Propellants: Lox/Kerosene. Thrust(vac): 24,459.000 kN (5,498,601 lbf). Isp: 299 sec. Isp (sea level): 260 sec. Burn time: 118 sec. Chambers: 1. Country: USA. Status: Study 1963. First Flight: 1977.
Operational date would have been July 1977. Recoverable stage. 10% plug nozzle.