Engine Model: Press Fed 5748k. Designer: TRW. Propellants: N2O4/UDMH. Thrust(vac): 56,368.000 kN (12,672,030 lbf). Thrust(sl): 51,723.200 kN (11,627,838 lbf). Isp: 267 sec. Isp (sea level): 245 sec. Diameter: 6.10 m (20.00 ft). Chambers: 1. Chamber Pressure: 20.41 bar. Area Ratio: 6.00. Thrust to Weight Ratio: 0.00. Country: USA. Status: Study 1968. 1960's designs for 'big dumb booster'..
Press Fed 5748k used on Rocket Stages