Encyclopedia Astronautica

8D43 engine
8D43 engine, originally intended as outboard gimballed engines for first stage of Proton UR-500 global rocket.
Credit: © Mark Wade
Kosberg N2O4/UDMH rocket engine. 559 kN. UR-500 stage 1 original concept. Hardware. Isp=316s. In early Proton design would be clustered with 4 x Glushko 11D43. Abandoned in favor of 6 x Glushko 11D48, but later developed into the RD-0208 and RD-0210.

Low-expansion ratio gimballed variant developed for UR-500. In initial configuration 4 would be clustered with 4 x Glushko 11D43. Abandoned in favor of 6 x Glushko 11D48. Further developed into the RD-0208 and RD-0210 engines.

Application: UR-500 stage 1 original concept.


Thrust (sl): 599.813 kN (134,843 lbf). Thrust (sl): 61,164 kgf. Chamber Pressure: 147.00 bar. Area Ratio: 28.5. Oxidizer to Fuel Ratio: 2.6.

Status: Hardware.
Thrust: 559.00 kN (125,668 lbf).
Specific impulse: 316 s.
Specific impulse sea level: 284 s.
Burn time: 115 s.

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Associated Countries
See also
Associated Launch Vehicles
  • Monoblock UR-500 Russian orbital launch vehicle. During UR-500 design studies, two variants of the first stage were considered: polyblock and monoblock. The monoblock approach was that the first stage be assembled from two separate modules with the same diameter: an upper oxidiser module and a lower fuel and engine block. In assembly trials of this design it proved difficult, because of the height of the first stage, to obtain access to the upper stages and payload atop the rocket. Although there was a payload advantage compared to the more compact polyblock design, this was relatively small and outweighed by the operational difficulties. More...
  • Polyblock UR-500 Russian orbital launch vehicle. UR-500 design studies considered two variants of the first stage: polyblock and monoblock. The polyblock variant consisted of a centre large diameter oxidizer tank surrounded by several smaller diameter fuel tanks. This version could be assembled in a special rig with the lateral blocks being sequentially mounted on the centre. In January 1962 this design was chosen as most advantageous, following studies that indicated improved wind loads and bending moment characteristics compared to the monoblock design. The developed version of the design would become known as the Proton. More...

Associated Manufacturers and Agencies
  • Kosberg Russian manufacturer of rocket engines. Kosberg Design Bureau, Russia. More...

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...

  • Afanasyev, Igor, "35 let RN Proton", Novosti kosmonavtiki, 1998, Issue 5, page 40.
  • Glushko, V P, Albom Konstruktsiy ZhRD, Vol. 1 1968, Vol. 3 & 4 1969 via Dietrich Haeseler.

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