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.

https://en.wikipedia.org/wiki/EmDrive

Anyone have a clue how this might work?

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.

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.

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 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.

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.