Satellites once used propellant for attitude control. When the propellant was used up, the satellite lost the ability to maintain or change orientation. Very much as this article describes, control moment gyroscopes took over because they didn't require propellant. They operate on the same principles that let a cat land on it's feet by twisting about as it falls.
However, there's a key difference between attitude control and movement. Changing your orientation doesn't involve changes in net kinetic energy, momentum, etc.. Changing speed (i.e. What a propulsion system does) does involve changes in these quantities, so Newtonian conservation laws come into play.
>"Genergo’s system generates thrust without using any propellant and without expelling reaction mass, by directly converting electrical energy into thrust through controlled electromagnetic impulses."
If this isn't hogwash, it might be something similar to an ion engine. i.e. It does operate by expelling propellant, but what it uses as propellant is background dust and ions, accelerated to a high velocity by electric fields and expelled.
If, as the site claims, this technology is currently working and produces non-negligible thrust, it could be very useful. They need to be very clear about what this is though, since vague and unscientific sounding claims will not attract clients.
Article is light on details but there’s a few options such as using sunlight or earths magnetic field to move around without propellent tanks near earth.
It’s surely hogwash. I like how it’s “validated” but does not mention power consumption or measured thrust.
For what it’s worth, one can very straightforwardly produce thrust using electromagnetism: just shine any sort of light out the back of your spaceship. This is called a photon rocket, and it works because light has momentum. Very little momentum: thrust = power / c. It’s only worth doing if energy is free in the way that light hitting a solar sail is free or if you power it with something absurdly energy-dense like antimatter.
Propellant is still used for rotation control. Reaction wheels can "saturate" if they compensate for rotation more in one direction than the other on net, so propellant is needed to get them back down.
Ion engines, generally speaking, do not use background dust. They still carry propellant, they just eject it electromagnetically.
An photon engine, basically just a laser pointed backwards, uses pure electricity to produce thrust. But of course the numbers all work out, since photons have momentum. They're extremely weak though, even lasers of staggering power produce very little force. There's no way you could put one on a satellite
> Reaction wheels can "saturate" if they compensate for rotation more in one direction than the other on net, so propellant is needed to get them back down.
Torque Rods can be used to desaturate wheels without needing any propellant
Am I correct in thinking that in some cases gyroscopic orientation results in turning 270° the “wrong way” to cancel out net gyroscope speed due to friction losses?
This article is quite frustrating, since all that it really tells me is that their system "generates thrust without using any propellant and without expelling reaction mass, by directly converting electrical energy into thrust through controlled electromagnetic impulses".
That's rather non-specific. My first thought was that they're using photon momentum, but thinking about that a little harder rules it out. The ratio of energy to momentum doesn't change with any properties of the photon (they're both proportional to frequency) so there's nothing to really develop there: so long as you waste very little power as heat, you might as well be shining a well-collimated flashlight.
Options 3 and 4 from [this paper](https://arxiv.org/pdf/2510.21743), _magnetic sails_ and _solar sails_, seem more promising. Is that what Genergo are doing? I have no idea. The article doesn't tell me.
"Scientifically tested!" is the marketing term for "The tests showed it didn't work, but we won't mention that second part!"
E.g.:
"successfully flight-tested" -- didn't break or leak anything when launched into space. A brick also has these properties.
"validated across three space missions" -- a brick could be flown multiple times too, this proves nothing except that this thing is space-rated.
"protected by a portfolio of granted international patents" -- we've got more lawyers than engineers!
"accumulated more than 700 hours of on-orbit operation" -- I could say the same thing about a brick left in orbit for a month.
"multiple on-orbit activation cycles have continued alongside data analysis and characterization activities" -- we kept turning it on and off in a futile attempt to work out why nothing was happening.
"confirmed system functionality in real space conditions" -- It definitely was "on", drawing power and everything!
"several long-duration tests were conducted in which it was observed, objectively and repeatedly, that motor activation produced a measurable acceleration or deceleration of the host spacecraft." -- we got confused by atmospheric drag, IMU drift, vibrations, and other confounding factors and called the experiment a success despite a string of failures for short-duration tests.
