Engine Model: RBCC. Designer: Rocketdyne. Developed in: 1999. Propellants: Lox/LH2. Thrust(sl): 111.158 kN (24,989 lbf). Isp (sea level): 3,500 sec. Country: USA. Rocket Based Combined-Cycle A5 Development Engine. Pressure-fed or pump-fed. The RBCC engine integrates rocket, air-augmented rocket, ramjet, and sramjet propulsion elements into a single flowpath. Rocket specific impulse 400 seconds; minimum thrust 600 lbs. Thrust and specific impulse values are at sea level.