Encyclopedia Astronautica
Otrag



zotrstg2.jpg
Otrag Stage Cutaway
Credit: courtesy Lutz Kayser
Otrag N2O4/Kerosene rocket engine. 27.5 kN. First and upper stages of low-cost booster. Out of production. Isp=297s. Pressure-fed, using cheapest possible propellants. Injection pressure: 40-15 bar; thrust control: 100-40 %. First flight 1977.

Pressurization: Compressed air 66% tank filling in blow-down mode; Injector: Radial like on like; Chamber cooling: Ablative phenolic; Material of injector, valves, bulkheads: AlMg5.

Application: First and Upper Stages.

Characteristics

Throttled thrust(vac): 11.000 kN (2,472 lbf). Thrust (sl): 25.000 kN (5,620 lbf). Thrust (sl): 2,500 kgf. Propellant Formulation: High Density Acid (HDA) (50% N2O4- 50% HNO3) Den: 1.66 gr/cm^3 / Diesel fuel or Kerosene.

Status: Out of production.
Diameter: 0.27 m (0.88 ft).
Thrust: 27.50 kN (6,182 lbf).
Specific impulse: 297 s.
Specific impulse sea level: 270 s.
Burn time: 150 s.
First Launch: 1975-1987.
Number: 1152 .

More... - Chronology...


Associated Countries
See also
Associated Launch Vehicles
  • Otrag $200 million was spent from 1975-1987 by Lutz Kayer in a serious attempt to develop a low-cost satellite launcher using clusters of mass-produced pressure-fed liquid propellant modules. The project was finally squelched by the German government under pressure from the Soviet and French. More...

Associated Manufacturers and Agencies
  • Otrag German manufacturer of rocket engines and rockets. Orbital Transport-und-Raketen Aktiengesellschaft, Germany. More...

Associated Propellants
  • N2O4/Kerosene Nitrogen tetroxide became the storable liquid propellant of choice from the late 1950's. Rocket propellant RP-1, or its foreign equivalents, is a straight-run kerosene fraction, which is subjected to further treatment, i.e., acid washing, sulphur dioxide extraction. Thus, unsaturated substances which polymerise in storage are removed, as are sulphur-containing hydrocarbons. More...

Bibliography
  • Kayser, Lutz, Personal communication, 2005.,

Associated Stages
  • Otrag N2O4/Kerosene propellant rocket stage. Loaded/empty mass 1,500/150 kg. Thrust 26.96 kN. Vacuum specific impulse 297 seconds. Clustered to form Otrag launch vehicles. Pressure-fed, using cheapest possible propellants. Injection pressure: 40 - 15 bar; Thrust control: 100% - 40 %; Pressurization: Compressed air 66% tank filling in blow-down mode; Injector: Radial like on like; Chamber cooling: Ablative phenolic; Material of injector, valves, bulkheads: AlMg5; Material of cylindrical tank sections: cold rolled low carbon stainless steel. More...

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