Boeing patent puts focus on laser-powered propulsion system (Update)

Boeing patent puts focus on laser-powered propulsion system
Credit: United States Patent and Trademark Office

Boeing has patented a laser powered propulsion system for airplanes. A number of sites reported on the patent, with eye-rubbing headlines that told the story. The BusinessInsider headline read, "Boeing just patented a jet engine powered by lasers and nuclear explosions." Benjamin Zhang said the US Patent and Trademark Office approved Boeing's application for a laser and nuclear-driven airplane engine.

Zhang noted that presently the Boeing Dreamliner is powered by multiple turbofan engines with their fans and turbines in place to compress air and ignite fuel to provide thrust. The engine presented in Boeing's patent application takes another route. Zhang said the laser engine may also be used to power rockets, missiles, and spacecraft.

The new engine would work by firing high-power lasers at radioactive material, said BusinessInsider. "The lasers vaporize the radioactive material and cause a fusion reaction—in effect a small thermonuclear explosion," said the article. "Hydrogen or helium are the exhaust byproducts, which exit the back of the engine under high pressure. Thrust is produced."

In this approach the inside wall of the engine's thruster chamber coated in uranium 238 reacts with the neutrons from the nuclear reaction and generates immense heat. "The engine harnesses the heat by running coolant along the other side of the uranium-coated combustion chamber," said Zhang. "This heat-energized coolant is sent through a turbine and generator that produces electricity to power the engine's lasers."

Three inventors named in the are Robert Budica, James Herzberg and Frank Chandler of California. The applicant is listed as The Boeing Company in Chicago. The patent was filed in 2012.

PatentYogi founder Deepak Gupta also attempted to shed light on this propulsion system; he explained how a stream of pellets containing nuclear material such as deuterium or tritium is fed into a "Hot-Spot" within a thruster of the aircraft:

Multiple high powered laser beams are focused on to the hot spot; the pellet is vaporized and the high temperature causes a . In effect, he said, it causes a tiny that scatters atoms and neutrons in all directions. "This flow of material is concentrated to exit out of the thruster, propelling the aircraft forward with great force."

He went on to say that "This is where Boeing has done something extremely clever. The inner walls of the thruster are coated with a fissile material like Uranium-238 that undergoes a nuclear fission upon being struck by the high energy neutrons. This releases enormous energy in the form of heat. A coolant is circulated along the inner walls to pick up this heat and power a turbine which in turn generates huge amounts of . And guess what this electric power is used for? To power the same lasers that created the electric power! In effect, this space-craft is self-powered with virtually no external energy needed."

Evan Ackerman in IEEE Spectrum presented a how-it-works explanation with clear brevity in a word picture: "you've got a cavity that's a sort of hemisphere shape, kind of like the business end of a rocket engine. You toss a pellet of fuel into that cavity, and then lasers blast the fuel pellet, causing it to release a bunch of energy (by exploding, fissioning, fusing, or whatever). That energy pushes against the walls of the cavity, and the cavity moves forward. At the same time, the explosion heats the walls of the cavity, and this heat is harvested to drive the lasers."

Sebastian Anthony on Saturday commented in Ars Technica: "It sounds completely crazy—and it is completely unrealistic given our current mastery of fusion, or lack thereof—but, in the future perhaps, this could be a rather ingenious solution."

Anthony also remarked that "it's nice to see that Boeing is at least looking into novel propulsion methods. Turbofan and rocket engines have done a good job of getting us around the Earth and into space, but if we want hypersonic on-Earth travel, or if we want to send humans to far-flung reaches of the Solar System, we'll need new and advanced propulsion technologies."


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Jul 12, 2015
"by firing high-power lasers at radioactive material, such as deuterium and tritium,"
Deuterium is not radioactive; furthermore the fusion reaction does not depend on the radioactivity of tritium.

