When NASA plans to return humans to the moon under the Artemis program, it will do so with an eye towards much longer habitation than the short jaunts of the Apollo missions. Artemis Base Camp, an outpost intended for the lunar south pole, will be designed to sustain human habitation on the moon, and operate as a metaphorical (and perhaps literal) launch pad to more distant cosmic destinations like Mars. In order to power that base, and manage energy flow between human habitation and other needs, NASA is partnering with Sandia National Laboratories in Albuquerque to design a resilient lunar microgrid.
To understand what the microgrid will require on the moon, Sandia is developing a simulation that can model a variety of scenarios. But, to keep within the constraints of a lunar mission, the modeled lunar grid is focused on managing energy collected from solar panels, stored in batteries, and put to use across the outpost. In the simulation, “we have the ability to control how much energy consumption there is, how much a generation there is,” Rachid Darbali-Zamora, an electrical engineer at Sandia Labs, told The Daily Beast.
While terrestrial microgrids can draw from a range of power sources, renewable and otherwise, working with just solar power for the planned lunar grids allows the focus to be on managing electricity generated one way, and building to the limits of the available power.
In the simulated environment, NASA will be able to challenge the grid by seeing how it handles abrupt changes, like the sudden loss of half its solar panels, to see if the rest of the power and storage can handle the lost load while still preserving essential functions. None of these will be more vital than keeping the astronauts alive.
“What we're proposing is not just one microgrid, but three microgrids, and each one of those has a particular functionality,” said Darbali-Zamora. One is for the lunar habitat itself. Another will be for powering lunar mining operations. And the last is production of resources like fuel, water, or oxygen after extraction from local material.
The entire grid is set to run all power as direct current so it loses the least amount of energy in transition, and the envisioned total power usage will be on the order of tens of kilowatts. The daily estimated electricity use for a home in the U.S. is just shy of 30 kilowatt hours. By default, these microgrids will manage their own power needs and sustain operation within the grid. But through their interconnection, the microgrids can rely on each other and transfer power if something goes awry.
“And let’s say that the controller, it realizes that we need more power for the lunar habitat,” said Darbali-Zamora. “It can draw power from either the mining or the production and give priority to giving power to the lunar habitat.”
Prioritizing the continued habitation of humans is an obvious and important goal, but it also reveals the extent to which this lunar base isn’t just about proving people can be sustained on the moon. It’s about treating the moon as a resource to exploit, with the machinery of celestial production managed by humans.
What’s Mine Is Mine
In its May 11 release on the lunar grid, Sandia Labs stated that the mining and processing facilities envisioned at this lunar base could produce “rocket fuel, water, oxygen and other materials needed for extended exploration of the lunar surface while decreasing supply needs from Earth.”
Many are especially hyped about extracting the moon’s water ice reserves, which can be a source of clean water for lunar inhabitants, or split into oxygen and hydrogen with a number of different uses, including propellant for spacecraft. The moon’s southern pole is thought to be something of a goldmine for water ice that can be easily extracted.
Mining water to convert it into rocket fuel has long been part of the Artemis program’s goals, even if the process still faces technological hurdles and will likely take years to refine (though patents are pending for new lunar ice extraction methods). And unlike water extracted for and kept in recirculation in a human habitat, water turned into fuel on the moon has no water cycle, artificial or otherwise, to bind it.
However this mining operation takes shape, the initial plan is for it to occur in connection with a human habitat designed for just four people. While moon miners are a staple of fiction, the more likely outcome of Artemis is for the humans to supervise automated processes run by machines.
On Earth, one of the largest and most automated mining processes can be found at Swedish mining company LKAB’s mine in Kiruna. The company plans to run it on sustainable, renewable energy entirely by 2045, with the full range of renewables available beyond just solar. But, as the company’s 2020 report notes, “[a] third of the electricity produced in Sweden today will be required” if it were to scale up to carbon-free production of the iron it extracts.
