In the Russian alternative-propulsion world, “reactionless drive” doesn’t always mean hidden rockets or exotic fields. Sometimes it means something much stranger—and much more mechanical: a sealed device that tries to turn swirling liquid into one-way thrust. At the center of this lineage sits Spartak M. Polyakov’s “liquid gyroscope” concept, later reworked by Valery A. Menshikov and documented in unusual detail by Alexander V. Frolov and New Energy Technologies*. The result is a rare paper trail: inventor claims, engineering iterations, bench measurements, and—briefly—an attempted step onto the world stage via an on-orbit test aboard the Yubileiny satellite.

A sealed liquid gyroscope for inertial propulsion

Polyakov’s “vortex drive” sits in a family of propulsion ideas that try to produce net motion without expelling propellant. In the Western imagination that usually triggers immediate red flags—momentum conservation, hidden reaction mass, measurement artifacts—but the Russian literature around this device treats it as an engineering problem first: how to “rectify” internal motion into a one-direction push.

The core motif is not a photon sail or an electromagnetic thruster. It’s a rotating working mass—often a liquid metal or water—forced through a changing radius of rotation inside a sealed housing. The claim is that when the radius changes under rotation, a short axial “push” appears along the spin axis.

That is a very specific kind of bet: not “new physics” in the abstract, but a proposed asymmetry in how impulse transfers between a rotating medium and the structure that contains it. The language is closer to inertial movers and “unbalanced centrifugal” devices than it is to warp drives.

What makes the Polyakov lineage historically interesting is the continuity. Multiple Russian inventors and writers circle the same motif—variable-radius rotation, vortex geometry, spiral trajectories—yet the strongest documentation in English tends to come from a small set of translated sources tied to Frolov’s editorial work.

Spartak M. Polyakov and the mercury prototype

In the sources translated through New Energy Technologies, Polyakov is described as an experimentalist who pursued the “liquid gyroscope” approach using heavy working fluids—most notably mercury—because dense liquids carry more momentum at a given volume. That choice, in turn, shapes the engineering: sealing, pumps, bearings, and the constant temptation for trivial explanations like vibration or frictional nonlinearity.

The reported method is simple to state: spin a working mass; then force the radius of that rotating mass to decrease in a controlled way. During the “radius-down” portion, an axial impulse appears; during the return, the thrust drops to zero (or is claimed to do so). The result is inherently impulsive unless the geometry can be arranged so the radius-changing condition is effectively continuous.

Polyakov’s influence appears partly through direct experimentation, and partly through the way others re-use his concept as an “ancestor design.” Menshikov’s later mercury-loop converter is explicitly presented as a close relative, and Frolov frames it as an evolution of Polyakov’s approach rather than a separate invention.

“Dr. Spartak Poliakov developed a device which rotated 10 kg of mercury. I visited him in 1998 to make a video and publication… Dr. Menshikov developed Poliakov’s idea but in his work the effect also is detected for only 30 min after the start.”
— Alexander V. Frolov, interview transcript (English translation)

That one sentence captures the essential tone of this whole saga: bold, concrete, and physical. No hand-waving about fields—just a claim that something heavy spun fast in a sealed assembly and seemed to do something interesting.

 The basic claim: thrust from controlled radius change

The Polyakov method, as summarized in the translated articles, treats the rotation radius as the key control parameter. The working mass is spun, then its radius is forced to shrink—like pulling in a spinning skater’s arms, except applied to a rotating liquid structure.

In that moment, the literature claims, an axial impulse “appears” along the rotation axis. The story is not that momentum is violated in a cartoon way; it’s that internal impulse exchange with the housing can be made directionally biased under very specific geometry and timing.

Crucially, the same sources also admit the built-in limitation: if the radius change is periodic—shrink, then expand back—then the thrust is not continuous. It comes in pulses, and the “return stroke” is where a careful experiment can lose everything to symmetry.

This is where the concept starts to resemble other inertial-drive families worldwide: lots of apparent “one-way” behavior during a transient, followed by a return phase that cancels the net when the full cycle is accounted for—unless some additional mechanism breaks that cancellation.

The “impulse problem” and why Menshikov’s version mattered

The translated material doesn’t only celebrate the idea; it also describes a failure mode that is almost fatal to the dream of a propellantless engine. If the thrust depends on a difference between the medium’s motion and the structure’s motion, then the effect can vanish as the system “spins up” and everything co-rotates.

