That's science fiction with no grounding in reality. You may as well be going on about transporters and transparent aluminium.

Every time a Moon mission comes up, Helium 3 gets trotted out, but it's just absurd.

For one, billions of tons of rock would have to be mined to extract any reasonable amount of Helium 3. Even with heavy machinery and robotic miners operating 24/7, this is a stretch.

But much more importantly, Helium 3 is utterly useless. It was proposed as one possible fusion fuel but then a much cheaper alternative was developed almost immediately: breeding the required fuel from a blanket of Lithium.

Last, but not least: There are exactly zero fusion power plant operational on Earth right now. There will be exactly zero commercial fusion power plants operational on Earth for at least a decade, no matter what new technologies are developed. At the current pace, according to current plans (e.g.: ITER/DEMO), there will be one (1) power plant generating a trivial amount of power staring in 2048. Likely well into the 2050s there won't be many more.

So to summarise mining lunar He3: We should spend trillions of dollars digging up the Moon for power plants that won't exist for three decades and don't need need the helium anyway.

It reminds me of an old saying: "if we had some eggs, we could make ham and eggs, if we had some ham."

If my grandmother had wheels, she'd be a bicycle.

The little old lady from Pasadena certainly has wheels, but she’s no bike

https://en.wikipedia.org/wiki/The_Little_Old_Lady_(from_Pasa...

> Transparent aluminium

Good sci-fi always has an eye towards the future - we have transparent aluminium now. The whole point of science is to push the boundries of our knowledge.

https://en.wikipedia.org/wiki/Aluminium_oxynitride

I just find those timelines hard to believe. We just condensed a 10 year vaccine development and rollout process into 1 year, and that was mostly because of human trials. The reality is that nobody is interested in funding such an effort for fusion.

> The reality is that nobody is interested in funding such an effort for fusion.

Go check out the money being spent building ITER. I won’t spoil the surprise here, just to say if it doesn’t make your eyes water there something wrong with your tear ducts.

https://en.wikipedia.org/wiki/ITER#Funding

In principle, it is in the best interests of every nation on Earth to get together and organise along the lines of the famous Manhattan Project to develop fusion. Throw money at it like we've been throwing at COVID. Multiple teams working in parallel in a race to solve the problem, like the vaccine development teams were. Eliminate the red tape. Cut the bullshit. Get on with it.

The payoff would be worth it a hundred times over. Not just because of cheap, clean energy, but also because the earlier we start weaning ourselves off of fossil fuels, the better.

But did you notice my choice of words? I said nations, not governments. Governments do not represent their nations. They represent themselves. And they are made up of a small number of greedy, self-interested, mostly corrupt individuals looking out for their own personal benefit. They benefit from bribes (coughconsulting jobscough) from their "partners" in industry. The oil industry. The coal industry. The gas industry. Not just mining! Even power generation industries have a vested interest in delaying fusion as long as possible.

There is no fusion industry yet, and non-existent industrialists cannot pay bribes.

This is the essence of why governments are disinterested in the future. They're only interested in the bribes they get in the here and now. Oh, I'm sorry. "Alleged" bribes, I mean... perfectly legal donations.

Worse, the scientific bodies involved in the nascent fusion industry, like ITER, have become cancerous. They exist now only to justify their own enormous scale. A growing bureaucracy that benefits only from its own size, not in achieving its goals. Hence the plans out to 2050. The longer the better. Got to think about all the project managers that want to reach retirement age and start collecting that pension without ever having to actually deliver.

There is no possibility of a Tokamak ever producing one commercially-viable erg of energy. It wouldn't matter if every nation on Earth joined in. The entire concept is useless. Even with absolute success at every step, such energy could never get below even 10x the cost of solar + wind + storage, even ignoring all the $billions already poured in.

There is exactly one reason we spend $billions every year on Tokamak: it is a jobs program for high-neutron-flux physicists, to maintain a population to draw on for weapons work.

That is not to say fusion is itself a dead end; just that Tokamak is stealing the funding that could otherwise develop practical fusion power. E.g., the FRC DFD project shows every sign of near-term viability, but is starved for the small amount of money that would take them to fully practical power generation and also spacecraft propulsion.

The project is in "Phase II" development under NASA, and needs just $50m to get to a viable prototype -- pocket change for the Tokamak club.

Precisely. Instead of one sunk cost fallacy after another used to justify ITER and its enormous bureaucracy, there should be a billion each thrown at a couple dozen likely alternative ideas.

I read a paper recently that basically said that the best bang for buck is to just work on better superconducting magnetic tape. Stronger fields make everything better, and the scaling law is cubic!

Even if such a tape is developed but doesn't lead to fusion, we'd have better MRIs and DC power lines as a side effect, so it's not even wasted effort!

Even the best HTS tapes won't make fusion competitive. Limits on power/area through the first wall guarantee fusion will have bad volumetric power density compared to fission, even at high magnetic fields.

It is my understanding that FRC fusion could make good use of HTS tape.

We can still say that no amount of HTS tape, or of anything else, will ever make Tokamak hot-neutron fusion competitive. But that is not a reason to abandon HTS tape development.

Hard problems aren't comparable in that way. The vaccine timeline was "shortened" because the timeline doesn't include decades of foundational work in molecular biology that made it possible for the vaccine formula to be determined within days of the virus' genome publication.

Even if we threw as much dollar into fusion as we do on military, it won't work. Because we're not lacking money but understanding.

If you postulate a still non-existent fusion reactor, and then postulate an enormous industrial lunar mining program- 150 tons of lunar regolith gets you 1 gram of He3- this might, might, might work out. Most people who crunch the numbers think that this will never be sufficient in and of itself to justify a lunar program, it only makes economic sense if it can piggyback on top of a program that exists for other reasons.

If you want helium3, seawater is probably a better source than the moon. The difference between 150 tons of lunar rock and something like five times that of seawater is probably a wash, even ignoring the expense of gravity wells.

There is no significant amount of 3He in seawater. Perhaps you were thinking of uranium?

Helium-3 coming from active seafloor vents has something like 10x (to in some locations 30x) the ratio of 3He/4He in the atmosphere. This is so consistent that it is often used as a way to detect underwater vulcanism. Yeah, it's still an order of magnitude less than in the lunar regolith, but we have lots of experience handling seawater at scale, and we have zero experience handling rocks in 1/6th G at scale, so I would probably bet on it taking a long time for the lunar mining to get to the same effectiveness as the seawater handling.

Deuterium and Tritium probably.

There's very little tritium in seawater either (and it was mostly put there by hydrogen bomb tests.)

Sci-fi author Charlie Stross had a wonderful take-down of He3[1] a decade ago. It's alas not very technical. The short of it is that there are no reactors, if we do make them they are going to be insanely fantastically hot (a billion degrees), there's only ~10 parts per billion (according to your wikipedia link) on the moon & mining that will be hard, and then we'd have to transport the stuff too.

I'd read something else about the challenges of reactor design, but not sure what it was. I haven't been enthused about He3 since. I feel like the one interesting use would be a Project Orion / Nuclear Pulse Propulsion system, but wow, boy does that seem like an expensive way to do propulsion: what's the use case?

[1] http://www.antipope.org/charlie/blog-static/2010/08/moonshin...

As there are no commercial fusion reactors using helium-3 or not. Why would we believe this resource has direct value within the next 5 decades?