Country of origin United States
Manufacturer Pratt & Whitney
Liquid-fuel engine
Propellant LOX / LH2
Mixture ratio 4.5 to 6.2
Cycle expander
Thrust (SL) 200-250 kN (50,000-65,000 lbf)
Thrust-to-weight ratio 59
Isp (vac.) 465 seconds (4.56 km/s)

The RL60 (also called MB-60) is a rocket engine under development by Pratt & Whitney. The design is a high energy LH2/LOX expander cycle, capable of multiple restarts in space.

In 2003, Pratt & Whitney Rocketdyne had 90% of the work completed for the new RL60 replacement of the RL10 engine.[1] The RL60 is a cryogenic upper stage engine, designed to produce 60,000 pounds of thrust with a specific impulse of 465 seconds (4.56 km/s) to meet the evolving needs of expendable launch requirements or human-rated missions.

The RL60 was to be built and tested domestically with key components to be provided by four international industry strategic suppliers; Volvo Aero of Sweden (Regen cooled nozzle), Ishikawajima-Harima Heavy Industries (IHI) of Japan (Fuel Turbopump), Techspace Aero of Belgium (Fuel Inlet and LOX control valve) and Chemical Automatics Design Bureau (CADB) of Russia (LOX Turbopump).


  1. ^ "Pratt & Whitney's RL60 Moves Closer to Completion" (Press release). Pratt & Whitney. April 22, 2003. Retrieved June 1, 2012. 

External links

  • P&W fact sheet
  • P&W photos
  • Astronautics RL60 page on astronautix.com