Liquid oxygen

 ( Rocket Oxidizers ) 

Liquid oxygen, sometimes abbreviated as LOX or LOXygen, is a clear cyan liquid form of dioxygen . It was used as the Oxidizing agent in the first liquid-fueled rocket invented in 1926 by Robert H. Goddard, an application which is ongoing.

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Physical properties Liquid oxygen has a clear cyan color and is strongly paramagnetism: it can be suspended between the poles of a powerful horseshoe magnet.

(2009). 9780495390794, Cengage Learning. . ISBN 9780495390794

Liquid oxygen has a density of , slightly denser than liquid water, and is cryogenics with a freezing point of and a boiling point of at . Liquid oxygen has an expansion ratio of 1:861 Cryogenic Safety. chemistry.ohio-state.edu. Characteristics. . Lindecanada.com. Retrieved on 2012-07-22. and because of this, it is used in some commercial and military aircraft as a transportable source of breathing oxygen.

Liquid oxygen is also a very powerful oxidizing agent: organic materials will burn rapidly and energetically in liquid oxygen. Further, if Oxyliquit, some materials such as coal briquettes, carbon black, etc., can Detonation unpredictably from sources of ignition such as flames, sparks or impact from light blows. , including Bitumen, often exhibit this behavior.

The tetraoxygen molecule (O₄) was predicted in 1924 by Gilbert N. Lewis, who proposed it to explain why liquid oxygen defied Curie's law. Modern computer simulations indicate that, although there are no stable O₄ molecules in liquid oxygen, O₂ molecules do tend to associate in pairs with antiparallel spins, forming transient O₄ units.

Liquid nitrogen has a lower boiling point at −196 °C (77 K) than oxygen's −183 °C (90 K), and vessels containing liquid nitrogen can condense oxygen from air: when most of the nitrogen has evaporated from such a vessel, there is a risk that liquid oxygen remaining can react violently with organic material. Conversely, liquid nitrogen or liquid air can be oxygen-enriched by letting it stand in open air; atmospheric oxygen dissolves in it, while nitrogen evaporates preferentially.

The surface tension of liquid oxygen at its normal pressure boiling point is .J. M. Jurns and J. W. Hartwig (2011). Liquid Oxygen Liquid Acquisition Device Bubble Point Tests With High Pressure LOX at Elevated Temperatures, p. 4.

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Uses In commerce, liquid oxygen is classified as an industrial gas and is widely used for industrial and medical purposes. Liquid oxygen is obtained from the oxygen found naturally in air by fractional distillation in a Air separation. Air forces have long recognized the strategic importance of liquid oxygen, both as an oxidizer and as a supply of gaseous oxygen for breathing in hospitals and high-altitude aircraft flights. In 1985, the USAF started a program of building its own oxygen-generation facilities at all major consumption bases.Arnold, Mark. 1U.S. Army Oxygen Generation System Development. RTO-MP-HFM-182. dtic.mil

Timmerhaus, K. D. (2013). 9781468431056, Springer Science & Business Media. . ISBN 9781468431056

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In rocket propellant Liquid oxygen is the most common Cryogenic fuel liquid oxidizer propellant for spacecraft rocket applications, usually in combination with liquid hydrogen, kerosene or liquid methane.

Liquid oxygen was used in the first liquid fueled rocket. The World War II V-2 missile also used liquid oxygen under the name A-Stoff and Sauerstoff. In the 1950s, during the Cold War both the United States' Redstone and Atlas rockets, and the USSR R-7 Semyorka used liquid oxygen. Later, in the 1960s and 1970s, the ascent stages of the Apollo Saturn rockets, and the Space Shuttle main engines used liquid oxygen.

As of 2025, many active rockets use liquid oxygen:

• Chinese space program
• CASC: Long March 5, Long March 6, Long March 7, Long March 8, Long March 12, Long March 9 (under development), Long March 10 (under development)
• Deep Blue Aerospace: Nebula-1 (under development)
• Galactic Energy: Pallas-1 (under development)
• i-Space: Hyperbola-3 (under development)
• LandSpace: Zhuque-2E, Zhuque-3 (under development)
• Orienspace: Gravity-2 (under development)
• Space Pioneer: Tianlong-2, Tianlong-3 (under development)
• Europe
• European Space Agency: Ariane 6
• Isar Aerospace: Spectrum (under development)
• Rocket Factory Augsburg: RFA One (under development)
• Indian Space Research Organisation: GSLV, LVM3
• JAXA (Japan): H3
• Korea Aerospace Research Institute: Nuri
• Roscosmos (Russia): Soyuz-2, Angara
• United States
• Blue Origin: New Shepard, New Glenn
• Firefly Aerospace: Firefly Alpha
• NASA: Space Launch System
• Northrop Grumman: Antares 300 (under development)
• Rocket Lab: Electron, Neutron (under development)
• SpaceX: Falcon 9, Falcon Heavy, SpaceX Starship
• Stoke Space: Nova (under development)
• United Launch Alliance: Atlas V, Vulcan

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History

• By 1845, Michael Faraday had managed to liquefy most gases then known to exist. Six gases, however, resisted every attempt at liquefaction Cryogenics. Scienceclarified.com. Retrieved on 2012-07-22. and were known at the time as "". They were oxygen, hydrogen, nitrogen, carbon monoxide, methane, and nitric oxide.
• In 1877, Louis Paul Cailletet in France and Raoul Pictet in Switzerland succeeded in producing the first droplets of liquid air.
  (2025). 9783319145532, Springer International Publishing. . ISBN 9783319145532
• In 1883, Polish professors Zygmunt Wróblewski and Karol Olszewski produced the first measurable quantity of liquid oxygen.

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See also

• Oxygen storage
• Industrial gas
• Cryogenics
• Liquid hydrogen
• Liquid helium
• Liquid nitrogen
• List of stoffs
• Natterer compressor
• Rocket fuel
• Solid oxygen
• Tetraoxygen

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Further reading