Hyperloop

Hyperloop is a proposed high-speed transportation system for both passengers and freight.^[1] The concept behind the Hyperloop originated in the late 17th century with the invention of the world's first artificial vacuum, which led to designs for underground rapid transit systems powered by pneumatics in the decades that followed. In 1799, inventor George Medhurst proposed the idea to move goods through cast-iron pipes using air pressure and in 1844 built a railway station (for passenger carriages) in London that relied on pneumatics until 1847.^[2][3] In 2013, entrepreneur Elon Musk published a white paper, where the hyperloop was described as a transportation system using capsules supported by an air-bearing surface within a low-pressure tube.^[4][5] Hyperloop systems have three essential elements: tubes, pods, and terminals. The tube is a large, sealed low-pressure system (typically a long tunnel). The pod is a coach at atmospheric pressure that experiences low air resistance or friction inside the tube^[6][7] using magnetic propulsion (in the initial design, augmented by a ducted fan). The terminal handles pod arrivals and departures. The hyperloop, in the form proposed by Musk, differs from traditional vactrains by relying on residual air pressure inside the tube to provide lift from aerofoils and propulsion by fans; however, many subsequent variants using the name "hyperloop" have remained relatively close to the core principles of vactrains.

Hyperloop was teased by Elon Musk at a 2012 speaking event, and described as a "fifth mode of transport".^[8] Musk released details of an alpha-version in a white paper on 22 August 2013, in which the hyperloop design incorporated reduced-pressure tubes with pressurized capsules riding on air bearings driven by linear induction motors and axial compressors.^[9] The white paper showed an example hyperloop route running from the Los Angeles region to the San Francisco Bay Area, roughly following the Interstate 5 corridor.^[4] Some transportation analysts challenged the cost estimates in the white paper, with some predicting that a hyperloop would run several billion dollars higher.^[10][11][12]

The hyperloop concept has been promoted by Musk and SpaceX, and other companies or organizations were encouraged to collaborate in developing the technology.^[13] A Technical University of Munich hyperloop set a speed record of 463 km/h (288 mph) in July 2019^[14][15] at the pod design competition hosted by SpaceX in Hawthorne, California.^[16] Virgin Hyperloop conducted the first human trial in November 2020 at its test site in Las Vegas, reaching a top speed of 172 km/h (107 mph).^[17] Swisspod Technologies unveiled a 1:12 scale testing facility in a circular shape to simulate an "infinite" hyperloop trajectory in July 2021 on the EPFL campus at Lausanne, Switzerland.^[18] In 2023, a new European effort to standardize "hyperloop systems" released a draft standard.^[19]

Hyperloop One, one of the best well-known and well-funded players in the hyperloop space, declared bankruptcy and ceased operations on 31 December 2023. Other companies continue to pursue hyperloop technology development.^[20]