I remember in the 80s, after mostly having given up on perpetuuum mobile, bunch of people were trying to invent something like this, using vibration etc which worked on Earth but would not in a vacuum... Looks like a new generation took the baton. Like this guy:
An Engineer Says He’s Found a Way to Overcome Earth’s Gravity
This new propulsion system could rewrite the rules of spaceflight—not to mention completely defy conventional physics.
"In 2001, British Electrical Engineer Roger Shawyer first introduced the “impossible drive,” known as the EmDrive. It was called “impossible” because its creator purported that the drive was reactionless, meaning no propellant required—in other words, it defied the known laws of physics (specifically, the conservation of momentum)."
It's easy to validate this claim, just link to its orbital tracking data.
I keep looking at the data for OPT-2[1] which is supposed to be a "quantum drive" from a IVO Ltd.[2] but haven't seen any significant orbital changes yet.
They say it works "by directly converting electrical energy into thrust through controlled electromagnetic impulses", so I assume it's reacting against the Earth's magnetic field using the Lorentz force?
Yes but they also don't seem to claim it does. The use cases they talk about are orbital station-keeping and de-orbiting of satellites. So that implies near-Earth use.
Their patents don't say anything about an external magnetic field, so at best they've accidentally rediscovered it through experimental error and don't know it yet.
I suspect that you’re right, but I believe that I heard something about a similar ‘drive’ being used on some sort of telescope satellite in the past (though I can’t remember the specifics).
Not possible according to the laws of physics. The closest you can get is a solar sail, but that's not "propellant-less" - photons are the propellant.
If a company thinks they've broken one of the most fundamental laws of physics (momentum transfer), they need to provide some serious evidence, and publish in full so their results can be replicated. A press release on an obscure website isn't how you do it.
It certainly sounds like "We managed to run our EM drive hardware in space, and our instruments say it did something" (as did EM drive proponent's, in error). Because if it really was even something like "we successfully produced thrust from ambient ions/earth's magnetic field/etc" then it would be much bigger news.
Anyone publishing a repeatable experiment demonstrating this would be more or less instantly handed a nobel prize, since it would have to unlock new fundamental physics.
It would also totally rock cosmology since you’d have to rework the whole age and evolution of the universe in light of those new physics, whatever they were.
This is almost definitely bunk. Either that or something mundane explained in a ridiculous hypey way.
Seems like the focus is on orbital dynamics, so I’m guessing it is reacting against the magnetic field of the planet or the particulates in the solosphere.
It would be cool, though, if it were actually interacting with the zero point field or some similar bunky stuff. We can already extract minute amounts of matter from the field, ostensibly experimentally proven, so I suppose it’s not impossible to imagine that you might somehow be able to push on Casimir forces, perhaps.
At first—like many others here—I thought it might just be a terribly-written explanation for a device that uses Earth's magnetic field, so that the planet itself is the "reaction mass" being pushed around... but I'm not seeing that in a quick patent search for the company.
Instead, there's a bunch of stuff that seems like perpetual-motion-machine crankery, where their "motor" depends on a oscillating some mass back and forth inside a chamber using special frequencies and "waveforms", which somehow imparts some acceleration which they explain as "generating mass."
Perhaps did use Earth's magnetic field through pure experimental error, and they either haven't realized it or think they can bilk investors by presenting it as something new.
> The inertial mass of an object varies with the variation of its magnetic field and therefore a variation of inertia can be created which leads to the generation of mass by varying the magnetization of the motor and its constituent elements (at given times, as explained above).
> [...] the variation of “mass” is generated by the overmagnetization or undermagnetization of the motor itself in conjunction with given “shocks” or interactions between the magnetic piston and the two buffer magnets [...]
> [In] general the motor or the moving system according to the present invention consists of an electromagnetically charged body which moves within a delimited volume of space being accelerated and decelerated electromagnetically in controlled manner during its movement within said volume of space.
> Such accelerations/decelerations generate a force on the volume inside which the mass moves and allow the volume of space to move.
I think you are right. Either they have accidentally used the Earth's field somehow, or they are mistaking other effects (drag, perturbations...) for a thrust.
