Author Topic: Boeing obtains fusion based jet engine patent.  (Read 48574 times)

Offline M_Puckett

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Boeing obtains fusion based jet engine patent.
« on: 07/09/2015 12:23 am »
Details are sketchy but here is a link to a story and the patent application:

http://www.businessinsider.com/boeing-just-patented-a-jet-engine-powered-by-lasers-and-nuclear-explosions-2015-7

Offline sanman

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Re: Boeing obtains fusion based jet engine patent.
« Reply #1 on: 07/09/2015 02:04 am »
Hmm, so jet engine - not a rocket - but maybe it could be used for both.

Is this based on any particular recent work, or are they just moving to patent some concepts they've had for a long time?





Looking beyond 7x7, maybe they could use this to launch an 8xx designation.
I don't think I'd want to book a wing-seat though.

Thunderbirds Are Go!

« Last Edit: 07/09/2015 02:12 am by sanman »

Offline Stan-1967

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Re: Boeing obtains fusion based jet engine patent.
« Reply #2 on: 07/09/2015 02:21 am »
Well, I know one of those "A"'s in NASA is for aeronautics, but this is a spaceflight board, but dangit the concept is too cool and interesting to not comment on.

My takeaways from the article:

1.  Business insiders commenters are poorly informed people.  I tried to set a few straight.
2.  Boeing is probably responding to LM's polyfusion black op's  announcement a few months back.  They have to stay edgy and appear to be leading edge and all that stuff.
3.  I too would not want a window seat if thing was hanging off a wing pylon outside seat 18A.   However I think any craft using this will have an airframe that is not a tube with wings like what we all are familiar with.
4.  This scheme uses the atmosphere as its primary reaction mass, the D-T ( I presume ) reaction is used to heat the air.   Therefore this invention does not have spaceflight applications that are not already  dicussed for pulse detonation schemes like project orion.  Might make a good atmospheric probe of a gas giant or Titan maybe?
5. Boeing is picking big fight with environmentalists and a public that is scared of anything nuclear.  Good luck to them



Offline Stan-1967

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Re: Boeing obtains fusion based jet engine patent.
« Reply #3 on: 07/09/2015 02:25 am »
I can just hear the chorus of contrail/chemtrail freaks warming up their voices to sing about this idea. 

Offline go4mars

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Re: Boeing obtains fusion based jet engine patent.
« Reply #4 on: 07/09/2015 02:34 am »
This could be welcome competition to the extremely high altitude supersonic intercontinental electric jet SpaceX is conceptualizing through it's current iteration; hyperloop competitions. 

The more the merrier says I!
« Last Edit: 07/09/2015 02:35 am by go4mars »
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Offline Stan-1967

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Re: Boeing obtains fusion based jet engine patent.
« Reply #5 on: 07/09/2015 03:10 am »
How would this be reduced to practice in a real aircraft?   I see the following problems

1.  The weight of the neutron absorber is going to be a big penalty.   Too thin and not enough heat gets generated, & radiation will kill craft occupants.   Too thick it will literally weight tons & reduce performance. 

1a.   Even with the U shield, neutron absorbtion is going to make the entire engine, and likely much of the airframe radioactive.   How will this be maintained by ground crew exactly?

2.  This engine will operate in pulse mode, so how will the design accommodate dampening vibrations? ( which aircraft just love ).   I just don't see a big heavy system of springs and dampers

3. Thermodynamics of the cycle would ideally heat all the air mass somewhat evenly so it can expand out of the nozzle.  How will this work in reality?   The fusion ignition temperautre is tens of millions of degrees at its center, but how quickly can it heat the air bypassed into the thrust chamber before it exits? 

4.  Weapons proliferation.   That U-238 shield will absorb neutrons to make Plutonium 239.  These engines are going to be generating Megawats of power per engine, that is going be accompanied by lots of neutrons,  so I think this is going to be a significant problem. 

Offline ChrisWilson68

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Re: Boeing obtains fusion based jet engine patent.
« Reply #6 on: 07/09/2015 04:42 am »
This could be welcome competition to the extremely high altitude supersonic intercontinental electric jet SpaceX is conceptualizing through it's current iteration; hyperloop competitions.

You really think there's a secret agenda behind the hyperloop competition?  You think it's a cover to work on high-altitude electric aircraft?

That makes no sense.  If Musk wanted a competition to work on high-altitude electric aircraft, he would simply say that's what he wants.  It's no more or less crazy an idea than hyperloop.  There's no reason whatsoever to say it's about hyperloop if it's actually about aircraft, and plenty of reasons not to, starting with the fact that having a competition for something related but not the same as what you actually want is never going to be as effective as having a competition for what you already want.

Offline sanman

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Re: Boeing obtains fusion based jet engine patent.
« Reply #7 on: 07/09/2015 06:04 am »
Meanwhile, even ignoring the weight challenges and radiation hazard to passengers, can this design realistically generate power from this method?

Will the exhaust itself be appreciably radioactive? I've been told that if you want to try nuclear-powered thrust here on Earth, then your fuel can't be the "working fluid" or propellant like in the case of a chemical rocket - ie. nuclear fuel has to be kept isolated from the exhaust stream to avoid releasing it into the environment. So that makes it too difficult.

So if this is a fusion-approach, then presumably you're avoiding any heavy isotope products in the output, and all you have to worry about is the neutron and gamma radiation?

Maybe it could work for an unmanned transport craft with a carbon fiber airframe?


Offline hkultala

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Re: Boeing obtains fusion based jet engine patent.
« Reply #8 on: 07/09/2015 06:12 am »
There is an image which says "coated with a fissile material like U-238".

AFAIK U-238 is not fissile material.

Offline Asteroza

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Re: Boeing obtains fusion based jet engine patent.
« Reply #9 on: 07/09/2015 06:21 am »
Here's a link for viewing the US patent 9,068,562

http://pdfpiw.uspto.gov/.piw?Docid=09068562

So I was reminded of the Ghost Ship design, which operates on similar properties.

http://www.icarusinterstellar.org/project-icarus-workshop-update-34-the-ghost-ship/

Ghost Ship uses direct neutron absorption to operate a nuclear pumped laser methodology, rather than Boeing going for thermal power extraction via turbogenerator to drive electric lasers (and perhaps a turbofan?).


As someone else mentioned, the Boeing concept is somewhat Orion-lite.

Using a intermediate coolant allows using a turbogenerator for more steady state power extraction, which may help with a fast ignition type ICF arrangement with primary pulse and the followup pulse as those are two different events.

Offline Star One

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Re: Boeing obtains fusion based jet engine patent.
« Reply #10 on: 07/09/2015 06:22 am »
I saw this but didn't post it here as I couldn't see that it had any spaceflight applications?

Offline sanman

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Re: Boeing obtains fusion based jet engine patent.
« Reply #11 on: 07/09/2015 06:37 am »
Could it be adapted for spaceflight somehow? Maybe for some kind of hypersonic SSTO type of vehicle?

