NASA is developing and testing new and innovative technologies that will enable the future of safe and efficient human exploration. Description: Pratt & Whitney Rocketdyne PWR and NASA successfully completed four deep throttling Common Extensible Cryogenic Engine CECE demonstrations, improving available cryogenic engine propulsion technology. The tests demonstrated that the engines could be throttled smoothly down to a new minimum power level of 5.9 percent of full power. Time Frame: This work took place over five years, resulting in 123 minutes of engine run time with multiple rapid restarts. Significance: Standard rocket engines typically cannot be throttled over a wide operating range because low power levels can cause engine pressure instability and possibly damage the engine or vehicle. Providing deep throttle capabilities can reduce the necessary amount of propellant, reducing the overall weight of the vehicle. A wide range of power variations may also allow soft surface landings for future missions. Application: NASA plans to initiate several new technology and flight demonstration projects to improve capabilities, reduce costs and expand the reach of future human and robotic missions. This partnership with PWR exemplifies NASA's goal to advance technological competition in the United States.