I would tend to think it uses Earth's magnetic field. Magnetizing or demagnetizing a moving mass would make its potential energy vary inside Earth's magnetic field. This may occur without reaction (I am not sure about this, my physics courses are far away and magnetic material physics is not that easy). Once they varied the potential energy of the moving mass, they would actually move it inside Earth's magnetic field, leading to a reaction force. The reaction force would be greater in one direction because of the cyclic magnetization/demagnetization.
And if the satellite's orbit is not perfectly circular, you may even be able to gain altitude by moving a mass at specifics times, like a kid on a swing or a skater in a ramp.
I am highly skeptical. A reactionless thruster is the holy grail of propulsion systems, but there are no known physics which permit it to work. A photon rocket would allow momentum exchange without mass consumption, but a quick look at the math shows it would be infeasible (hundreds of megawatts per newton).
My guess is this works at all, it is inadvertently expelling reaction mass somehow, such as ablating off small amounts of volatiles from polymer parts (like an inefficient version of a pulsed plasma thruster).
I'd love to be wrong, but this very much falls into the "extraordinary claims" category for me.
A photon rocket would involve use of mass. The only conceivable way to power one would be something like fusion or antimatter matter annihilation, which converts mass into energy. It’s just a rocket with the maximum possible exhaust velocity: c.
Photons have no mass. Massive particles cannot travel at c. Massive particles experience time. Photons have momentum because they contain energy, but no mass. Momentum being expelled is how the mass is accelerated. You don't need a propellant, but you do need a means of generating momentum.
Photons have mass in the sense that energy and mass are equivalent. What I meant is that a ship with a photon rocket is expending mass, given that the power requirements demand some kind of mass energy conversion to get enough photons. Viable photon rockets able to move anything of any size would require petawatts of power.
If you do the rocket equation math it kind of behaves like you are throwing mass at c even though you are not. You are converting mass to energetic photons and throwing them at c.
There’s a rough breakdown I saw once on a forum about future space flight tech:
Launch is dominated by thrust. Your T/W ratio must be >1. Travel within the solar system is dominated by specific impulse. Small thrust for a long time can get you going real fast, but you can only carry so much propellant. Interstellar flight or beyond is dominated by raw energy. To get to the stars in any “reasonable” time requires you to be doing a fair amount of E=mc^2-ing.
Torque rods do work in MEO/GEO, but you need significantly more magnetic moment to get the same torque (ie: larger rods and more current).
It's more a question of how much momentum you need to dump that determines if they are practical or not - magnetorquers are rarely used for direct attitude control, since they don't produce much torque. Instead, they are used "dump" excess momentum stored in the spacecraft's reaction wheels. The wheels can generate high torque, but they do so by changing their rotational speed, storing angular momentum. Ultimately, wheels have a finite maximum rotation speed, so they need to be "desaturated" by transferring angular momentum elsewhere. Magnetorquers provide a way to slowly transfer the angular momentum to the earth over time via its magnetic field.
They're sometimes used on small/micro sats that don't have any reaction wheels or CMGs.
Solar sailing (pitching the solar panels) is another (and more "free") way to dump momentum by using the solar wind. Obviously you need a big solar array for this to be practical.
> "Genergo’s system generates thrust without using any propellant and without expelling reaction mass, by directly converting electrical energy into thrust through controlled electromagnetic impulses."
Maybe its possible to generate motion using the Earth's magnetic field under the right circumstances, though I'm not sure if that's really feasible. Or they might be able to create a very small thrust by emitting photons, but that must be very very small if its actually the case.
If you have a source of energy on the spacecraft, like a solar panel, you could theoretically convert some of that energy to particle pairs with mass. But this is such an inefficient process (and so inherently low-mass with any practical energy source) that I doubt the claimed thruster could work this way.
Skimmed the patent. Its 99% a pedantic and exhaustive explanation of a linear motor. The only interesting thing they mention, is this:
The inertial mass of an object varies with the variation of its magnetic field and therefore a variation of inertia can be created
But they provide no explanation whatsoever for how a glorified linear motor is relativistically (or otherwise) affecting inertial mass. This could be operating under a novel application of ECE Theory, wherein they are using magnetism to affect gravity, but I doubt it. They would have claimed so.