Offline Generic Username

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Re: Boeing obtains fusion based jet engine patent.
« Reply #12 on: 07/09/2015 06:45 am »
I saw this but didn't post it here as I couldn't see that it had any spaceflight applications?
*IF* it works, I can think of a few spacecraft applications:
1) Main engines on a first stage carrier aircraft like Stratolaunch
2) Flyback engines on a first stage rocket booster
3) Flyback engines on a spaceplane (assuming that these things are lighter than regular jets & fuel)
4) Long duration high altitude drones to replace cel towers and comsats and the like
5) Aircraft for Mars, Venus, Jupiter, Titan
6) Ground-based power generation on Mars... use 'em as turbogenerators
7) Ground based power generation on Earth for laser launch systems
8) Probably not inconceivable to convert them into the equivalent of a solid core nuclear thermal rocket. NERVA-like performance with presumably much less radiation
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Offline john smith 19

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Re: Boeing obtains fusion based jet engine patent.
« Reply #13 on: 07/09/2015 08:04 am »
Details are sketchy but here is a link to a story and the patent application:

http://www.businessinsider.com/boeing-just-patented-a-jet-engine-powered-by-lasers-and-nuclear-explosions-2015-7
So let's see if I have this right.

Boeing is planning to reduce the contents of the National Ignition Facility to the size of an engine pod, make the reaction chamber partly out of U235 and use the neutrons from the fusion to trigger fission heating which will be tapped by a power plant to generate the electricity for the lasers.

Say hello to the NIF
https://str.llnl.gov/etr/pdfs/12_94.2.pdf

It is 85m wide and 200 m long. Or for American readers that's 250 feet wide  x 600 feet long.

And it still didn't achieve as much energy output as the laser light put into the capsule.

So Boeing will shrink this to the size of a turbojet pod and hang it on a wing.

For those who've been anywhere near a cattle or dairy farm there's a 1 word description of this patent, but I'll settle for a simple ROTFLMFAO.

Thanks for putting a real chuckle on my day .  :)  :)
MCT ITS BFR SS. The worlds first Methane fueled FFSC engined CFRP SS structure A380 sized aerospaceplane tail sitter capable of Earth & Mars atmospheric flight.First flight to Mars by end of 2022 TBC. T&C apply. Trust nothing. Run your own #s "Extraordinary claims require extraordinary proof" R. Simberg."Competitve" means cheaper ¬cheap SCramjet proposed 1956. First +ve thrust 2004. US R&D spend to date > $10Bn. #deployed designs. Zero.

Offline CameronD

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Re: Boeing obtains fusion based jet engine patent.
« Reply #14 on: 07/09/2015 08:07 am »
This could be welcome competition to the extremely high altitude supersonic intercontinental electric jet SpaceX is conceptualizing through it's current iteration; hyperloop competitions.

You really think there's a secret agenda behind the hyperloop competition?  You think it's a cover to work on high-altitude electric aircraft?

That makes no sense.  If Musk wanted a competition to work on high-altitude electric aircraft, he would simply say that's what he wants.  It's no more or less crazy an idea than hyperloop.  There's no reason whatsoever to say it's about hyperloop if it's actually about aircraft, and plenty of reasons not to, starting with the fact that having a competition for something related but not the same as what you actually want is never going to be as effective as having a competition for what you already want.

I disagree.  Musk is an engineer who thinks outside the box and ISTM that the people he wants working for him need to think outside the box also.  As an engineer whose full-time job is doing stuff you don't learn in college, I know from personal experience that the best people to work on my projects are those who are really, really good at getting their heads around concepts no-one else has thought of before - whatever that may be.

Maybe aircraft isn't enough of a brain-stretch for Musk.. but Hyperloop certainly is.  And IMHO whoever wins his approval in that arena is sure to become (given the right environment) a better-than-first-class engineer.

If there's any 'secret agenda', I'd say it's to recruit prime candidates for his work-force... whether they accept or not is something else entirely.

With sufficient thrust, pigs fly just fine - however, this is not necessarily a good idea. It is hard to be sure where they are
going to land, and it could be dangerous sitting under them as they fly overhead.

Offline STS-200

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Re: Boeing obtains fusion based jet engine patent.
« Reply #15 on: 07/09/2015 01:50 pm »
There is an image which says "coated with a fissile material like U-238".

AFAIK U-238 is not fissile material.

It is when hit by high energy neutrons, like those produced in various types of fusion reactor.
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Offline watermod

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Re: Boeing obtains fusion based jet engine patent.
« Reply #16 on: 07/09/2015 03:00 pm »
The Convair NB-36H was a bomber that carried a nuclear reactor. It was also known as the "Crusader".[1] It was created for the Aircraft Nuclear Propulsion program, or the ANP, to show the feasibility of a nuclear-powered bomber.
https://en.wikipedia.org/wiki/Convair_NB-36H

Offline sanman

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Re: Boeing obtains fusion based jet engine patent.
« Reply #17 on: 07/09/2015 04:56 pm »
There is an image which says "coated with a fissile material like U-238".

AFAIK U-238 is not fissile material.

It is when hit by high energy neutrons, like those produced in various types of fusion reactor.

I think the operative word here may be "fertile" rather than "fissile". Fissile means it can sustain a chain reaction, while fertile merely means it can absorb neutrons to decay into other elements while releasing energy in the process.

https://en.wikipedia.org/wiki/Uranium-238

Quote
Uranium-238 (238U or U-238) is the most common isotope of uranium found in nature. It is not fissile, but is a fertile material: it can capture a slow neutron and after two beta decays become fissile plutonium-239. 238U is fissionable by fast neutrons, but cannot support a chain reaction because inelastic scattering reduces neutron energy below the range where fast fission of one or more next-generation nuclei is probable.

So as you've said, the fusion from the lasers is what's providing the supply of neutrons to keep things from fizzling out. Can this design then be considered a pulsed variant of the Energy Amplifier, which is a sub-critical reactor?

https://en.wikipedia.org/wiki/Energy_amplifier
« Last Edit: 07/09/2015 05:00 pm by sanman »

Offline Lobo

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Re: Boeing obtains fusion based jet engine patent.
« Reply #18 on: 07/09/2015 05:32 pm »
There is an image which says "coated with a fissile material like U-238".

AFAIK U-238 is not fissile material.

Yea, it'd have to be U-235 or Pl-239 (or U-233 bred from thorium).

Aren't those the only 3 actually fissile materials?

Offline Lobo

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Re: Boeing obtains fusion based jet engine patent.
« Reply #19 on: 07/09/2015 05:35 pm »
There is an image which says "coated with a fissile material like U-238".

AFAIK U-238 is not fissile material.

It is when hit by high energy neutrons, like those produced in various types of fusion reactor.

But doesn't it become Pl-239 then?

Offline go4mars

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Re: Boeing obtains fusion based jet engine patent.
« Reply #20 on: 07/09/2015 05:48 pm »
You really think there's a secret agenda behind the hyperloop competition?  You think it's a cover to work on high-altitude electric aircraft?
I replied on a hyperloop thread:

http://forum.nasaspaceflight.com/index.php?topic=37994.msg1402232#msg1402232
« Last Edit: 07/09/2015 06:01 pm by go4mars »
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Offline ArbitraryConstant

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Re: Boeing obtains fusion based jet engine patent.
« Reply #21 on: 07/09/2015 06:04 pm »
There is an image which says "coated with a fissile material like U-238".

AFAIK U-238 is not fissile material.
Agreed. Not super sure where they're going with this? Fast neutrons from fusion reactions would fission U238 (it can absorb neutrons to become Pu-239, but the cross section for that at fusion neutron energies ought to be pretty small). As you point out that's not a chain reaction. It would result in extra energy, but also fission products and afterheat, two big problems with fission reactors.

Offline chipguy

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Re: Boeing obtains fusion based jet engine patent.
« Reply #22 on: 07/09/2015 10:56 pm »
There is an image which says "coated with a fissile material like U-238".