Jul 12, 2015
Turbine? Propulsion? Lasers? The turbine and generator must go, energy built into the ship, something like the battery that starts your car, with an infinite power density, but the entire ship is composed of the stuff with a built hyper-computer that can reshape the EM Fields that are every-where, to jump to hyperspace,once in hyperspace simply shape the increased field input, so we would probably cruise along galaxys, store energy. Safe inertial system defined with an instantaneous response to every object to maintain spatial comfort.

Jul 12, 2015
Space-Jet

Jul 12, 2015
easier to control matter than splattering it everywhere, greater efficiency, use the "field" luke

Jul 12, 2015
old patent, new people.....

Jul 12, 2015
Else peel yourself away from the rear of your LPP at take-off, if anyone lives after prototyping!

Must first understand, exactly what is mass, is not a stupid question? Learn to find out for yourself and learn from a mass of particles, +&-, at a given point in space and time with attributes placed upon a 4D space ... simple investigation before identification before control ..
particle or wave has no "mass of particles" relative to another mass of particles, that's gravity, i.e. a multi-polar response solvable with superposition. particles emit waves, particles are not waves, you are hypnotizing yourselves starring at a mirror.

Jul 12, 2015
And yes if you like, anti-matter is when the + is - and the - is +, then anti-matter is matter with reversed position, easy to see; a large group of forward and revered rolls the system will settle upon a single + or - as the universal rota-tor, but better described as the probability of an atom being normal or reversed, calculable from stability conditions. We need to stop making up sh$t!

Jul 12, 2015
It will never take off.

Jul 12, 2015
the fusion reaction does not depend on the radioactivity of tritium.
So tell us how this works.

Jul 12, 2015
What exactly is "patentable" about this design?

The concept of both fission and fusion based rockets has been around sine the Nerva design. What's so special about this?

Jul 12, 2015
I think it's the uranium shell and the coolant loop that's patentable. Because otherwise this is an idea that has already been explored pretty thoroughly. And it's still the case that now, as before, achieving a sufficient fusion reaction is incredibly difficult.

Jul 12, 2015
Lasers are only a few percent efficient.

Uranium parts? Did they concoct this after a night of absinthe?

Jul 12, 2015
This is neither clever nor useful

Jul 12, 2015
In all reality, I drew an engine sketch about like that one, that was almost identical, the curve of the cone is different, is about all, plus the fuel was also the coolant for the nuclear reactor producing enough energy to power the lasers, and that would pre-heat the fuel, hydrogen or Deut/Trit mix, either or a mix of different fuels, to a very high heat to begin with, and then when illuminated by the lasers it would fuse that much more easily. Much more push per pound of fuel, the higher you can heat it first and then fuse it.

So, if I, as a KID, could have figured something like this out and sent it to NASA, should I not actually get some recognition for my foresight and clarity? I truly did this, I am shocked to see this picture, even though it is not the exact same as I drew for NASA, but the theory is exactly the same.

I drew the sketch at about 11 yrs old, with even more detail and clear notation, and it was almost precisely detailed and the year was 1973.

Jul 12, 2015
This chamber starts with a fusion process optimally located at sufficient distance to prevent overheating the chamber walls, but allowing enough fusion byproducts to reach the the U238 coating on the inside chamber walls for generation of fast neutrons.

A slow & carefully generated rate of neutrons freed from U238 keeps the chamber walls under low but constant heat which is carried away by the coolant in contact with the exterior walls of the chamber. I imagine the hot leg of the coolant would be several hundred degrees as it enters the high pressure end of the turbo-generator if there is a multi-stage turbine. Gotta think about this some more though, it was only a couple hours ago I first read about this......time to dig out the old textbooks I guess.


Jul 12, 2015
Steelwolf: This idea is actually very old, and was proposed for spacecraft long before it was tried for stationary power plants. And you're right, a smart grade school kid can figure it out.
Are you sure you're not confusing this with a radioisotope thermocouple? These are used on board some satellites using only the heat generated by the radioactive decay process.


rgw
Jul 12, 2015
This is neither clever nor useful


Thus spake Zarathustra...

