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 to an asteroid and Mars.
“I just have to say pretty bluntly here: We’ve been there before,” he said. “There’s a lot more of space to explore, and a lot more to learn when we do.”
The United States has since reversed 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 space flight efforts in decades. It began with the launch of its massive SLS moon rocket and Orion spacecraft on Nov. 16, a mission without any people on board. The Artemis I mission will be followed by subsequent flights with astronauts — first orbiting the moon and then eventually landing on the surface.
But despite the progress, the concern raised by Obama 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 head of NASA’s science mission directorate, begins with the presence of water.
“It’s important to recognize that we’re going back to a moon that’s really different than the moon we left when we took off during Apollo,” Zurbuchen said in an interview. “It was a moon that was dry. … Our understanding of the moon is massively different.”
As a result, NASA has made establishing an enduring presence on the moon central to its future space ambitions. It will allow the program to practice how to live in space sustainably. It will allow scientists to tap into the moon’s considerable scientific value to learn more about how Earth was formed. And perhaps, it would also serve as a steppingstone to Mars and other deep-space destinations years in the future.
Water is not only key to sustaining human life, but its component parts — hydrogen and oxygen — can be used as rocket propellant, making the moon a gas station in space. That could be critical for long-duration missions, allowing spacecraft to refuel on the moon instead of lugging all the fuel from Earth. And since the moon’s gravity is one-sixth of Earth’s, it is a relatively easy springboard 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 Earth came to be. Without an atmosphere, it’s a time capsule. The Apollo astronauts’ footsteps remain intact, undisturbed by weather or wind, as do the scars of billions of years worth 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 certainly is about the journey to life,” Zurbuchen said. “The moon can tell us a lot about our own solar system, the violent processes that created our planets and scarred their surfaces. … Part of our history is right there, hanging out over our heads, 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 a lot of 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 the short-term probes to long-term lunar homesteading — from exploration to expansion — will require a serious commitment of resources and new technologies.
Which is why NASA is looking to build a nuclear reactor on the moon.
It’s one of several initiatives NASA has begun under its Artemis program, designed to help astronauts stay for extended periods when they’ll 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 mold the lunar regolith (also known as moon dirt) into bricks for habitats.
The effort is still very much in its nascent stages, and the funding NASA would need for the long term has not materialized in full. A sustainable presence, despite the rosy predictions coming from the top echelons of the agency, is still years away, and the technical challenges are immense.
But NASA has begun developing the technologies that would be needed to sustain astronauts on the surface for extended periods. In June of last year, the agency and the Energy Department awarded contracts, worth $5 million each, to three companies to develop nuclear power systems that could be ready to launch by the end of the decade for a test on the moon. The systems would generate 40 kilowatts of power, enough energy to power six or seven American households, and last about 10 years.
“They’re starting to put real money into that technology development process,” said Casey Dreier, chief advocate of the Planetary Society, a nonprofit that advocates for space exploration. “ … I think that’s a really critical piece of technology that has broader applications beyond just the moon, obviously, on Mars and perhaps other places as well.”
NASA is also looking to build solar farms, using arrays that point vertically and catch the angle of the sun over the horizon. And it’s exploring how best to exploit what are called “in situ resources” — meaning those that already exist, such as the regolith.
“When people explored the Earth, they had the opportunity to build a house using local resources,” Pam Melroy, the deputy NASA administrator and a 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 for now are “modest,” Melroy said they involved using a simulated regolith on Earth and seeing how it responds. “How do we compress it? Is there something we need to do it to make it a building block?”
But some of those same resources can also create problems of their own, leaving NASA to figure out ways to deal with them.
“A lot of people don’t realize how dangerous the regolith is, how damaging to spacesuits and human lungs,” former NASA administrator Jim Bridenstine said in an interview. During some of the Apollo missions, “the regolith that got inside the capsule was extremely dangerous because it’s so fine and so sharp.”
There is also the matter of figuring out how to find the water on the moon, and how to best 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’re going to have a map in their hand that shows where the ice is, and where the best place to build a gas station might be.”
The moon presents many challenges. But as NASA seeks to create a permanent settlement on what some have called “the eighth continent,” it also represents a tremendous opportunity.
It lies just three days away — close enough to get home in the case of an emergency, as the crew of Apollo 13 did — and is a natural place to practice how to sustainably live in deep space. The lunar poles have at least 600 billion kilograms of water ice — or enough to fill 240,000 Olympic-size pools, according to the Planetary Society — and an on-the-ground investigation could yield the discovery of vast amounts more.
“The time is now right to take a giant leap by using the moon to learn how to live off the land, thus enabling sustained 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 conduct human space exploration because such a program based upon international competition is not sustainable,” he said.
For the Artemis program, NASA is relying on a robust commercial space industry, led by SpaceX, which won the contract to develop the spacecraft that NASA would use to ferry its astronauts to and from the surface of the moon.
[How to be a space tourist: Go boldly, but pack lightly]
Jeff Bezos’s Blue Origin also has set its sights on the moon. (Bezos owns The Washington Post.) Like SpaceX, Blue Origin is building a spacecraft capable of flying astronauts and cargo there for NASA. And in recent years, Blue Origin has hired a number of experts in how to extract lunar resources, such as water. Earlier this year, it said it was buying Honeybee Robotics, a company that builds systems for extreme environments and has developed technology that is on the Mars Perseverance and Curiosity rovers.
“Our innovative solutions make it possible for scientists to capture, contain, and analyze planetary regolith samples throughout our Solar System,” the company’s website says. “We’ve designed, built and tested hardware destined for all of the planets between Mercury and Saturn, including the elusive asteroids and comets.”
First, NASA needs to get there. The successful Artemis I mission was a huge first step, a test flight that NASA said was flawless as the Orion spacecraft flew within 80 miles of the lunar surface, snapping dramatic photos along the way before it returned to Earth.
The splashdown in the Pacific Ocean occurred 50 years to the day of the Apollo 17 mission touching down on the lunar surface and symbolized the space agency’s renewed commitment to the moon. The significance of the Apollo program was transforming “the impossible and making it possible,” NASA Administrator Bill Nelson said. “Now we are going to do that again, but for a different purpose. This time we go back to the moon to learn, to live, to work, to invent, to create in order to go out into the cosmos to further explore.”