The the RL-50 is an advanced, high-performance upper-stage rocket engine being developed by Pratt & Whitney for both domestic and international launch vehicles. The RL-50 meets future launch vehicle requirements for increased payload delivery capability, improved launch system operability and enhanced system cost effectiveness. It provides more than twice the thrust of existing upper-stage Lox/LH2 engines. The RL-50 is to be available in 2003, and incorporates modern technologies to simplify the engine and decrease costs.