 The RD-856 engine is intended to control flight of the
Cyclone LV second stage in all channels. The stage flight control is provided by gimbaling each chamber in one tangential plate.
Design simplicity and high reliability.
The autonomous four-chamber pump-fed steering engine of a single run operates on hypergolic propellants under the generator scheme
(without afterburning of the generator gas)
The engine provides tapping of both propellants to the gas generator of oxidizer tank pressurization, as well as tapping of the generator
gas for the mixer to pressurize the fuel tank. The TPU turbine's working medium is a gas produced by the gas generator at combustion
of the main propellants. The TPU rotor is spinned up during the startup by pyrostarter.
| Sea level thrust, kgf | 5530 |
| Vacuum specific impulse, s: | 280.5 |
| Mass, kg | 112.5 |
| Combustion chamber absolute pressure, kgf/cm2 | 73 |
| Nozzle exit absolute pressure, kgf/cm2 | 0.25 |
| Mixture ratio | 1.98 |
| Thrust deviation from the nominal value, % | ±13 |
| Chambers gimbal angle, deg | ±30 |
Propellants:
- oxidizer
- fuel |
NTO
UDMH |
Min inlet propellant absolute pressure, kgf/cm2, at +35°Ñ temperature:
- oxidizer
- fuel |
4.5
1.45 |
| Firing time, s | 163 |
|
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