Fusion in Space: New Plasma Thruster Tested Successfully
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- Опубліковано 28 тра 2024
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Last week I saw a lot of headlines about a space propulsion system that uses nuclear fusion. The news comes from a company by name RocketStar Inc. which announced in a press release that they have “reinvented” spacecraft by releasing the “world’s first fusion-enhanced space thruster, the FireStar™ Fusion Drive. They claim that the FireStar TM Fusion Drive improves their water powered pulsed plasma thruster by harnessing aneutronic nuclear fusion by 50%. In this video I explain what this all means.
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#science #sciencenews #technews #technews #space #nuclear - Наука та технологія
Einstein already has a unit named for him. Ein Stein = 1 mug of beer.
I think i have just witnessed my first German Dad joke. I'll be stealing this if it ever comes up in conversation.
You win the internet for the day! :D
bravo!
Ampère, Newton, Tesla and Volta have SI units named after them. "Bertie" does not.
@@anthonyshiels9273 On the other hand, he does have an element named after him.
"The concept of riding on shock waves became the founding principle of social media"! (6:40) How very true!
🤣
Wondering if that was a reference to "Shockwave Rider" by John Brunner?
I do love this girl's sense of humor.
@@tsamuel6224 damn u must be very old to say this girl instead of this woman .
The deadpan deliver killed me.
Boron fusion makes more sense for a rocket than for a powerplant. On a powerplant you need to have energy output to be bigger than input. In a plasma thruster you spend energy to throw away propellent anyway, so if some of that propellent fuses, that's free energy right there. Same thing works with regular rocket engines, they can fly by just pumping fuel out very fast without ever igniting, but it is way less efficient than burning all the fuel
How does the fusion generate thrust? I assume the decay products (3xHe4) are thrown off in random directions with high energy meaning velocity). Those thrown off in the direction of the nozzle exit would add to thrust, but those thrown off in the opposite direction would do the opposite.
@@FredPlanatia that is why a thruster has a shell, to bounce propellant into the direction we want.
Burning the fuel / propellant is just the source of energy. Ion thrusters so common on satellites for orbit adjustments use solar generated electricity as the source of energy.
@@FredPlanatiathose thrown in the direction of the rocket are the ones that contribute to thrust. The ones that go directly through the exit are wasted energy. The fusion products can only propel the rocket, not drag it
@@FredPlanatia Sure they just interact with the magnetic conduit the plasma already runs through. Those helium nuclei are already charged alpha particles, you can do the same with fission products in a magnetic field.
I humbly propose an Einstein as a unit of a misattributed quotation. "His history paper has 2.5 Einsteins per page."
It's important to remember Orion was abandoned for political reasons, not any technical issues. A model (called the Hot Rod) using chemical explosives successfully flew and now sits in the Air and Space museum.
It really wasn’t practical.
@@melgross For political reasons, primarily the nuclear test ban treaty. In terms of engineering it was perfectly workable.
@@melgross It wasn't practical? By what standards?
It could theoretically make it up to .1c. Nothing we have ever built has ever come close to what amounts to interstellar velocities like that.
Speaking of 'Efficiency' in a rocket engine is a tricky thing, the most literal measure would be how much energy that is liberated IN the device becomes kinetic energy in the expelled propellant in the desired direction which is what actually gives you the thrust. In this regard Chemical rocket engines are actually far more efficient as they reach something like 98% efficiency, while conversly Ion engines expend large amounts of energy to first ionize atoms and THEN accelerate them, the ionization step is a pure loss, in addition their are a lot of ions physically coliding with the walls of these devices which both wear away the walls and represent a loss, lastly magnetic nozzles use curving magnetic field lines which can never be fully parrelel, thus a lot of the ejected ions move out in a cone with some of their kinetic energy orthogonal to the desired thrust which is likewise a waste called cosine loss. All in All an electrical ion type thruster will have efficiency down in the 50-60% range.