AFAIK U-238 is not fissile material.

It is when hit by high energy neutrons, like those produced in various types of fusion reactor.

But doesn't it become Pl-239 then?

Slow neutrons convert U238 into Pu. Very fast neutrons simply fission it. Fission
itself doesn't release fast enough neutrons to sustain a chain reaction in U238 so
it isn't appropriate to call it fissile.

DT fusion releases most of its energy as high energy neutrons. Great for boosting
nuke primaries but very, very bad for lightweight propulsion.

Sounds to me like buck rogers PR rather than anything even half serious.

Offline sanman

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Re: Boeing obtains fusion based jet engine patent.
« Reply #23 on: 07/10/2015 03:16 am »
I saw this but didn't post it here as I couldn't see that it had any spaceflight applications?
*IF* it works, I can think of a few spacecraft applications:
1) Main engines on a first stage carrier aircraft like Stratolaunch
2) Flyback engines on a first stage rocket booster
3) Flyback engines on a spaceplane (assuming that these things are lighter than regular jets & fuel)
4) Long duration high altitude drones to replace cel towers and comsats and the like
5) Aircraft for Mars, Venus, Jupiter, Titan
6) Ground-based power generation on Mars... use 'em as turbogenerators
7) Ground based power generation on Earth for laser launch systems
8) Probably not inconceivable to convert them into the equivalent of a solid core nuclear thermal rocket. NERVA-like performance with presumably much less radiation


Regarding the Stratolaunch idea - the wingspan of the Stratolaunch carrier aircraft is 117m. So if you had some comparably large-wingspan aircraft with the engines mounted on the very ends of the wingtips, that separation distance from the main fuselage could considerably reduce its exposure to the radiation coming from them.

So even if the engines become more radioactive over time, they could be treated as modules to be replaced after some period.




Offline Generic Username

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Re: Boeing obtains fusion based jet engine patent.
« Reply #24 on: 07/10/2015 04:17 pm »

Regarding the Stratolaunch idea - the wingspan of the Stratolaunch carrier aircraft is 117m. So if you had some comparably large-wingspan aircraft with the engines mounted on the very ends of the wingtips, that separation distance from the main fuselage could considerably reduce its exposure to the radiation coming from them.

If radiation is a concern, then you're generally better off putting the reactors *way* back in the tail, and using the fuselage not only to gain you distance but to use the structure as shielding. This is much more difficult when using the wing, since the wing is thin and flexes. What might be fifty meters of shielding on the ground becomes fifty meters of clear air once the wing flexes upwards.
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Offline francesco nicoli

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Re: Boeing obtains fusion based jet engine patent.
« Reply #25 on: 07/10/2015 04:38 pm »
I can't stop thinking "I want to fit it on a SABRE skylon engine" even if I know makes no sense and being an economist does not help too much with engineering.  air-breathing fusion roket engine anyone? :)

Offline DanielW

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Re: Boeing obtains fusion based jet engine patent.
« Reply #26 on: 07/10/2015 05:26 pm »
Here is the actual patent application. http://patents.justia.com/patent/9068562

It should be noted that this patent is NOT for a jet engine. The patent is for a nuclear thermal rocket with a laser ingition neutron source. It will not function out side of a vacuum.

From my reading it works like this

1) a hollow pellet is injected into a parabolic or magnetic nozzeled thrust chamber.
2) When it gets to the focal point of the chamber, a laser vaporizes the pellet and contents.
3) The shape of the chamber / nozzel produce thrust.

That is the minimum case and not terribly useful but they wanted to cover it in the patent. There are a few add-ons.

2.1) the pellet contains deuterium and tritium. Some of which fuse providing a bit of an energy boost. Just a bit more thrust for energy in, but NOT to the break even point.
3.1) In the case where fusion is happening, the parabolic reflector is coated with U-238. This absorbs some of the high energy neutrons and splits releasing further energy as excess heat.
3.2) This excess heat expands a coolant that then powers a turbine and creates some or all of the power needed for the ignition lasers.
3.3) The above coolant (possibly hydrogen) can be used in an open loop fashion and be exhausted through ports in the parabolic reflector to produce yet more thrust.

The patent layers on each step one by one so they can still claim rights to a partial solution. But the whole idea is a pulsed nuclear U-238 reactor sustained by the Neutrons from a small fusion ignition provided by lasers. In this configuration nearly all the energy is from Fission of the U-238 and a negiligble amount comes from the fusion.

The thrust is primarily from the exhaust of hydrogen coolant with some additional provided by the vaporized pellet. (My take on it)

« Last Edit: 07/10/2015 05:56 pm by DanielW »

Offline Bob Shaw

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Re: Boeing obtains fusion based jet engine patent.
« Reply #27 on: 07/10/2015 05:55 pm »
Regarding the Stratolaunch idea - the wingspan of the Stratolaunch carrier aircraft is 117m. So if you had some comparably large-wingspan aircraft with the engines mounted on the very ends of the wingtips, that separation distance from the main fuselage could considerably reduce its exposure to the radiation coming from them.

So even if the engines become more radioactive over time, they could be treated as modules to be replaced after some period.


The USAF tried this back in the 50s, but never let their reactor go critical. It was a fairly Strangelovian idea, about as rational as PLUTO!

The place to use such engines is in deep space, full stop.

Offline Bob Shaw

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Re: Boeing obtains fusion based jet engine patent.
« Reply #28 on: 07/10/2015 05:58 pm »
This could be welcome competition to the extremely high altitude supersonic intercontinental electric jet SpaceX is conceptualizing through it's current iteration; hyperloop competitions. 

The more the merrier says I!

I thought Hyperloop was extremely *low* altitude?

Offline DanielW

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Re: Boeing obtains fusion based jet engine patent.
« Reply #29 on: 07/10/2015 06:01 pm »
As the background info in the patent application refers to ISP trades for ion engines, I assume that this engine is intended for faster transit times to the desired orbital slot and for long term deep space missions.

I personally think it is an ingenious hybrid.

Offline Stan-1967

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Re: Boeing obtains fusion based jet engine patent.
« Reply #30 on: 07/10/2015 06:32 pm »
Here is the actual patent application. http://patents.justia.com/patent/9068562

It should be noted that this patent is NOT for a jet engine. The patent is for a nuclear thermal rocket with a laser ingition neutron source. It will not function out side of a vacuum.

From my reading it works like this

1) a hollow pellet is injected into a parabolic or magnetic nozzeled thrust chamber.
2) When it gets to the focal point of the chamber, a laser vaporizes the pellet and contents.
3) The shape of the chamber / nozzel produce thrust.

That is the minimum case and not terribly useful but they wanted to cover it in the patent. There are a few add-ons.

2.1) the pellet contains deuterium and tritium. Some of which fuse providing a bit of an energy boost. Just a bit more thrust for energy in, but NOT to the break even point.
3.1) In the case where fusion is happening, the parabolic reflector is coated with U-238. This absorbs some of the high energy neutrons and splits releasing further energy as excess heat.
3.2) This excess heat expands a coolant that then powers a turbine and creates some or all of the power needed for the ignition lasers.
3.3) The above coolant (possibly hydrogen) can be used in an open loop fashion and be exhausted through ports in the parabolic reflector to produce yet more thrust.

