Aerometro — a concept for an urban transport system proposed by Nizhny Novgorod engineer-physicist Igor Knyaginichev, who writes under the pen name Professor Rastolkovskiy.[1] Giant "carousels," suspended from tethered aerostats, spin above the city; passenger gondola cars detach from one carousel and attach to the next at the point where their circular paths are tangent, allowing riders to travel from one end of the city to the other without completing a full circle. The concept dates to the late 1990s, was presented publicly in Nizhny Novgorod around the turn of the 2010s, and never progressed beyond diagrams: not a single element of the aerometro was ever built.
How It Works
The basis of the concept is an ordinary fairground carousel scaled up to city dimensions. If the radius of rotation is extended to roughly half a kilometer, the cable carrying the suspended cars would need to reach a height of one kilometer; building towers for this purpose would be prohibitively expensive, so the inventor suspends the structure from a tethered aerostat instead.
The aerostat holds a "mother beam" — a horizontal support that rotates around the suspension point and carries gondolas with passengers at each end. Two beams are required: they counterbalance each other during rotation.
The most essential feature of the concept is the transfer between carousels. At the point where the circular paths of two adjacent carousels are tangent, their instantaneous velocity vectors coincide, allowing a gondola to transfer without any jolt or overload — the passenger simply experiences a change in the direction of centripetal acceleration. For this to work, the city is covered by a grid of carousels like a chessboard: adjacent cells rotate in opposite directions.
The calculated travel speed is approximately 180 kilometers per hour at an altitude of more than one hundred meters. Boarding and alighting points serve as stations analogous to those of a metro and are located beneath the centers of rotation — that is, roughly every 500 meters.
How to Board
The simplest way to enter the system is via a lift running up a cable descending from the aerostat: the passenger is raised and simultaneously set spinning in a spiral, so that by the time they reach the top their speed matches the circular speed of the carousel. An angled lift is also possible, joining the circular path from outside along a tangent with the help of a vertical wing.
The fastest and most exotic boarding method the inventor called the water-jet rocket: a gondola with passengers is launched directly from the ground to the start of the route, bypassing the lifts entirely. Descent is by parachute; on landing, the tail section of the rocket acts as a damper, and launch pads are to be equipped with water, electricity, and a dedicated parachute-packing specialist.
Economics of the Concept
The inventor considered cost to be the chief advantage: the price per linear meter of aerometro "roadway" is determined mainly by the cost of cables rather than earthworks and surfacing, and is therefore, by his calculations, hundreds of times lower than the cost of asphalt roads. It was separately noted that the vertical wings of the carousels could harvest wind energy and feed any surplus into the city grid.
The Inventor and Related Concepts
Igor Knyaginichev was born on 16 July 1960 in Yakutsk; from 1977 to 1982 he studied at the radiophysics faculty of Gorky's Lobachevsky University, and later worked at the Nizhny Novgorod Lenin Television Plant.[1] He describes himself as a theorist of sling applications in outer space and the inventor of the orbit-exchanging space sling.[2]
The aerometro belongs to the same family as his other projects: the Razgonoplan (Boost-Plane) — a glider with a water-jet engine — the Space Trebuchet, and Trebuchet-Cosmonautics — a method of placing payloads into orbit using a rotating sling in place of a rocket. The aerometro in this context is the same principle of spinning carousels, only close to the ground.
Since 2018 the inventor has had an account on Habr with a single post about delivering cargo to the Moon by mass exchange; his last activity there is dated 19 September 2022, with Moscow listed as his place of residence.[2] The aerometro does not appear among the sections of his personal website: its place has been taken by the razgonoplan and trebuchet cosmonautics.[3]
Another Project with the Same Name
In January 2026, a completely different concept — unrelated to the Nizhny Novgorod one — appeared in the news under the name "aerometro." A Novosibirsk resident, Matvey Filatov, proposed to the city hall that lightweight elevated structures be built above streets, along which ordinary self-driving minibuses would run in a continuous line, without intersections. City hall replied that the proposed means of transportation does not qualify as a certified vehicle type, and recommended that he approach research institutes instead.[4]
Sources
- razgonoplan.nnewer.ru — Razgonoplan — Professor Rastolkovskiy — pen name of engineer-physicist Igor Knyaginichev (archive)
- habr.com — Habr — Profile of Igor Rastolkovskiy-Knyaginichev (archive)
- razgonoplan.nnewer.ru — Razgonoplan — Igor Rastolkovskiy's unofficial website (archive)
- ngs.ru — NGS (Novosibirsk) — Novosibirsk resident proposes that city hall build an "aerometro" (archive)