What IS much higher for the Ion engine is its Specific Impulse, the amount of thrust produced per unit of propellet mass expelled, becasuse they throw that material so much faster, basically they maximize A in F=MA. This measure is often called 'Efficiency' of a rocket engine but this is slopy use of language and should be avoided. It is like conflating the energy density of Uranium and Coal with a powerplants Efficiency, A Nuclear powerplay is going to use fewer kg of fuel to make the same MWh of electricity, but the THERMAL efficiency, aka heat to electricity conversion of a nuclear powerplant is typically lower then a coal powerplant (30% vs 50%).
Hello Sabine,
There is already a unit called Einstein and named after Albert Einstein. One difinition of this unit reflects the number of light quanta, i.e. photons, that are absorbed or emitted, e.g. in chemical or biological processes. One Einstein corresponds to one mole and is therefore nothing other than the numerical value of Avogadro's constant in mol−1, i.e. approximately 1 E = 6.022 ⋅ 10 ^23 photons. An second, conflicting, difinition of this unit is the energy in one mole of photons, i.e.
1 E = 1 mol × L x h x f = 1 mol × 6.02214076×1023 mol^−1 × 6.62607015×10^−34 J s × f = 3.9903127128934321×10^−10 J s × f,
where L is the Avogadro constant, h is the Planck constant, and f is the frequency.
I first saw this unit in an older patent (US 3749679) on a light-emitting chemical reaction. In this patent it was used to indicate the quatum yield in the form E/mol
However, the Einstein is not an SI unit and obsolete.
The fun part: The size of a mole of photons can be the same size as just one. Pauli doesn't count here.
But that one spot will get real hot, real fast.
I thought I remembered seeing this unit in some rather aged textbooks
@@chaosopher23what do you mean 'the size of the photon'? Do you mean its energy? According to the OP, the Einstein is always a mole of photons. The amount of energy just depends on their frequency. So you could imagine an Einstein of photons of a low frequency (say radiowave photons) having the same energy as a single photon of much higher frequency (say a cosmic gamma ray).
@@FredPlanatia Its physical size. A mole must have more energy than one, but one can be a gamma.
@@chaosopher23 photons do not get bigger when they have more energy. What you say though is correct (and its exactly what i said in my last comment). One photon of a high frequency like a gamma ray can have as much energy as a whole mole of radio wave photons (which have very low frequency and therefore each carries a tiny amount of energy.
"Alien Pan Dealer" lol 😂
Well, life in plastic. It's fantastic.
I broke out laughing at that one.
@@heisag What's not fantastic is the toxisity of Teflon. I really hope that Teflon is never used in earth's atmosphere.
Energy efficiency is usually not an issue in space applications as long as you don't want to fly further away from the Sun than Mars.
If you stay withing Mars orbit you have (usually) all the power you need from just a solar panel, often times more than 23 hours of sunlight per day with no weather to get in the way ever.
So the only thing that matters is fuel efficiency. If you can get extra 50% efficiency, meaning you get 50% hotter exhaust at the cost of increasing your power consumption by 100%, you go for it, It's worth doing because you're saving fuel by spending electricity. Electricity recharges but fuel does not.
Plasma thrusters also make lots more waste heat than ion thrusters since you don't have to heat your propellant with a lossy magnetron. Having some amount of fusion going on in your plasma can make up for some of the waste heat, or we can continue have burn times longer than transit times with plasma.
Yeah but what about during night time?
Just kidding
Plus there are much more efficient solar panels then what is offered to the public to put on your roof.
As someone else has mentioned, "energy efficiency" is not the issue for thrusters. Mass, density, storage and specific impulse (ISP) are the more important metrics. For most Hall effect thrusters, they already have good ISP, but thrust is low. A favored thrust propellant is xenon, which trades off lower ISP for better thrust. It's easily storeable, dense, and isn't corrosive. However, xenon is incredibly expensive, which is why Starlink switched to krypton as a propellant. The fusion enhanced thruster mentioned here would be a welcome step forward because it adds extra energy at just the right time and place to get a relatively low mass (high ISP) propellant to exit at a significantly higher velocity, hence higher thrust. There have also been studies looking at fission/fusion hybrids that use the high energy density of fission reactors plus some of their neutrons to drive fusion reactions in propellants. The fusion reactions are not used as an energy source, but they are used to increase thrust and ISP for your propellant mass.
aren't Starlinks using argon Hall thrusters these days?
