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Helium-3 (He3) is gas that has the potential to be used as a fuel in future nuclear fusion power plants. There is very little helium-3 available on the Earth. H

Helium-3 (He3) is gas that has the potential to be used as a fuel in future nuclear fusion power plants. There is very little helium-3 available on the Earth. However, there are thought to be significant supplies on the Moon. Several governments have subsequently signalled their intention to go to the Moon to mine helium-3 as a fuel supply. http://www.explainingthefuture.com/helium3.html http://www.explainingthefuture.com/helium3.html

zitterbewegung 9y ago
The problem with this is that even if you did successfully move helium 3 to earth or LEO what would you do with it ? A better thing to do would be to mine for metals and make stuff with it (satellites / or outposts).
- lowpro 9y ago
  I wonder if it would be very useful in a moon base to actually launch further into the universe considering the lower gravity well. With a single fusion power point and just using moon materials to make a single launch point outside of earth. You wouldn't need to 'colonize' the moon in that a single base could make more practical sense. That being said, how much He-3 do we really need for fusion? I was under the impression fusion reactions lasted a very long time considering the energy output to mass used, so would mining the substance once or twice suffice for as many fusion reactors as we would need on Earth? Total energy usage across the globe was about 18.0 terawatts in 2013, and apparently the ITER fusion reactor would produce 500 Megawatts of power using a 1/2 gram of hydrogen per year [1], so if Helium 3 was more efficient, we would need hardly any to cover global power generation, and even plan for future power usage. [1] https://www.extremetech.com/extreme/123837-500mw-from-half-a-gram-of-hydrogen-the-hunt-for-fusion-power-heats-up https://www.extremetech.com/extreme/123837-500mw-from-half-a...
  - philipkglass 9y ago
    From the article you linked, "ITER is hoping to produce 500 megawatts over 1,000 seconds from just 50 megawatts of input power and 0.5 grams of hydrogen fuel." (My emphasis.) The half-gram of fuel is to run for minutes, not months. With optimistic assumptions, complete fusion of one gram of He-3 (with deuterium) can produce 1/3 * 6.02 * 10^23 * 18.354 * 4.4505 * 10^-20 = 163913 kWh of primary (thermal) energy. If world primary energy demand is 18 terawatts, that's 18 * 10^9 * 24 * 365 = 157680000000000 kWh annually. 157680000000000 / 163913 = 961973729 grams (962 metric tons) of He-3 per year to cover all primary energy demand.
semi-extrinsic 9y ago
I'm highly skeptical, for three reasons: 1) He3 fusion requres much higher temperatures than other kinds of fusion, so it's even farther away from our grasp than ordinary fusion. This makes the "low-radiation" aspects of He3 irrelevant. 2) There isn't that short supply of He3 on earth, in particular there is quite a bit in natural gas, something like 30 kg produced annually just in the US at current rates. 3) You need a huge installation on the moon processing millions of tons of regolith. Basically large scale strip mining on the moon. Big, energy demanding mechanical equipment that requires frequent maintenance and spare parts and human intervention (just ask any regular miner) while being subjected to extreme temperature swings doesn't sound like something I'd want to put in space. And we haven't even mentioned the environmentalists and the relevant space treaties yet.
- mc32 9y ago
  Why would environmentalists care? There are no known native living organisms. I can see someone caring about scarring the landscape, but that's a bit orthogonal to environmentalism.
dTal 9y ago
Required reading: www.thespacereview.com/article/2834/1 tl:dr There's absolutely no indication this is practical. We don't know how to fuse He3, it's probably impractical to mine it, and "He3 mining on the moon" is more of scifi wishful thinking mentioned offhand in exactly the manner you just did, than a serious engineering proposal.
ProblemFactory 9y ago
> Helium-3 (He3) is gas that has the potential to be used as a fuel in future nuclear fusion power plants. There is potential, but this is for very far in the future. Getting an energy-positive fusion reaction going in ITER is still at minimum 20 years away - and it uses the simpler to fuse Deuterium+Tritium fuel. Getting commercial fusion power plants, and ones that fuse Helium-3 instead, might easily be 50-100 years away. With the price of wind and solar energy dropping fast, people and politicians are getting less and less interested in funding fusion research at all. My prediction is that nobody will be willing to pay for Helium-3 mining on the Moon in this century.
philipkglass 9y ago
Mining the Moon to fuel fusion reactors with helium 3 is a cockamamie scheme for the foreseeable future. First, nobody has made a fusion reactor that produces net electricity even with the least demanding fuel (deuterium-tritium). He-3-deuterium fusion requires significantly higher temperatures. Second, if He-3 did become a valuable fuel, it can be manufactured here on Earth by irradiating lithium with neutrons, just like tritium; it's what tritium decays to. Finally, the lunar regolith concentrations of He-3 are at the parts per billion level. The latest He-3 prices I can find are around $2000/liter (~$15,000 per gram). At 18.354 MeV per D-He3 fusion and 40% thermal-to-electrical efficiency (generously), one gram of He-3 yields 1/3 * 6.02 * 10^23 * 18.354 * 0.4 * 4.4505 * 10^-20 = 65565 kilowatt hours of electricity. To produce 1 kilowatt hour of electricity, the helium 3 cost alone would be 23 cents. For comparison, the average retail price, delivered for electricity in the US is below 11 cents per kWh. Even if you had a working fusion reactor all ready to turn He-3 to electricity, He-3 would need to be an order of magnitude cheaper to have a prayer of He-3 fusion competing economically against other electricity sources. And if He-3 is an order of magnitude cheaper that makes it correspondingly harder to turn a profit mining the Moon for it. Helium 3 lunar mining is not an investment opportunity. It's the end product of motivated reasoning, where the motivation is "I want humans to be doing more things in space."
- DennisP 9y ago
  There's a fundamental reason why lunar He3 isn't worth mining: if you can get net power from D-He3, you can also get net power from the easier D-D reaction, and the output of that reaction is half He3 and half tritium. If your D-D reactor is profitable then the He3 is effectively free. Ycombinator-funded fusion startup Helion is working on a hybrid D-D/D-He3 reactor, and says the combined reaction would release only 6% of its energy as neutron radiation (compared to 80% with D-T).

