An anonymous reader shared this report from the Washington Post: Finnish tech firm Bluefors, a maker of ultracold refrigerator systems critical for quantum computing, has purchased tens of thousands of liters of Helium-3 from the moon — spending "above $300 million" — through a commercial space company called Interlune. The agreement, which has not been previously reported, marks the largest purchase of a natural resource from space. Interlune, a company founded by former executives from Blue Origin and an Apollo astronaut, has faced skepticism about its mission to become the first entity to mine the moon (which is legal thanks to a 2015 law that grants U.S. space companies the rights to mine on celestial bodies). But advances in its harvesting technology and the materialization of commercial agreements are gradually making this undertaking sound less like science fiction. Bluefors is the third customer to sign up, with an order of up to 10,000 liters of Helium-3 annually for delivery between 2028 and 2037... Helium-3 is lighter than the Helium-4 gas featured at birthday parties. It's also much rarer on Earth. But moon rock samples from the Apollo days hint at its abundance there. Interlune has placed the market value at $20 million per kilogram (about 7,500 liters). "It's the only resource in the universe that's priced high enough to warrant going out to space today and bringing it back to Earth," said Rob Meyerson [CEO of Interlune and former president of Blue Origin]... [H]eat, even in small doses, can cause qubits to produce errors. That's where Helium-3 comes in. Bluefors makes the cooling technology that allows the computer to operate — producing chandelier-type structures known as dilution refrigerators. Their fridges, used by quantum computer leader IBM, contain a mixture of Helium-3 and Helium-4 that pushes temperatures below 10 millikelvins (or minus-460 degrees Fahrenheit)... Existing quantum computers have been built with more than a thousand qubits, he said, but a commercial system or data center would need a million or more. That could require perhaps thousands of liters of Helium-3 per quantum computer. "They will need more Helium-3 than is available on planet Earth," said Gary Lai [a co-founder and chief technology officer of Interlune, who was previously the chief architect at Blue Origin]. Most Helium-3 on Earth, he said, comes from the decay of tritium (an isotope of hydrogen) in nuclear weapons stockpiles, but between 22,000 and 30,000 liters are made each year... "We estimate there's more than a million metric tons of Helium-3 on the moon," Meyerson said. "And it's been accumulating there for 4 billion years." Now, they just need to get it. Interlune CEO Meyerson tells the post "It's really all about establishing a resilient supply chain for this critical material" — adding that in the long-term he could also see Helium-3 being used for other purposes including fusion energy.Read more of this story at Slashdot.