Engine Model: Ottobrunn 300N. Designer: Ottobrunn. Application: Upper stages. Propellants: Lox/LH2. Thrust(vac): 300.000 kN (67,440 lbf). Isp: 415 sec. Mass Engine: 1.88 kg (4.15 lb). Length: 0.39 m (1.27 ft). Chambers: 1. Chamber Pressure: 5.00 bar. Area Ratio: 57.00. Oxidizer to Fuel Ratio: 5.50. Country: Germany. Status: Developed 2000. This 300 N cryogenic propellant engine had a vacuum Isp of 415 seconds - the highest value ever achieved in Europe for an engine of such small size. Characteristic chamber length was 0.4 m; overall efficiency 91%; thrust could be varied from 240 to 480 N with the chamber pressure varying from 4 to 8 bar, mixture ratio from 3.5 to 6.5, and the propellant mass flow rate from 0.06 - 0.12 kg/s.