This could be welcome competition to the extremely high altitude supersonic intercontinental electric jet SpaceX is conceptualizing through it's current iteration; hyperloop competitions.
I saw this but didn't post it here as I couldn't see that it had any spaceflight applications?
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
Quote from: go4mars on 07/09/2015 02:34 amThis 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.
There is an image which says "coated with a fissile material like U-238".AFAIK U-238 is not fissile material.
Quote from: hkultala on 07/09/2015 06:12 amThere 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.
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.
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?
Quote from: STS-200 on 07/09/2015 01:50 pmQuote from: hkultala on 07/09/2015 06:12 amThere 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?
Quote from: Star One on 07/09/2015 06:22 amI 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 Stratolaunch2) Flyback engines on a first stage rocket booster3) 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 like5) Aircraft for Mars, Venus, Jupiter, Titan6) Ground-based power generation on Mars... use 'em as turbogenerators7) Ground based power generation on Earth for laser launch systems 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.
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.
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!
Here is the actual patent application. http://patents.justia.com/patent/9068562It 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 this1) 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)
Quote from: DanielW on 07/10/2015 05:26 pmHere is the actual patent application. http://patents.justia.com/patent/9068562It 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 this1) 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.
Patent HistoryPatent number: 9068562Type: GrantFiled: Oct 05, 2012Issued: Jun 30, 2015Assignee: 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 WongwianAssistant Examiner: William BreazealApplication Serial: 13/645,816
Here is a PDF version of the patent.
Quote from: M_Puckett on 07/09/2015 12:23 amDetails 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-2015-7So 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.pdfIt 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 .
Quote from: john smith 19 on 07/09/2015 08:04 amQuote from: M_Puckett on 07/09/2015 12:23 amDetails 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-2015-7So 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.pdfIt 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_reactorhttps://en.wikipedia.org/wiki/Nuclear_fusion-fission_hybridAt 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.
Just proofs that you can get a patent for anything these days, especially if you are a big corporation.
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 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.
Quote from: Damon Hill on 07/11/2015 03:25 amBecause 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.
15. An aircraft laser propulsion system comprising: an aircraft comprising: ...
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.
Quote from: DanielW on 07/10/2015 09:48 pmThe 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.Quote15. 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.
Quote from: R7 on 07/11/2015 08:01 amQuote from: DanielW on 07/10/2015 09:48 pmThe 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.Quote15. 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.
Quote from: watermod on 07/12/2015 12:40 amWell 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...
So is tritium absolutely mandatory for this? What about just D-D, or 3He, or p+B11, or something less toxic than tritium?
Quote from: sanman on 07/12/2015 05:33 amSo 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.
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.
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.
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.”
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
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.
Quote from: Coastal Ron on 07/12/2015 01:46 amQuote from: watermod on 07/12/2015 12:40 amWell 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.
Quote from: Spaniard on 07/13/2015 10:20 amFor 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.
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.)
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.
QuoteRegarding 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,
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,
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...
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
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."
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 ..."
Some past designs:http://enformable.com/2015/07/nuclear-powered-airplane-plans-should-remain-grounded/
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.