The patent layers on each step one by one so they can still claim rights to a partial solution. But the whole idea is a pulsed nuclear U-238 reactor sustained by the Neutrons from a small fusion ignition provided by lasers. In this configuration nearly all the energy is from Fission of the U-238 and a negiligble amount comes from the fusion.

The thrust is primarily from the exhaust of hydrogen coolant with some additional provided by the vaporized pellet. (My take on it)


Your link to the patent show it dated to Oct. 2012.  The business insider line shows a patent date of June 30, 2015.   The newer date has a "B1" extension, so is this then additional claims under the initial patent?

The diagrams in the Business Insider link, and the Youtube link sure look like an airbreathing engine, why else the intake?  For space applications it does seem interesting if you can run the turbine on a closed loop closed cycle, or "near" close loop if you wanted a temporary thrust boost. 

Offline DanielW

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Re: Boeing obtains fusion based jet engine patent.
« Reply #31 on: 07/10/2015 07:22 pm »
Here is the actual patent application. http://patents.justia.com/patent/9068562

It should be noted that this patent is NOT for a jet engine. The patent is for a nuclear thermal rocket with a laser ingition neutron source. It will not function out side of a vacuum.

From my reading it works like this

1) a hollow pellet is injected into a parabolic or magnetic nozzeled thrust chamber.
2) When it gets to the focal point of the chamber, a laser vaporizes the pellet and contents.
3) The shape of the chamber / nozzel produce thrust.

That is the minimum case and not terribly useful but they wanted to cover it in the patent. There are a few add-ons.

2.1) the pellet contains deuterium and tritium. Some of which fuse providing a bit of an energy boost. Just a bit more thrust for energy in, but NOT to the break even point.
3.1) In the case where fusion is happening, the parabolic reflector is coated with U-238. This absorbs some of the high energy neutrons and splits releasing further energy as excess heat.
3.2) This excess heat expands a coolant that then powers a turbine and creates some or all of the power needed for the ignition lasers.
3.3) The above coolant (possibly hydrogen) can be used in an open loop fashion and be exhausted through ports in the parabolic reflector to produce yet more thrust.

The patent layers on each step one by one so they can still claim rights to a partial solution. But the whole idea is a pulsed nuclear U-238 reactor sustained by the Neutrons from a small fusion ignition provided by lasers. In this configuration nearly all the energy is from Fission of the U-238 and a negiligble amount comes from the fusion.

The thrust is primarily from the exhaust of hydrogen coolant with some additional provided by the vaporized pellet. (My take on it)


Your link to the patent show it dated to Oct. 2012.  The business insider line shows a patent date of June 30, 2015.   The newer date has a "B1" extension, so is this then additional claims under the initial patent?

The diagrams in the Business Insider link, and the Youtube link sure look like an airbreathing engine, why else the intake?  For space applications it does seem interesting if you can run the turbine on a closed loop closed cycle, or "near" close loop if you wanted a temporary thrust boost.

I am not sure what the B1 means but the date discrepancy is merely the application date vs the issue date. Scroll to the end of the page for the relevant dates.

Quote
Patent History
Patent number: 9068562
Type: Grant
Filed: Oct 05, 2012
Issued: Jun 30, 2015
Assignee: The Boeing Company (Chicago, IL)
Inventors: Robert J. Budica (Laguna Hills, CA), James S. Herzberg (Long Beach, CA), Frank O. Chandler (Huntington Beach, CA)
Primary Examiner: Phutthiwat Wongwian
Assistant Examiner: William Breazeal
Application Serial: 13/645,816

Offline RonM

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Re: Boeing obtains fusion based jet engine patent.
« Reply #32 on: 07/10/2015 07:24 pm »
Here is a PDF version of the patent.

Offline DanielW

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Re: Boeing obtains fusion based jet engine patent.
« Reply #33 on: 07/10/2015 08:36 pm »
Here is a PDF version of the patent.

Thanks for that. My link did not have the graphics. That makes it plain that this is a rocket engine. The diagrams in the article are not accurate. Well the whole article is not accurate.

Offline Burninate

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Re: Boeing obtains fusion based jet engine patent.
« Reply #34 on: 07/10/2015 09:29 pm »
Details are sketchy but here is a link to a story and the patent application:

http://www.businessinsider.com/boeing-just-patented-a-jet-engine-powered-by-lasers-and-nuclear-explosions-2015-7
So let's see if I have this right.

Boeing is planning to reduce the contents of the National Ignition Facility to the size of an engine pod, make the reaction chamber partly out of U235 and use the neutrons from the fusion to trigger fission heating which will be tapped by a power plant to generate the electricity for the lasers.

Say hello to the NIF
https://str.llnl.gov/etr/pdfs/12_94.2.pdf

It is 85m wide and 200 m long. Or for American readers that's 250 feet wide  x 600 feet long.

And it still didn't achieve as much energy output as the laser light put into the capsule.

So Boeing will shrink this to the size of a turbojet pod and hang it on a wing.

For those who've been anywhere near a cattle or dairy farm there's a 1 word description of this patent, but I'll settle for a simple ROTFLMFAO.

Thanks for putting a real chuckle on my day .  :)  :)

I am similarly incredulous - this seems many orders of magnitude away from a proper application because flight is so mass-sensitive.  The notion of having this in an aircraft is probably obfuscation.

Minor correction though: Unlike the NIF, this is not an attempt to make a self-sustaining fusion reactor.  They're using the DT fusion reaction as a neutron source for a subcritical fission reaction.  Depending on the neutron source, this general approach could be a very promising avenue for energy production.  I would like to see how a 1GeV synchrotron hitting a spallation target, compares with a laser-driven ICF fusion, compares with a Polywell or other IEC fusion.   These things are not distant technologies if you remove the requirement for a self-sustaining breakeven reaction via a few tons of uranium or thorium.

https://en.wikipedia.org/wiki/Subcritical_reactor
https://en.wikipedia.org/wiki/Nuclear_fusion-fission_hybrid

At the moment I am trying to puzzle through whether anyone's working on a reactor using a small IEC neutron source to fission a big liquid fluoride thorium fuel blanket.

Offline DanielW

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Re: Boeing obtains fusion based jet engine patent.
« Reply #35 on: 07/10/2015 09:48 pm »
Details are sketchy but here is a link to a story and the patent application:

http://www.businessinsider.com/boeing-just-patented-a-jet-engine-powered-by-lasers-and-nuclear-explosions-2015-7
So let's see if I have this right.

Boeing is planning to reduce the contents of the National Ignition Facility to the size of an engine pod, make the reaction chamber partly out of U235 and use the neutrons from the fusion to trigger fission heating which will be tapped by a power plant to generate the electricity for the lasers.

Say hello to the NIF
https://str.llnl.gov/etr/pdfs/12_94.2.pdf

It is 85m wide and 200 m long. Or for American readers that's 250 feet wide  x 600 feet long.

And it still didn't achieve as much energy output as the laser light put into the capsule.

So Boeing will shrink this to the size of a turbojet pod and hang it on a wing.

For those who've been anywhere near a cattle or dairy farm there's a 1 word description of this patent, but I'll settle for a simple ROTFLMFAO.

Thanks for putting a real chuckle on my day .  :)  :)

I am similarly incredulous - this seems many orders of magnitude away from a proper application because flight is so mass-sensitive.  The notion of having this in an aircraft is probably obfuscation.

