Solid propellant rocket stage. . Used cluster of four motors with Nylon-B propellant.
Gross mass: 12,200 kg (26,800 lb). Unfuelled mass: 2,200 kg (4,800 lb). Specific impulse: 200 s. Specific impulse sea level: 200 s. Diameter: 1.85 m (6.06 ft). Span: 1.85 m (6.06 ft).