This is very likely either nonsense or something very mundane explained poorly.
Reactionless drives are probably impossible and inventing them would be an earthshattering breakthrough.
Drives "powered" by photon reactions are possible but to get a meaningful amount of thrust you have to produce just an absurd amount of light. (using one in orbit would be a weapon of mass destruction, brighter than the sun, etc)
Otherwise, I don't know, maybe this is something mundane with a little bit of thrust interacting with sparse upper atmosphere gas or something.
If anything were ever invented that looked like "reactionless drive", I'm betting dollars to donuts the idea it was reactionless would be short-lived and eventually it would lead to updates in our understanding of matter and what reaction means. Like, maybe some day someone discovers a way to emit gravitons. IDK, I'm sure someone thought the idea of emitting photons without the use of a chemical reduction reaction was preposterous at some point in time, too. But then the reaction would be with space itself. By the end of it, it still wouldn't be "reactionless".
The JPL had a project called M2P2 that explored using magnetic field lines and plasma to create a solar sail out of ionized gas. The idea being that it can be regenerated in the face of micrometeoroids and other space debris.
Tethers.inc wanted to, among other things, used cables as a drag line to either lower satellites in orbit by absorbing electrical flux from passing through the magnetosphere, or pulse the cable to push against it to raise the orbit.
I mean, there are propellant-free ways to change trajectory-- gravitational assists, aerobraking, solar sails, etc.
You can even boost with something like an electrodynamic tether in theory (a magnetic field gradient lets you apply a net force). But field gradients out at LEO are low, and I don't think that's what's being claimed.
Italy has a strong north/south cultural and wealth divide, much like the US (at least before the recent cultural reconfiguration). Northern Italy has always been at the forefront of industry, AFAIU, but Italian diaspora largely came from the poorer, southern regions, giving rise to many negative stereotypes of Italians generally outside of Italy; stereotypes many Northern Italians also hold of the southern regions. Of course, free from various structural and cultural barriers these people were eventually able to thrive, just like anyone else.
Satellites once used propellant for attitude control. When the propellant was used up, the satellite lost the ability to maintain or change orientation. Very much as this article describes, control moment gyroscopes took over because they didn't require propellant. They operate on the same principles that let a cat land on it's feet by twisting about as it falls.
However, there's a key difference between attitude control and movement. Changing your orientation doesn't involve changes in net kinetic energy, momentum, etc.. Changing speed (i.e. What a propulsion system does) does involve changes in these quantities, so Newtonian conservation laws come into play.
>"Genergo’s system generates thrust without using any propellant and without expelling reaction mass, by directly converting electrical energy into thrust through controlled electromagnetic impulses."
If this isn't hogwash, it might be something similar to an ion engine. i.e. It does operate by expelling propellant, but what it uses as propellant is background dust and ions, accelerated to a high velocity by electric fields and expelled.
If, as the site claims, this technology is currently working and produces non-negligible thrust, it could be very useful. They need to be very clear about what this is though, since vague and unscientific sounding claims will not attract clients.
Article is light on details but there’s a few options such as using sunlight or earths magnetic field to move around without propellent tanks near earth.
Their patents don't mention the Earth's magnetic field or ambient material, so I'd go with "hogwash".
https://news.ycombinator.com/item?id=45932763
It’s surely hogwash. I like how it’s “validated” but does not mention power consumption or measured thrust.
For what it’s worth, one can very straightforwardly produce thrust using electromagnetism: just shine any sort of light out the back of your spaceship. This is called a photon rocket, and it works because light has momentum. Very little momentum: thrust = power / c. It’s only worth doing if energy is free in the way that light hitting a solar sail is free or if you power it with something absurdly energy-dense like antimatter.
Propellant is still used for rotation control. Reaction wheels can "saturate" if they compensate for rotation more in one direction than the other on net, so propellant is needed to get them back down. Ion engines, generally speaking, do not use background dust. They still carry propellant, they just eject it electromagnetically. An photon engine, basically just a laser pointed backwards, uses pure electricity to produce thrust. But of course the numbers all work out, since photons have momentum. They're extremely weak though, even lasers of staggering power produce very little force. There's no way you could put one on a satellite
> Reaction wheels can "saturate" if they compensate for rotation more in one direction than the other on net, so propellant is needed to get them back down.