Minor correction though: Unlike the NIF, this is not an attempt to make a self-sustaining fusion reactor.  They're using the DT fusion reaction as a neutron source for a subcritical fission reaction.  Depending on the neutron source, this general approach could be a very promising avenue for energy production.  I would like to see how a 1GeV synchrotron hitting a spallation target, compares with a laser-driven ICF fusion, compares with a Polywell or other IEC fusion.   These things are not distant technologies if you remove the requirement for a self-sustaining breakeven reaction via a few tons of uranium or thorium.

https://en.wikipedia.org/wiki/Subcritical_reactor
https://en.wikipedia.org/wiki/Nuclear_fusion-fission_hybrid

At the moment I am trying to puzzle through whether anyone's working on a reactor using a small IEC neutron source to fission a big liquid fluoride thorium fuel blanket.

The patent never ever indicated that this would be used in a plane. Quite the opposite. This whole thread is based on an article that referenced a home-made video that completely missed the point of the engine. It is a deep space engine period.

Offline KelvinZero

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Re: Boeing obtains fusion based jet engine patent.
« Reply #36 on: 07/10/2015 10:08 pm »
So this sits somewhere between an NTR and a fission fragment rocket I guess.

Is it aiming to be higher thrust or higher ISP than, eg, electric propulsion?

Is it rare to have ideas that only use U-238 as fuel? This seems a very nice feature.

Offline Elmar Moelzer

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Re: Boeing obtains fusion based jet engine patent.
« Reply #37 on: 07/10/2015 11:06 pm »
I don't really see this working. Laser fusion with the principle shown here is impractical as it is, even for uses on the ground. It will never be economic for energy production. So I am not sure it will be economic for regular flight. It may be economic for the more expensive space applications (if they can handle certain things right).
The neutron shielding for T+D fusion is pretty substantial and the components will get radioactive.
The engine will emit highly radioactive fission (and some fusion) products.
The design also omits the capacitors (which will be big and heavy) that are needed for a pulsed power supply (I can already predict that the generator will not produce enough energy during the length of the laser pulse to power the lasers).
I do not see much of an advantage over the old (and tested) nuclear jet engine designs that the US researched for the their nuclear bomber program with the exception that you have (radioactive and very hard to store) Tritium instead of fission fuel. In return you get a much more radioactive exhaust than the old fission engines produced.
Generally, it seems like a really complicated solution for a jet engine and I am not even sure what exactly is patent worthy about it. Laser fusion is not new, fusion driven engines are not new. Their idea is a variation of existing designs. I think there might be plenty of prior art to it.
Just proofs that you can get a patent for anything these days, especially if you are a big corporation.
« Last Edit: 07/10/2015 11:23 pm by Elmar Moelzer »

Offline llanitedave

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Re: Boeing obtains fusion based jet engine patent.
« Reply #38 on: 07/11/2015 12:24 am »

Just proofs that you can get a patent for anything these days, especially if you are a big corporation.

You don't have to be a big corporation.  You can be a little patent troll, too.  Just because a patent is granted doesn't mean it has to have anything to do with reality.


Or even legality, unless it gets challenged in court.
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Offline Bob Shaw

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Re: Boeing obtains fusion based jet engine patent.
« Reply #39 on: 07/11/2015 12:34 am »
Slightly OT, are there any thorium reactor studies for spaceflight applications?

Offline Damon Hill

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Re: Boeing obtains fusion based jet engine patent.
« Reply #40 on: 07/11/2015 03:25 am »
Because thorium isn't fissile, it doesn't directly make for a reactor, as I understand it.  For most spaceflight applications, highly enriched uranium is the way to go for simplicity and compactness.

Offline sanman

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Re: Boeing obtains fusion based jet engine patent.
« Reply #41 on: 07/11/2015 04:12 am »
Because thorium isn't fissile, it doesn't directly make for a reactor, as I understand it.  For most spaceflight applications, highly enriched uranium is the way to go for simplicity and compactness.

U238 isn't fissile either. This design doesn't use fissile material, because it's not trying to cause a chain-reaction. So thorium might be a valid material, except that has a lower nuclear cross-section, and its decay chain infamously has a high-gamma radiator which could be very deadly.

Quote from: DanielW
The patent never ever indicated that this would be used in a plane. Quite the opposite. This whole thread is based on an article that referenced a home-made video that completely missed the point of the engine. It is a deep space engine period.

The current design is supposed to heat an airstream, which isn't available in deep space. But maybe it could be adapted to work with a rocket propellant.

Offline daveklingler

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Re: Boeing obtains fusion based jet engine patent.
« Reply #42 on: 07/11/2015 04:40 am »
Okay, first of all the forum topic needs to be changed to "Boeing obtains fusion-based rocket engine patent." 

The whole misunderstanding lies at the feet of the goofy patent guy, who posted a wildly erroneous explanation of the patent on Youtube, upon which some reporters based their stories without reading the original patent.

Because thorium isn't fissile, it doesn't directly make for a reactor, as I understand it.  For most spaceflight applications, highly enriched uranium is the way to go for simplicity and compactness.

The current design is supposed to heat an airstream, which isn't available in deep space. But maybe it could be adapted to work with a rocket propellant.

Having just skimmed over the patent myself, I read that this engine doesn't heat an airstream.  It heats helium or hydrogen. 

"3. The propulsion apparatus of claim 1 wherein the thrust-producing medium comprises a hydrogen gas or a helium gas."

From what little I've read so far, this is potentially very innovative.  By designing a nuclear thermal rocket around a non-fissile material, they've possibly invented a workaround for the requirement in NTRs up until now for weapons-grade uranium.  That makes it the first NTR design I've ever seen that could be more practical than the Pewee design developed almost 50 years ago.

Not only that, they're claiming much higher Isp figures than Pewee could ever achieve.  I'm too tired to look at it tonight, but tomorrow I'll hopefully be able to sit down and study this patent.  If my first take is correct, this is really a very exciting patent.

Offline R7

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Re: Boeing obtains fusion based jet engine patent.
« Reply #43 on: 07/11/2015 08:01 am »
The patent never ever indicated that this would be used in a plane. Quite the opposite. This whole thread is based on an article that referenced a home-made video that completely missed the point of the engine. It is a deep space engine period.

No, the patent mentions aircraft five times. Most explicit in claim 15.

Quote
15. An aircraft laser propulsion system comprising:

    an aircraft comprising:

    ...

Viability of the idea is another story. Propelling aircraft with an open ended fast breeder nuclear device spewing traces of tritium and U-238/Pu-239 fission products may have some permit issues.
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Offline R7

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Re: Boeing obtains fusion based jet engine patent.
« Reply #44 on: 07/11/2015 08:15 am »
I think the operative word here may be "fertile" rather than "fissile". Fissile means it can sustain a chain reaction, while fertile merely means it can absorb neutrons to decay into other elements while releasing energy in the process.

The word beginning with "fissi" the article author was looking for is fissionable. U-238 is both fissionable and fertile but not fissile.

Fertile denotes stuff convertible into nuclear reactor fuel (fissile by thermal neutrons).
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Offline DanielW

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Re: Boeing obtains fusion based jet engine patent.
« Reply #45 on: 07/11/2015 02:28 pm »
The patent never ever indicated that this would be used in a plane. Quite the opposite. This whole thread is based on an article that referenced a home-made video that completely missed the point of the engine. It is a deep space engine period.

No, the patent mentions aircraft five times. Most explicit in claim 15.

Quote
15. An aircraft laser propulsion system comprising:

    an aircraft comprising:

    ...

