress, Obama’s concern still hovers over the space program: We’ve been there, done that. Why return to the moon?
The answer, said Thomas Zurbuchen, the recently retired chief of NASA’s science missions directorate, begins with the presence of water.
“It’s important to recognize that we’re going back to a moon that’s very different from the one we left when we ascended during Apollo,” Zurbuchen said in an interview. “It was a moon that was dry. … Our understanding of the moon is vastly different.
As a result, NASA has made establishing a sustainable presence on the moon central to its future space ambitions. This allows the program to practice how to live sustainably in space. It allows scientists to tap into the moon’s considerable scientific value to learn more about how the Earth formed. And perhaps years in the future it would also serve as a springboard to Mars and other distant space destinations.
Not only is water key to sustaining human life, but its constituent parts – hydrogen and oxygen – can be used as rocket propellant, turning the moon into a gas station in space. That could be critical for long-duration missions, allowing spacecraft to refuel on the moon instead of lugging all of Earth’s fuel. And since the moon’s gravity is one-sixth that of Earth’s, it’s a relatively easy stepping stone to other points of the solar system.
[Inside the rockets that NASA and SpaceX plan to send to the moon]
The moon also has a story to tell – both about the formation of the solar system and how the Earth came to be. With no atmosphere, it’s a time capsule. The footsteps of the Apollo astronauts remain intact, unaffected by wind or weather, as do the scars of billions of years of bombardment of asteroids and comets that were part of the early formation of the solar system.
“It’s less about finding life itself, but it’s definitely about the journey until life,” Zurbuchen said. “The moon can tell us a lot about our own solar system, the violent processes that have created our planets and scarred their surfaces. … Part of our history hangs over our heads there, and it is eminently possible to travel there.
Getting to the moon is extremely difficult. Living there is even more so, and it’s not something NASA has much experience with. The last of the Apollo crews, Apollo 17, spent the most time on the moon — just over three days. And that was in 1972.
The evolution from short-term probes to long-term lunar homesteading – from exploration to expansion – requires a serious commitment of resources and new technologies.
That’s why NASA wants to build a nuclear reactor on the moon.
It’s one of several initiatives NASA has begun under the Artemis program, designed to help astronauts stay for extended periods when they need power, transportation, and the ability to use the moon’s resources. They would need habitats, rovers and mining equipment, along with tools to extract the water and shape the lunar regolith (aka lunar dirt) into habitat bricks.
The effort is still in its infancy, and the long-term funding NASA would need has not been fully realized. A sustainable presence, despite the rosy predictions of the top of the agency, is still years away and the technical challenges are immense.
But NASA has begun to develop the technologies needed to keep astronauts on the surface for extended periods of time. Last June, the agency and the energy department awarded contracts worth $5 million each to three companies to develop nuclear power systems that could be ready for testing on the moon by the end of the decade. The systems would generate 40 kilowatts of power, enough energy to power six or seven U.S. homes, and last about 10 years.
“They’re really starting to put money into that technology development process,” said Casey Dreier, lead attorney for the Planetary Society, a nonprofit organization that advocates for space exploration. “…I think this is a really crucial piece of technology that has wider applications than just the moon, of course, on Mars and maybe other places as well.”
NASA is also looking into solar farms, using arrays that point vertically and capture the sun’s angle above the horizon. And it explores how best to exploit the so-called “in situ resources” – that is, the ones that already exist, such as the regolith.
“When people explored Earth, they had the opportunity to build a home using local resources,” Pam Melroy, deputy NASA administrator and former astronaut, said in an interview. “So we should be thinking about using lunar regolith to build facilities, and NASA is funding several efforts in this area.”
While those efforts are “modest” for now, Melroy said they used a simulated regolith on Earth and see how it reacts. “How do we compress it? Is there anything we need to do to turn it into a building block?”
But some of those same sources can also create problems of their own, leaving NASA to figure out how to deal with them.
“Many people don’t realize how dangerous the regolith is, how damaging it is to spacesuits and human lungs,” former NASA administrator Jim Bridenstine said in an interview. During some of the Apollo missions, “the regolith that got into the capsule was extremely dangerous because it’s so fine and so sharp.”
There’s also the matter of figuring out how to find the water on the moon and how best to access it. NASA’s plan is to use the Volatiles Investigating Polar Exploration Rover, or VIPER. It would explore the moon’s south pole in late 2024, NASA says, for a 100-day mission.
“VIPER is going to help us with in-situ resource utilization by mapping where the ice is,” Melroy said. “So when astronauts show up, they have a map in their hand that shows where the ice is and where the best place is to build a gas station.”
The moon presents many challenges. But as NASA tries to create a permanent settlement on what some call “the eighth continent,” this also presents a great opportunity.
It’s only three days away — close enough to get home in an emergency, as the Apollo 13 crew did — and it’s a natural place to practice living sustainably in deep space. The lunar poles have at least 600 billion pounds of water ice — or enough to fill 240,000 Olympic swimming pools, according to the Planetary Society — and a ground-based survey could reveal vast amounts more.
“The time is now right to take a giant leap in using the moon to learn how to live off the land, enabling a sustainable human presence on Earth while stimulating a new sector of our economy,” Clive Neal, a professor of earth sciences at the University of Notre Dame, told the National Space Council in 2019. There are platinum group and rare-earth metals on the moon, as well as Helium-3, which is a potential fuel for nuclear fusion. Those resources, he said, could help stimulate a lunar economy that would help sustain a permanent presence.
While the Apollo program was a monumental achievement, “it also showed us how not to explore human space, because such a program based on international competition is not sustainable,” he said.
For the Artemis program, NASA relies on a robust commercial spaceflight industry, led by SpaceX, which won the contract to develop the spacecraft that NASA would use to transport its astronauts to and from the surface of the moon.
[How to be a space tourist: Go boldly, but pack lightly]
Jeff Bezos’ Blue Origin also has its sights set on the moon. (Bezos owns The Washington Post.) Like SpaceX, Blue Origin is building a spacecraft that can fly astronauts and cargo there for NASA. And in recent years, Blue Origin has hired a number of experts to extract lunar resources, such as water. Earlier this year it said it bought Honeybee Robotics, a company that builds systems for extreme environments and developed technology that resides on the Mars rovers Perseverance and Curiosity.
“Our innovative solutions enable scientists to capture, embed and analyze planetary regolith samples across our solar system,” the company’s website states. “We designed, built and tested hardware destined for all the planets between Mercury and Saturn, including the elusive asteroids and comets.”
NASA has to get there first. The successful Artemis I mission was a huge first step, a test flight that NASA says went flawlessly as the Orion spacecraft flew within 80 miles of the lunar surface, capturing dramatic photos along the way before returning to Earth.
The Pacific Ocean splash occurred 50 years to the day of the Apollo 17 mission’s landing on the lunar surface and symbolized the space agency’s newfound commitment to the moon. The meaning of the Apollo program was to transform “the impossible and make it possible,” said NASA Administrator Bill Nelson. “Now we are going to do that again, but with a different goal. This time we go back to the moon to learn, live, work, invent, create and then go out into the cosmos to explore further.”