RD-866
Engine · Ukraine
Original archive entry. The text, images and links below are kept as they were written.

Credit: Yuzhnoye
Yuzhnoye N2O4/UDMH rocket engine. RT-23 MIRV-bus. Out of Production. Engine consisted of two turbopumps with gas generators and two feeders; a single chamber main engine; and 16 liquid thrusters for attitude control and translation.
The RD-866 engine powered the MIRV distribution bus. The engine provided:
- delivery of fuel delivery to the steering units used for missile flight control at the end of the first stage burn and during the second and third stage engine burns
- roll control during third stage burn
- during dispensing of multiple independently targeted warheads, provision of attitude and translation forces in multiple burns of the main engine and peripheral thrusters
- fuel delivery to the hydraulic actuators that gimbaled the main engine during warhead distribution
The multifunction engine operated under a generator scheme. Propellants were fed under a combined scheme (pressure-fed and pump delivery). A broad range of flow-rates and pressures were provided according to the engine mode. The engine consisted of a centralized propellant supply source composed of two turbopumps with gas generators and two feeders; a single chamber main engine; and 16 liquid thrusters for attitude control and translation. Overall vacuum thrust of between minus 926 KN to plus 5036 kN could be provided at a mean specific impulse of 305.5 seconds for the design dispensing profile. The thrusters could be fired in continuous or 10 Hz pulsed modes.
Summary: One main and 16 control thrusters. 5.20 kN + 16 x 116 N. Chamber pressure 40.7 / 5.56 bar. Specific impulse 305.5 / 245 sec. Burn time 330 / 1200 sec. Oxidizer to fuel ratio 2.03 / 1.85.
Chambers: 1 + 16. Engine: 125 kg (276 lb). Chamber Pressure: 40.70 bar. Thrust to Weight Ratio: 4.22. Oxidizer to Fuel Ratio: 2.03.