Encyclopedia Astronautica
RD-857



rd857.jpg
RD-857
Credit: via Dietrich Haeseler
Yuzhnoye N2O4/UDMH rocket engine. 137.3 kN. RT-20P missile stage 2. Out of production. Isp=329s. Designed for second stage of mixed propulsion missile, only flight tests. Thrust vector control by secondary gas injection into nozzle. First flight 1967.

Second thrust level at 12.75 kN.

Application: Combined missile (RT-20P) stage 2.

Characteristics

Engine: 190 kg (410 lb). Chamber Pressure: 127.50 bar. Thrust to Weight Ratio: 73.68. Oxidizer to Fuel Ratio: 2.6.

AKA: 15D12.
Status: Out of production.
Unfuelled mass: 190 kg (410 lb).
Height: 2.10 m (6.80 ft).
Diameter: 0.93 m (3.04 ft).
Thrust: 137.30 kN (30,866 lbf).
Specific impulse: 330 s.
Burn time: 215 s.
First Launch: 1963-67.
Number: 12 .

More... - Chronology...


Associated Countries
See also
Associated Launch Vehicles
  • RT-20P Ukrainian intercontinental ballistic missile. Following the protracted development of Shavyrin's Gnom air-augmented ICBM, it was decided to let Yangel tackle the problem of developing a 30 tonne gross mass ICBM using more conventional technology. At first a three-stage solid propellant design was considered. But it was found impossible to achieve the launch weight with such an approach. Yangel's solution was to propose the only mixed propulsion ICBM ever developed - a solid propellant first stage, and high performance ampulised storable liquid propellant second stage. The draft project for the missile was completed in December 1964 and a decree to proceed with development was issued on 24 August 1965. Shortly thereafter Shavyrin died and Gnom was cancelled, leaving Yangel's RT-20P the lead project for the mobile ICBM requirement. Designs for silo-launched and submarine-launched versions of the missile were to be developed as well. More...

Associated Manufacturers and Agencies
  • Yuzhnoye Ukrainian manufacturer of rockets, spacecraft, and rocket engines. Yangel Design Bureau, Dnepropetrovsk, Ukraine. 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...

Bibliography
  • Rakhmanin, V F, Odnazhdy i Navsegda, NPO Energomash, Moscow 1998 via Dietrich Haeseler.
  • Siddiqi, Asif A, Soviet Space Web Page, 1999 via Dietrich Haeseler. Web Address when accessed: here.
  • Shnyakin, V N, Shidkostnye Raketye Dvigateli - Opisanie i Osnovnye Tekhnicheskie Dannye, GKB Yuzhnoe "Yangel", Dnepropetrovsk 1996 via Dietrich Haeseler.

Associated Stages
  • 8K94 N2O4/UDMH propellant rocket stage. Loaded/empty mass 9,800/900 kg. Thrust 147.00 kN. Vacuum specific impulse 330 seconds. Empty mass estimated. More...

Home - Browse - Contact
© / Conditions for Use