Engine Model: HM-10. Designer: SEP, Ottobrunn. Propellants: Lox/LH2. Thrust(vac): 61.800 kN (13,893 lbf). Isp: 443 sec. Mass Engine: 145 kg (319 lb). Diameter: 1.00 m (3.20 ft). Chambers: 1. Chamber Pressure: 30.00 bar. Area Ratio: 61.00. Thrust to Weight Ratio: 43.45. Country: France. Status: Developed 1990's. Engine for potential Ariane 5 upper stage.