@@dylant0000 You might be right. I know the early ones used Kr, but Ar is dirt cheap, which is a consideration when you have to launch such a huge number of satellites with a relatively short life span. I believe they are ~6000 or so right now.
Another problem is that an Orion-style spacecraft is essentially a flying stockpile of tactical nuclear bombs, making it politically, er, radioactive.
@@ericlipps9459 Yeah. That is the main reason why nuclear powered propulsion sits on a folder whereas rtgs are launched no problem. Sigh.
@@dylant0000 Yes they are switching to that apparently from Krypton.
Lol at shockwaves and social media. Also boron isn't boring. Also, efficiency, German.
It's important to note that Orion was abandoned not because it wouldn't work, but because treaties prevented blowing up nuclear bombs in space.
It's also worth noting that the most revolutionary possible propulsion would be one that required only energy as an input. Getting energy isn't difficult in space. It's carrying all the mass that you need to chuck out the back that's difficult. There's no currently known way to convert energy into net propulsion, however. It will require something fundamentally new.
There's a possibility of just that, just read about it...Charles Buhler apparently is working on an asymmetric electric drive....
@@mikereid1195 No, he just believes he is. It's a complete dead end.
Laser propulsion is your friend.
@@skynet5828 That will work fine when the lasers are on Earth and the collection areas are on the spacecraft. As soon as you put the laser on the spacecraft, the effects cancel out, and you get no propulsion.
@@TrueThanny Don't bother with Lasers on Earth. Build them directly in space.
the dry humor hidden in the videos...🤣 social media will never be the same again
Now I understand what social media is all about.
the funniest thing was her opera ad
We devloped the FEEP-Ion Thruster technology here in Austria - so we have some knowledge about this. We always get questions about fusion in space - and yes it would be nice. But to really harness the power of fusion energy you also need a method to transform this enormous amount of heat into electricity with almost no losses - otherwise you have to get rid of these losses - which is very hard in space as there is no medium for cooling. And if people talk about fusion the usually talk about MW and GW - so with the actual technology I see no way to get rid of this amount of "heat" ...
Please be carefull with fusion in space!
Another question for any kind of alpha particle related thrusters: How many do you need and how do you guid their thrust in one direction in a cheap and realistic way?
I would think you would need at least 2 engines that swivel 180 degrees unless you used some sort of vent system that could open and close paths. My min concern would be the reaction speed of the engines as the produce very low thrust. If it took a bit for the thrust to alter the course you would need to know far in advance to alter it. I am also concerned that they wouldn't be able to overcome gravity. One thing I have learned from these videos is most of them are pipe dreams. Like the ones on cold fusion. Great on paper but no way to put them in practice.
They are using energy from the fusion process to boost thrust directly it seems
I guess you have to hope that as the heat is mostly in the KE of the alpha particles and you are throwing them out the back, the only heat left to deal with is how much heat the alpha particles which were not already going backwards (50% of them, I'd say) impart onto the "engine bell" surfaces as they bounce off them. In traditional rocket engines, the bell is kept sufficiently cool by running the cryogenic temperature fuel through it before you burn it. In a big ion thruster, you'd probably have to use a dedicated coolant loop running to radiator panels to lose the heat - like the ISS has.
Instead of thrusting... How about pulling..? Like a light Is magnetic rail.You will follow the path that is mapped without hitting anything.
Reverse thinking..?
@@user-pu2ho4ip3d did you just invent the sail-boat with a fan on the deck pointing at the sails?
"Alien pan dealer" - absolutely love your comedy, Sabine. 😂
For electric thrusters, energy efficiency is usually not the most pressing issue as these are usually intended to be fed by solar panels, and energy supply considered virtually infinite. The more pressing issues are thrust-to-weight ratio and/or specific impulse. Plasma thrusters seem to target a regime between high TWR chemical and high ISP ion thrusters (which are technically also ejecting plasma but I didnt choose the names). So more thrust is virtuous on its own, since the gap between chemical and plasma is still so large. It would be interesting if they could also increase power-to-weight ratio, as this seems to have reached a ceiling across all technologies.
