RD861K
Yuzhnoye Design Bureau
The RD861K is a restartable main engine with turbopump feed system developed by Yuzhnoye SDO, using a gas generator cycle with exhaust generator gas injected into the supersonic nozzle section for enhanced efficiency. It burns nitrogen tetroxide and UDMH propellants and is designed for upper stage applications on Cyclone-family launch vehicles, supporting up to 5 […]
Key figurescomparable across the catalogue
- Mass
- 214 kg
- Thrust
- 7.92 N
- Specific impulse
- 330 s
- TRL
- 8
Normalised to common units so this product can be compared with others in its category. The supplier's own wording is below.
As published by the supplier
- Propellants
- NT + UDMH
- Vacuum Thrust
- 7.916 tf
- Specific Impulse (vacuum)
- 330 s
- Propellant Mixture Ratio
- 2.4
- Number of Starts
- 5
- Engine Weight
- 214 kg
- Feed System
- Turbopump (gas generator cycle)
- TRL
- 8
About
The RD861K is a restartable main engine with turbopump feed system developed by Yuzhnoye SDO, using a gas generator cycle with exhaust generator gas injected into the supersonic nozzle section for enhanced efficiency. It burns nitrogen tetroxide and UDMH propellants and is designed for upper stage applications on Cyclone-family launch vehicles, supporting up to 5 restarts for multi-burn mission profiles including geostationary transfer orbit and sun-synchronous orbit insertions. With a vacuum thrust of 7.916 tf and specific impulse of 330 seconds, it provides high-efficiency propulsion derived from the proven Cyclone-4 program. TRL 8 reflects its near-operational readiness. The engine weighs 214 kg and has undergone extensive ground development testing as part of the Cyclone-4 and Cyclone-4M programs.
Documentation
No public datasheet yet — request the datasheet / ICD from the supplier.