Jul 12, 2015
IIRC, the British Interplanetary Society's brave 'Project Daedalus' expected pulsed nuclear fusion to come good 'real soon'. The major problems were financing and launching enough hardware to 'bootstrap' the project, mining gas giants for fuel, then devising self-repairing hardware & software for each one-way mission's ~25yr journey to, then brief fly-by of a nearby star...

At the time, no extrasolar planets were known. IIRC, most suspected planets turned out to be telescope artefacts or 'brown dwarfs'...

Sadly, pulsed fusion remains a way off, also AI and economical launches. 3D prototyping is, literally, a toe in the water...

Jul 12, 2015
I think they expect to be able to use a controllable set of multi-frequency lasers to initiate atomic fusion or fission or something like. To be used as controllable propulsion. But, it's going to take maybe a 100 years to define this space since we have not accepted what is obvious; we still think gravity is a separate force of nature. We do not realize the field equations are unified. Its the idea of the existence of different fields that add the discrepancy. We also have poor definition of the Poynting vector, sorry GR, not possible. A correction is needed for the universal constants that use the Kg. It'll take 50 years to tabulate the phony theories and put them into a syfy novel about the beginning of the 21st century, using 19th century ignorance. But we will not have the ability for proper simulations until we understand this actuality and design optical computers beyond binary.

Jul 12, 2015
The computer will define flawless code by design and define proper communication, with sensory perception throughout all allowed domains. Something like Watson with multiple PhDs on steroids.

Politicians will fight against suggest improvements to our genetics as we continue to go round and around; so subjective that everybody sees only whats in the mirror. We will vote down immortality and population control first time around.

Jul 12, 2015
The idea that something we already know is new, can only happen upon earthlings who believe in magic and rush to define this nonsense. In fact, we could teach atomic physics to first graders using a proper GUI. People do not have to be ignorant because those that think they know can't simplify.

Jul 12, 2015
...uranium shell absorbs neutrons and generates immense heat....And Gamma Rays!
All flights come with a personal oncologist for the next three to six months. You wont need one much after that.

Jul 12, 2015
I love systems that generate their own power to keep themselves running. Like Chernobyl and Fukushima!!

Just hope they have enough backup systems in place to restart an engine when the thermal loop side of this engine stops. Hey don't for an instant think I'm knocking nuclear, I love the stuff, but I always get nervous about relying on self contained loops with anything nuclear.

Be interesting sat on board one of these planes, and instead of seeing an engine flair out, you'd be witnessing the whole engine melt!!!!

Jul 12, 2015
Another wild eyed paper patent, this one with numerous sequential steps each requiring 6 sigma reliability, involving fission, fusion and U238, truly a witches brew, subject to catastrophic flare out requiring a second engine. May be viable in a few decades, if nothing simpler comes along. In the good old days the patent office requested a working or at least a demo prototype.

Jul 13, 2015
Is this enjin gon'be break-even, or is it one of those unicorn-powered great ideas for flying around?

Jul 13, 2015
Might be useful off-world (depending on how long the uranium shell will be able to work. That part will eventually degrade and then the lasers won't get ebough power for further ignition blasts).

But I don't see this as something I'd want to have in the skies above me on those hypersonic jets.

Jul 13, 2015
Using bombs, because that's what we know, for acceleration, just might leave the passengers that survive a little uncomfortable. I would watch this on TV. OMG! woo hooo!

Jul 13, 2015
Nuclear rockets and aircraft were submitted (as hidden) patents during the Manhattan (Engineering District) Project during the 40s.

Seriously, that's a known and documented, but forgotten, fact.

Jul 13, 2015
We had two fission powered aircraft programs in the 50's. One based on a direct cycle air cooled reactor. The other on an indirect cycle with liquid metal as the primary coolant. The only thing that actually got built was a gigantic hanger in the desert for maintaining the aircraft. Per unit power there are more neutrons given off in a fusion reaction than in a fission reaction. The shielding of crew and electronics will add more weight than other structure and payload combined. All exposed structures will be made radioactive by interaction with the 14 Mev neutrons form fusion or the fission spectrum neutrons from the Uranium. I would be embarrassed to have my name attached to the patent.