As someone who just yesterday through a random UA-cam video, learned the basics of fusion and fusion experimentation on Earth...
This is amazing news!
Have you not heard of Einsteinium?
I believe in German the element is succinctly called Dermannderdieallgemeinerelativitätstheorieerfandium
It doesn't exist anymore tho
@tedarcher9120
Once was enough...:)
That's an element, not a unit of measure.
😁👍🏻
a) the second equation in the video is 250% stronger than the H-B reaction. it's the one that gave the Castle Bravo detonation its bad rep. the neutrons generated should not be a problem due to the axis of reaction, which should be at least 45 degrees away from the spaceship, so all neutrons "should" add to the thrust. b) the H-Li7 reaction is twice as strong as the H-B11 albeit with a lower cross section, so a compromise using lithium borohydride LiBH4, using the Li6 and the H and deuterium isotopes should enhance the yield. c) then again, to rain on the parade, a solar sail gives 7-9 micronewtons per sq. meter, so 1 sq.km. will give 7-9 newtons of thrust, 500 times the power of the ion one and cheaper to build
3:49 missed an opportunity to call it an alien pan handler..
but they just be looking for fuel themselves
6:37 Well THAT caught me off guard.
Someone should clip it and share on social media.
The einstein (symbol E) is an obsolete unit with two conflicting definitions.
It was originally defined as the energy in one mole of photons (6.022E23 photons). Because energy is inversely proportional to wavelength, the unit is frequency dependent. This unit is not part of the International System of Units (SI) and is redundant with the joule.
Later, the unit was used differently in studies of photosynthesis to mean one mole of photons, rather than the energy in one mole of photons. Photosynthetically active radiation (PAR) was formerly often reported in microeinsteins per second per square meter (μE m−2 s−1). This usage is also not part of the SI and when used this way it is redundant with the mole.
Since the unit does not have a standard definition and is not part of the SI system, it has long been considered obsolete.
I like it. Einstein means "one stone", so one einstein is one one stone, two einsteins is two one stones, three would be three one stones and so on.
Brilliant! The best part of this video for me is your idea of measuring ingenuity. 1 Einstein (E) = 1 unit of innovative problem-solving
But, not all problems are the same. If 1 Einstein is the amount of problem solving required to invent General Relativity, then most people are operating at the level of milliEinsteins.
There is already a unit called Einstein and named after Albert Einstein. One difinition of this unit reflects the number of light quanta, i.e. photons, that are absorbed or emitted, e.g. in chemical or biological processes. One Einstein corresponds to one mole and is therefore nothing other than the numerical value of Avogadro's constant in mol−1, i.e. approximately 1 E = 6.022 ⋅ 10 ^23 photons. An second, conflicting, difinition of this unit is the energy in one mole of photons, i.e.
1 E = 1 mol × L x h x f = 1 mol × 6.02214076×1023 mol^−1 × 6.62607015×10^−34 J s × f = 3.9903127128934321×10^−10 J s × f,
where L is the Avogadro constant, h is the Planck constant, and f is the frequency.
I first saw this unit in an older patent (US 3749679) on a light-emitting chemical reaction. In this patent it was used to indicate the quatum yield in the form E/mol
However, the Einstein is not an SI unit and obsolete.
Aneutronic fusion was also "achieved", at small scale, by the "cold fusion" experiments Heavy Metal elements in the catalysts composing the electrolytic cells absorbed protons and released subatomic particles.
Nice explanation, thanks!
Wonderful explanation. Don't you need a Newton bobblehead now?
Haha, she should have quite a few of them. Bonus for a Musk bobblehead, since he doesn't call that often these days...
Sabine could have bobble-heads of all the famous physicists on a time line, then we could see how old/new the ideas are.