zitterbewegung 9y ago

The problem with this is that even if you did successfully move helium 3 to earth or LEO what would you do with it ? A better thing to do would be to mine for metals and make stuff with it (satellites / or outposts).

lowpro 9y ago
I wonder if it would be very useful in a moon base to actually launch further into the universe considering the lower gravity well. With a single fusion power point and just using moon materials to make a single launch point outside of earth. You wouldn't need to 'colonize' the moon in that a single base could make more practical sense. That being said, how much He-3 do we really need for fusion? I was under the impression fusion reactions lasted a very long time considering the energy output to mass used, so would mining the substance once or twice suffice for as many fusion reactors as we would need on Earth? Total energy usage across the globe was about 18.0 terawatts in 2013, and apparently the ITER fusion reactor would produce 500 Megawatts of power using a 1/2 gram of hydrogen per year [1], so if Helium 3 was more efficient, we would need hardly any to cover global power generation, and even plan for future power usage. [1] https://www.extremetech.com/extreme/123837-500mw-from-half-a-gram-of-hydrogen-the-hunt-for-fusion-power-heats-up https://www.extremetech.com/extreme/123837-500mw-from-half-a...
- philipkglass 9y ago
  From the article you linked, "ITER is hoping to produce 500 megawatts over 1,000 seconds from just 50 megawatts of input power and 0.5 grams of hydrogen fuel." (My emphasis.) The half-gram of fuel is to run for minutes, not months. With optimistic assumptions, complete fusion of one gram of He-3 (with deuterium) can produce 1/3 * 6.02 * 10^23 * 18.354 * 4.4505 * 10^-20 = 163913 kWh of primary (thermal) energy. If world primary energy demand is 18 terawatts, that's 18 * 10^9 * 24 * 365 = 157680000000000 kWh annually. 157680000000000 / 163913 = 961973729 grams (962 metric tons) of He-3 per year to cover all primary energy demand.

