Encyclopedia Astronautica

Isayev Nitric acid/UDMH rocket engine. 1.961 kN. Molniya 1, Mars 1, Venera 1, Zond 2-3 maneuvering engine. Out of Production. Spacecraft maneuvering engine. Isp=272s.

Application: Molniya 1, Mars 1, Venera 1, Zond 2-3 maneuvering engine.

Engine: 61 kg (134 lb). Chamber Pressure: 11.80 bar. Propellant Formulation: AK20F/UDMH. Thrust to Weight Ratio: 3.27. Oxidizer to Fuel Ratio: 2.6.

AKA: S5.19; KTDU-414; 11D414.
Status: Out of Production.
Unfuelled mass: 61 kg (134 lb).
Height: 1.02 m (3.34 ft).
Diameter: 0.74 m (2.42 ft).
Thrust: 1.96 kN (441 lbf).
Specific impulse: 272 s.
Burn time: 40 s.
First Launch: 1960-65.

More... - Chronology...

Associated Countries
Associated Spacecraft
  • Venera 1VA Russian Venus probe. 2 launches, 1961.02.12 (Sputnik 7) to (Venera 1). The 1VA probe, the first spacecraft sent towards Venus, consisted of a cylindrical body topped by a dome, totaling 2 meters in height. More...
  • Mars 2MV-4 Russian Mars flyby probe. 2 launches, 1962.10.24 (Sputnik 22) to 1962.11.01 (Mars 1). Mars probe intended to photograph Mars on a flyby trajectory. More...
  • Molniya-1 Russian military communications satellite. 37 launches, 1964.06.04 (Molniya-1 s/n 2 Failure) to 1975.09.02 (Molniya 1-31). This was the first Soviet communications satellite, using the twelve-hour elliptical orbit later dubbed a 'Molniya orbit'. More...
  • Mars 3MV-4A Russian Mars flyby probe. 2 launches, 1964.11.30 (Zond 2) to 1965.07.18 (Zond 3). Mars probe intended to photograph Mars on a flyby trajectory. Elaboration of station systems and scientific research in interplanetary space. More...

See also
Associated Manufacturers and Agencies
Associated Propellants
  • Nitric acid/UDMH Drawing on the German World War II Wasserfall rocket, nitric acid (HNO3) became the early storable oxidiser of choice for missiles and upper stages of the 1950's. To overcome various problems with its use, it was necessary to combine the nitric acid with N2O4 and passivation compounds. These formulae were considered extremely secret at the time. By the late 1950's it was apparent that N2O4 by itself was a better oxidiser. Therefore nitric acid was almost entirely replaced by pure N2O4 in storable liquid fuel rocket engines developed after 1960. 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...

  • Kudryavtseva, V M, ed., Zhidkostnikh Raketnikh Dvigatley, Visshaya Shkola, Moscow, 1993.
  • Glushko, V P (ed), Kosmonavtika Entsiklopedi, Moscow 1985 via Dietrich Haeseler.
  • Russian Arms Catalogue, Vol 5 and 6, Military Parade, Moscow via Dietrich Haeseler.
  • Siddiqi, Asif A, Soviet Space Web Page, 1999 via Dietrich Haeseler. Web Address when accessed: here.

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