United Launch Alliance successfully launched the first operational Delta IV Heavy expendable launch vehicle, from Cape Canaveral, carrying the 2,360kg (5,200lb) USAF Defense Support Program-23 ballistic missile warning satellite. The rocket's December 2004 maiden flight was failed to reach its planned altitude owing to fuel cavitation problems in the liquid-oxygen feed system that resulted in premature shutdown of three Rocketdyne RS-68 engines. United has since made unspecified software and hardware fixes.
Source: Flight International