Universe Today
Helium-3 (He-3) on the Moon's surface has drawn attention for decades. In 1939, a paper first noted the presence of Helium-3 on the Moon. Still, it really came into the collective consciousness of space resource enthusiasts during the 1980s when they realized just how valuable a resource it was and how much the Moon had of it. Now, a new paper from a company called Interlune, a relatively new start-up based out of Seattle, presented a paper at the recent Lunar and Planetary Science Conference that discusses plans to try to mine some of that wealth of material economically.
There is plenty of wealth to go around. According to the paper, the current price of He-3 is $20M per kg. That would make it one of the most expensive substances in the world, though its biggest use case, in a specific type of nuclear fusion reactor, still has yet to be proven. Advocates say the high price of He-3 is one of the reasons why it has been so hard to get fusion off the ground to begin with.
Interlune hopes to lower the cost of collecting it from the Moon while maintaining a profit. Estimates put the total amount of He-3 on the Moon at around one million metric tons, putting the overall value of the He-3 on the Moon at $20,000,000,000,000,000 for those space resource enthusiasts who like a lot of zeros after a dollar sign.
Fraser discusses the perils of mining the Moon.
Unfortunately, the He-3 is deposited by the solar wind in tiny localized quantities over the entire surface of the Moon, so to unlock significant amounts of it, any potential miner would have to process lots and lots of regolith. That is precisely what Interlune is proposing to do.
Their calculations point to ilmenite, one of the most common minerals on the Moon, as a good repository for He-3. The older the ilmenite, the better, as it has had more time to be subjected to the solar wind and, therefore, has had He-3 deposited in it. Also, the smaller the grain, the larger the percentage of He-3, making it less energy-intensive to process the smaller grain sizes.
Combining this with collected data from Clementine, a mission the US launched in the 1990s to track the composition of the Moon, Interlune states that ilmenite concentrations can be mapped as a function of titanium dioxide concentrations—more titanium dioxide means higher concentrations of ilmenite. And since titanium dioxide can be seen from space, we already know where high concentrations of ilmenite are—the nearside maria.
Fraser interviews Phil Metzger, one of te world's experts on in-situ resource utilization.
These sites, which Apollo astronauts have already visited, would potentially provide access to (relatively) abundant He-3 if enough regolith could be processed to collect it. That is precisely what Interlune plans to do with a project called Prospect Moon. Prospect Moon, which will utilize a commercial lunar lander similar to the ones currently having mixed success in actually landing on the Moon, would include four main pieces of equipment: a regolith sampling system, a He-3 processing system, a mass spectrometer, and a multispectral camera.
Essentially, Prospect Moon would attempt to land in a maria, scoop up some regolith, isolate any He-3 that might be lying in it, and then collect data to prove it did so. In other words, it would act literally like a lunar prospector. The paper describes how the company would be happy to share its data with NASA and the planetary science community and suggests a program similar to NASA's commercial development of small satellites to support lunar mining operations.
The company itself seems to have been founded in 2024. Since then, it has received a grant to test its regolith processing tech and another from the Department of Energy to increase the domestic supply of He-3. However, the word "domestic" in this context might be pushing the geographical definition a little far. It also received an $18M seed investment round around a year ago, so, at least for now, the company seems well-supported. They are also actively hiring several types of engineers in the Seattle area if you are interested in mining the Moon.
Prospect Moon is currently planned to launch in 2027. That is an ambitious timeline, especially given the trials and tribulations of the current fleet of commercial spacecraft attempting to land on the Moon. If the company receives enough funding, successfully demonstrates its technology, and doesn't entirely crash the market for one of the world's most expensive materials, somebody actively mining the Moon might be closer than even most space enthusiasts thought.
Learn More:
E. A. Frank - PROSPECT MOON: INTERLUNE’S COMMERCIAL MISSION TO THE LUNAR SURFACE
UT - What is Moon Mining?
UT - Spacecraft Could Shuttle Astronauts and Supplies to and From the Moon on a Regular Basis
UT - What is ISRU, and How Will it Help Human Space Exploration?