Mining helium-3 on the Moon and then returning it to Earth ultimately seems more expensive than using the resources on the Moon directly. For instance, by placing quatum computers there, or fusion reactors there, or whatever.
Would be interesting to see the economics of the various hypothetical business models.
perihelions•4mo ago
The direct alternative is to simply make more of it in nuclear fission reactors. (WaPo fails to even mention the option?!) It scales well, as would be needed for scaling up nuclear fusion power.
The current method is neutron capture of deuterium, but you'd get much larger amounts, fast, using lithium; particularly if it's isotopically enriched. Either way you get radioactive tritium, which decays to helium-3 over a 14-year half-life. The tritium is what fusion reactors want.
It's regrettable we've let China establish a world monopoly over lithium enrichment. This is yet another thing they could have a large starting advantage on, with their immediate access to lithium-6 at scale.
ethmarks•4mo ago
Could you elaborate on this? Enriching lithium sounds much more feasible than setting up a moon base, but it still sounds like it would be economically infeasible.
First, am I understanding correctly that you aren't talking about DT fuel, but are instead suggesting that we use the tritium to produce helium-3 by letting it decay? This sounds extremely inefficient, and it also seems like it would cause supply chain issues where power production relies on helium-3 that we started producing decades ago. This would mean that the infrastructure we set up wouldn't be useful for decades, and that if production stopped for a few months there would be a helium-3 shortage decades later. Lunar helium-3 extraction would have a shorter feedback delay, making it less vulnerable to latent shortages and more useful as a medium-term power source.
Second, isn't lithium-6 a rare material? Lithium is abundant, but brine and rock deposits that are cheap and easy to extract are quite limited. Also IIRC something like 92% of it is lithium-7 which is much less useful in enrichment. And that's not even considering the geopolitical factors you mentioned. I'm obviously not saying that tapping into harder-to-access deposits and filtering for lithium-6 would be more difficult than sifting lunar regolith for helium-3, but it still sounds extremely difficult.
perihelions•4mo ago
The article is talking about kilogram-scale amounts of helium-3, so lithium abundance (billions of tons) isn't remotely a factor.
> "there would be a helium-3 shortage decades later"
There's a conceptual misunderstanding: radioactive decay is continuous—there's no latency of waiting. You get a stream of decay product right from the start.
where to start, first up is the moon is most definitly shared equaly by every human, and cant be bought or sold, though my mother swears that she payed 25¢ for a square inch of the moon when she was a kid in Pennsylvania, but we cant find the title, yet. second 300 mill cant get nothing to the moon, let alone back, so this is looking like some bizzare shuffle game, stake jumper , snake oil and red eye stunt, but with He³ instead of Au, brought on by the certainty that China is going to set up first.
But before anyone trys to pull a fast one, they better go clear things with my mom first.
nwah1•4mo ago
Would be interesting to see the economics of the various hypothetical business models.
perihelions•4mo ago
https://en.wikipedia.org/wiki/Breeding_blanket#Tritium_breed...
The current method is neutron capture of deuterium, but you'd get much larger amounts, fast, using lithium; particularly if it's isotopically enriched. Either way you get radioactive tritium, which decays to helium-3 over a 14-year half-life. The tritium is what fusion reactors want.
It's regrettable we've let China establish a world monopoly over lithium enrichment. This is yet another thing they could have a large starting advantage on, with their immediate access to lithium-6 at scale.
ethmarks•4mo ago
First, am I understanding correctly that you aren't talking about DT fuel, but are instead suggesting that we use the tritium to produce helium-3 by letting it decay? This sounds extremely inefficient, and it also seems like it would cause supply chain issues where power production relies on helium-3 that we started producing decades ago. This would mean that the infrastructure we set up wouldn't be useful for decades, and that if production stopped for a few months there would be a helium-3 shortage decades later. Lunar helium-3 extraction would have a shorter feedback delay, making it less vulnerable to latent shortages and more useful as a medium-term power source.
Second, isn't lithium-6 a rare material? Lithium is abundant, but brine and rock deposits that are cheap and easy to extract are quite limited. Also IIRC something like 92% of it is lithium-7 which is much less useful in enrichment. And that's not even considering the geopolitical factors you mentioned. I'm obviously not saying that tapping into harder-to-access deposits and filtering for lithium-6 would be more difficult than sifting lunar regolith for helium-3, but it still sounds extremely difficult.
perihelions•4mo ago
> "there would be a helium-3 shortage decades later"
There's a conceptual misunderstanding: radioactive decay is continuous—there's no latency of waiting. You get a stream of decay product right from the start.
> "economically infeasible"
It's the sole source of helium-3 today.