@@geirmyrvagnes8718 Perhaps Musk is busy to liquid the money to fund Sabine´s research on "indefinfte causal structure" stuff (measurement problem)
A 50% increase in thrust SHOULD mean compared to the thrust they got from the same energy in an ordinary plasma thruster. The reason fusion will work in rocket engines long before fusion reactors will make power is that a small % of break-even can produce a large increase in thrust. Generating net power output is way harder. Boron-deuteride fusion fuel has been researched for quite some time, but this idea of scooping up water in a 5 gallon bucket from the swimming pond and tossing boron in that to burn has got to be the most awesome method yet.
I like your Einsteinian scale. Makes for a good grounding in reality.
Its kinda relative though...
@@procerusgigas I like this guy
Wow. I used to play with water rockets when I was a kid, and now they're actually going to be used in space. :-)
Thanks for the Video Sabine :)
I think non chemical propulsion is a great idea, but I always become a little skeptical when overture is suggested and there are hints of a hidden battery lol
Love your videos subscribed and watching all of them👍👍
I forget when but.... but I thought of this concept briefly in a fit of tiredness, comparing it to similar concepts using normal hypergolic propellant's. i remember being amazed at the possibility, especially in outter space because of the Shear amount of energy density of nuclear reactions.. im truly amazed that people has actually went with the concept and already gotten something that is even testable WOW!.. this kind of ''Marrying'' of different technologies might just get us out of our issues, truly a prospect to behold..
Having a small nuclear reactor to power giant high thrust ion engines would be the best option for long efficient space travel, it could also power the life support and spacecraft systems too. It’s also completely doable with modern technology too. Really technology that has existed for at least 30 years.
Not mentioned was also the plasma temperature used to support the tests thus far. A fan of VASIMR, I was rooting for some sort of 'afterburner' to enable it as a fusion drive. The plasma production stage using RF (microwave) excitation looks similar. VASIMR developed thus far needs 200 kW power (via in space kilopower nuclear fission generators) to target 5 N of thrust. Mars in 39 days needs 200 MW; so if fusion drives provide a gain of 1000 times over such systems, it'd be worth it.
"Riding the shockwave became the founding principle of social media" Literally Gold. But i still smell sock-waves. That's not confirmation bias, it actually stinks.
I'm glad this research is moving forward, but the hype about it moves ahead so much faster.
You miss why electric thrusters are more “efficient.” It is not that they use energy better but rather fuel. They accelerate the fuel leaving the ship to much higher speeds than chemical rockets can so less fuel is required for the same thrust. But there is a limit to how fast electric systems can accelerate. At best they can get the propellant to a few keV of kinetic energy. Fusion produced alphas have MeVs of energy and so produce higher energy thrust. It won’t produce energy but it may provide higher ISP for slightly more power.
I don't think the goal is to minimize electricity or to be energy efficient, but to minimize fuel loss. Most orbiters have solar panels for electricity production. The problem is it's hard to refuel in outerspace, so you want to get as much thrust as possible for the amount of fuel you have.
I think, Sabina that the point is how much trust you get from the MASS, not the energy you throw at it. You have alot of Solar energy available, but just not so much mass.
That still looks like fission to me. Since your final product is 3 helium
Well it's proton capture followed by a decay. So you can either call the proton capture "fusion" or call the decay "fission" or both?
@@SabineHossenfelderFussion
@@SabineHossenfelder
Somewhat off topic, but when you were promoting your sponsor Opera web browser, the way that you pronounced it sounded like "Oprah." Not criticism, just an observation.
@@spaceman081447What? You don't browse the internet with Oprah? 😉
@@SabineHossenfelder Fission in a standard nuclear reactor is neutron capture followed by a decay. I don't think anyone calls that neutron capture fusion. So what's the difference?
Opera, not to be confused with Oprah. 😛
I think several separate quality metrics are being confused here: energy efficiency, energy consumption and specific impulse.
Ion and plasma thrusters by intent use far more energy per unit thrust then chemical rockets. This is because they are designed to have a high exhaust velocity,
which means more kinetic energy per unit momentum.
This greater energy use per unit momentum change is a net win because the limiting factor is available reaction mass. There is unlimited energy available (eg from solar panels) but only a finite tank of reaction mass available.
Fusion boosting is _plausible_ for this application if it results in a higher average exhaust velocity, even if the fusion is a net energy consumer. A fusion reaction that consumes more energy than it produces isn't useful for generating energy, but if it increases exhaust velocity then it is useful for reducing the amount of reaction mass consumed.
