435096main_S4B_during_mating Published on April 12, 2017 in 15 April 1970, 01:09:40 UTC: T Plus 077:56:40.0Full resolution (611 × 800) ← Previous A Saturn IB S-IVB second stage with its Rocketdyne J-2 engine. This S-IVB was part of Saturn IB SA-206 (NASA)