This is exactly what the sources describe for the mercury converter lineage: an initial thrust impulse, then a decay to nothing when the liquid and the rotating tube synchronize. If true, it explains why early devices might look promising on startup and then “die,” and why inventors would chase ever more elaborate geometries to keep the differential alive.

From an engineering standpoint, this is the key transition point. The project stops being “does it push?” and becomes “can it push continuously, in a way that scales?” That is a different, harder problem—and it’s where the Polyakov → Menshikov → Frolov evolution is easiest to follow.

“Such kind of interaction… provides a short term propulsive burn… which eliminates… when the speed of the liquid equals the speed of the tube rotation.”
— New Energy Technologies (English translation), describing the mercury converter behavior

If nothing else, this is a refreshingly testable statement. It predicts a very specific temporal signature: thrust only during the transient mismatch, fading when synchronization occurs.

Menshikov’s cone-spiral mercury converter and the utility-model trail

Menshikov enters the record not just as a name, but as a bridge between “garage physics” and institutional space hardware. In the English-translated descriptions, his converter is tied to an official Russian utility model: a device intended to convert rotational motion into unidirectional translational motion using a cone-shaped spiral tube, a pump, and mercury circulating through the spiral.

The described operating picture is almost cinematic. The cone-spiral tube rotates, dragging mercury; a pump returns mercury along the axis from base to top; the mercury then travels continuously through the spiral. During the initial phase—when there is speed differential between the mercury and the rotating spiral—an axial “burn” appears.

But the same texts treat this as a partial success at best. The “impulse problem” shows up again: once the mercury matches the tube’s rotation speed, the axial impulse disappears. The converter “works” only in the transient.

That assessment leads directly to the next proposed step: preserve a constant relative speed difference (or constant radius-change condition) so the device produces continuous force rather than an initial kick.

From mercury loop to water vortex: the “natural vortex” rotor

The later “water vortex propulsion drive” write-up broadens the idea from a specific mercury loop into a more general design philosophy: copy the geometry of natural vortices. In this framing, a gas or liquid vortex naturally forms a non-linear expanding spiral with changing radius and changing pitch—and an optimal rotor shape should be close to that natural vortex form.

That’s an attempt to turn an impulsive trick into an always-on machine. Instead of a single “radius change” event per cycle, the working mass is forced along a spiral trajectory where the radius is continually reducing (or continually being forced to deviate from co-rotation) relative to the structure.

The document goes further than armchair theory. It specifies a compact bench-scale build: an aluminum case and rotor, rotor diameter around 80 mm at the base and ~20 mm near the outlet, driven by a 12 V motor, consuming ~50 W, operating in the 30–300 rpm range, using water and denser liquids as the working medium.

From a narrative perspective, this is where the Polyakov lineage becomes “device-like” in a modern sense: not just a one-off mercury gyroscope, but a repeatable apparatus with dimensions, power draw, and a test procedure.

Bench tests: what was built, what was measured

The strongest “lab-bench” claims in these sources are cautious in one way and bold in another. They emphasize measurement resolution—electronic scales “to within 0.1 g”—and they report a thrustlike force detected under those conditions, without claiming a spacecraft-ready engine.

The hardware description matters because it constrains the easy explanations. A 50 W, 12 V, sub-kilogram benchtop assembly in the 30–300 rpm range is far from a vibration-isolated torsion pendulum experiment; it’s closer to something that could be fooled by mechanical coupling, airflow, cable forces, bearing friction, thermal drift, or scale nonlinearities—unless extreme care is taken.

At the same time, the authors present the measurements as sufficient to justify continued development—specifically toward carriers that “need no base or jet rejection of mass.” In other words: not just a curiosity, but a proposed propulsion method for vehicles.

Whether the data supports that leap is the open question—and it’s why these documents are best treated as a map of claims and designs, not a final verdict.

“The received results let us draw a positive conclusion about the performance of this method and of its practical application.”
— New Energy Technologies (English translation), summarizing the bench-test takeaway

That line is the hinge point between “interesting transient effect” and “fundable technology.” Everything after it depends on replication, isolation of artifacts, and demonstrating net impulse over full cycles.

