 The IB-CE used the same configuration as the Saturn IB for the first two stages however with the addition of a Centaur D/E rocket as the third stage.It was to be capable of delivering 22,000 kg to low earth orbit and 5,590 kg into a translunar trajectory.Although this version never flew, a similar rocket, the Titan IIIE, built primarily for the U.S. Air Force, but launching a few NASA payloads, including the "Viking" and "Voyager" spacecraft, had the same equivalent thrust as the Saturn IB-CE.