Status: Design concept 2007. Thrust: 88.00 kN (19,783 lbf). Specific impulse: 345 s. Burn time: 4,000 s. Height: 1.67 m (5.47 ft).

The engine was evidently a restartable version of the RD-8 Zenit-2 second stage vernier engine assembly and had the following features:

• Long service life (4000 seconds, five restarts)
• Designed for installation in the upper stage after a factory firing test without the need for post -test refurbishment
• Stage flight control is effected by gimballing each combustion chamber �10% in one plane.
• All four-chambers pump-fed using a combustion scheme with oxidizer-rich gas feeding the turbopumps.
• Turbine rotor spun-up by a pneumatic starter
• Propellants in the combustion chamber and gas generator ignited by dedicated startup fuel
• Pneumatic gimbal units used helium gas delivered via electric-pneumatic valves
• Single-mode engine providing constant thrust and propellant mixture ratio within �4.5% / �8.
• Pressure sensors provide data for automatic startup and shutdown of engine

Chambers: 4. Chamber Pressure: 87.75 bar. Oxidizer to Fuel Ratio: 2.5. Restarts: 6.