The RD-861K engine is intended for thrust creation and flight control of Cyclone-4 LV third stage. The engine is designed on the basis of the high-reliable serial RD-861 engine used on the Cyclone LV third stage.
Usage of basic components of the previous engine (RD-861) ensures high energetic performance and reliability.
The one-chamber pump-fed with self-igniting propellants rocket is designed under the scheme without afterburning of generator gas.
The RD-861K engine has the following characteristics in comparison with its forerunner:
- the engine’s specific impulse is increased in 15.6 s;
- number of restarts in flight is increased;
- the burning time is increased by 3 times.
The RD-861K has next advantages:
- the thrust vector control system is fed by high-pressure fuel;
- the propellants mixture ratio is ensured with accuracy of ±1,0%, on conditions that ordinary operating terms are provided.