Engine Model: Press Fed 25k. Propellants: Lox/Kerosene. Thrust(vac): 245.200 kN (55,123 lbf). Thrust(sl): 208.800 kN (46,940 lbf). Isp: 270 sec. Isp (sea level): 230 sec. Mass Engine: 270 kg (590 lb). Diameter: 0.67 m (2.19 ft). Chambers: 1. Area Ratio: 5.00. Thrust to Weight Ratio: 92.59. Country: USA. Status: Design concept 1960's. 1960's designs for 'big dumb booster'..