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So they've built a fusion powered rocket engine

Last posted Apr 29, 2013 at 08:21PM EDT. Added Apr 29, 2013 at 03:18PM EDT
21 posts from 14 users

Source:

To power a rocket, the team has devised a system in which a powerful magnetic field causes large metal rings to implode around this plasma, compressing it to a fusion state. The converging rings merge to form a shell that ignites the fusion, but only for a few microseconds. Even though the compression time is very short, enough energy is released from the fusion reactions to quickly heat and ionize the shell. This super-heated, ionized metal is ejected out of the rocket nozzle at a high velocity. This process is repeated every minute or so, propelling the spacecraft.

On a related note, this might be only two years away after all:

Last edited Apr 29, 2013 at 03:19PM EDT
Apr 29, 2013 at 03:18PM EDT
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Even if I don’t understand chemistry and stuff, this is stunning.
I wonder how we’ll be in 20 years.

Apr 29, 2013 at 04:01PM EDT
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I’m skeptical. So far, the researchers have been able to accelerate a field-reversed plasma, but not trap it. Fusion is way off still.

Apr 29, 2013 at 04:16PM EDT
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opspe wrote:

I’m skeptical. So far, the researchers have been able to accelerate a field-reversed plasma, but not trap it. Fusion is way off still.

There are other more pressing issues. They’re going to need an extremely powerful magnet to compress gases to the point where their own charges are negated and their constituent atoms can be close enough to merge. That kind of magnet, while possible to build, will wreck havoc on electronics systems even in short time frames. The fusion tech is the least bit of worry, that kind of required shielding complicates things.

Last edited Apr 29, 2013 at 04:26PM EDT
Apr 29, 2013 at 04:26PM EDT

Sonata Dusk wrote:

There are other more pressing issues. They’re going to need an extremely powerful magnet to compress gases to the point where their own charges are negated and their constituent atoms can be close enough to merge. That kind of magnet, while possible to build, will wreck havoc on electronics systems even in short time frames. The fusion tech is the least bit of worry, that kind of required shielding complicates things.

You might want to check out some more of the source article:

But is this really feasible?

Slough and his colleagues at MSNW think so. They have demonstrated successful lab tests of all portions of the process. Now, the key will be combining each isolated test into a final experiment that produces fusion using this technology, Slough said.

The research team has developed a type of plasma that is encased in its own magnetic field. Nuclear fusion occurs when this plasma is compressed to high pressure with a magnetic field. The team has successfully tested this technique in the lab.

Only a small amount of fusion is needed to power a rocket – a small grain of sand of this material has the same energy content as 1 gallon of rocket fuel.
Apr 29, 2013 at 04:48PM EDT
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Platus wrote:

You might want to check out some more of the source article:

But is this really feasible?

Slough and his colleagues at MSNW think so. They have demonstrated successful lab tests of all portions of the process. Now, the key will be combining each isolated test into a final experiment that produces fusion using this technology, Slough said.

The research team has developed a type of plasma that is encased in its own magnetic field. Nuclear fusion occurs when this plasma is compressed to high pressure with a magnetic field. The team has successfully tested this technique in the lab.

Only a small amount of fusion is needed to power a rocket – a small grain of sand of this material has the same energy content as 1 gallon of rocket fuel.

I wasn’t referring to that. The kind of energy required to power that strong of an electromagnet would need a rather large reactor. More than what you’re going to get from a solar generator, and WAY more than what you’ll get from a radio-decay reactor. Add a power plant to this spacecraft.

Then you’ll need to properly shield electronic materials to prevent them from being damaged – there are some buffering techniques we currently use, but the equipment is kinda large.

I’m not saying the tech isn’t possible – it clearly is. It’s just that when new technologies arrive, they tend to spawn even more engineering issues. It would take years just to assemble this kind of spacecraft in orbit (because you’re definitely not going to find a large enough rocket to take it up fully assembled). I don’t work for NASA (yet [one day, Crazy, one day]), so I don’t know what else they have in the works – but I really doubt we’ll have even a good concept design within the five-to-ten years, much less two.

Apr 29, 2013 at 04:58PM EDT

The main problem with fusion is the amount of energy that is needed to be put in to get a favorable result with limited damage. Currently, we do not possess the technology to generate the conditions needed to generate a fusion reaction. The only practical solution I can foresee is ion propelled spacecraft powered by liquid fluorine thorium reactors, a cheap and highly efficient solution.

@Crazy
If you need a power plant then just use Thorium, it has a high energy value that far exceeds Plutonium and Uranium. It is also low pressured and operates around an optimal 400o C for fission within a relatively small system.

Last edited Apr 29, 2013 at 05:10PM EDT
Apr 29, 2013 at 05:01PM EDT
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Obviously, there are a LOT of things to work out here. Still, PROGRESS!

Once we have nuclear powered rockets, we can switch to nuclear energy entirely. The only ecological difficulty is what to do with the nuclear waste--OH WAIT; WE LAUNCH IT INTO SPACE.

Apr 29, 2013 at 05:03PM EDT
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Space already has enough radiation as is… why add more, Serious?
Imagine if mutated aliens invaded us because they’re pissed at us sending radiation out there… what would we do?

