Encyclopedia Astronautica
KTDU-425A


Isayev N2O4/UDMH rocket engine. 18.890 kN. Mars 4-7, Venera 9-16, Vega 1-2, and Phobos 1-2 maneuvering engine. Out of Production. Could be throttled to 9.86/9.5/2870. Chamber pressure 149 - 95 bar. Isp=315s. First flight 1973.

Application: Mars 4-7, Venera 9-16, Vega 1-2, and Phobos 1-2 maneuvering engine.

Throttled thrust(vac): 9.856 kN (2,216 lbf). Engine: 70 kg (154 lb). Chamber Pressure: 149.00 bar. Thrust to Weight Ratio: 27.54. Oxidizer to Fuel Ratio: 1.9. Coefficient of Thrust vacuum: 0. Coefficient of Thrust sea level: 0.

AKA: 11D425A.
Status: Out of Production.
Unfuelled mass: 70 kg (154 lb).
Height: 0.71 m (2.32 ft).
Diameter: 0.70 m (2.29 ft).
Thrust: 18.89 kN (4,247 lbf).
Specific impulse: 315 s.
Burn time: 560 s.
First Launch: 1972-75.

More... - Chronology...


Associated Countries
Associated Spacecraft
  • Mars M-73 Russian Mars lander. 4 launches, 1973.07.21 (Mars 4) to 1973.08.09 (Mars 7). The M-73 spacecraft series was built for 1973 Mars missions. More...
  • Venera 4V-1 Russian Venus probe. 6 launches, 1975.06.08 (Venera 9) to 1981.11.04 (Venera 14). More...
  • Venera 4V-2 Russian Venus probe. 2 launches, 1983.06.02 (Venera 15) to 1983.06.07 (Venera 16). Venera radar mappers which used an 8 cm band side-looking radar to study the surface properties of Venus. More...
  • Vega 5VK Russian Venus probe. 2 launches, 1984.12.15 (Vega 1) to 1984.12.21 (Vega 2). The Vega 5VK spacecraft was designed for a mission combining a flyby of the planet Venus followed by an encounter with Halley's Comet. More...
  • Fobos 1F Russian Mars orbiter. 5 launches, 1988.07.07 (Phobos 1) to 1988.07.12 (1F PPS). The 1F spacecraft was flown on the Phobos mission to Mars, consisting of 2 nearly identical spacecraft. More...

See also
Associated Manufacturers and Agencies
Associated Propellants
  • N2O4/UDMH Nitrogen tetroxide became the storable liquid propellant of choice from the late 1950's. Unsymmetrical Dimethylhydrazine ((CH3)2NNH2) became the storable liquid fuel of choice by the mid-1950's. Development of UDMH in the Soviet Union began in 1949. It is used in virtually all storable liquid rocket engines except for some orbital manoeuvring engines in the United States, where MMH has been preferred due to a slightly higher density and performance. More...

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