Viability of the idea is another story. Propelling aircraft with an open ended fast breeder nuclear device spewing traces of tritium and U-238/Pu-239 fission products may have some permit issues.

Oops, you are correct. I only read background and detail sections carefully. The html version I saw did not have the drawings, and I only skimmed the claims at the end to make sure they were only a reiteration of the technical description.

I would like to note that the primary intent of the engine remains spacecraft and the parts that do mention aircraft do so in a kind of off-hand "our lawyers made us do it" kind of way. "a vehicle, a spacecraft, a rocket, an aircraft, a missile, or another type of structure"

Claim 15 does address an aircraft more specifically than the other types of vehicles, but that is Boeing's bread and butter, they need to single that out. I still see no mention of using the atmosphere as a working fluid. It is not ruled out, but the only working fluids specifically mentioned that I saw were hydrogen and helium.

Thus, whatever it propels, this is more properly called a "rocket engine" especially in light of the fact that even in the short aircraft section they mention that the thrust member is configured to reflect the thrust producing flow.

Offline watermod

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Re: Boeing obtains fusion based jet engine patent.
« Reply #46 on: 07/12/2015 12:40 am »
The patent never ever indicated that this would be used in a plane. Quite the opposite. This whole thread is based on an article that referenced a home-made video that completely missed the point of the engine. It is a deep space engine period.

No, the patent mentions aircraft five times. Most explicit in claim 15.

Quote
15. An aircraft laser propulsion system comprising:

    an aircraft comprising:

    ...

Viability of the idea is another story. Propelling aircraft with an open ended fast breeder nuclear device spewing traces of tritium and U-238/Pu-239 fission products may have some permit issues.

Oops, you are correct. I only read background and detail sections carefully. The html version I saw did not have the drawings, and I only skimmed the claims at the end to make sure they were only a reiteration of the technical description.

I would like to note that the primary intent of the engine remains spacecraft and the parts that do mention aircraft do so in a kind of off-hand "our lawyers made us do it" kind of way. "a vehicle, a spacecraft, a rocket, an aircraft, a missile, or another type of structure"

Claim 15 does address an aircraft more specifically than the other types of vehicles, but that is Boeing's bread and butter, they need to single that out. I still see no mention of using the atmosphere as a working fluid. It is not ruled out, but the only working fluids specifically mentioned that I saw were hydrogen and helium.

Thus, whatever it propels, this is more properly called a "rocket engine" especially in light of the fact that even in the short aircraft section they mention that the thrust member is configured to reflect the thrust producing flow.

Well if it really is a space use rocket engine ...  then, launching something on a chemical first stage that had U-238 used on a latter stage shouldn't be a public nuclear launch PR-disaster if the used nuclear engine never returns to earth.


Offline Coastal Ron

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Re: Boeing obtains fusion based jet engine patent.
« Reply #47 on: 07/12/2015 01:46 am »
Well if it really is a space use rocket engine ...  then, launching something on a chemical first stage that had U-238 used on a latter stage shouldn't be a public nuclear launch PR-disaster if the used nuclear engine never returns to earth.

Well, I think the main concern is if the U-238 makes an unplanned return to Earth...
If we don't continuously lower the cost to access space, how are we ever going to afford to expand humanity out into space?

Offline sanman

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Re: Boeing obtains fusion based jet engine patent.
« Reply #48 on: 07/12/2015 05:33 am »
So is tritium absolutely mandatory for this? What about just D-D, or 3He, or p+B11, or something less toxic than tritium?

Perhaps there's just no way to avoid the radioactive hazard to the environment?


Offline watermod

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Re: Boeing obtains fusion based jet engine patent.
« Reply #49 on: 07/12/2015 06:21 am »
Well if it really is a space use rocket engine ...  then, launching something on a chemical first stage that had U-238 used on a latter stage shouldn't be a public nuclear launch PR-disaster if the used nuclear engine never returns to earth.

Well, I think the main concern is if the U-238 makes an unplanned return to Earth...

An unused engine with U-238 shouldn't be any different than a depleted U-238 shell or tank armor and that stuff flies about all the time.   

Offline ArbitraryConstant

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Re: Boeing obtains fusion based jet engine patent.
« Reply #50 on: 07/12/2015 10:24 am »
So is tritium absolutely mandatory for this? What about just D-D, or 3He, or p+B11, or something less toxic than tritium?
Tritium isn't that bad. Relatively low energy beta. It's safe in lights as long as you don't have workers licking paint brushes with tritium paint.

All the other reactions require higher energies and have lower reaction rates, so it's irrelevant until we can be energy positive on D+T. Also aneutronic reactions suffer from bremsstrahlung losses, where charged particles smashing into each other carry energy out of the reaction via x-rays so it's harder to have a self-sustaining reaction. The polywell folks will tell you they've cracked this, in the manner of someone seeking investment rather than the manner of trillionaires that have solved all our energy problems.

In other words tritium is not compulsory but demonstrating the technology is compulsory and that hasn't been done with tritium which is the easiest reaction.
« Last Edit: 07/12/2015 10:26 am by ArbitraryConstant »

Offline R7

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Re: Boeing obtains fusion based jet engine patent.
« Reply #51 on: 07/12/2015 03:01 pm »
Wondering on what grounds was this patent even issued. There's nothing new, it is as if Boeing patented VISTA from 1987.
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Offline Burninate

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Re: Boeing obtains fusion based jet engine patent.
« Reply #52 on: 07/12/2015 05:20 pm »
So is tritium absolutely mandatory for this? What about just D-D, or 3He, or p+B11, or something less toxic than tritium?
Tritium isn't that bad. Relatively low energy beta. It's safe in lights as long as you don't have workers licking paint brushes with tritium paint.

All the other reactions require higher energies and have lower reaction rates, so it's irrelevant until we can be energy positive on D+T. Also aneutronic reactions suffer from bremsstrahlung losses, where charged particles smashing into each other carry energy out of the reaction via x-rays so it's harder to have a self-sustaining reaction. The polywell folks will tell you they've cracked this, in the manner of someone seeking investment rather than the manner of trillionaires that have solved all our energy problems.

In other words tritium is not compulsory but demonstrating the technology is compulsory and that hasn't been done with tritium which is the easiest reaction.
You're right, but remember the context here: This is being used *as a neutron source*, specifically because it permits a fusion gain of ~0.01 or ~0.1 instead of ~10 to ~100.  An aneutronic reaction would be useless for that.

Offline sanman

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Re: Boeing obtains fusion based jet engine patent.
« Reply #53 on: 07/12/2015 06:36 pm »
An unused engine with U-238 shouldn't be any different than a depleted U-238 shell or tank armor and that stuff flies about all the time.

But depleted U-238 shells/armor don't get exposed to high-energy neutron bombardment that creates fission products.

Quote from: ArbitraryConstant
Tritium isn't that bad. Relatively low energy beta. It's safe in lights as long as you don't have workers licking paint brushes with tritium paint.

The half life of Tritium is ~12 years, and if it was to be released in the upper atmosphere, it's light enough that it could stay up there.

So maybe could this type of engine be useful for an upper stage rather than a lower stage?



Offline sanman

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« Last Edit: 07/13/2015 12:48 am by sanman »

Offline M_Puckett

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Re: Boeing obtains fusion based jet engine patent.
« Reply #55 on: 07/13/2015 01:29 am »
I read the article at that link and am dumber for having done so.  It was drivel. 

To sum:
"Greenpeace says Nuclear Bad, Solar good!"