Last edited Apr 29, 2013 at 05:10PM EDT
Apr 29, 2013 at 05:07PM EDT
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@CrazyMoon:

You’re entirely correct, I hadn’t considered that.


@Platus:

I read the article, along with the researchers’ website and stuff. They said the best fluid (i.e. classical) analgoue for a field-reversed plasma is a vortex ring. The self-contained air convection causes the characteristic toroidal shape:

A field-reversed plasma has a similar, but with magnetic field lines instead of air flow. The plasma behaves like a series of vortex rings aligned along the z axis inside a cylindrical coil, to form a prolate spheroid.

The cylindrical coil needs to be generating an axial magnetic field. The plasma is contained by an internal magnetic field, similar to a vortex ring.

(Also I work in a plasma physics lab.)


@Tim:

Thorium rectors, well, require thorium, which is not easy to come by. And there’s the waste problem. You can always jettison radioactive waste into space, but it’s not nice to have floating around in the atmosphere.


@Mark:

There’s a huge difference between radiation and radioactive material. Space contains huge amounts of radiation, but very VERY little radioactive material.

Last edited Apr 29, 2013 at 05:15PM EDT
Apr 29, 2013 at 05:12PM EDT
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Although we’re a very long way away from proper sustainable fusion power, it appears we’ve taken the first step, which is ecstatically exciting. The potential benefit of this could be massive!

Last edited Apr 29, 2013 at 05:34PM EDT
Apr 29, 2013 at 05:32PM EDT
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@Tim
I don’t think you’re seeing the problem here: reactors tend to be, well, large. You obviously don’t need one that’s sized to power a city, but it’s definitely going to be bigger than anything we’ve ever used in space before. One of the reasons we use RTGs for distant spacecraft, and solar-films for orbiters is because they’re compact and of low mass. Reactors are neither of these things.

Outside of that, thorium reactors use a system that allows gravity to take care of pesky density issues. In a freefall environment, that system isn’t applicable. You can simulate it using pumps, but it’s not as efficient. Then there’s the danger issues – if there’s a leak, that material isn’t going to cool off nearly as quickly as it would if there were an atmosphere around it – if any of it spews out and comes into contact with the hull..

Last edited Apr 29, 2013 at 05:39PM EDT
Apr 29, 2013 at 05:37PM EDT

“Thorium, which is not easy to come by.”
Thorium is approximately three to four times as abundant as uranium in the earth’s crust. In addition, thorium generally is present in higher concentrations (2-10%) by weight than uranium (0.1-1%).

Thorium is also commonly found with rare earth metals that we need to develop future technology.
The issue of finding thorium is not a concern. I am willing to acknowledge that the issue of waste can be a concern but it is relatively low.

Also the Thorium fission cycle can last approximately a decade before the fuel needs to be changed to remove harmful byproducts, a fairly reasonable time span for traveling across the solar system.

@Crazy
LFTRs were designed for aircrafts; to be lightweight, and compact. Back in the 1950’s the government contracted the Oak Ridge National Laboratory to create a new reactor for military aviation. I do acknowledge that modifications are needed for outer space but they are not monumental. In fact Kirk Sorensen an aerospace engineer who worked at NASA, stumbled across Thorium while doing research on how to power a lunar community, so it has applications in low gravity and possibly zero gravity. The issue of leaks is also a valid concern but due to it’s low pressure design, the risk of leaks of the liquid fuel is greatly reduced.

Last edited Apr 29, 2013 at 06:11PM EDT
Apr 29, 2013 at 05:40PM EDT
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@Crazy

Oh, you were going on about the “two years” thing. That was a joke – the image I have there is from Bakc to the Future, whre Doc Brown comes back from 2015 (i.e. two years from now) with a fusion reactor running his car. I was going for a quip in the same spirit as the “where’s my hoverboard” stuff you hear sometimes. I don’t honestly believe that we’ll have portable fusion reactors up and running in two years.

Apr 29, 2013 at 07:03PM EDT
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Fridge wrote:

Although we’re a very long way away from proper sustainable fusion power, it appears we’ve taken the first step, which is ecstatically exciting. The potential benefit of this could be massive!

Yeah. All these…

Benefits.

Apr 29, 2013 at 07:06PM EDT
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What I see when I read this thread:

Science the science to compress the sciencium (which may or may not be rare) using the science array into a fusible science that is then ejected from the back of the rocket. But wait, the Science Principle clearly shows that sciencing the science into a compressed state to trigger science is impossible using our current level of science. It’ll be at least fifty years until science can advance enough for the science to science.

(I thought we were still at the “dump more power into getting it to fuse than we get out of the actual fusion” stage of fusion power.)

Apr 29, 2013 at 07:12PM EDT
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@The skepticism

Although the limitations are obvious, one must still admit that this is a pretty good step forward.

There are many more steps to make along the way before we can efficiently use fusion technology in our everyday lives but at least this is progress.

Fusion reactors wont be in our time machines by 2015 but it just may be, sometime while our generation is still alive

Apr 29, 2013 at 07:55PM EDT
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Skeletor-sm

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