LOx/LH2 propellant rocket stage. Engines 1 x M-1 plus 2 x J-2.
Status: Study. Thrust: 8,820.00 kN (1,982,810 lbf). Gross mass: 302,183 kg (666,199 lb). Unfuelled mass: 32,558 kg (71,778 lb). Specific impulse: 410 s. Specific impulse sea level: 345 s. Height: 29.00 m (95.00 ft). Span: 18.60 m (61.00 ft).