Tonka (also TONKA-250 and R-Stoff) is the name given to a

German German(s) may refer to: * Germany (of or related to) ** Germania (historical use) * Germans, citizens of Germany, people of German ancestry, or native speakers of the German language ** For citizens of Germany, see also German nationality law **Ge ...

-designed

rocket propellant Rocket propellant is the reaction mass of a rocket. This reaction mass is ejected at the highest achievable velocity from a rocket engine A rocket engine uses stored rocket propellants as the reaction mass for forming a high-speed propuls ...

first used in the

Wasserfall The ''Wasserfall Ferngelenkte FlaRakete'' (Waterfall Remote-Controlled A-A Rocket) was a German guided supersonic surface-to-air missile project of World War II. Development was not completed before the end of the war and it was not used operati ...

missile, and recently used by

North Korea North Korea, officially the Democratic People's Republic of Korea (DPRK), is a country in East Asia. It constitutes the northern half of the Korea, Korean Peninsula and shares borders with China and Russia to the north, at the Yalu River, Y ...

. It was used in the

Soviet Union The Soviet Union,. officially the Union of Soviet Socialist Republics. (USSR),. was a transcontinental country that spanned much of Eurasia from 1922 to 1991. A flagship communist state, it was nominally a federal union of fifteen national ...

under the name TG-02, for example in the engine designs of the A.M. Isayev Chemical Engineering Design Bureau. Its name is a reference to the

tonka bean ''Dipteryx odorata'' (commonly known as "cumaru", "kumaru", or "Brazilian teak") is a species of flowering tree in the pea family, Fabaceae. The tree is native to Central America and northern South America South America is a continent ...

. Being invented during the

Second World War World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposin ...

, it has no connection to the similarly named toys. Its composition is approximately 50%

triethylamine Triethylamine is the chemical compound with the formula N(CH2CH3)3, commonly abbreviated Et3N. It is also abbreviated TEA, yet this abbreviation must be used carefully to avoid confusion with triethanolamine or tetraethylammonium, for which TEA ...

and 50%

xylidine Xylidine can refer to any of the six isomers of xylene amine, or any mixture of them. The chemical formula of xylidines is C8H11N or, more descriptively, (CH3)2C6H3NH2. The CAS number for the isomer mixture is . They are colorless solids or liqui ...

, most commonly used with

nitric acid Nitric acid is the inorganic compound with the formula . It is a highly corrosive mineral acid. The compound is colorless, but older samples tend to be yellow cast due to decomposition into oxides of nitrogen. Most commercially available nitri ...

or its anhydrous

nitric oxide Nitric oxide (nitrogen oxide or nitrogen monoxide) is a colorless gas with the formula . It is one of the principal oxides of nitrogen. Nitric oxide is a free radical: it has an unpaired electron, which is sometimes denoted by a dot in its che ...

derivatives (classified as the AK-2x family in the Soviet Union) as the oxidiser; the combination is

hypergolic 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. The two propellant components usually consist of a fuel and an oxidizer. The ...

and has a maximum practical

specific impulse Specific impulse (usually abbreviated ) is a measure of how efficiently a reaction mass engine (a rocket using propellant or a jet engine using fuel) creates thrust. For engines whose reaction mass is only the fuel they carry, specific impulse i ...

of approximately at sea level, with the latter figure stated as a specification for the R-21 Submarine Launched Ballistic Missile, first fielded in 1963. The Soviet Union reverse-engineered the Wasserfall missile and investigated the use of hypergolic propellants for the eventually abandoned

Burya The ''Burya'' ("Storm" in Russian; russian: Буря) was a supersonic, intercontinental cruise missile, developed by the Lavochkin design bureau (chief designer Naum Semyonovich Chernyakov) under designation La-350 from 1954 until the program can ...

ICBM An intercontinental ballistic missile (ICBM) is a ballistic missile with a range greater than , primarily designed for nuclear weapons delivery (delivering one or more thermonuclear warheads). Conventional, chemical, and biological weapons c ...

project. It put TG-02/AK-2x fuelled engines into service with the

Kh-22 The Kh-22 (russian: Х-22; AS-4 'Kitchen') is a large, long-range anti-ship missile developed by MKB Raduga in the Soviet Union. It was designed for use against aircraft carriers and carrier battle groups, with either a conventional or nuclear wa ...

cruise missile and the

S5.4 The S5.4 (AKA TDU-1, GRAU Index 8D66), was a Russian liquid rocket engine burning TG-02 and AK20F in the gas generator cycle. It was originally used as the braking (deorbit) engine of the Vostok, Voskhod, and Zenit spacecraft, which later swit ...

de-orbit engine used on the

Vostok Vostok refers to east in Russian but may also refer to: Spaceflight * Vostok programme, Soviet human spaceflight project * Vostok (spacecraft), a type of spacecraft built by the Soviet Union * Vostok (rocket family), family of rockets derived from ...

and Voskhod spacecraft and the

Zenit Zenit, meaning "zenith", may refer to: Spaceflight and rocketry * Zenit (rocket family), a Soviet family of space launch vehicles * Zenit (satellite), a type of Soviet spy satellite * Zenit sounding rocket, a Swiss rocket Sports * Zenit (sports ...

satellite. The most globalized use of Tonka is as an igniter in many Soviet Scud missile variants and its descendants, such as the North Korean Nodong, which are principally propelled by nitric acid and

kerosene Kerosene, paraffin, or lamp oil is a combustible hydrocarbon liquid which is derived from petroleum. It is widely used as a fuel in aviation as well as households. Its name derives from el, κηρός (''keros'') meaning "wax", and was regi ...

(TM-185). This combination is not hypergolic so needs an ignition source, supplied by a system that injects a few kilograms of Tonka fuel when ignition is desired. The progenitor Scud engine, the S2.253, with a specific impulse of at sea level, popularized this ignition arrangement. Triethylamine/xylidine mixtures composed the TX and TX2 fuels of the French SEPR rocket engines of the 1950s, used for auxiliary rocket power in the

Mirage IIIC The Dassault Mirage III () is a family of single/dual-seat, single-engine, fighter aircraft developed and manufactured by French aircraft company Dassault Aviation. It was the first Western European combat aircraft to exceed Mach number, Mach 2 ...

. In aircraft use, TX fuels were later replaced by non-toxic kerosene jet fuels, simplifying fuelling of the aircraft. Little change was required to the engines but as this was no longer hypergolic with nitric acid, a small tank of TX was retained for ignition. The use of Tonka by amateurs is not advised, because the exact proportions of ingredients necessary for the mixture to work as desired, rather than fail catastrophically, is a function both of the purity of the ingredients and their temperature during use.

References

{{reflist, colwidth=35em Rocket fuels German inventions of the Nazi period

See also

References