Nuclear fusion for space propulsion

If this EmDrive works out we are on our way.

www.digitaltrends.com...

originally posted by: DonVoigt
I don't know enough about this myself to know if it is realistic. So I'm posing this question to the ATS community to learn more. It is to my understanding that a nuclear power plant is like essentially a high pressure steam engine in where high pressure steam is sent through a turbine which spins electrical generators. Well what if you take the spinning turbines out of the equation and have straight pipes coming out of the back of the spacecraft using that high pressure steam as the propulsion system for the space craft. Would that or would that not be a workable system to propel you through space.

It would not be, as steam requires water.. Think about how much water is required, stored on a spaceship.

However, what I am wondering is what other uses of nuclear power could be used on spaceships beyond electricity and so on?

originally posted by: Bluntone22
a reply to: DonVoigt


That would work perfectly.

But how much water do ya think it would take to get to mars? If you need to carry that much water you might as well carry a more efficient fuel.

I don't think that steam from a nuclear reactor has enough lift to get the spaceship out of the gravitational pull of the Earth, beyond the problems with water storage requirements.

a reply to: Quetzalcoatl14

I agree that it would not be enough to get you out of the atmosphere, gravity and drag would inhibit that, however in space there is no gravity or drag

originally posted by: DonVoigt
a reply to: Quetzalcoatl14

I agree that it would not be enough to get you out of the atmosphere, gravity and drag would inhibit that, however in space there is no gravity or drag

so then you mean once out in space. Still, the amount of water you would need would be space/weight prohibitive.

a reply to: DonVoigt

There is gravity on everything everywhere....technically a star a billion light years still exerts 'some' force on you, technically virtually zero to a rather large point but it still exerts some force.

Drag could still be a factor as small particles traveling the opposite way hit your craft it will make a very small change due to impact.

The numbers normally are very low but over a long distance its going to cause problems.

a reply to: DonVoigt

Here is the Wikipedia entry on electric powered space flight: Electrically powered spacecraft propulsion.

Not all of them have been actualized as a prototype. The Hull drive has though. They are going to add a small one to a CubeSat to test it out. As noted in the entry, this type of drive is nice for puttering around short distances (like the solar system). For interstellar travel another mode of movement will be needed (at which point you would really need mass reduction).

Have fun making your brain hurt thinking of the impossible!

Well, how about "slow" fusion?

Instead of detonating all the fuel at once in a fusion explosion, how about we just fuse a little bit of material at a time and let it stream out the back of the rocket? Kind of like the way a bomb and a chemical rocket are basically the same things but detonated differently. Blast the fuel out the back (maybe even from a web of smaller guns so it won't build to critical mass too early, hit it with a massive laser, and "burn" it, rather than detonate it. You wouldn't have to carry all that water.

My other plan is to create a "phantom mass" at the front of the spacecraft by lens focusing gravity waves so that the spacecraft continuously "falls" toward it. The problems with that one, of course, are fairly obvious, including carrying a power plant large and powerful enough to generate and focus gravity waves.

Essentially, you are describing a fission fragment rocket of which there are several designs. There have been various concepts to produce a reactor based rocket since the 60's . The simplest being a reactor pile with the coolant vented to a rocket nozzle.
Fission Fragment
More amazing stuff here
Nuclear thermal

PSS and the Princeton Plasma Physics Lab are collaborating on a new fusion technology. Direct Fusion Drive is a a revolutionary direct-drive, fusion-powered rocket engine. Compact and clean-burning, each 1-10 MW Direct Fusion Drive (DFD) engine can produce both power and thrust and high specific power. Power and propulsion are both generated from a single engine, which shortens trip times and increases capability for a wide variety of space missions: robotic missions to the outer planets, human missions to the moon or Mars, missions to interstellar space.

DFD is based on the Princeton Field-Reversed Configuration reactor (PFRC), a technology developed by Dr. Sam Cohen of PPPL. The reactor employs a unique “odd-parity” RF heating method, producing a steady-state, closed-field configuration with a highly efficient current drive. The PFRC-2 experimental machine is currently in operation at PPPL, a plasma pulse is shown below.

Princeton Satellite Systems - Fusion (picture of plasma pulse!)

In my nuclear fusion travels I ran across an item returned from the search. Instead of building a huge reactor like ITER to provided hundreds of megawatts of power they are going to make less power. That means the reactor size shrinks. It is even smaller than Lockheed's compact fusion reactor (what I was searching for).

More info...

The aim for the fusion drives is to get about 1 kilowatt of power per 2.2 lbs. (1 kilogram) of mass. A 10-megawatt fusion rocket would therefore weigh about 11 tons (10 metric tons).

"It would probably be 1.5 meters [4.9 feet] in diameter and 4 to 8 meters [13 to 26 feet] long," Paluszek said.

Nuclear fusion requires extremely high temperatures and pressures to force atoms to fuse, a process that converts some of the mass of the atoms into energy. The fusion reactors that Princeton Satellite Systems is developing uses low-frequency radio waves to heat a mix of deuterium and helium-3, and magnetic fields to confine the resulting plasma in a ring.

space.com - Will Mini Fusion Rockets Provide Spaceflight's Next Big Leap?

The thing looks like a jet engine instead of the donut shaped fusion reactors under development. They will confine the plasma, heat it up, create a aneutronic fusion reaction, exhaust some out through a nozzle (BASS was right! Should never doubt that guy), keep the rest hot for adding more fuel.

Problem is nobody has made a fusion reactor let alone one that is hot enough to make an aneutronic reaction. And helium-3 is also a moon dream at the moment unless made in a fission reactor.

The great news is that it is being worked on! Princeton Sat. Systems want to demo in 2019 or 2020.

This idea seems to have caught the media's attention!

Princeton Satellite Systems is working on a small-scale fusion reactor that would only be 1.5 meters across and 4-8 meters long (4.9 by 13-26 feet). A experimental fusion power plant might cost $20 billion, but the smaller version being developed by Princeton Satellite Systems should only cost about $20 million. NASA seems interested in the idea, too. It’s given Princeton Satellite Systems three grants so far to pursue its research.

ExtremeTech.com - NASA-Funded Startup to Build Fusion-Powered Rockets.

- and -

ScientificAmerican.com - Could Tiny Fusion Rockets Revolutionize Spaceflight?

The SA article is nearly a word-for-word reprint of the space.com (even has the same quotes).

But I think it is the idea that counts! Should this actually be realized we would truly be bound for the stars! Or at least be capable of saving humankind should some astronomical event trigger an ELE.