Rocket propellant

Toxic Propellant Hazards ~ 1966 NASA KSC; Hydrazine Rocket Fuel & Nitrogen Tetroxide Oxidizer

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• published: 12 Sep 2016
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Chemistry playlist: https://www.youtube.com/playlist?list=PL_hX5wLdhf_KyuOalV6rwHjo810Zaa6xq NASA & Space Miscellany playlist: https://www.youtube.com/playlist?list=PL_hX5wLdhf_K3mK1TZNCkmdD-JMZYGew1 more at: http://scitech.quickfound.net NASA training film for workers handling hydrazine and nitrogen tetroxide at Kennedy Space Center and other NASA installations. "This NASA safety film demonstrates the dangers of rocket fuels, including hydrazine and nitrogen tetroxide, and instructs workers in their safe handling." Film produced by Technicolor, Inc. NASA film KSC-6. Public domain film from the US National Archives, slightly cropped to remove uneven edges, with the aspect ratio corrected, and one-pass brightness-contrast-color correction & mild video noise reduction applied. The soundtrack was also processed with volume normalization, noise reduction, clipping reduction, and/or equalization (the resulting sound, though not perfect, is far less noisy than the original). http://creativecommons.org/licenses/by-sa/3.0/ https://en.wikipedia.org/wiki/Hypergolic_propellant A hypergolic propellant combination used in a rocket engine is one whose components spontaneously ignite when they come into contact with each other. The two propellant components usually consist of a fuel and an oxidizer. Although commonly used hypergolic propellants are difficult to handle because of their extreme toxicity and/or corrosiveness, they can be stored as liquids at room temperature and hypergolic engines are easy to ignite reliably and repeatedly. In contemporary usage, the terms "hypergol" or "hypergolic propellant" usually mean the most common such propellant combination, dinitrogen tetroxide plus hydrazine and/or its relatives monomethylhydrazine and unsymmetrical dimethylhydrazine... History Soviet rocket engine researcher Valentin Glushko experimented with hypergolic fuel as early as 1931. It was initially used for "chemical ignition" of engines, starting kerosene/nitric acid engines with an initial charge of phosphorus dissolved in carbon disulfide. Starting in 1935, Prof. O. Lutz of the German Aeronautical Institute experimented with over 1000 self-igniting propellants. He assisted the Walter Company with the development of C-Stoff which ignited with concentrated hydrogen peroxide... Hypergolic propellants were discovered independently, for the third time, in the U.S. by GALCIT and Navy Annapolis researchers in 1940. They developed engines powered by aniline and nitric acid. Robert Goddard, Reaction Motors and Curtiss-Wright worked on aniline/nitric acid engines in the early 1940s, for small missiles and jet assisted take-off (JATO)... Advantages Hypergolic rockets are usually simple and reliable because they need no ignition system... The most common hypergolic fuels, hydrazine, monomethylhydrazine and unsymmetrical dimethylhydrazine, and oxidizer, nitrogen tetroxide, are all liquid at ordinary temperatures and pressures. They are therefore sometimes called storable liquid propellants. They are suitable for use in spacecraft missions lasting many years... Because hypergolic rockets do not need an ignition system, they can fire any number of times by simply opening and closing the propellant valves until the propellants are exhausted and are therefore uniquely suited for spacecraft maneuvering... Disadvantages Relative to their mass, traditional hypergolic propellants are less energetic than such cryogenic propellant combinations as liquid hydrogen / liquid oxygen or liquid methane / liquid oxygen. A launch vehicle that uses hypergolic propellant must therefore carry a greater mass of fuel than one that uses these cryogenic fuels. The corrosivity, toxicity, and carcinogeneity of traditional hypergolics necessitate expensive safety precautions. Hypergolic combinations Common - Aerozine 50 + nitrogen tetroxide (N2O4) – widely used in historical American rockets, including the Titan 2; all engines in the Apollo Lunar Module; and the Service Propulsion System in the Apollo Service Module. Aerozine 50 is a mixture of 50% UDMH and 50% straight hydrazine (N2H4). - Unsymmetrical dimethylhydrazine (UDMH) + nitrogen tetroxide (N2O4) – frequently used by the Russians, such as in the Proton (rocket family) and supplied by them to France for the Ariane 1 first and second stages (replaced with UH 25); ISRO PSLV second stage. - UH 25 is a mixture of 25% hydrazine hydrate and 75% UDMH. - Monomethylhydrazine (MMH) + nitrogen tetroxide (NTO) – smaller engines and reaction control thrusters:[citation needed] Apollo Command Module reaction control system; Space Shuttle OMS and RCS; Ariane 5 EPS; Draco thrusters used by the SpaceX Dragon spacecraft. The corrosiveness of nitrogen tetroxide can be reduced by adding several percent nitric oxide (NO), forming mixed oxides of nitrogen (MON)...