Jonathan
_less_ energy efficient than chemical rockets. The kinet
3:15 - Working fluid, that is, reaction mass, actually. Energy "lasts" for as long as your solar panels do.
7:40 whoa! Haircut.
Sabine, I love your sense of humor 😄
Fascinated lay person here. You mention opposite and equal reactions and that F = MA, but I felt like there wasn't enough time spent on the beautiful simplicity of that equation. Particularly in space travel, where there are basically no other options, you really need 2 things to produce thrust: 1. particles to throw out the back, and 2. energy with which to throw those particles. Once you have those it's just a matter of balancing other variables, for example: how fast is the thrust, how much other resource(s) does it take, how heavy is it, how long can it last, how safe is it, how much does it cost.
Chemical rockets are nice in that they provide both necessary items -- burning AND throwing the result out the back are both done in a simple "burn" or "explosion" reaction. Thus, energy source and particles are the same "fuel". Additionally, these reactions happen quite fast, so both the energy and the particles are provided quickly. These rockets' advantage is the large thrust produced, but their disadvantage is relatively low efficiency and thus high weight. These lead to not lasting terribly long and being darned expensive. As you mention, though, they're currently the only way to get enough thrust to actually leave Earth.
If you can get your energy another way (say, solar), there are several other methods to produce thrust. This video is about plasma, and ion thrusters are very similar (or a subset?). In comparison to rockets, these throw the individual particles (fuel) much, much faster, spending more of the energy on less of the fuel. This means less fuel required and less weight, and therefore over a longer lifespan. But they lack (with present designs) any way to do this in high amounts quickly -- the number of particles thrown is orders of magnitude smaller for the same space & weight. For non-takeoff flight this isn't an issue, so they're usually better (at least in theory) than rockets, especially if you can use a fuel you can find in space (like water?).
To get off the ground better than chemical rockets, we'll need to find a way to throw the particles faster and convert energy more quickly, in a lighter package, while still being somewhat safe (I don't think anyone wants a nuke hitting Cape Canaveral). That's kind of a tall order and is why it's still being used over 50 years since landing on the moon.
All kinds of brain teasers offered in a single vide and comments to it! I would add one. Think why you pretty much cannot keep using liquid fuels, when you have got up to low or no gravity region (and additionally are past the acceleration provided gravity equivalent effect). Where does your fuel “settle” in the tank? How can you push or pump it to the “burner”? On the other hand, how do you get both positive and negative charged particles of the plasma mismash shoot out in the same direction? Or don’t you care, given the 1800x mass difference, as long as the negative ones are electrons (and not heavy ions). Just for funny thoughts…
I have never known anyone so obsessed then Sabine. Her devotion to mentioning the Isles is becoming legendary.
Thank you very much for the video.
One must pay close attention to get your very dry humor. I think I love you.
I love the Albert figure in these videos
Why not Use both types of thrusters
Boron + H aneutronic fusion: isn’t it the same, as what Dr Lerner has been pursuing for years with his Dense Plasma Focus Fusion device? His approach in using plasma instability/collapse to compress the fusion material is quite unique.
Brilliant suggestion for name of new unit of measurement
I've used Opera for years in
Linux, good stuff!
Me too, and yes, it is.
@@phantomcruizer , It parses everything very nicely, and great features under the hood (Americanism for "nice internal design"). Glad they're sponsoring Dr. H.
You are such a good teacher
Ion drives are interesting because it is like the fuel is partially solar for example that gets added to the acceleration. So it kind of relies on the magnitudes of electrical power vs physical acceleration. Also you have reduced launch mass. Also I think they pulse it because it raises the electrical potential for the particle, which get fired then overall for a longer duration. My understanding it that basically in orbital transfers, you can add thrust as slowly as you want and you get the same result. For direct body escape, you want as much thrust as quickly as possible.
Shockwave Rider... was that a John Brunner reference?
