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That’s a lovely utopian scenario, nemmart, but I doubt FF would bring it about. While fuel costs are a significant part of the cost of airline operations, they are by no means the only costs involved — labour costs and capital outlays will always be there, and FF does nothing to address those. At best you might get a 30% reduction in the cost of air transportation, which is not small, but of course transportation is only a small part of the cost of transported goods, so that reduction will play a very small role in the final price of a product, and likely be washed out by other competitive factors.

If FF works it will indeed be fantastic, but I don’t think it’s enough to produce the radical changes you posit.

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Commercial aircraft operate between extremely well-equipped points, so there is really no reason that they have to carry their power generation actually on board — they could more easily be run on batteries that are swapped out between flights, or (as has been pointed out before), powered with conventional jet engines using synthetically-produced fuel. Successful and cheap FF will be a game changer, but it doesn’t have to be directly used to have that effect — no one is going to drive a FF-powered car, and there’s no real reason to use FF in jets. (It makes far more sense for vehicles like ships and submarines, where travel times are very long, and space, where refueling isn’t really much of an option.)

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Brian H wrote:
The size of the reactor core is about a refrigerator’s, but the associated Carnot-steam-cycle stuff is still pretty massive

Yep, in the end it’s still a standard “let’s use incredibly sophisticated technology to split the atom…so we can boil some water” approach.

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I guess NIF makes sense because one of its main functions (which isn’t discussed that much publicly) is testing related to nuclear weapons. I don’t know that much about ITER’s functions beyond being a step towards commercial fusion, which would be obviated by the success of FF.

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Aeronaut wrote: There sure are going to be a lot of embarrassed “experts” & “leaders” if FF delivers as promised.

That’s true in general — just think of the poor folks who demanded billions for ITER and NIF!

Truly, if FF delivers, it will be a revolution.

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Brian H wrote: At $50 million per 25MW electric output, it is only 20-40X as expensive as FF.

It’s also arguably far farther along to a commercial product, and the technological issues are not as fundamental. It’s pricing is also less speculative than for FF. Don’t get me wrong, I have every hope that LPP succeeds, and that it has a product soon. But in the competitive space, Hyperion is a similarly-sized solution, and will be to market much more quickly. Of course, if FF actually proves itself, the competitive space will change very rapidly — it is hard to imagine any other technology being able to compete if LPP (and/or some of the other aneutronic fusion companies) produce a working fusion generator.

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It appears Hyperion has developed a joint venture with a Chinese manufacturing company. I’m guessing that this move may help them get around US regulatory issues — their Asian partner can assist them in cranking out modules for the developing world.

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KeithPickering wrote: VASIMR’s advantage is higher thrust.

Higher and variable, as full name (Variable Specific Impulse Magnetoplasma Rocket) implies — unlike most other “ion-drive” type devices, it can trade off thrust for Isp, and thus is far more versatile than typical drives. I don’t know how easy it would be to do this with a FF propulsion system.

Another advantage is that the plasma never comes in contact with the electrodes, so there is no electrode erosion — I’d guess this would be an issue for long-term use of FF-based space propulsion.

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Salgado wrote: how come all fusion experiments and ideas revolve around high energy plasma?

Historically, there have been claims of fusion in non-plasmas — that’s pretty much what the “cold fusion” research claims (fusion in solids), and is also the case in alleged “sonofusion” (where collapsing bubbles in a liquid produce the necessary pressure and temperature for fusion events). Both of these approaches are very controversial, and none has unequivocal experimental support.

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But are there significant advantages to making it spherical, or even cylindrical? What is the efficiency loss relative to the ease-of-construction of something like a box?

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Does the x-ray capturing device really need to be spherical? I realize that shape probably optimizes the capture, but how less efficient would it be to simply create a box with flat sides of laminated materials? Surely that would be far easier to construct, and there may already be flat laminated foils in existence that could be used, rather than creating something new.

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Brian H wrote: Once again, I insist that you misunderstand the purpose of patents.

Brian, I am not talking specifically of patents. Perhaps I have indeed misunderstood the issue you’re pursuing, but all I was addressing is the original claim that government grants impede the free flow of information among researchers. My point is that researchers who are publicly funded have no motivation to avoid publishing in academic journals, whereas the kind of “publishing” that commercial researchers do is often just patents, which are applied for well after the basic research is done, and which do no tend to offer the same wealth of information that academic journal articles do. I am not at all against commercial research or patents, but I think it is important to recognize the enormous and foundational contribution to the general knowledge of our species that is performed by publicly funded researchers who freely share their findings with each other and with us.

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vansig wrote: I’ve experienced the opposite: extreme paranoia and protectiveness within academics, because there are limited research dollars to go around.

But for pure academics (i.e., those without commercial ties), publication is the coin of the realm — it’s what gets you tenure, it’s what gets you promoted, it’s what builds your reputation. Such researchers may not share unpublished work, but that’s because they are eager to scoop others in official published articles. In other words, the motivation in academics is to “share” via publication. There is no such motivation for commercial research.

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I’ve done some back-of-the-envelope calculations from:

http://www.asi.org/adb/02/09/he3-intro.html

I get that to meet the energy requirements of the US for a year, one would have to strip mine 200 square kilometres of moon surface to a depth of three metres, digging up and processing using energy intensive processes about two billion tons of regolith to get the 25 tons of He3 needed (He3 is 13 parts per billion in the regolith). All of this will have to be done using heavy duty industrial mining equipment sent into space and landed safely on the moon, and the resulting material will need to be lifted off the moon surface and landed safely on earth.

For reference, strip-mined coal costs about $25/ton, which has to be close to how much it costs to simply move that much material. So if we were simply mining He3 on earth, it would cost approximately $50 billion just to move an amount equivalent to the regolith needed. This ignores the processing requirements, which are massive (since, unlike coal, all that regolith has to be heated to 600 C and the boiled off He3 captured), and ignores that we have to get equipment to move two billion tons of regolith onto the moon, and get the He3 back.

I cannot imagine any reasonable near-term technological advances that would make such a proposition anywhere near an affordable solution. Certainly it would be far cheaper to build solar power satellites, or thorium-based reactors, or vastly expand solar/wind/tidal/wave/geothermal generation.

Or successfully build pB11 fusion generators.

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vansig, what you say may be true for commercial research where the goal is to patent, but isn’t the case for much of basic academic research, which often doesn’t have direct commercial application.

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