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.
Anyone have a clue how this might work?
(I don't think you can do this but I'm not a physicist...)
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.
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.
If the "propellant" is electricity that our solar panels can generate, that's functionally propellant-less!
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.
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.
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)."
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.
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.
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.
Mass and energy are convertible but not equivalent.
You are confusing momentum and mass, which are two different concepts.
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.
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.
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.
https://en.wikipedia.org/wiki/Electrodynamic_tether
But the 'pulses' make it sound like EmDrive hogwash.
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.
Who's gullible? Pretty much all of the comments show skepticism, but some are curious what is this about.
> Anyone have a clue how this might work?
> This is amazing. I wonder how it works. I would be cool if they published it.
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 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.
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.
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.
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.
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.
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.
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.
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...
a-priori•2mo ago
nickff•2mo ago
drillsteps5•2mo ago
a-priori•2mo ago
Terr_•2mo ago
https://news.ycombinator.com/item?id=45931224
Terr_•2mo ago