Thanks Sabine, you're the best 😊
I like that Einstein unit of measurement 😊
the problem with detonating nuclear bombs as way of propelling a spacecraft is that nuclear explosions are much less dramatic in a vacuum without an atmosphere to play with. They mostly generate radiation which is why China has considered "Nuking" defense satellites to shut them down, not by the explosion but the radioactive pulse.
Thank you.
Hands down the best science communicator alive.
Nuclear fusion is probably the only thing that will get us interstellar travel.
There’s a guy in Popular Mechanics who recons that he’s manage to break the laws of gravity with with his thrust drive today.
That’s cute 😅
I saw that headline go by in my news feed today. I skipped it. While PM doesn't go into conspiracy/crackpot territory, their coverage of physics is not quite what I'd call solid.
@@DrunkenUFOPilot too much time spent doing pure maths no doubt.
love the swipe at social media
Now this is the real and actual bladeless fan.
Plasma thrusters are more propellant efficient, not generally more energy efficient. Chemical rockets with optimized nozzles convert about 70% of the chemical energy in the propellant into kinetic energy of the exhaust. Plasma thrusters vary in efficiency, but are generally less energy efficient than a bipropellant rocket. The reason they use less propellant is because they accelerate it to higher velocities; this is less energy efficient, but if you have large amounts of energy from solar or nuclear power you can save propellant mass.
Lots of comments already but to be clear the part of the video about energy efficiency is potentially misleading.
Simplistically, energy efficiency (in terms of the amount of fuel potential energy that ends up as rocket kinetic energy) is inversely proportional to exhaust velocity (Isp) for good Newtonian reasons: while the change in momentum of the fuel and rocket are always equal and opposite, the higher the exhaust velocity (lower mass flow rate for same thrust) the greater the proportion of the kinetic energy of the system ends up in the exhaust gasses - ie less of the fuel energy ends up as rocket KE. KE goes with the square of velocity while P is linear with velocity. Propellant efficiency is the opposite - higher Isp means you need less propellant mass. This is the so called Tyranny of the Rocket Equation. Less simplistically a higher Isp engine allows you to carry less propellant mass and therefore you need less energy to accelerate it , which does offset the lower energy efficiency of the engine over the mission.
Galileo neither has a unit named after him. I think that is an historical mistake. I propose to name kg*m/seg as 1 Galileo the unit of momentum that he already study and deserve.
😂😂😂😂😂😂 you killed me with “alien pan dealer”
"a reaction drive's efficiency as a weapon is in direct proportion to its efficiency as a drive." Larry Niven
Love the new unit of measurement ❤
actually the reason I believe that this might work is that it doesn't have to be Q+, just more efficient than increasing the plasma velocity by 50%.
The thing is hall effect or gridded ion thrusters are far cheaper, lighter, and electricity efficient (less waste heat for a given jet power; less solar and radiator mass) that the extra exhaust velocity of plasma won't matter to mission profiles.
why does everyone talk about propulsion or thrust or newton's third law like it's magic? "throw something in one direction and you'll move in the opposite direction just because". when you throw or move something in someway, there is resistance to moving that object because of its mass, so you move away from it because you are essentially pushing against it, like a wall, before it starts to move. with rockets, hot gas is being pumped out the end faster than that gas can dissipate, and pushes back against the rocket.
With the show, 3 body problem and others exploring the possibility of nuclear propulsion in other space, a video on the different modes of outer-space transportation and their pros and cons might be a good topic to cover next( ie nuclear solar sail vs project orion shock-wave )
40MN is why we need to be working on industrial infrastructure in space.
Hello Sabine and thanks for the excellent video!
Talking about propulsion, I'm looking forward to hear your take about the exodus drive.
If you ask me, it doesn't work but I'd like to know your opinion.
I like the Einstein as a unit of ingenuity. Every one knows that, as Helen of Troy is the face that launched a thousand ships, a milliHelen is the amount of beauty required to launch exactly one ship. In accordance, when somebody says "How cool is that?" I reply in Fonzies, the unit of coolness. The unit of fun is the Disney (equivalent to one day at Disneyland), the unit of cuteness is the Shirley Temple, and the unit of awesomeness is the pNorris (the negative logarithm of how awesome something is compared to Chuck Norris). Noone gets below .2 pNorris.