Jul 13, 2015
Benni: No, the RTG is entirely different. It isn't even a "reactor"
I brought it up the thermocouple because there are those who think some satellites have miniature fission plants on board, I just wanted to clear that off the table for consideration right away

This, and similar previous proposals, are actually miniature fusion bombs, and in this case, the excess neutrons are used to trigger fission in the uranium, providing more energy.


A fusion process, yes, but not a bomb. Not a bomb because the initiation of energy release is the exact reverse of the H- bomb. An H-bomb requires fission to generate heat for initiating fusion, but the process has been reversed here; fusion first by lasers, this followed by fusion byproducts initiating thermal processes within the U238 coating. When I saw U238 inside the chamber in a reverse sequence of the fusion process, the first thing that came to mind was "fast neutrons".

cont'd.......

Jul 13, 2015
cont'd.....

"Fast neutrons" are peculiar to U238, not U235. if you were intending to perform an efficient fission reaction you would coat the chamber with U235 & use slower moving "thermal neutrons". The fact they were explicit in their use of U238 tells a tale of something explicit with the use of "fast neutrons".

You do not want to create fission conditions on the surface of the heat exchanger, it'll melt. But if all you want to do is create a manageable heating/cooling cycle of the heat exchanger, you come up with a heating process whereby the chamber is not destroyed, this where U238 & "fast neutrons" may come in handy.

The fusion process is intended to generate "fast neutrons" so as to interact with U238 in an incomplete fission process. A process whereby fission itself does not actually occur but through which heat is generated through initiating radioactive decay with bombardment of the U238 with fast neutrons, similar to the radioisotope thermocouple.

Jul 14, 2015
Actually, a fusion bomb can be built with laser initiation


Building a bomb of whatever manner is not what is being fabricated here. What is needed is something that provides THRUST to accelerate this chamber. You are suggesting Controlled Explosions via fusion to accomplish this.....then what is the purpose of the U238 coating?

Your scenario of Controlled Fusion Explosions using the laser as a trigger does not account for the use of the U238 fabricated onto the walls of the thrust chamber, it obviously is not there because engineers designing this thing didn't know what else to do with their time. If in your scenario Controlled Fusion Explosions provide the forward thrust, what is there about the design requiring the presence of U238?

Jul 14, 2015
If in your scenario Controlled Fusion Explosions provide the forward thrust, what is there about the design requiring the presence of U238?

Directy from the article:
"In this approach the inside wall of the engine's thruster chamber coated in uranium 238 reacts with the neutrons from the nuclear reaction and generates immense heat. "The engine harnesses the heat by running coolant along the other side of the uranium-coated combustion chamber," said Zhang. "This heat-energized coolant is sent through a turbine and generator that produces electricity to power the engine's lasers."

So please read the article again.

Jul 14, 2015
If in your scenario Controlled Fusion Explosions provide the forward thrust, what is there about the design requiring the presence of U238?


Directy from the article:
"In this approach the inside wall of the engine's thruster chamber coated in uranium 238 reacts with the neutrons from the nuclear reaction and generates immense heat


Read again & notice that the results of the "nuclear reaction" are "neutrons" which "reacts" with the U238,
at which point the heating effects powerup to provide thrust. What neutrons are reacting with U238? Only Fast Neutrons because thermals will not react with U238.

"The engine harnesses the heat by running coolant along the other side of the uranium-coated combustion chamber," said Zhang. "This heat-energized coolant is sent through a turbine and generator that produces electricity to power the engine's lasers."
It is noticeably clear there is no discussion by Zang with regard to how thrust is generated.


Jul 14, 2015
nkal:

With regard to "exploding fuel pellets" to provide thrust, do you really want explosions going off inside this small of a chamber? The fusion rate needs to be severely restricted, if those pellets of tritium fuse all at once in an uncontrollable fashion that you are describing as an explosion, then it's worthless.

