NBC news link Eurekalert link They squeeze a plasma by mangetically crushing a metal ring, then after ignition the plasma is ejected out the back. It looks promising and they'll test it this summer.
I'm always amazed how small the financial help seems when compared to other spendings, especially the military. The military spends millions on a simple helicopter or a tank that for the most part just sits there waiting to be used and such important scientific projects have to get by with a mere 600.000 dollars. Boggles the mind sometimes to imagine what we could have achieved by now if the roles were switched.
It's not just money; its the needs of a civilization. Two thousand years ago, the Greeks invented the first computer. The computer was used to record the motions of the celestial bodies. This development was not applied to other areas of expertise. http://en.wikipedia.org/wiki/Antikythera_mechanism
Controlled fusion has been a decade away for several times that, so I am skeptical that it will occur any time soon.
The thing is, UNCONTROLLED fusion is relatively easy. Controlled fusion is hard because of the "control" part: superheated metallic plasma is hard to control and nearly impossible to extract useful energy from it. This technique is essentially a very small fusion bomb being detonated inside of a rocket nozzle and so the working principle is pretty simple. It only needs to be controlled well enough to not obliterate the entire engine, and that's just a matter of conventional rocket science.
Ironically, the first major computer in modern times was used to calculate firing solutions for battleship guns. So it's not so much the needs of civilization, but the PRIORITIES of civilization. When you live in a militaristic country run by imperialists, the best thing you can do is try to sell your lab to the military and siphon off some of that defense spending. Which I think these guys ought to do. It shouldn't be that hard to convert this fusion drive into a kind of low-energy fusion weapon, maybe using an explosively-pumped power supply to compress the ring around the fusion target and trigger the reaction. A device that uses, say, a hundred kilograms of explosives as a trigger could yield the equivalent of a hundred tons of TNT. In the modern world, it's easier to beat a sword into a plowsheer than vice versa. If you want to make a bigger plow, what you really need is to convince the warriors that they need a bigger sword.
Is there any danger that this technology could be used to create a fusion bomb without a fissile trigger? I would hate it if such project gets shelved because of fear.
Yes, but an extra guided missile frigate is surely worth a thousand times more than fusion engines - or something... However, I'd say the size of the grant is more a reflection of how much money they need to test the prototype, not how much we'll spend in further development if the device shows lots of promise. Obviously getting a working prototype into orbit will cost several billion dollars, just to cover the R&D and launch.
The other day I was running some numbers for adding a Mars orbit to the mechanism, and there were several pretty good solutions. 284 (71*4) Earth years almost exactly equals 151 Mars years (150.99 or so), with an error of about an hour at the end of the 284 years, and those gears are pretty easy to cut. 37,157 Earth years hits an even number of Mars years even closer, despite the longer time span, accurate to about 0.05 seconds per year, but requires something like a 449 tooth gear. So anyway, to get better orbital data I downloaded the latest and greatest method we use for planetary orbits, VSOP87. As it turns out, VSOP87 is just a computerized way of calculating with a bunch of little gears. A planet's orbital elements are simply the sum of a bunch of terms Q = Q + k1 * COS(k2 + k3*T) where T is time. There's nothing inherently elliptical about it. So the clockwork method lives!!!
It IS a fusion bomb without a fissile trigger. It's just not a very large one (more of a hot plasma fart than an actual explosion). It could, however, be configured to use larger amounts of fusion fuel and produce an energy gain significantly greater than a chemical or electrical trigger, which would be a way of boosting explosive yields above conventional levels but far below that of a "standard" nuclear weapon... say, a "chemo-nuclear" device. I've dabbled with that concept in the past. Don't have the actual numbers in front of me right now, but my feeling is with the right setup it's easily doable. Something like that would pack the punch of a conventional weapon two or three times its size while only being fifty times more expensive and is therefore perfect for Pentagon procurement strategies.