Torque Rods can be used to desaturate wheels without needing any propellant
https://en.wikipedia.org/wiki/Magnetorquer
This is widely used in smaller satellites operating in Earth orbit.
However, this doesn't mean that TFA isn't BS.
It could be a legitimate conductive tether system. These have flown on the space shuttle and cubesats: see TEPCE and MiTEE.
https://en.wikipedia.org/wiki/Electrodynamic_tether
But the 'pulses' make it sound like EmDrive hogwash.
Am I correct in thinking that in some cases gyroscopic orientation results in turning 270° the “wrong way” to cancel out net gyroscope speed due to friction losses?
This article is quite frustrating, since all that it really tells me is that their system "generates thrust without using any propellant and without expelling reaction mass, by directly converting electrical energy into thrust through controlled electromagnetic impulses".
That's rather non-specific. My first thought was that they're using photon momentum, but thinking about that a little harder rules it out. The ratio of energy to momentum doesn't change with any properties of the photon (they're both proportional to frequency) so there's nothing to really develop there: so long as you waste very little power as heat, you might as well be shining a well-collimated flashlight.
Options 3 and 4 from [this paper](https://arxiv.org/pdf/2510.21743), _magnetic sails_ and _solar sails_, seem more promising. Is that what Genergo are doing? I have no idea. The article doesn't tell me.
"Scientifically tested!" is the marketing term for "The tests showed it didn't work, but we won't mention that second part!"
E.g.:
"successfully flight-tested" -- didn't break or leak anything when launched into space. A brick also has these properties.
"validated across three space missions" -- a brick could be flown multiple times too, this proves nothing except that this thing is space-rated.
"protected by a portfolio of granted international patents" -- we've got more lawyers than engineers!
"accumulated more than 700 hours of on-orbit operation" -- I could say the same thing about a brick left in orbit for a month.
"multiple on-orbit activation cycles have continued alongside data analysis and characterization activities" -- we kept turning it on and off in a futile attempt to work out why nothing was happening.
"confirmed system functionality in real space conditions" -- It definitely was "on", drawing power and everything!
"several long-duration tests were conducted in which it was observed, objectively and repeatedly, that motor activation produced a measurable acceleration or deceleration of the host spacecraft." -- we got confused by atmospheric drag, IMU drift, vibrations, and other confounding factors and called the experiment a success despite a string of failures for short-duration tests.
I've been involved in enough futile in-orbit demonstrations to say everything here is absolutely correct.
Yeah, this is exactly the lens that I was reading their release through. Seemed like a bunch of careful weasel word phrases.
I remember in the 80s, after mostly having given up on perpetuuum mobile, bunch of people were trying to invent something like this, using vibration etc which worked on Earth but would not in a vacuum... Looks like a new generation took the baton. Like this guy:
https://www.popularmechanics.com/space/rockets/a65924333/eng...
An Engineer Says He’s Found a Way to Overcome Earth’s Gravity
This new propulsion system could rewrite the rules of spaceflight—not to mention completely defy conventional physics.
"In 2001, British Electrical Engineer Roger Shawyer first introduced the “impossible drive,” known as the EmDrive. It was called “impossible” because its creator purported that the drive was reactionless, meaning no propellant required—in other words, it defied the known laws of physics (specifically, the conservation of momentum)."
is this EmDrive v2.0? [0]
https://en.wikipedia.org/wiki/EmDrive
Thought of it as soon as I read it
It's easy to validate this claim, just link to its orbital tracking data.
I keep looking at the data for OPT-2[1] which is supposed to be a "quantum drive" from a IVO Ltd.[2] but haven't seen any significant orbital changes yet.
[1] https://celestrak.org/NORAD/elements/graph-orbit-data.php?CA...
[2] https://ivolimited.us/
1. No info given about how this system works.
2. No info about how it supposedly produces thrust.
3. No numbers given except for number of hours tested in orbit. No thrust or power consumption figures.
4. Violates pretty widely accepted law of physics.
Yeah, I'm ever so slightly skeptical.
It so happens that a friend of a friend of mine works at this company. I'll ask for some details.