This all comes back to the sequences of events Zhang is clear about. I know an Electrical Engineer who works at Boeing, I left him an email to see what he's heard about this, I'm unable to see how thrust can be generated that is sustainable.

Jul 14, 2015
how is this different from a standard neutron generator? And they why could we simply use an particle acceleratir, like the neutron generators use, in order to aim the neutrons at the uranium?


Jul 15, 2015
how is this different from a standard neutron generator? And they why could we simply use an particle acceleratir, like the neutron generators use, in order to aim the neutrons at the uranium?


It is different through the use of U238 which is not used in neutron generators. This design explicitly focuses on U238 as being the target of neutron byproducts AFTER fusion occurs. The only neutron byproducts of fusion that can react with U238 are "fast neutrons" which obviously are intended to initiate radioactive decay of the U238, this for the purpose of raising the temperature of the shell of the heat exchanger.

Zhang is being very coy in not explaining anything about the thrust capability of this design. It isn't enough to just raise the temperature of something to get sustained thrust, there needs to be a supply for continually expanding gas inside a well sealed chamber to generate thrust.

Jul 15, 2015
"Boeing has patented a laser powered propulsion system for airplanes. A number of sites reported on the patent, with eye-rubbing headlines that told the story. The BusinessInsider headline read, "Boeing just patented a jet engine powered by lasers and nuclear explosions." Benjamin Zhang said the US Patent and Trademark Office approved Boeing's application for a laser and nuclear-driven airplane engine."

@nkalanaga: In the article it's described as an "airplane engine" & a "jet engine", not a rocket, just read it for yourself immediately above. Thus, the "reaction mass" is not required to be directed as you suggest to provide thrust.

Because this is a "jet engine", the whole concept as you described is moot, as it is the ram features of incoming air rapidly expanding & then exhausted that provides the forward thrust.


Jul 16, 2015
If you look at Boeing's diagram, there are no "ram features of incoming air rapidly expanding & then exhausted", because the front of the reaction chamber is solid. It would be possible to build such an engine, using fusion to heat other reaction mass.


.....why would there be "ram features", this is the nuclear nodule section, why would you put the entire engine in this diagram? They're not claiming a patent on that part. Just how much thrust do you think that tiny nodule of "reaction mass" will create? I can't see that thing getting a two seater Cessna off a runway.

How do you manage to confuse a jet engine with a rocket engine when you say: "A rocket IS a type of "jet engine". I'm a Nuclear/Electrical Engineer, so give me some latitude on terminology here, but yours is the first claim I've ever heard that "rocket engine" is interchangeable with "jet engine". Are you an Aeronautical Engineer who knows this is a common use of aeronautical terminology?

Jul 16, 2015
This is nothing new! My grandma built one out of her old dentures! Silly Boeing engineers.

Jul 17, 2015
nkalanaga: You are going to great lengths redefining "rocket" & "jet" propulsion systems. In Aeronautics there is clear delneation between the two types of engines, but it doesn't matter for the purposes of the information with regard to the functions of the nuclear nodule by Boeing.

There is not a scintilla of information provided by Zhang that the purpose for the tritium is for the purpose of anything other than to function as a source of (fast) neutrons to react with the U238, period. Boeing is the manufacturer of the engine component & they say the engine that provides thrust for the "airplane" is a "jet engine", period. Any interpretation other than what Boeing provides is guesswork, period.

Any re-explanation to make a "rocket" out of this fusion nodule has no basis from the information Zhang provides with regards to the purpose of the tritium fuel. Nowhere does he hint there is a dual purpose for the use of the tritium fueled fusion reaction.

Jul 18, 2015
Hi nk:

I do see the points you are making. There are several different "experts" aside from Zhang who are providing their interpretations of how this thing is supposed to work.

There's Ackerman from IEEE claiming to explain with great brevity how "energy pushes against the walls of the cavity to provide thrust". Millions of degrees of heat are involved here that must be cooled before the fusion energy reaches the U238 while it is undergoing a reaction with the fast high energy neutrons. This is a poorly written synopsis of a powerplant that probably can never be built .

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