THE SMART TRICK OF AMBIQ APOLLO3 THAT NOBODY IS DISCUSSING

The S-IVB also continued to thrust in a low degree by venting gaseous hydrogen, to maintain propellants settled in their tanks and stop gaseous cavities from forming in propellant feed strains. This venting also maintained Risk-free pressures as liquid hydrogen boiled off during the fuel tank. This venting thrust quickly exceeded aerodynamic drag.[