NOT KNOWN FACTUAL STATEMENTS ABOUT APOLLO4 BLUE PLUS

The S-IVB also ongoing to thrust at a low stage by venting gaseous hydrogen, to keep propellants settled inside their tanks and forestall gaseous cavities from forming in propellant feed strains. This venting also managed Secure pressures as liquid hydrogen boiled off from the fuel tank. This venting thrust simply exceeded aerodynamic drag.[citatio