Report back.
They say it works "by directly converting electrical energy into thrust through controlled electromagnetic impulses", so I assume it's reacting against the Earth's magnetic field using the Lorentz force?
That would be "using Earth's magnetic field to create propulsion" and obviously would not work in deep space.
Yes but they also don't seem to claim it does. The use cases they talk about are orbital station-keeping and de-orbiting of satellites. So that implies near-Earth use.
Their patents don't say anything about an external magnetic field, so at best they've accidentally rediscovered it through experimental error and don't know it yet.
https://news.ycombinator.com/item?id=45931224
Ugh, wrong link https://news.ycombinator.com/item?id=45932763
I suspect that you’re right, but I believe that I heard something about a similar ‘drive’ being used on some sort of telescope satellite in the past (though I can’t remember the specifics).
Link to relevant patent: https://patents.google.com/patent/US11462985B2/en
Classic perpetual motion using magnets nonsense. Are there really that many gullible people on HN?
> Are there really that many gullible people on HN?
Who's gullible? Pretty much all of the comments show skepticism, but some are curious what is this about.
They are now, but when this was posted they were more like...
> Anyone have a clue how this might work?
> This is amazing. I wonder how it works. I would be cool if they published it.
It only takes one crackpot being correct to change the world. Chances are low but are you not at least curious what this is about?
Not possible according to the laws of physics. The closest you can get is a solar sail, but that's not "propellant-less" - photons are the propellant.
If a company thinks they've broken one of the most fundamental laws of physics (momentum transfer), they need to provide some serious evidence, and publish in full so their results can be replicated. A press release on an obscure website isn't how you do it.
It certainly sounds like "We managed to run our EM drive hardware in space, and our instruments say it did something" (as did EM drive proponent's, in error). Because if it really was even something like "we successfully produced thrust from ambient ions/earth's magnetic field/etc" then it would be much bigger news.
Anyone publishing a repeatable experiment demonstrating this would be more or less instantly handed a nobel prize, since it would have to unlock new fundamental physics.
It would also totally rock cosmology since you’d have to rework the whole age and evolution of the universe in light of those new physics, whatever they were.
This is almost definitely bunk. Either that or something mundane explained in a ridiculous hypey way.
Seems like the focus is on orbital dynamics, so I’m guessing it is reacting against the magnetic field of the planet or the particulates in the solosphere.
It would be cool, though, if it were actually interacting with the zero point field or some similar bunky stuff. We can already extract minute amounts of matter from the field, ostensibly experimentally proven, so I suppose it’s not impossible to imagine that you might somehow be able to push on Casimir forces, perhaps.
My money's on fake woo-woo.
At first—like many others here—I thought it might just be a terribly-written explanation for a device that uses Earth's magnetic field, so that the planet itself is the "reaction mass" being pushed around... but I'm not seeing that in a quick patent search for the company.
Instead, there's a bunch of stuff that seems like perpetual-motion-machine crankery, where their "motor" depends on a oscillating some mass back and forth inside a chamber using special frequencies and "waveforms", which somehow imparts some acceleration which they explain as "generating mass."
Perhaps did use Earth's magnetic field through pure experimental error, and they either haven't realized it or think they can bilk investors by presenting it as something new.
_________
https://patents.google.com/patent/US11462985B2/en :
> The inertial mass of an object varies with the variation of its magnetic field and therefore a variation of inertia can be created which leads to the generation of mass by varying the magnetization of the motor and its constituent elements (at given times, as explained above).
> [...] the variation of “mass” is generated by the overmagnetization or undermagnetization of the motor itself in conjunction with given “shocks” or interactions between the magnetic piston and the two buffer magnets [...]
https://patents.justia.com/patent/11462985 :
> [In] general the motor or the moving system according to the present invention consists of an electromagnetically charged body which moves within a delimited volume of space being accelerated and decelerated electromagnetically in controlled manner during its movement within said volume of space.
> Such accelerations/decelerations generate a force on the volume inside which the mass moves and allow the volume of space to move.
I think you are right. Either they have accidentally used the Earth's field somehow, or they are mistaking other effects (drag, perturbations...) for a thrust.
