Pictured is a J-2 engine being processed at Marshall Space Flight Center (MSFC). A single J-2 engine was utilized on the S-IVB stage, the second stage of the Saturn IB and the third stage of the Saturn V vehicles, while a cluster of five J-2 engines powered the second (S-II) stage of the Saturn V launch vehicle. The Saturn V was designed, developed, and tested by engineers at MSFC.