The two propellant components usually consist of a fuel and an oxidizer. The main advantages of hypergolic propellants are that they can be stored as liquids at room temperature and that engines which are powered by them are easy to ignite reliably and repeatedly. Although commonly used, hypergolic propellants are difficult to handle due to their extreme toxicity and/or corrosiveness.
In contemporary usage, the terms "hypergol" or "hypergolic propellant" usually[citation needed] mean the most common such propellant combination, dinitrogen tetroxide plus hydrazine and/or its relatives monomethylhydrazine (MMH) and unsymmetrical dimethylhydrazine.
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.[citation needed]
In Germany from the mid-1930s through World War II, rocket propellants were broadly classed as monergols, hypergols, non-hypergolsand lithergols. The ending ergol is a combination of Greek ergon or work, and Latin oleum or oil, later influenced by the chemical suffix -ol from alcohol.[Note 1] Monergols were monopropellants, while non-hypergols were bipropellants which required external ignition, and lithergols were solid/liquid hybrids. Hypergolic propellants (or at least hypergolic ignition) were far less prone to hard starts than electric or pyrotechnic ignition. The "hypergole" terminology was coined by Dr. Wolfgang Nöggerath, at the Technical University of Brunswick, Germany.[4]
The only rocket-powered fighter ever deployed was the Messerschmitt Me 163B Komet. The Komet had a HWK 109-509, a rocket motor which consumed methanol/hydrazine as fuel and high test peroxide as oxidizer. The hypergolic rocket motor had the advantage of fast climb and quick-hitting tactics at the cost of being very volatile and capable of exploding with any degree of inattention.
The trend among western space launch agencies is away from large hypergolic rocket engines and toward hydrogen/oxygen engines with higher performance.
https://en.wikipedia.org/wiki/Hypergolic_propellant
The trend among western space launch agencies is away from large hypergolic rocket engines and toward hydrogen/oxygen engines with higher performance. Ariane 1 through 4, with their hypergolic first and second stages (and optional hypergolic boosters on the Ariane 3 and 4) have been retired and replaced with the Ariane 5, which uses a first stage fueled by liquid hydrogen and liquid oxygen. The Titan II, III and IV, with their hypergolic first and second stages, have also been retired. Hypergolic propellants are still widely used in upper stages when multiple burn-coast periods are required, and in Launch escape systems.
https://en.wikipedia.org/wiki/Hypergolic_propellant
- Kerosene + (high-test peroxide + catalyst) – Gamma, with the peroxide first decomposed by a catalyst. Cold hydrogen peroxide and kerosene are not hypergolic, but concentrated hydrogen peroxide (referred to as high-test peroxide or HTP) run over a catalyst produces free oxygen and steam at over 700 °C (1,300 °F) which is hypergolic with kerosene.[14]
Less-common and obsolete[according to whom?] hypergolic propellants include:[citation needed]
- Hydrazine + nitric acid (toxic but stable),[13][failed verification]
- Aniline + nitric acid (unstable, explosive), used in the WAC Corporal[citation needed]
- Aniline + hydrogen peroxide (dust-sensitive, explosive)
- Furfuryl alcohol + IRFNA (or red fuming nitric acid)
- Turpentine + IRFNA (flown in French Diamant A first-stage)
- UDMH + IRFNA – MGM-52 Lance missile system[citation needed]
- T-Stoff (stabilised >80% peroxide) + C-Stoff (methanol, hydrazine, water, catalyst) – Messerschmitt Me 163 World War II German rocket fighter aircraft, for its Walter 109-509A engine
- Kerosene + (high-test peroxide + catalyst) – Gamma, with the peroxide first decomposed by a catalyst. Cold hydrogen peroxide and kerosene are not hypergolic, but concentrated hydrogen peroxide (referred to as high-test peroxide or HTP) run over a catalyst produces free oxygen and steam at over 700 °C (1,300 °F) which is hypergolic with kerosene.[14]
- Tetramethylethylenediamine + IRFNA – A less toxic and non-mutagenic alternative to Hydrazine and its derivatives.
- Pentaborane(9) and diborane + nitrogen tetroxide – Pentaborane(9), a so-called Zip fuel, was used in combination with nitrogen tetroxide by the Soviet RD-270M rocket engine.
- Chlorine trifluoride (ClF3) + all known fuels – Briefly considered as an oxidizer given its high hypergolicity with all standard fuels, but largely abandoned due to the difficulty of handling the substance safely.[15]
Related technology[edit]
Pyrophoric substances, which ignites spontaneously in the presence of air, are also sometimes used as rocket fuels themselves or to ignite other fuels. For example a mixture of triethylborane and triethylaluminium (which are both separately and even more so together pyrophoric), was used for engine starts in the SR-71 Blackbird and in the F-1 engines on the Saturn V rocket and is used in the Merlin engines on the SpaceX Falcon 9 rockets.
Notes[edit]
- ^ "-ergol", Oxford English Dictionary
https://en.wikipedia.org/wiki/Hypergolic_propellant
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https://en.wikipedia.org/wiki/Hypergolic_propellant
Trihydrogen cations hydrazine hydride ions HHeH helium hydraz ions fract-part wave part sol-gel-liq-air phase mods phase interlock/interstate etc. qms
HYDROGEN OXYGEN TRIANGLE CASCADE ETC.
arc angels
circul
angular momentum
08-09-2021-0022 - Tritium, Trihydrogen Cation, Helium Hydride Trihydrocats, tritons, dihydrocat, ion hel hyride, helios, etc.
helium hydrides
ozones ozoniums oximes oxanes oxines oxets oxs
epoxy ex
cyclic ozone
ringulars trittys
helium hydride ion or hydridohelium(1+) ion or helonium i
08-09-2021-0006 - Helium Hydride Ion/Hydrogen Hydride Ion
08-09-2021-0022 - Tritium, Trihydrogen Cation, Helium Hydride Trihydrocats, tritons, dihydrocat, ion hel hyride, helios, etc.
helium hydrides
ozones ozoniums oximes oxanes oxines oxets oxs
epoxy ex
cyclic ozone
ringulars trittys
helium hydride ion or hydridohelium(1+) ion or helonium i
08-09-2021-0006 - Helium Hydride Ion/Hydrogen Hydride Ion
thermonuclear fusion u
reionization dark matter
Hydrostatic equilibrium
fluid mechanics (sol gel liq air plas etc.)
hydraulics
reionization dark matter
Hydrostatic equilibrium
fluid mechanics (sol gel liq air plas etc.)
hydraulics
Thermal shocks
depth-drop charge
In nuclear engineering, a neutron moderator is a medium that reduces the speed of fast neutrons, ideally without capturing any, leaving them as thermal neutrons with only minimal (thermal) kinetic energy. These thermal neutrons are immensely more susceptible than fast neutrons to propagate a nuclear chain reaction of uranium-235 or other fissile isotope by colliding with their atomic nucleus.
https://en.wikipedia.org/wiki/Neutron_moderator
In nuclear engineering, a neutron moderator is a medium that reduces the speed of fast neutrons, ideally without capturing any, leaving them as thermal neutrons with only minimal (thermal) kinetic energy. These thermal neutrons are immensely more susceptible than fast neutrons to propagate a nuclear chain reaction of uranium-235 or other fissile isotope by colliding with their atomic nucleus.
https://en.wikipedia.org/wiki/Neutron_moderator
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