The orbital test: Yubileiny and the “gravitsapa” controversy

The Polyakov lineage would likely be obscure outside Russia if not for the strange moment when “reactionless drive” headlines attached themselves to an actual space mission. In 2009, Russian media reported that a propellantless engine had been installed on the Yubileiny educational satellite (launched in 2008), and that tests had been conducted.

Some accounts identify Valery A. Menshikov—described as a director/manager tied to the relevant institute—as publicly claiming successful tests of a “reactionless” engine on orbit. The language in English-language reporting even drifted into “perpetual motion machine” framing, which did the project no favors internationally.

The backlash inside Russia was sharp. Critics argued that any apparent thrust could be explained by mundane non-linear bearing friction or other internal effects that do not translate to net orbital change in microgravity. In later summaries, the episode is described as yielding “zero result” in space, earning the nickname “gravitsapa” (a pop-culture reference), and becoming a cautionary tale used by skeptical scientists.

Most importantly for the historical record: prominent Russian scientific criticism later claimed that the installed device did not change the satellite’s orbit by even a tiny measurable amount—effectively calling the on-orbit experiment a failure, whatever the ground tests may have suggested.

Similar devices, key differences, and the measurement minefield

It’s tempting to treat “reactionless propulsion” as one category, but the documents themselves place the vortex drive among many cousins: eccentric-mass inertial movers, variable-radius centrifugal devices, mechanisms with internal reflectors, and even magnetohydrodynamic concepts that push liquid in strong fields.

The Polyakov/Menshikov/Frolov thread distinguishes itself by insisting on a fluid working mass and a radius-changing spiral trajectory—attempting to avoid the fatigue and structural limits of solid eccentrics while claiming better “specific properties” at higher rotational speeds.

But the measurement traps are also unusually dense here. Any device that spins liquid, pumps it, and couples to a housing can generate forces that look like thrust on a scale: vibration rectification, torque reactions at mounts, dynamic friction curves that are non-linear with rpm, cable stiffness effects, and thermal changes in a scale’s load cell. A serious test has to isolate all of that.

That’s why the “impulse signature” described in the texts matters so much. A claim that thrust appears only during speed differential—and vanishes when co-rotation occurs—can be attacked (or supported) by designing experiments that deliberately control and measure that differential, then integrating force over full cycles to see whether the net impulse is truly non-zero.

A fair reading of this literature is not “it works” or “it’s nonsense.” It’s: the documents preserve a coherent design lineage and they inadvertently describe the most likely failure mode. That combination is exactly what a good replication program needs.

What the Polyakov vortex drive represents

Even if the Polyakov vortex drive never produces net propulsion in a clean replication, it still matters historically—because it shows how unconventional propulsion concepts evolve when they’re treated as engineering projects rather than internet folklore.

Frolov’s role (as author/editor and translator/publisher) is central here. New Energy Technologies effectively functions as a bridge across a language barrier that, for decades, separated Russian “inertial propulsion” traditions from Western discussions—first by politics and access, later simply by the friction of translation and discoverability.

That divide helps explain why Western audiences often encounter these ideas only as rumors (“Russia launched a reactionless drive!”) while Russian audiences may have access to technical sketches, utility models, and bench claims. The “iron curtain” becomes an information curtain—one that turns messy technical histories into distorted headlines.

The best outcome of re-examining this record is not a premature verdict. It’s clarity: who built what, what they claimed, what failure mode they themselves described, what was actually measured, and what would count as a decisive test. In a field flooded with noise, a clean paper trail is valuable—even when it ends in a null result.

References

Water vortex propulsion drive (Alexander V. Frolov)

Poliakov (Polyakov) Lab Film Footage 1998 (Alex Galan)

New Energy Technologies: 9-1 (Nov-Dec 2002) — PDF compilation (contains multiple stories)

New Energy Technologies: 18-1 (Issue #3, 2004) — English-language PDF compilation (contains multiple stories)

New Energy Technologies 21 (Issue #2, 2005) — PDF issue/compilation (contains multiple stories)

Yubileiny (educational satellite) — Wikipedia (English)

“Russian scientists test perpetual motion machine in space” — Pravda (English, Apr 14, 2009)

“In space, tests of a ‘perpetual motion machine’ are underway” — Vesti.ru (Russian, Apr 13, 2009)

“Russian ‘perpetual motion machine’ passed first tests…” — IZ.ru (Russian, Apr 13, 2009)