LOx/Kerosene propellant rocket stage. Masses estimated based on total vehicle mass of 117 metric tons. This stage was a close cousin of that developed for the Molniya launch vehicle.
AKA: 8K513 Blok V. Thrust: 66.60 kN (14,972 lbf). Gross mass: 8,500 kg (18,700 lb). Unfuelled mass: 1,000 kg (2,200 lb). Specific impulse: 350 s. Burn time: 380 s. Height: 4.60 m (15.00 ft). Diameter: 2.41 m (7.90 ft). Span: 2.41 m (7.90 ft).