Gross Mass: 10,489,000 kg.
Empty Mass: 626,000 kg. Thrust (vac): 15,997,000 kgf. Isp: 443 sec. Burn time: 268 sec. Propellants: Lox/LH2Isp(sl): 379 sec. Diameter: 24.4 m. Span: 26.2 m. Length: 75.9 m. Country: USA. No Engines: 24. HP-1Status: Study 1963. Comments: Operational date would have been April 1975. SSTO - payload 1,042,000 lbs. .