Pratt & Whitney hopes NASA's emerging requirement for an orbital spaceplane (OSP) will create a much-needed market for its RL60 cryogenic upper-stage engine. Launching a spaceplane weighing up to 34,000kg (75,000lb) on either a Boeing Delta IV or Lockheed Martin Atlas V evolved expendable launch vehicle (EELV) will require a more-powerful upper stage, the company believes.
The 60,000lb (267kN) thrust-class RL60 is under development, with test-firing of a demonstrator engine planned for next May. But the company-funded programme lacks a customer, as Boeing has decided it will equip the Delta IV EELV with an advanced upper stage powered by the MB-60 cryogenic engine under joint development by its Rocketdyne division and Mitsubishi.
The RL60 programme has taken on added significance since P&W and partner Aerojet stopped work on the Cobra liquid-hydrogen/liquid-oxygen engine under development for a second-generation reusable launch vehicle. NASA halted work on the Cobra in September after deciding to focus funding on kerosene-fuelled engines under development by Rocketdyne and TRW.
The RL60 is now the only cryogenic engine under development at P&W. The company is not developing a hydrocarbon-fuelled engine, although it has unsuccessfully offered NASA a version of the Russian RD-180 kerosene rocket motor which P&W and Energomash are supplying for the Atlas V.
Source: Flight International