Some space propulsion does without throwing stuff out of the spacecraft, but rather hits the spacecraft with external stuff that already moves fast in the preferred direction. I believe it’s called “a solar sail” or something.
Fusion doesn't need to be efficient for space travel. As the inefficient portion can be performed Earth side, such as creating Fusion Pellets. So you can have a situation where you are using more energy to create fusion than you get out of it, that is actually beneficial for space travel. As you create a incredibly energy dense fuel that weighs fractions of what a chemical rocket would weigh. Which means better payloads. Or in this case, a massive amount of fuel for long distance space travel.
Fascinating indeed... I'm not superstitious, but I'm crossing my fingers. 😊
Thanks, Sabine!
Stay safe there with your family! 🖖😊
Orion was tested with conventional explosives. It worked. It _was_ kinda bumpy.
You don't throw fuel. Fuel provides the energy, propellant provides the momentum. You throw propellant, which in a traditional rocket is mostly but not entirely fuel. It is only all fuel if you have a stoichiometric mix, which is super weird.
Looks like we're a step closer to torchships
If you did it in a continuous pulse yet rotated the emitter, at a certain rpm, I’m sure you would get a water wheel effect that would propel you some what efficiently
I've thought for a long time that we should rename the kilogram the Einstein or just the Stein. This tidies up SI units which is messed up by the kilogram base unit having an untidy factor prefix. Einstein deserves a unit, and given E=mc2 mass is a good candidate. Also "ein stein" means one stone, which is naturally a unit of mass, and a typical stone would weigh about 1 kilogram.
I do not assume to know much about what Sabine discusses here. But that shockwave vis a vis social media... it made me chuckle!😅
She´s so special...
Dear Sabine, you are wrong: Einstein is already an established unit. 1 mole of photons: en.wikipedia.org/wiki/Einstein_(unit)
Assuming that the fusion reaction works as advertised, yes it gets you some extra energy, but for thrust you need to give your propellant momentum backwards. Where does the extra momentum come from?
I think you answered your own question. They are working on a spacecraft engine because they don't have to worry about containment.
BTW, rocket scientists make a distinction between fuel and propellant. You don't (generally) push fuel out. That's what propellant is for. You use fuel to power a reaction that increases the activity and efficiency of the propellant. With a Hydrolox system, hydrogen is the fuel, oxygen is the oxidizer, and water is the propellant. Of course, hydrogen is a better propellant than water due to specific heat, so they often run it rich to increase performance, meaning some of the fuel is propellant.
Very humourous.
🟨 Welcome to the Physics Dept. 🟨
Yes . . . . that's a coffee machine.
Please don't touch that plasma thru💥 . . . . . . . .
Lol😉
Totally digging those Iron Man like animations. I need that as my screensaver / background.
I have no clue what you said but this sounds pretty revolutionary 😂❤️
Starting at about 03:46 in this video...
Sabine: *_"...which is hard to do with Teflon, unless possibly an alien pan dealer comes your way.'_*
🤭🤭🤭
🤔 Wild thought here. The thing about this is that during normal fusion the alpha particles shoot out in random directions. That means you need either an electric or magnetic field to direct the things. Therefore, this field must do work on the alphas. If you can direct them into a stream and then stop it with a strong field the energy of the alpha charge should be converted into momentum into what ever is creating the field. 👍???👎
I would also focus on the dynamics of movement, Tesla's model for water could also be valid against air resistance!
"YOU GET AN INTERNET BROWSER, AND YOU GET AN INTERNET BROWSER... EVERYONE GETS AN INTERNET BROWSER!!!" - Opera
Frau Hossenfelder @sabinehossenfelder "Thank you for one of the most thought provoking subject to date! First and foremost I am NOT a scientist nor an academic, But very curriouse to say the least. None the less just an idea to put forward. Why not build an engine/power source around the 3 "most" volitile elements then encapsulate it twice. First shell around the engine would be Boren the second would be water. Again just a thought. Thank again for your knowledge. avb (And to the readers of this post, don't be negative on the replies, just point out my error.)