I would tend to think it uses Earth's magnetic field. Magnetizing or demagnetizing a moving mass would make its potential energy vary inside Earth's magnetic field. This may occur without reaction (I am not sure about this, my physics courses are far away and magnetic material physics is not that easy). Once they varied the potential energy of the moving mass, they would actually move it inside Earth's magnetic field, leading to a reaction force. The reaction force would be greater in one direction because of the cyclic magnetization/demagnetization.
And if the satellite's orbit is not perfectly circular, you may even be able to gain altitude by moving a mass at specifics times, like a kid on a swing or a skater in a ramp.
I am highly skeptical. A reactionless thruster is the holy grail of propulsion systems, but there are no known physics which permit it to work. A photon rocket would allow momentum exchange without mass consumption, but a quick look at the math shows it would be infeasible (hundreds of megawatts per newton).
My guess is this works at all, it is inadvertently expelling reaction mass somehow, such as ablating off small amounts of volatiles from polymer parts (like an inefficient version of a pulsed plasma thruster).
I'd love to be wrong, but this very much falls into the "extraordinary claims" category for me.
A photon rocket would involve use of mass. The only conceivable way to power one would be something like fusion or antimatter matter annihilation, which converts mass into energy. It’s just a rocket with the maximum possible exhaust velocity: c.
Photons have no mass. Massive particles cannot travel at c. Massive particles experience time. Photons have momentum because they contain energy, but no mass. Momentum being expelled is how the mass is accelerated. You don't need a propellant, but you do need a means of generating momentum.
Photons have mass in the sense that energy and mass are equivalent. What I meant is that a ship with a photon rocket is expending mass, given that the power requirements demand some kind of mass energy conversion to get enough photons. Viable photon rockets able to move anything of any size would require petawatts of power.
If you do the rocket equation math it kind of behaves like you are throwing mass at c even though you are not. You are converting mass to energetic photons and throwing them at c.
There’s a rough breakdown I saw once on a forum about future space flight tech:
Launch is dominated by thrust. Your T/W ratio must be >1. Travel within the solar system is dominated by specific impulse. Small thrust for a long time can get you going real fast, but you can only carry so much propellant. Interstellar flight or beyond is dominated by raw energy. To get to the stars in any “reasonable” time requires you to be doing a fair amount of E=mc^2-ing.
> Photons have mass in the sense that energy and mass are equivalent
Mass and energy are convertible but not equivalent.
You are confusing momentum and mass, which are two different concepts.
Torque rods are not a new thing. Lots of LEO spacecraft use them. They don't work for MEO/GEO because Earth's magnetic field decreases 1/R^3.
https://en.wikipedia.org/wiki/Magnetorquer
Torque rods do work in MEO/GEO, but you need significantly more magnetic moment to get the same torque (ie: larger rods and more current).
It's more a question of how much momentum you need to dump that determines if they are practical or not - magnetorquers are rarely used for direct attitude control, since they don't produce much torque. Instead, they are used "dump" excess momentum stored in the spacecraft's reaction wheels. The wheels can generate high torque, but they do so by changing their rotational speed, storing angular momentum. Ultimately, wheels have a finite maximum rotation speed, so they need to be "desaturated" by transferring angular momentum elsewhere. Magnetorquers provide a way to slowly transfer the angular momentum to the earth over time via its magnetic field.
Okay. They "work", but far less efficiently.
They're sometimes used on small/micro sats that don't have any reaction wheels or CMGs.
Solar sailing (pitching the solar panels) is another (and more "free") way to dump momentum by using the solar wind. Obviously you need a big solar array for this to be practical.
> "Genergo’s system generates thrust without using any propellant and without expelling reaction mass, by directly converting electrical energy into thrust through controlled electromagnetic impulses."
Anyone have a clue how this might work?
Maybe its possible to generate motion using the Earth's magnetic field under the right circumstances, though I'm not sure if that's really feasible. Or they might be able to create a very small thrust by emitting photons, but that must be very very small if its actually the case.
AFAIK that would require very powerful superconducting magnets or long tethers. This seems to be neither.
Generating matter somehow via E/c^2=m?
(I don't think you can do this but I'm not a physicist...)