That’s a tremendous power load, and a reminder that while the need for humans can be removed from the mines, energy input cannot. And mining equipment, once in motion, needs to be scaled down rather than abruptly shut off to ensure continued safe functioning. That complicates the microgrid’s task of energy management, as prioritizing the continued habitation of humans can come into conflict with mitigating harm to expensive productive equipment.
In the planned context of the self-contained lunar base, with its mining, habitation, and production grids, those energy trade-offs can be handled internally. But without the dense atmosphere and powerful gravity of earth, mining can also risk launching debris and hurling rocks or dust at unsafe speeds into the surrounding area.
To protect other lunar bases or operations from such dangerous debris, the 2020 Artemis Accords let nations set out and coordinate “safety zones” around their operations, which following NASA estimates for debris travel are pegged at two kilometers from the edge of the operation.
“You can’t claim sovereign territory on the moon if you’re a nation state, according to the Outer Space Treaty,” Fred Scharmen, author of Space Forces, told The Daily Beast. But while that 1967 UN Outer Space Treaty treaty limits the parameters of what states can claim territorial control over, the safety zones of the U.S.-authored Artemis Accords can provide an alternative way to exercise control over lunar territory.
“It effectively says, ‘Hey, nobody else can conduct operations within two kilometers,’” said Scharmen, explaining what that might mean for a site located on the moon’s southern pole. If the U.S. sets up operations around a particularly resource-rich spot, like the moon’s south pole, it can effectively argue that safety concerns exclude any other countries from operating nearby and extracting those same resources.
In 2020, NASA released an overview that detailed early plans for an Artemis base at the lunar south pole, including a little diagram overlaying the Washington, DC Capital Beltway over the south pole’s Shackleton Crater. Three bases, each supported by a microgrid and with transit lines for power conduction in between, wouldn’t be the same as swallowing the crater into the Beltway, but it would put some large swath of lunar surface inside a NASA-determined safety zone.
The extrageopolitics of lunar control and resource extraction (to say nothing of the contested cultural space around who, if anyone gets to permanently alter the face of the moon) are beyond the scope of a planned lunar grid development, though they are not unrelated.
What is closer to practicality is the way that Sandia envisions its microgrid research helping build power resiliency not just on the moon, but on Earth.
“Let's say that you have a microgrid that is connected to the bulk grid, the larger utility and a hurricane passes or an earthquake, and the bulk grid is no longer able to support the system,” said Darbali-Zamora. “Then a microgrid could disconnect from the bulk grid, become an isolated system or a microgrid and provide its own local generation for the amount of time that it's designed for.”
Darbali-Zamora pointed to examples in Puerto Rico and also in Alaska, where microgrid power flow, management, and rationing combined with renewable sources to offer durability and resiliency when existing systems crumble.
Sandia Labs microgrid research goes beyond just its work for Artemis base. But it also falls under the broader tradition of smuggling terrestrial technology development under the flashier mission of designing for life beyond Earth. As Eleanor S. Armstrong, a postdoc researcher at Stockholm University studying the social studies of outer space, told The Daily Beast, one need look no further for evidence than isolation experiments where people live in remote modules for several months and pretend they are living on Mars or the moon. Some famous examples include sites in the Canadian arctic, or Ramon crater in the Negev Desert.
The point of using an analog is not just to simulate a challenge in a much more hospitable environment than the void of space, but also to develop a technology that would be needed in the difficult and isolating environment of operating remotely.
These analogs, said Armstrong, are used “to develop things that are ostensibly for going to Mars, like distance medicine, or water purification systems. But what they're actually solving in these cases is problems that people in those local communities experience.”
Remote medicine and water purification, like renewable energy management and grid resilience, are hardly problems that will be faced by astronauts alone. Keeping that terrestrial perspective in mind, even while developing for the possible extractive space industries of the near future, allows the microgrid research to be grounded in real human need.
“I'm originally from Puerto Rico, I came to work at Sandia because of projects like this,” said Darbali-Zamora. “And I hope that the lessons learned through this project are lessons that I can take back to my home.”