Status: Study Boeing 1967. Thrust: 1,031.60 kN (231,913 lbf). Gross mass: 118,400 kg (261,000 lb). Unfuelled mass: 14,100 kg (31,000 lb). Specific impulse: 421 s. Specific impulse sea level: 200 s. Burn time: 411 s. Height: 17.79 m (58.36 ft). Diameter: 6.61 m (21.68 ft). Span: 6.61 m (21.68 ft).