Pure fear mongering with no explanation as to why it is bad.

Lets compare something capable of hypersonic flight with something that can be outran on the ground by a thirty year old Yugo.

Offline sanman

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Re: Boeing obtains fusion based jet engine patent.
« Reply #56 on: 07/13/2015 05:08 am »
Well, it's worth asking how the issue of the fission products would be dealt with:


Quote
Regarding the Boeing scheme, the result of the Uranium-238 being struck by neutrons would be some it being transformed into Plutonium-239, said Morgan. Plutonium has long been described as the most toxic radioactive substance, and Plutonium-239 has a half-life of 24,100 years, thus once created it remains radioactive for 240,000 years.

“I don’t understand how they are going to overcome the emissions problems and how the shielding issue would be handled,” said Morgan.

As to a crash of an airplane with atomic engines, “It would be a real mess. You’d have lethal material spread all over the place.”

Offline Spaniard

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Re: Boeing obtains fusion based jet engine patent.
« Reply #57 on: 07/13/2015 10:20 am »
What about Compact Fusion of Lockheed modified?

Instead two magnetic mirrors, assymetric to allow, at certain levels of energy, some particles to pass through to magnetic barrier. Using He3, most energy come as photons, mostly non radioactive. Using a shielding with thermoelectrics to recycle energy to and freezing using a propelent by the outside layer, mix this propelent with the escaped particles of the fusion chamber and make a steam of particles very hot. Perhaps with enough ISP to be used as a SSTO (600-800?). With water fuel. Very cheap and enough compact.

For fusion, use He3. Only a small quantity is needed. The challenge is to build a fusion chamber with a confinement enough good to heating the plasma itself.

Offline dchill

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Re: Boeing obtains fusion based jet engine patent.
« Reply #58 on: 07/13/2015 01:02 pm »
The Convair NB-36H was a bomber that carried a nuclear reactor. It was also known as the "Crusader".[1] It was created for the Aircraft Nuclear Propulsion program, or the ANP, to show the feasibility of a nuclear-powered bomber.
https://en.wikipedia.org/wiki/Convair_NB-36H

I used to give plant tours to college interview candidates at the GD Convair plant in San Diego in the late '80s.  The crew compartment from the NB-36H was still there.  It was stuck in a dark corner of a manufacturing building.  We couldn't climb in it, which is probably good given the amount of lead it had in it. 

I'm afraid Boeing won't be able to use it.  It probably got hauled out to a dump (and hopefully the lead got recycled) when GD sold it's cruise missile production to Raytheon in the early 90's. 

Offline KelvinZero

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Re: Boeing obtains fusion based jet engine patent.
« Reply #59 on: 07/13/2015 08:43 pm »
For fusion, use He3. Only a small quantity is needed. The challenge is to build a fusion chamber with a confinement enough good to heating the plasma itself.
Im all for someone patenting a fusion rocket if they can figure out how to build one ;)

I think this patent is all about using an already achievable sort of fusion which is not required to create more energy than put in merely as a neutron source though, to get fission energy from U-238, which is otherwise pretty inert and safe enough (radiation wise and proliferation wise) to throw at the enemy in 'depleted uranium rounds'. It is inert and just used because it is so dense.

The 'jet' angle is just drowning an idea I would like to hear more about.

Offline aceshigh

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Re: Boeing obtains fusion based jet engine patent.
« Reply #60 on: 07/14/2015 01:47 am »
Well if it really is a space use rocket engine ...  then, launching something on a chemical first stage that had U-238 used on a latter stage shouldn't be a public nuclear launch PR-disaster if the used nuclear engine never returns to earth.



Well, I think the main concern is if the U-238 makes an unplanned return to Earth...

An unused engine with U-238 shouldn't be any different than a depleted U-238 shell or tank armor and that stuff flies about all the time.
Can't we mine u238 or at least enrich u236 directly on the moon? The launch interplanetary nuclear spacecraft from there.

The way i see it, the only thing we should launch from earth in a future space economy is people.
« Last Edit: 07/14/2015 01:51 am by aceshigh »

Offline sanman

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Re: Boeing obtains fusion based jet engine patent.
« Reply #61 on: 07/14/2015 02:25 am »
For fusion, use He3. Only a small quantity is needed. The challenge is to build a fusion chamber with a confinement enough good to heating the plasma itself.
Im all for someone patenting a fusion rocket if they can figure out how to build one ;)

I think this patent is all about using an already achievable sort of fusion which is not required to create more energy than put in merely as a neutron source though, to get fission energy from U-238, which is otherwise pretty inert and safe enough (radiation wise and proliferation wise) to throw at the enemy in 'depleted uranium rounds'. It is inert and just used because it is so dense.

The 'jet' angle is just drowning an idea I would like to hear more about.

Okay, sounds good - as long as we recognize that hitting the inert U-238 with the neutrons means it turns into the dangerously toxic Plutonium-239, which we don't want to release into our atmosphere - which would happen with a jet engine.

Not sure if we'd want to use it on Mars or the Moon either, since a pollutant that stays radioactive for 240,000 years might then infringe upon our future planned activities for Mars or the Moon.

But maybe we can use it out in deep space, or even when exploring the gas giants of our solar system.

(Also, not on Europa - the Monoliths might get mad at us over that.)



Offline KelvinZero

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Re: Boeing obtains fusion based jet engine patent.
« Reply #62 on: 07/14/2015 07:21 am »
But maybe we can use it out in deep space, or even when exploring the gas giants of our solar system.

(Also, not on Europa - the Monoliths might get mad at us over that.)
Yeah just deep space, same as ion drives. Despite the mention of aircrafts I see nothing to encourage me to consider that. I expect there are reasons to patent stuff just in case and it does not imply any sort of intention.

But also as far as I can tell the principle is way better than fission propulsion in general. Usually in those cases you start with tons of something horrible that you have to store in dispersed form because horrible things happen if you even put elements close together. In this case you start with something inert, and most of the fission does not even go via the nasty products that other NTR schemes are chocka with on launch. The fast  neutrons cause fission on the U-238, and only secondary slow neutrons cause the nasty stuff, roughly. There are probably ways to encourage most of the slow neutron energy to go into heating propellant Im guessing. For starters the fast neutron are radiating from a point whereas the slow neutrons would have more random directions. You could probably exploit that.

Offline aceshigh

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Re: Boeing obtains fusion based jet engine patent.
« Reply #63 on: 07/14/2015 11:15 pm »
the PuFF (Pulsed Fission‐Fusion Propulsion) system by Dr Rob Adams seems more developed and interesting imho.

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20140008774.pdf

http://www.nasa.gov/content/pulsed-fission-fusion-puff-propulsion-system/#.VaWXYc9VhrM

http://www.nasa.gov/sites/default/files/files/Adams_2013_PhI_PuFF_inProgress.pdf


obviously, not any scientific merit in it, but Dr Rob Adams also seems a very nice guy



Offline Coastal Ron

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Re: Boeing obtains fusion based jet engine patent.
« Reply #64 on: 07/14/2015 11:23 pm »
Can't we mine u238 or at least enrich u236 directly on the moon? The launch interplanetary nuclear spacecraft from there.

I don't know about the prevalence of uranium on the Moon, but processing of uranium into usable material here on Earth requires a lot of infrastructure.  It would be cheaper to make it here and send it up in frequent small batches to lower the risk.

Quote
The way i see it, the only thing we should launch from earth in a future space economy is people.

