A hypergolic propellant is a rocket propellant combination used in a rocket engine, whose components spontaneously ignite when they come into contact with each other.
Unsymmetrical dimethylhydrazine (abbreviated as UDMH; also known as 1,1-dimethylhydrazine, heptyl or Geptil) is a chemical compound with the formula H2NN(CH3)2 that is primarily used as a rocket propellant. At room temperature, UDMH is a colorless liquid, with a sharp, fishy, ammonia-like smell typical of organic amines. Samples turn yellowish on exposure to air and absorb oxygen and carbon dioxide. It is miscible with water, ethanol, and kerosene. At concentrations between 2.5% and 95% in air, its vapors are flammable. It is not sensitive to shock.
Dinitrogen tetroxide, commonly referred to as nitrogen tetroxide (NTO), and occasionally (usually among ex-USSR/Russian rocket engineers) as amyl, is the chemical compound N2O4. It is a useful reagent in chemical synthesis. It forms an equilibrium mixture with nitrogen dioxide. Its molar mass is 92.011 g/mol.
Red fuming nitric acid (RFNA) is a storable oxidizer used as a rocket propellant. It consists of 84% nitric acid, 13% dinitrogen tetroxide and 1–2% water. The color of red fuming nitric acid is due to the dinitrogen tetroxide, which breaks down partially to form nitrogen dioxide. The nitrogen dioxide dissolves until the liquid is saturated, and produces toxic fumes with a suffocating odor. RFNA increases the flammability of combustible materials and is highly exothermic when reacting with water.
A propellant is a mass that is expelled or expanded in such a way as to create a thrust or another motive force in accordance with Newton's third law of motion, and "propel" a vehicle, projectile, or fluid payload. In vehicles, the engine that expels the propellant is called a reaction engine. Although technically a propellant is the reaction mass used to create thrust, the term "propellant" is often used to describe a substance which contains both the reaction mass and the fuel that holds the energy used to accelerate the reaction mass. For example, the term "propellant" is often used in chemical rocket design to describe a combined fuel/propellant, although the propellants should not be confused with the fuel that is used by an engine to produce the energy that expels the propellant. Even though the byproducts of substances used as fuel are also often used as a reaction mass to create the thrust, such as with a chemical rocket engine, propellant and fuel are two distinct concepts.
Monomethylhydrazine (MMH) is a highly toxic, volatile hydrazine derivative with the chemical formula CH6N2. It is used as a rocket propellant in bipropellant rocket engines because it is hypergolic with various oxidizers such as nitrogen tetroxide and nitric acid. As a propellant, it is described in specification MIL-PRF-27404.
C-Stoff was a reductant used in bipropellant rocket fuels developed by Hellmuth Walter Kommanditgesellschaft in Germany during World War II. It was developed for use with T-Stoff as an oxidizer, which together with C-Stoff as the fuel, forms a hypergolic mixture.
The Nedelin catastrophe or Nedelin disaster, known in Russia as the Catastrophe at Baikonur Cosmodrome, was a launch pad accident that occurred on 24 October 1960 at the Baikonur Cosmodrome in Soviet Kazakhstan. As a prototype of the R-16 intercontinental ballistic missile was being prepared for a test flight, an explosion occurred when the second stage engine ignited accidentally, killing an unknown number of military and technical personnel working on the preparations. Despite the magnitude of the disaster, information was suppressed for many years and the Soviet government did not acknowledge the event until 1989. With more than 54 casualties, it is the deadliest disaster in space exploration history. The catastrophe is named for the Chief Marshal of Artillery Mitrofan Ivanovich Nedelin, who was the head of the R-16 development program and perished in the explosion.
A liquid-propellant rocket or liquid rocket utilizes a rocket engine burning liquid propellants. (Alternate approaches use gaseous or solid propellants.) Liquids are desirable propellants because they have reasonably high density and their combustion products have high specific impulse (Isp). This allows the volume of the propellant tanks to be relatively low.
The R-16 was the first successful intercontinental ballistic missile deployed by the Soviet Union. In the West it was known by the NATO reporting name SS-7 Saddler, and within Russia, it carried the GRAU index 8K64.
Aerozine 50 is a 50:50 mix by weight of hydrazine and unsymmetrical dimethylhydrazine (UDMH), developed in the late 1950s by Aerojet General Corporation as a storable, high-energy, hypergolic fuel for the Titan II ICBM rocket engines. Aerozine continues in wide use as a rocket fuel, typically with dinitrogen tetroxide as the oxidizer, with which it is hypergolic. Aerozine 50 is more stable than hydrazine alone, and has a higher density and boiling point than UDMH alone.
The highest specific impulse chemical rockets use liquid propellants. They can consist of a single chemical or a mix of two chemicals, called bipropellants. Bipropellants can further be divided into two categories; hypergolic propellants, which ignite when the fuel and oxidizer make contact, and non-hypergolic propellants which require an ignition source.
Furfuryl alcohol is an organic compound containing a furan substituted with a hydroxymethyl group. It is a colorless liquid, but aged samples appear amber. It possesses a faint odor of burning and a bitter taste. It is miscible with but unstable in water. It is soluble in common organic solvents.
UH 25 is a fuel mixture for rockets. It was developed for the European Ariane 2–4 launch vehicles.
Tonka is the name given to a German-designed rocket propellant first used in the Wasserfall missile, and recently used by North Korea. It was used in the Soviet Union under the name TG-02, for example in the engine designs of the A.M. Isayev Chemical Engineering Design Bureau.
Taifun was a German World War II anti-aircraft unguided rocket system. Waves of small, relatively cheap, Taifun flak rockets were to be launched en masse into Allied bomber formations. Although never deployed operationally, the Taifun was further developed in the US as the 76mm HEAA T220 "Loki" Rocket.
2-Dimethylaminoethylazide (DMAZ) is a liquid rocket fuel being investigated for use as a spacecraft propellent to replace the toxic, carcinogenic monomethylhydrazine. It is a member of the competitive impulse non-carcinogenic hypergol (CINCH) family which were assessed as a replacement for hydrazine-derived propellants. DMAZ was also found to be sensitive to impact, direct flame, shock wave, heat in confined space, and electrostatic discharge.
Rocket propellant is the reaction mass of a rocket. This reaction mass is ejected at the highest achievable velocity from a rocket engine to produce thrust. The energy required can either come from the propellants themselves, as with a chemical rocket, or from an external source, as with ion engines.
The Bell Aerosystems Company XLR81 was an American liquid-propellant rocket engine, which was used on the Agena upper stage. It burned UDMH and RFNA fed by a turbopump in a fuel rich gas generator cycle. The turbopump had a single turbine with a gearbox to transmit power to the oxidizer and fuel pumps. The thrust chamber was all-aluminum, and regeneratively cooled by oxidizer flowing through gun-drilled passages in the combustion chamber and throat walls. The nozzle was a titanium radiatively cooled extension. The engine was mounted on a hydraulic actuated gimbal which enabled thrust vectoring to control pitch and yaw. Engine thrust and mixture ratio were controlled by cavitating flow venturis on the gas generator flow circuit. Engine start was achieved by solid propellant start cartridge.
Mélange is a liquid oxidant rocket propellant component that was "used during the Soviet era as one of two components to propel small and medium range missiles." It is highly toxic and aggressive mixture of nitric acid and dinitrogen tetroxide (18-27%) and other additives and impurities with very limited amount of water. As the mixture is an extremely strong oxidant, it can ignite combustibles upon contact. Upon decomposition it produce red fumes of nitrogen tetroxide and nitric acid.
