[HN Gopher] An Italian Company Builds the First Known Propellant...
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       An Italian Company Builds the First Known Propellantless Space-
       Propulsion System
        
       Author : maremmano
       Score  : 47 points
       Date   : 2025-11-14 19:43 UTC (3 hours ago)
        
 (HTM) web link (www.satcom.digital)
 (TXT) w3m dump (www.satcom.digital)
        
       | a-priori wrote:
       | 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?
        
         | nickff wrote:
         | 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).
        
         | drillsteps5 wrote:
         | That would be "using Earth's magnetic field to create
         | propulsion" and obviously would not work in deep space.
        
           | a-priori wrote:
           | 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.
        
         | Terr_ wrote:
         | 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
        
       | mlyle wrote:
       | 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.
        
       | frankfrank13 wrote:
       | As a layman I have no idea which part of this to be skeptical of,
       | but, cool!
        
         | drillsteps5 wrote:
         | The part where it violates basic laws of physics, like
         | conservation of momentum, for one.
        
       | snow_mac wrote:
       | This is amazing. I wonder how it works. I would be cool if they
       | published it.
        
       | phpnode wrote:
       | is this EmDrive v2.0? [0]
       | 
       | https://en.wikipedia.org/wiki/EmDrive
        
         | augusto-moura wrote:
         | Thought of it as soon as I read it
        
       | BurningFrog wrote:
       | > _" 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?
        
         | buildbot wrote:
         | Generating matter somehow via E/c^2=m?
         | 
         | (I don't think you can do this but I'm not a physicist...)
        
           | philipkglass wrote:
           | Known physics allows for it:
           | 
           | 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.
        
           | jfengel wrote:
           | 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.
        
         | verzali wrote:
         | 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.
        
       | kbelder wrote:
       | It's amusing to me that I hear "Italians build propellantless
       | space propulsion system", and my first reaction is " _Italians_?
       | No way. "
        
         | Jabrov wrote:
         | Yes casual racism is very amusing
        
           | maremmano wrote:
           | And anyway, we Italians have done some good things in the
           | past. Not that this can't be a new EmDrive.
        
         | verzali wrote:
         | Alessandro Volta was from Como, the same place as this. He
         | invented the electric battery.
        
       | wat10000 wrote:
       | 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.
        
         | maremmano wrote:
         | It so happens that a friend of a friend of mine works at this
         | company. I'll ask for some details.
        
       | hbrav wrote:
       | 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.
        
       | fudged71 wrote:
       | Extraordinary claims need extraordinary evidence
        
       | drillsteps5 wrote:
       | 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)."
        
       | Terr_ wrote:
       | 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.
        
         | verzali wrote:
         | 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.
        
       | Sanzig wrote:
       | 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.
        
       | beloch wrote:
       | 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.
        
         | Retric wrote:
         | 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.
        
         | hinkley wrote:
         | Am I correct in thinking that in some cases gyroscopic
         | orientation results in turning 270deg the "wrong way" to cancel
         | out net gyroscope speed due to friction losses?
        
       | visviva wrote:
       | Impossible claim with no evidence offered - curious why this is
       | on the front page.
        
       | colechristensen wrote:
       | 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.
        
       | cjameskeller wrote:
       | Link to relevant patent:
       | https://patents.google.com/patent/US11462985B2/en
        
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       (page generated 2025-11-14 23:00 UTC)