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Fusion Thrusters For Space Travel
kgeiger writes "John J. Chapman, a physicist and electronics engineer at NASA's Langley Research Center, envisions a laser-pumped fusion drive. Chapman estimates the drive can produce thrust 40 times more efficiently than existing ion engines such as those on the Dawn mission now exploring the asteroid belt."
Alrighty so I haven't RTFA but this is the kind of stuff NASA should be doing more. Hire ambitious smart people with grand ideas, give them resources and turn 'em loose! Probably much of what they do will amount to nothing but you just never know (a great concept may become reality).
mfwright@batnet.com
How will the shark tanks work in space with zero Gs?
love is just extroverted narcissism
The reaction is
1H + 11B -> 12C -> 4He + 8Be -> 4He + 4He + 4He
so there are more output nuclei than input.
However, I suppose it is true that all of the energy is coming from fusion, as 12C -> 4He + 4He + 4He is exothermic. (The reverse reaction is an energy source for stars under some circumstances.)
12C is normally stable, so for this reaction to go as stated the nucleus must be created in some suitable excited state.
Quattuor res in hoc mundo sanctae sunt: libri, liberi, libertas et liberalitas.
When I think about how much more the US could do if we didn't squander our money on bullshit
We spend the equivalent of a huge forest of money trees on USELESS aggression; bring those troops and ships home, destroy deployed equipment in place, sell it to the locals, or bring it home if practical, leave the military brought home employed for a strong standing defense, and (a) we'd be acting morally for the first time in decades and (b) the money spent on the standing army, now home, would go right back into our OWN economy, and (c) we'd have huge overall spending reductions we could apply to the debt and perhaps once again, someday, have money to spend for our actual benefit.
Our budget problems are 100% solvable. All you need to do is get the cowards out of congress. Somehow.
I've fallen off your lawn, and I can't get up.
That's a myth.
Thirty-forty years ago, optimistic predictions were for working fusion power plants circa the first decade of the new millennium. Realistic predictions were somewhat further away. And those optimistic predictions were made with the assumption that the intervening decades would see continual, government funded R&D into the subject (because no private enterprise is going to throw billions at something with a forty year payoff).
The R&D funding was not received. Turns out governments don't like throwing billions at the long term anymore than businessmen do, to say nothing of the minor problem that science and engineering tend to get slashed every time there's a budget crisis (want to go back and count how many times that's happened in the past half century?) The prototypes we could have been building weren't built. Progress was slow, though thankfully not nonexistent.
As a result, a decade after the optimists predicted the first fusion power station, we're only now building the testbed prototype. Interestingly, we're not nearly as far behind as most current pessimists like to think. Net-energy producing fusion will probably be seen as unattainable by some people right up until the point where it's attained.
Want to know where the "fusion has been 10-20 years away fro 60 years" meme got going? Morons. Morons who don't get the idea that you can't sit around waiting for progress to happen. Morons who think that research is something that "just happens" and don't seem to realize that sometimes that vital, civilization advancing research requires a lot more money and patience than we as a culture are prepared to give. Morons who looked back at the rosy view of the future and didn't see the little disclaimer about how much work it would take to get there.
Morons repeated this meme until it became accepted fact and a glib response, brought up every time there's a news story about fusion research. It's time to let this meme, this myth, die.
Erotic is when you use a feather. Exotic is when you use the whole chicken.
We should have these power collectors/transmitters in orbit around the Sun, pointed down at the Earth to collectors floating on the seas. Where they could electrolyze water, or any of a number of other ways to get the energy back to the land where it can be consumed. Emissions free, vastly more power than we can use for the foreseeable future.
The beams would have to be only a few times the intensity of sunlight, but shine all day/night (courtesy of geosync relay satellites) over a few dozen square kilometers on each station. No danger from a beam missing the target, though extra protection added by laser interlocks back from the surface to space that drop both up and down beams when the down beam goes off the target.
That system would require several $billion, perhaps several hundred $billion, investment. But at $0.01:KWh, and $100B is only 1KW:m^2 * 3intensity * 36Km^2 * 6stations * $0.01:KWh = 22.5 months payback time. That's better than 50% ROI, on hundreds of $billions. Plus the value of eliminating emissions, terrestrial fuel production and distribution, energy wars and corruption. And regaining the envy of the world.
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make install -not war