You don't need to go that far. Light has momentum, and you can use that directly. It has the maximum possible specific impulse.
https://en.wikipedia.org/wiki/Photon_rocket
However, it requires a lot of energy and we are nowhere near a practical model. It's also not "propellant-less"; the photons are the propellant.
The practical point of being "propellant-less" is that you don't use up some finite supply of propellant.
If the "propellant" is electricity that our solar panels can generate, that's functionally propellant-less!
Known physics permits creating matter from energy:
https://en.wikipedia.org/wiki/Pair_production
If you have a source of energy on the spacecraft, like a solar panel, you could theoretically convert some of that energy to particle pairs with mass. But this is such an inefficient process (and so inherently low-mass with any practical energy source) that I doubt the claimed thruster could work this way.
100% this would never be practical, more wondering if that technically, it’s possible. Which it seems to be, thanks for the reference!
Skimmed the patent. Its 99% a pedantic and exhaustive explanation of a linear motor. The only interesting thing they mention, is this:
The inertial mass of an object varies with the variation of its magnetic field and therefore a variation of inertia can be created
But they provide no explanation whatsoever for how a glorified linear motor is relativistically (or otherwise) affecting inertial mass. This could be operating under a novel application of ECE Theory, wherein they are using magnetism to affect gravity, but I doubt it. They would have claimed so.
This is very likely either nonsense or something very mundane explained poorly.
Reactionless drives are probably impossible and inventing them would be an earthshattering breakthrough.
Drives "powered" by photon reactions are possible but to get a meaningful amount of thrust you have to produce just an absurd amount of light. (using one in orbit would be a weapon of mass destruction, brighter than the sun, etc)
Otherwise, I don't know, maybe this is something mundane with a little bit of thrust interacting with sparse upper atmosphere gas or something.
If anything were ever invented that looked like "reactionless drive", I'm betting dollars to donuts the idea it was reactionless would be short-lived and eventually it would lead to updates in our understanding of matter and what reaction means. Like, maybe some day someone discovers a way to emit gravitons. IDK, I'm sure someone thought the idea of emitting photons without the use of a chemical reduction reaction was preposterous at some point in time, too. But then the reaction would be with space itself. By the end of it, it still wouldn't be "reactionless".
The JPL had a project called M2P2 that explored using magnetic field lines and plasma to create a solar sail out of ionized gas. The idea being that it can be regenerated in the face of micrometeoroids and other space debris.
Tethers.inc wanted to, among other things, used cables as a drag line to either lower satellites in orbit by absorbing electrical flux from passing through the magnetosphere, or pulse the cable to push against it to raise the orbit.
For everybody claiming that locomotion without the impulse of a reaction mass is impossible: https://arxiv.org/abs/2112.09740v2
and before anybody only reads "spacetime curvature" and thinks the paper is talking about a warp drive, it is not.
Anyway, this Genergo thingy seems to be nonsense IMO, or they would have actually explained how it works.
Impossible claim with no evidence offered - curious why this is on the front page.
This is amazing. I wonder how it works. I would be cool if they published it.
As a layman I have no idea which part of this to be skeptical of, but, cool!
The part where it violates basic laws of physics, like conservation of momentum, for one.
Not possible under standard physics.
I mean, there are propellant-free ways to change trajectory-- gravitational assists, aerobraking, solar sails, etc.
You can even boost with something like an electrodynamic tether in theory (a magnetic field gradient lets you apply a net force). But field gradients out at LEO are low, and I don't think that's what's being claimed.
Extraordinary claims need extraordinary evidence
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Italy has a strong north/south cultural and wealth divide, much like the US (at least before the recent cultural reconfiguration). Northern Italy has always been at the forefront of industry, AFAIU, but Italian diaspora largely came from the poorer, southern regions, giving rise to many negative stereotypes of Italians generally outside of Italy; stereotypes many Northern Italians also hold of the southern regions. Of course, free from various structural and cultural barriers these people were eventually able to thrive, just like anyone else.
Yes casual racism is very amusing
And anyway, we Italians have done some good things in the past. Not that this can't be a new EmDrive.
Alessandro Volta was from Como, the same place as this. He invented the electric battery.