semi-extrinsic 9y ago

I'm highly skeptical, for three reasons: 1) He3 fusion requres much higher temperatures than other kinds of fusion, so it's even farther away from our grasp than ordinary fusion. This makes the "low-radiation" aspects of He3 irrelevant. 2) There isn't that short supply of He3 on earth, in particular there is quite a bit in natural gas, something like 30 kg produced annually just in the US at current rates. 3) You need a huge installation on the moon processing millions of tons of regolith. Basically large scale strip mining on the moon. Big, energy demanding mechanical equipment that requires frequent maintenance and spare parts and human intervention (just ask any regular miner) while being subjected to extreme temperature swings doesn't sound like something I'd want to put in space. And we haven't even mentioned the environmentalists and the relevant space treaties yet.

mc32 9y ago
Why would environmentalists care? There are no known native living organisms. I can see someone caring about scarring the landscape, but that's a bit orthogonal to environmentalism.

dTal 9y ago

Required reading: www.thespacereview.com/article/2834/1 tl:dr There's absolutely no indication this is practical. We don't know how to fuse He3, it's probably impractical to mine it, and "He3 mining on the moon" is more of scifi wishful thinking mentioned offhand in exactly the manner you just did, than a serious engineering proposal.

ProblemFactory 9y ago

> Helium-3 (He3) is gas that has the potential to be used as a fuel in future nuclear fusion power plants. There is potential, but this is for very far in the future. Getting an energy-positive fusion reaction going in ITER is still at minimum 20 years away - and it uses the simpler to fuse Deuterium+Tritium fuel. Getting commercial fusion power plants, and ones that fuse Helium-3 instead, might easily be 50-100 years away. With the price of wind and solar energy dropping fast, people and politicians are getting less and less interested in funding fusion research at all. My prediction is that nobody will be willing to pay for Helium-3 mining on the Moon in this century.

philipkglass 9y ago

Mining the Moon to fuel fusion reactors with helium 3 is a cockamamie scheme for the foreseeable future. First, nobody has made a fusion reactor that produces net electricity even with the least demanding fuel (deuterium-tritium). He-3-deuterium fusion requires significantly higher temperatures. Second, if He-3 did become a valuable fuel, it can be manufactured here on Earth by irradiating lithium with neutrons, just like tritium; it's what tritium decays to. Finally, the lunar regolith concentrations of He-3 are at the parts per billion level. The latest He-3 prices I can find are around $2000/liter (~$15,000 per gram). At 18.354 MeV per D-He3 fusion and 40% thermal-to-electrical efficiency (generously), one gram of He-3 yields 1/3 * 6.02 * 10^23 * 18.354 * 0.4 * 4.4505 * 10^-20 = 65565 kilowatt hours of electricity. To produce 1 kilowatt hour of electricity, the helium 3 cost alone would be 23 cents. For comparison, the average retail price, delivered for electricity in the US is below 11 cents per kWh. Even if you had a working fusion reactor all ready to turn He-3 to electricity, He-3 would need to be an order of magnitude cheaper to have a prayer of He-3 fusion competing economically against other electricity sources. And if He-3 is an order of magnitude cheaper that makes it correspondingly harder to turn a profit mining the Moon for it. Helium 3 lunar mining is not an investment opportunity. It's the end product of motivated reasoning, where the motivation is "I want humans to be doing more things in space."

DennisP 9y ago
There's a fundamental reason why lunar He3 isn't worth mining: if you can get net power from D-He3, you can also get net power from the easier D-D reaction, and the output of that reaction is half He3 and half tritium. If your D-D reactor is profitable then the He3 is effectively free. Ycombinator-funded fusion startup Helion is working on a hybrid D-D/D-He3 reactor, and says the combined reaction would release only 6% of its energy as neutron radiation (compared to 80% with D-T).