THE SMART TRICK OF AMBIQ APOLLO3 THAT NOBODY IS DISCUSSING

The S-IVB also ongoing to thrust in a lower stage by venting gaseous hydrogen, to help keep propellants settled in their tanks and prevent gaseous cavities from forming in propellant feed traces. This venting also maintained Harmless pressures as liquid hydrogen boiled off within the fuel tank. This venting thrust easily exceeded aerodynamic drag.[