Gross Mass: 5,517,000 kg.
Empty Mass: 680,000 kg. Thrust (vac): 11,115,000 kgf. Isp: 454 sec. Burn time: 194 sec. Propellants: Lox/LH2Isp(sl): 377 sec. Diameter: 21.3 m. Span: 28.0 m. Length: 61.3 m. Country: USA. No Engines: 18. CD ModuleStatus: Study 1963. Comments: Operational date would have been July 1977. Recoverable stage. 10% plug nozzle. .