Until we figure out how to grow organic material in mass quantities off-Earth, that is going to be a distant dream.
If we don't continuously lower the cost to access space, how are we ever going to afford to expand humanity out into space?

Offline Vultur

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Re: Boeing obtains fusion based jet engine patent.
« Reply #65 on: 07/17/2015 05:40 am »
Quote
Regarding the Boeing scheme, the result of the Uranium-238 being struck by neutrons would be some it being transformed into Plutonium-239, said Morgan. Plutonium has long been described as the most toxic radioactive substance,

Um... what?

Plutonium is less radioactively dangerous than stuff with shorter half-lives (polonium for example has a far lower lethal dose).

It's chemically toxic too, but its chemical toxicity isn't all that exceptional (IIRC the ingested lethal dose is supposedly comparable to that of caffeine, though I wouldn't want to drink a plutonium soda/coffee).

This 'plutonium is the deadliest thing ever' stuff is just fear-mongering.

There are plenty of purely chemical (i.e. not radioactive) substances which are handled daily which are far more dangerous than plutonium.
« Last Edit: 07/17/2015 05:44 am by Vultur »

Offline aceshigh

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Re: Boeing obtains fusion based jet engine patent.
« Reply #66 on: 07/17/2015 02:26 pm »
in 1987, in Goiânia, central Brazil, 4 people died and over 250 were found to have substantial levels of radioactive material in their bodies, after a small (5x4.5cm) capsule containing only 90 grams of Cesium 147 was stolen by scavengers who invaded an abandoned hospital in the absence of the security guard (an imbecile court order from a dispute between owners of the hospital and of the building prevented the hospital owners from removing equipment from inside, even though they were warning the court and even the National Atomic Energy Comission about the dangers) of it.



here is a chart showing radiation dosage, fatalities and who survived. It might help determine how dangerous radiation from Plutonium might be...
https://upload.wikimedia.org/wikipedia/commons/thumb/4/49/Goi%C3%A2nia_accident_-_Health_outcomes.svg/979px-Goi%C3%A2nia_accident_-_Health_outcomes.svg.png


the problem of course, is how to relate fatalities that happen a long time later to the radiation. The Association of Victims of the Cesium 137 of Goiania, claimed in 2012 that 104 people have died so far of illnesses related to Cesium incident. I guess everyone who dies of cancer among the 112 thousand people that were examined back in 1987, is considered a victim... :P



but anyway, I guess this should be used as a long range propulsion scheme only. So either the uranium should be mined elsewhere (Moon?) to fuel spaceships already in orbit, or maybe it would be possible to send the fuel in very, very sealed capsules able to withstand explosions and reentry without leaking?
« Last Edit: 08/15/2015 11:13 pm by Chris Bergin »

Offline RonM

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Re: Boeing obtains fusion based jet engine patent.
« Reply #67 on: 07/17/2015 02:46 pm »
the problem of course, is how to relate fatalities that happen a long time later to the radiation. The Association of Victims of the Cesium 137 of Goiania, claimed in 2012 that 104 people have died so far of illnesses related to Cesium incident. I guess everyone who dies of cancer among the 112 thousand people that were examined back in 1987, is considered a victim... :P

Statistically, researchers know what percentage of the population will die from cancer based of age and many other factors. Any excess in cancer deaths of that group could be attributed to the exposure, especially if it is the types of cancer caused by radiation exposure.

Because of the possible radiation issues, the Boeing patent is really for a space propulsion system. I'm pretty sure the aircraft part was suggested by the lawyers so the patent could cover any situation.

Offline Vultur

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Re: Boeing obtains fusion based jet engine patent.
« Reply #68 on: 07/18/2015 03:17 am »
in 1987, in Goiânia, central Brazil, 4 people died and over 250 were found to have substantial levels of radioactive material in their bodies, after a small (5x4.5cm) capsule containing only 90 grams of Cesium 147

This seems unlikely; wikipedia claims that cesium-147 has a half life of 0.235 seconds, so I don't see how one could keep any quantity of it in a capsule.

Cesium-137 is a problem in places like Chernobyl, but its half life is 30 years so it is far more radioactive than plutonium-239 (short half life = high radioactivity as energy is released more quickly).

Offline aceshigh

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Re: Boeing obtains fusion based jet engine patent.
« Reply #69 on: 07/18/2015 04:31 am »
it was clearly a typo. In the end of the post I had written 137.

" The Association of Victims of the Cesium 137 of Goiania, claimed in ..."
« Last Edit: 07/18/2015 04:32 am by aceshigh »

Offline Stormbringer

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Re: Boeing obtains fusion based jet engine patent.
« Reply #70 on: 07/18/2015 06:59 am »
here is the radiation shielding for hulls and for reactor shields:

http://phys.org/news/2015-07-metal-foams-capable-shielding-x-rays.html

Quote
The researchers tested shielding performance against several kinds of gamma ray radiation. Different source materials produce gamma rays with different energies. For example, cesium and cobalt emit higher-energy gamma rays, while barium and americium emit lower-energy gamma rays.

The researchers found that the high-Z foam was comparable to bulk materials at blocking high-energy gamma rays, but was much better than bulk materials – even bulk steel – at blocking low-energy gamma rays.

Similarly, the high-Z foam outperformed other materials at blocking neutron radiation.

The high-Z foam performed better than most materials at blocking X-rays, but was not quite as effective as lead.

"However, we are working to modify the composition of the metal foam to be even more effective than lead at blocking X-rays – and our early results are promising," Rabiei says. "And our foams have the advantage of being non-toxic, which means that they are easier to manufacture and recycle. In addition, the extraordinary mechanical and thermal properties of composite metal foams, and their energy absorption capabilities, make the material a good candidate for various nuclear structural applications."


When antigravity is outlawed only outlaws will have antigravity.

Offline Vultur

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Re: Boeing obtains fusion based jet engine patent.
« Reply #71 on: 07/19/2015 03:32 am »
it was clearly a typo. In the end of the post I had written 137.

" The Association of Victims of the Cesium 137 of Goiania, claimed in ..."

Ah, sorry.

In any case it's still not really comparable as that stuff has far higher radioactivity (shorter half-life) and is a beta/gamma emitter while plutonium-239 is an alpha emitter.

That means plutonium-239 is mostly hazardous if inhaled* (but is very hazardous in that case) since alpha particles don't penetrate skin, but cesium-137 can be hazardous in other circumstances also.

*it can also get inside the body other ways, but the ingested lethal dose is much larger than the inhaled one

Offline Bob Shaw

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Offline Bob Shaw

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Re: Boeing obtains fusion based jet engine patent.
« Reply #73 on: 08/09/2015 12:53 am »
Safe RTG fuel casks were devised in the 1960s, and their use was demonstrated on Apollo 13. Ideally, you put the fuel into what is in effect a man-rated capsule and then transfer it to where it will do what it does when safely in orbit.
« Last Edit: 08/15/2015 11:13 pm by Chris Bergin »

Offline ArbitraryConstant

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Re: Boeing obtains fusion based jet engine patent.
« Reply #74 on: 08/15/2015 04:47 pm »
The half life of Tritium is ~12 years, and if it was to be released in the upper atmosphere, it's light enough that it could stay up there.
I think you'll find hydrogen of any isotope needs little encouragement to oxidize. :P It'll end up as tritiated water. However this diffuses down to negligible concentrations very quickly and does not concentrate.

The fission products from this design are a far greater concern.

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