A Delta 4 rocket, seen here in the family portrait, will use a MB-60 engine is 2004. Photo: Boeing

The Rocketdyne Propulsion & Power business of The Boeing Company and Mitsubishi Heavy Industries Ltd. have announced a long-term joint effort to design and develop a new liquid oxygen/liquid hydrogen upper-stage engine to address the worldwide need for new, higher performing propulsion systems for the next-generation of expendable launch vehicles.

The engine, designated "MB-XX," will provide high-efficiency, affordable, low-risk propulsion. Full-scale development of the engine was initiated in January 1999. The first derivative version of the MB-XX, designated by Boeing as the "MB-60," is a 60,000 lb.-thrust engine, targeted for use on the Boeing Delta 4 vehicle and will be available to support launch operations in 2004.

For 45 years, Boeing Rocketdyne has developed and manufactured rocket propulsion systems for virtually every major U.S. space program. Rocketdyne developed the Space Shuttle Main Engine, still the world's only large reusable liquid-fueled booster engine. Rocketdyne also produces RS-27A engines for Delta 2 and Delta 3 launch vehicles and is currently testing the RS-68 engine for the Boeing Delta 4 family of launch vehicles and the XRS-2200 linear aerospike for NASA's X-33 reusable launch vehicle prototype.